Dissertations / Theses on the topic 'DDT (insecticide)'

1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) residues (DDTr) are widespread and persistent environmental contaminants, and have been classed as priority pollutants by the United Nations Environment Programme (UNEP). DDTr are potent endocrine disrupting molecules, and have been associated with reproductive abnormalities in juvenile alligators and rats. Microorganisms that metabolise DDTr both aerobically and anaerobically have been isolated and characterised. Bacteria that degrade DDTr aerobically typically utilise a dioxygenase to initiate degradative reactions through ring-hydroxylation, and convert DDTr to 4-chlorobenzoate without further degradation. Terrabacter sp. strain DDE-1 was isolated from DDTr-contaminated soil from Canterbury, New Zealand, and aerobically degrades 1,1-dichloro-2,2-bis-(4-chlorophenyl)-ethylene (DDE) to 4-chlorobenzoate, when grown in the presence of biphenyl (BP). The intermediates of degradation were inferred to be the end products of dioxygenase activity. Sequencing of a large linear plasmid, pBPH-1, from strain DDE-1 identified a cluster of genes with high levels of sequence similarity to BP-degradation genes from Rhodococcus spp. and Pseudomonas spp. This plasmid is lost at high frequency producing the plasmid-cured strain MJ-2, which has lost the ability to degrade BP or DDE. The aim of this study was to confirm that DDE-degradation in strain DDE-1 is encoded by the bph operon located on pBPH-1. No genetic systems to study gene function in either DDE-1 or MJ-2 could be developed using an array of broad-host range vectors. However, heterologous expression of the bph genes in Rhodococcus erythropolis strain TA422 was successful, with the recombinant strain TA425, obtaining the ability to utilise BP and DDE as a sole source of carbon and energy. DDE-1 was shown to convert indole to indigo, but MJ-2 could not, indicating that the biphenyl dioxygenase located on pBPH-1 is responsible for this activity. The bph genes from strain DDE-1 also conferred the ability to produce indigo from indole on strain TA425, confirming successful expression of the functional biphenyl dioxygenase in this strain. Despite several attempts to show quantitative degradation in strain TA425 using gas chromatography, the results were inconclusive Further analysis is needed to provide unequivocal evidence of DDE-degradation by strain TA425. Attempts to express the bph genes in rhizosphere-colonising bacteria, such a Rhizobium spp. or Pseudomonas spp., were unsuccessful, as evidenced by the inability to produce indigo, hence the lack of a functional biphenyl dioxygenase. However, RT-PCR did indeed indicate that P. aeruginosa strain Fin1 produced a bphA1 transcript, indicating that an error is occurring post-transcriptionally in these strains, to prevent production of the functional enzyme. New Zealand has recently been shown to contain hotspots of DDTr-contamination. The second aim of this study was to determine the prevalence of DDTr-degrading bacteria and to gain insight into the types of bacteria that inhabit sites contaminated with DDTr. To investigate this, culture-dependent and culture-independent techniques were employed. Enrichment for DDTr-degrading bacteria yielded species of Rhodococcus and Ralstonia using DDTr-overlayer plate assays. The polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) were used to amplify and analyse the 16S rDNA and 16S rRNA for the identification of dominant and active bacteria in soil samples. The results of this analysis identified bacteria such as Williamsia spp. and Gordonia spp. that degrade other types of pollutants. This analysis did not identify a predominance of Rhodococcus or Ralstonia spp., or other bacteria that have been shown to degrade DDTr. To identify ecologically relevant members of the bacterial communities in DDTr-contaminated soils, and potentially important metabolic pathways, identification of ring-hydroxylating dioxygenase (RHD) genes was performed. PCR and restriction fragment length polymorphism (RFLP) analysis were employed together with phylogenetic analyses. The results showed that the RHD genes identified, clustered separately to those genes previously characterised from cultivated bacteria. Among these genes, one phylogenetic group was most closely related to the dioxygenase genes from Ralstonia eutropha H850, which is potent PCB-degrading bacterium that possesses a dioxygenase with a wide substrate range for many types of heavily chlorinated, PCB congeners. The identification of a predominance of genes with similarity to phenyl-propionate dioxygenases has been not been recognised previously in soil studies.

Thesis (M.S.)--University of West Florida, 2009.
Submitted to the Dept. of Environmental Studies. Title from title page of source document. Document formatted into pages; contains 119 pages. Includes bibliographical references.

DDT, an extremely widely used organochlorine pesticide, was banned in most developed countries more than 30 years ago. However, DDT residues, including 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), still persist in the environment and have been identified as priority pollutants due to their toxicity and their ability to bioaccumulate and biomagnify in the food chain. In particular, DDE was long believed to be "enon-biodegradable"e, however some microorganisms have now been isolated that are able to metabolise DDE in pure culture. Terrabacter sp. strain DDE-1 was enriched from a DDT-contaminated agricultural soil from the Canterbury plains and is able to metabolise DDE to 4-chlorobenzoic acid when induced with biphenyl. The primary objective of this study was to identify the gene(s) responsible for Terrabacter sp. strain DDE-1�s ability to metabolise DDE and, in particular, to investigate the hypothesis that DDE-1 degrades DDE cometabolically via a biphenyl degradation pathway. Catabolism of biphenyl by strain DDE-1 was demonstrated, and a biphenyl degradation (bph) gene cluster containing bphDA1A2A3A4BCST genes was identified. The bphDA1A2A3A4BC genes are predicted to encode a biphenyl degradation upper pathway for the degradation of biphenyl to benzoate and cis-2-hydroxypenta-2,4-dienoate and the bphST genes are predicted to encode a two-component signal transduction system involved in regulation of biphenyl catabolism. The bph gene cluster was found to be located on a linear plasmid, designated pBPH1. A plasmid-cured strain (MJ-2) was unable to catabolise both biphenyl and DDE, supporting the hypothesis that strain DDE-1 degrades DDE cometabolically via the biphenyl degradation pathway. Furthermore, preliminary evidence from DDE overlayer agar plate assays suggested that Pseudomonas aeruginosa carrying the strain DDE-1 bphA1A2A3A4BC genes is able to catabolise DDE when grown in the presence of biphenyl. A second objective of this study was to characterise pBPH1. The complete 84,054-bp sequence of the plasmid was determined. Annotation of the DNA sequence data revealed seventy-six ORFs predicted to encode proteins, four pseudogenes, and ten gene fragments. Putative functions were assigned to forty-two of the ORF and pseudogenes. Besides biphenyl catabolism, the major functional classes of the predicted proteins were transposition, regulation, heavy metal transport/resistance, and plasmid maintenance and replication. It was shown that pBPH1 has the terminal structural features of an actinomycete invertron, including terminal proteins and terminal inverted repeats (TIRs). This is the first report detailing the nucleotide sequence and characterisation of a (linear) plasmid from the genus Terrabacter.

Thesis (MSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Dichloro-diphenyl-trichloroethane (DDT) was extensively used in agriculture pest control and is still used for indoor residual spraying to control malaria. The lipophylicity of DDT and its breakdown product dichloro-diphenyl-dichloroethylene (DDE) dictates that they associate with membranes, lipids and hydrophobic proteins in the biological environment. Their poor degradable nature causes DDT and DDE to persist for decades in the environment and in individuals who are or were in contact with the pesticide. In many countries the synchronised resistance of the mosquito vector to insecticides and the malaria parasite towards antimalarial drugs led to a drastic rise in malaria cases and to malaria epidemics. This study assesses the influence of low level exposure of DDT and DDE on chloroquine (CQ) resistance of the dire human malaria parasite, Plasmodium falciparum. The in vitro activity of p,p’-DDT and p,p’-DDE towards blood stages of chloroquine sensitive (CQS) P. falciparum D10 and chloroquine resistant (CQR) P. falciparum Dd2 was determined using two complementary in vitro assays (Malstat and SYBR Green 1). The 50% inhibition concentrations (IC50s) of p,p’-DDT and p,p’-DDE were found to be ±14 to 38 μM (5-12 μg/mL) and highly similar towards CQS and CQR P. falciparum strains. This result indicated that the proteins involved in CQ resistance have no effect on the activity of the insecticide DDT and it breakdown product DDE. In order to assess the influence of DDT and DDE on CQ activity, in vitro fixed ratio drug combination assays were performed, as well as isobologram analysis. We found that CQ works in synergy with p,p’-DDT and p,p’-DDE against CQS P. falciparum D10. However, both p,p’-DDT and p,p’-DDE were antagonistic toward CQ activity in CQR P. falciparum Dd2. This indicated that p,p’-DDT and p,p’-DDE do have an effect on CQ resistance or on the action of CQ via a target other than hemozoin polymerization. The observation of reciprocal synergism of p,p’-DDT and p,p’-DDE with CQ against CQS D10 and antagonism against CQR Dd2 strain is highly significant and strongly indicates selection of CQ resistant strains in the presence of p,p’-DDT and p,p’-DDE. People who have low levels of circulating DDE and/or DDT could be at a high risk of contracting CQR malaria. However, medium term (nine days) DDE exposure of CQS P. falciparum D10 did not induce resistance, as no significant change in activity of CQ, p,p’-DDT and p,p’-DDE towards blood stages the CQS strain was observed. This exposure was, however, shorter than expected for a malaria infection and would be addressed in future studies. From our results on the interaction of CQ with p,p’-DDT and p,p’-DDE, it was important to assess the residual DDT and DDE variable and how much of residual p,p’-DDT and/or p,p’- DDE would enter into or remain in the different compartments (the RPMI media, erythrocytes and infected erythrocytes) over time. In combination with liquid-liquid extraction, we developed a sensitive GC-MS analyses method and a novel HPLC-UV analysis method for measuring DDT and DDE levels in malaria culturing blood and media. Whilst the HPLC-UV method was relatively cheaper, faster, and effective in determining high DDT and DDE concentrations, the optimised GC-MS method proved to be effective in detecting levels as low as 78 pg/mL (ppt) DDE and 7.8 ng/mL (ppb) DDT in biological media. Using both the HPLC and GC-MS methods we observed that malaria parasites influence distribution of the compounds between the erythrocytic and media fractions. P. falciparum D10 infection at ±10% parasitemia lead to must faster equilibration (less than 8 hours) between compartments. Equimolar distribution of p,p’-DDE was observed, but the parasites lead to trapping of the largest fraction of p,p’-DDT in the erythrocyte compartment. These results indicate that a substantial amount would reach the intra-erythrocytic parasite and could influence the parasite directly, possibly leading to either synergistic or antagonistic drug interactions. This study is the first to illustrate the “good and bad” of the insecticide DDT in terms of CQ resistance and sensitivity toward the human malaria parasite P. falciparum. These results will hopefully have an important influence on how future policies on malaria control and treatment particularly in endemic areas will be addressed and could also have an impact on the anti-malarial drug discovery approach.
AFRIKAANSE OPSOMMING: Dichlorodifenieltrichloroetaan (DDT) is op groot skaal in landbouplaagbeheer gebruik en word nog steeds gebruik vir binnenshuise oppervlakbespuiting om malaria te beheer. Die lipofilisiteit van DDT en sy afbraakproduk dichlorodifenieldichloroetileen (DDE) dikteer dat hulle met membrane, lipiede en hidrofobiese proteïene in die biologiese omgewing assosieer. Stadige afbraak veroorsaak dat DDT en DDE vir dekades in die omgewing agterbly, asook in individue wat in kontak is, of was met die insekdoder. In baie lande het gesinkroniseerde weerstand van die muskietvektor teenoor insekdoders en die malariaparasiet teenoor antimalariamiddels gelei tot 'n drastiese styging in malariagevalle en tot malariaepidemies. In hierdie studie word die invloed van lae vlak blootstelling van DDT en DDE op chlorokien (CQ) weerstand van die mens malariaparasiet, Plasmodium falciparum, geëvalueer. Die in vitro aktiwiteit van p,p'-DDT en p,p'-DDE teenoor die bloedstadia van chlorokiensensitiewe (CQS) P. falciparum D10 en chlorokien-weerstandbiedende (CQW) P. falciparum Dd2 is bepaal deur gebruik te maak van twee komplementêre in vitro toetse (Malstat en SYBR Groen toetse). Die 50% inhibisie konsentrasies (IC50s) van p,p'-DDT en p,p'-DDE is bepaal as ±14 to 38 μM (5-12 μg/mL) en was hoogs vergelykbaar tussen CQS en CQW P. falciparum stamme. Hierdie resultaat het aangedui dat die proteïene betrokke by CQ weerstand geen effek op die aktiwiteit van die insekdoder DDT en die afbraakproduk DDE het nie. Om die invloed van DDT en DDE op CQ aktiwiteit te evalueer, is die aktiwiteit van kombinasies van die verbindings in vaste verhoudings getoets, tesame met isobologram ontleding. Ons het gevind dat CQ sinergisties saam met p, p'-DDT en p, p'-DDE teen CQS P. falciparum D10 werk. Daarteenoor het beide p, p'-DDT en p, p'-DDE antagonistiese werking getoon teenoor CQ aktiwiteit met CQW P. falciparum Dd2 as teiken. Dit het aangedui dat p,p'-DDT en p, p'-DDE wel 'n invloed op CQ weerstand het of ‘n aktiwiteit van CQ, anders as hemozoin polimerisasie, beïnvloed. Die waarneming van resiproke sinergisme en antagonisme van p, p'-DDT en p, p'-DDE in kombinasie met CQ teenoor die CQS D10 en CQW DD2 stamme respektiewelik, is hoogs betekenisvol en dui op seleksie van CQweerstandige stamme in die teenwoordigheid van p, p'- DDT en p, p'-DDE. Mense wat lae vlakke van sirkulerende DDE/DDT het, het dus 'n hoër risiko om CQW malaria te kry. Verder is gevind dat medium termyn (nege dae) DDE blootstelling van CQS P. falciparum D10 nie weerstand nie veroorsaak nie, want geen beduidende verandering in die aktiwiteit van CQ, p,p'-DDT en p,p'-DDE teenoor die bloed stadiums van die CQS stam is waargeneem nie. Hierdie blootstelling is egter korter as in 'n malaria-infeksie en sal verder bestudeer word in toekomstige studies. Vanuit die interaksie resultate van CQ met p, p'-DDT en p, p'-DDE was dit belangrik om die residuele DDT en DDE veranderlike te evalueer, asook die distribusie van p,p'-DDT en p,p'- DDE tussen die verskillende kompartemente (die kultuurmedium, eritrosiete en geïnfekteerde rooibloedselle) oor verloop van tyd. In kombinasie met vloeistof-vloeistof ekstraksie, het ons 'n sensitiewe GC-MS en nuwe HPLC-UV analisemetode ontwikkel vir die meet van DDT en DDE-vlakke in bloed (normale en geïnfekteerde eritrosiete) en die kultuurmedium. Terwyl die HPLC-UV metode relatief goedkoper, vinniger en effektief in die bepaling van hoë DDT en DDE-konsentrasies is, was die geoptimaliseerde GC-MS metode doeltreffend in die opsporing van vlakke so laag as 78 pg/mL (dpt) DDE en 7.8 ng/mL (dpb) DDT in biologiese media. Met behulp van beide die HPLC-UV en GC-MS metodes is waargeneem dat die malariaparasiet die ekwilibrasie van die verbindings tussen die eritrosiet- en media kompartemente beïnvloed. P. falciparum D10 infeksie met ± 10% parasitemia lei tot vinniger ekwilibrasie (minder as 8 uur) tussen die kompartemente. Ekwimolêre verspreiding van p,p'- DDE is waargeneem, maar die parasiete het die grooste fraksie van p,p'-DDT in die eritrosiet kompartement vasgevang. Hierdie resultate wys dat 'n aansienlike fraksie die intraeritrositiese parasiet kan bereik en sodoende die parasiet direk kan beïnvloed en moontlik kan lei tot sinergistiese of antagonistiese middel interaksies. Hierdie studie is die eerste om die "goed en sleg" van die insekdoder DDT in terme van CQ weerstand en sensitiwiteit teenoor die menslike malariaparasiet P. falciparum te illustreer. Hierdie resultate sal hopelik 'n belangrike invloed hê op die toekomstige beleid oor die beheer van malaria en behandeling, veral in endemiese gebiede, en mag ook 'n impak hê op die antimalariamiddel navorsing.

Orientador: Lilian Madi-Ravazzi
Banca: Carlos Roberto Ceron
Banca: Alba Regina De Abreu Lima
Resumo: D. melanogaster e D. simulans são espécies irmãs nativas da África tropical que divergiram de um ancestral comum a cerca de dois Myr. Estas espécies têm sido comparadas em vários traços, incluindo a morfologia, fisiologia, comportamento sexual, aloenzimas e outras proteínas, inversões cromossômicas, DNA nuclear e mitocondrial, elementos transponíveis, infecção por Wolbachia entre outros. Entretanto, estudos em populações da América do Sul, inclusive do Brasil, são escassos. O objetivo principal do trabalho foi comparar linhagens geográficas de D. melanogaster e D. simulans do Brasil, África e França, quanto à suscetibilidade ao inseticida DDT, ao padrão de beta e alfa esterases, principalmente em relação à frequência do polimorfismo da esterase- 6 em indivíduos fenotipados como resistentes e suscetíveis, e a atividade da glutationa S-transferase. Ambas as espécies mostraram uma ampla variabilidade nos valores da CL50 obtidos. Os maiores valores foram observados nas linhagens africanas de D. melanogaster e D. simulans, TANA (447,89 μg/mL), e TANA-4 (920 μg/mL). A linhagem Canton-S de D. melanogaster foi a que apresentou o menor valor de CL50 = 2,99 μg/mL. Comparando as populações de mesma localidade de ambas as espécies verifica-se que as linhagens de D. melanogaster mostraram valores de CL50 maiores que os de D. simulans, com exceção da linhagem FLO onde D. simulans apresentou um valor de CL50 (94,60) ligeiramente superior ao de D. melanogaster (81,82). Foram analisadas duas bandas α-esterásicas, denominadas de α-1 e α-2, sendo que a banda α-2 foi observada em 100% de todos os indivíduos analisados de ambas as espécies. Os dados mostram maior variabilidade genética para D. melanogaster em relação à resistência ao DDT, alta resistência para as linhagens africanas de ambas as espécies, indicando que estas populações continuam sendo selecionadas por este...
Abstract: D. melanogaster and D. simulans are sister species native to tropical Africa which diverged from a common ancestor about two Myr. These species have been compared in several traits, including morphology, physiology, sexual behavior, allozymes and other proteins, chromosomal inversions, nuclear and mitochondrial DNA, transposable elements, Wolbachia infection among others. However, studies in populations of South America, including Brazil, are scarce. The main objective of the study was to compare geographic strains of D. melanogaster and D. simulans from Brazil, Africa and France, for susceptibility to the insecticide DDT, the pattern of α and β esterases, especially in relation to the frequency of the polymorphism of esterase-6 in individuals phenotyped as resistant and susceptible, and the activity of glutathione-S-transferase . Both species showed a wide variability in LC50 values obtained. The highest values were observed in African strains of D. melanogaster and D. simulans, TANA (447.89 mg / mL), and TANA-4 (920 / mL). The Canton-S strain of D. melanogaster was the one with the lowest LC50 = 2.99 mg / mL. Comparing populations from the same location of both species the strains of D. melanogaster showed LC50 values larger than D. simulans, except FLO D. simulans strain had a LC50 (94.60) slightly higher than D. melanogaster (81.82). We analyzed two bands α-esterases, which we call α-1 and α-2, and the band α-2 was observed in 100% of all individuals analyzed in both species. The data show greater genetic variability for D. melanogaster for resistance to DDT, high resistance to African strains of both species, indicating that these populations continue to be selected by this or another insecticide, the lack of a cline for the F and S alleles in strains of both species, suggest that treatment with DDT may have selected individuals heterozygous for some strains, which may have masked the...
Mestre

Thesis (MPhil)--Stellenbosch University, 2003.
Full text to be digitised and attached to bibliographic record.
ENGLISH ABSTRACT: This assignment is devoted to an in depth analysis of the pro- and the contra-positions in the long-standing and costly debate about the question whether to spray with DDT or not in the fight against malaria. I argue that the dilemma whether or not to spray with DDT is born out of a political agenda, hype, exaggeration and misinformation of the first order. Radical environmentalists appear to insist that DDT is a principal contributor of environmental degradation, and the major cause of death amongst wildlife and humans. Worse still, many Western people seem to be under the impression that mosquitoes cannot cause so much human misery as purported, and that malaria is caused by some kind of plant form of life, or even a virus. The proponents of DDT, on the other hand, appear to be convinced that DDT is a saviour of humankind, and argue that the horrors associated with DDT are exaggerated and baseless, as they are not backed by scientific inquiry. Proponents of DDT also believe that anything that is overused may kill, even ordinary table salt. Inthis assignment, both of these positions are scrutinized. On the basis of an historical overview in Chapter I of the history of the use of DDT, and the emergence of the debate about DDT in the wake of Rachel Carson's Silent Spring (1962), Chapter 2 is devoted to an evaluation of seven basic arguments against the use of DDT, while in Chapter 3 six arguments for the use of DDT are weighed. In Chapter 4 a resolution of the dilemma is proposed in which a case is made for a limited use of DDT only for indoor spraying of huts and houses against malaria mosquitoes until such time as a less dangerous alternative for DDT is found that can be used as effectively in the fight against malaria. As such, this case is informed by the strong moral conviction that we cannot allow poor people of colour to die because of a general ban on the use of DDT. Further research on this ethical debate is encouraged.
AFRIKAANSE OPSOMMING: Hierdie werkstuk is toegespits op 'n in-diepte analise van die pro- en kontra-posisies in die voortslepende, asook duur debat oor die gebruik van DDT al dan nie in die bekamping van Malaria. Ek argumenteer dat die dilemma rondom die vraag of DDT gebruik moet word of nie, aangewakker word deur politieke agendas, sensasie, oordrywing en foutiewe informasie van die eerste orde. Radikale omgewingsgesindes dring oënskynlik daarop aan dat die gebruik van DDT 'n hoof-oorsaak is van die agteruitgang van die omgewing, asook 'n primêre oorsaak van dood onder wild en mense. Erger nog, dit wil voorkom of heelwat Westerse mense onder die indruk is dat muskiete nie werklik soveel menslike lyding kan veroorsaak as wat voorgegee word nie, en dat malaria eerder veroorsaak word deur 'n sekere soort plantvorm van lewe, of selfs deur 'n virus. Die voorstaanders van DDT, aan die ander kant, is klaarblyklik oortuig dat DDT 'n redder van die mensdom is, en argumenteer dat die gruwels wat geassosieer word met DDT 'n grondelose oordrywing is, aangesien dit nie deur wetenskaplike ondersoek gesteun word nie. Voorstaanders van DDT glo verder dat enige stof wat in oormaat gebruik word, die dood kan veroorsaak, selfs gewone tafelsout. In hierdie werkstuk word albei hierdie posisies krities bestudeer en bespreek. Op grond van 'n historiese oorsig in Hoofstuk 1 oor die gebruik van DDT, en die ontstaan van die debat oor DDT na aanleiding van Rachel Carson se Silent Spring (1962), word Hoofstuk: 2 gewy aan 'n evaluasie van sewe basiese argumente teen die gebruik van DDT, terwyl in Hoofstuk 3 ses argumente vir die gebruik van DDT oorweeg word. In Hoofstuk 4 word 'n voorstel gemaak vir die resolusie van die dilemma deur 'n saak uit te maak vir die beperkte gebruik van DDT, nl. slegs vir binneshuise gebruik in hutte en huise teen malaria-muskiete tot tyd en wyl 'n minder gevaarlike alternatief vir DDT gevind word wat net so effektief sal wees in die stryd teen malaria. As sulks word hierdie studie gerugsteun deur die sterk morele oortuiging dat ons nie kan toelaat dat mense van kleur sterf as gevolg van 'n algemene verbod op die gebruik van DDT nie. Verdere navorsing oor hierdie etiese debat word aangemoedig.

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Os agrotóxicos aplicados nas áreas agrícolas podem ser carreados, por diversos mecanismos, até os corpos d’água da rede hidrográfica. Além disso, estes produtos são comumente utilizados na aqüicultura para o controle de parasitoses. O teflubenzuron (TFB) é um inseticida registrado em alguns países da Europa para o controle de parasitas de peixes. Os possíveis efeitos tóxicos e risco ambiental do TFB podem ser avaliados inicialmente em condições de laboratório por meio de testes de toxicidade aguda com organismos-teste eleitos internacionalmente. Os objetivos deste trabalho foram avaliar a toxicidade aguda e o risco de intoxicação ambiental do uso agrícola e em aqüicultura do TFB, com base nos valores de CE50 e CL50 estimados em testes com Daphnia magna, Lemna minor e Poecilia reticulata, utilizados como organismos bioindicadores. Os testes de ecotoxicidade aguda foram realizados de acordo com normas nacionais e internacionais para estas espécies. A CE50-48h estimada para D. magna foi 0,00026 mg.L- 1, o que caracteriza este inseticida como altamente tóxico para esta espécie. Para L. minor, a CE50-7d estimada foi 1.176,16 mg.L-1, e para P. reticulata CL50-96h, 2.707,87 mg.L- 1, que classificam o TFB como praticamente não-tóxico para estas duas espécies. Devido à alta toxicidade do TFB para daphnídeos, mesmo em pequenas contaminações, pode causar desequilíbrio na cadeia alimentar aquática. Para minimizar o risco ambiental, o TFB pode ser utilizado de forma controlada e diluído em quantidades restritas de água.
The pesticides used in agriculture areas can be transported to water bodies of the local hydrographic basin in several ways. Moreover, these chemicals are commonly used in aquaculture to fish parasite control. The teflubenzuron (TFB) is a registered insecticide in some European countries to this use. The possible effects of the TFB and environmental risk can be evaluated initially in laboratory conditions by tests of acute toxicity with internationally elected organisms. The objectives of this study were to evaluate the acute toxicity and the environmental risk due to agriculture and aquaculture use of TFB, based on the values of EC50 and LC50 estimated in tests with Daphnia magna, Lemna minor and Poecilia reticulata, internationally used as bioindicators organisms. The acute ecotoxicity tests were performed in accordance with national and international standards for these species. The EC50-48h estimated to D. magna was 0,00026 mg.L-1, which characterizes that as very highly toxic insecticide for this species. For L. minor, EC50-7d was estimated 1.176,16 mg.L-1, and P. reticulata LC50-96h, 2.707,87 mg.L-1, which classified the TFB as practically non-toxic to these species. Due to the high toxicity of the TFB to daphnids, even in little contamination, can cause a loss of equilibrium in the aquatic food chain. To minimize the environmental risk, the TFB can be used in a controlled way and diluted in limited quantities of water.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O inseticida diflubenzuron (DFB), comercializado como Dimilin®, é empregado em pisciculturas no tratamento de ecotoparasitoses em peixes. Este composto inibe a síntese de quitina, componente do exoesqueleto dos parasitas. A utilização deste inseticida se deve à sua baixa toxicidade aos peixes e eficácia no controle dos ectoparasitas. Porém, no ambiente aquático o DFB pode ser tóxico à espécies sensíveis e não-alvos, a concentração empregada no tratamento das ectoparasitoses é de 2 mg.L-1. Os objetivos deste estudo foram avaliar a toxicidade do DFB para as espécies de Daphnia magna, Poecilia reticulata e Lemna minor, classificar o produto quanto à sua toxicidade e risco ambiental e avaliar o efeito do sedimento na biodisponibilidade do DFB na água. Os organismos-teste foram submetidos a concentrações crescentes do inseticida em salas climatizadas do Laboratório de Ecotoxicologia da FCAV-UNESP. Os testes com D. magna foram realizados em volume de 10 mL a 20° C e cinco organismos neonatos por concentração, durante 48 horas na presença e ausência de sedimento. Os peixes (P. reticulata) foram expostos às concentrações do DFB por 96 horas em testes na presença e ausência de sedimento. O volume final foi de 3000 mL e cinco animais por concentração à 25° C. As plantas de L. minor foram expostas ao DFB por sete dias na presença e ausência de sedimento. O volume final foi de 100 mL e 12 frondes por concentração à 24° C. Os testes foram realizados com três réplicas incluindo o controle. As CE50-48h calculadas para D. magna foram de 0,56 μg.L-1 e 1,51 μg.L-1 na ausência e presença de sedimento respectivamente; as CL50-96h para P. reticulata foram 152,00 mg.L-1 e 277,83 mg.L-1 na ausência e presença de sedimento respectivamente; e as CE50-7dias para L. minor foram 459,50 mg.L-1 e 698,25 mg.L-1 na ausência e presença de sedimento respectivamente...
The insecticide diflubenzuron (DFB), marketed as Dimilin®, is used in fish farms to treat ectoparasites in fishes. This compound inhibits the chitin synthesis, exoskeleton component of the parasites. The use of this insecticide is due to its low toxicity for fish and effectiveness in the control of ectoparasites. However, the DFB in the aquatic environmental can be toxic to sensitive species and non-targed, the concentration used in the treatment of ectoparasites is 2 mg.L-1. The aims of this study were to evaluate the toxicity of the DFB for the species of Daphnia magna, Poecilia reticulata and Lemna minor, classify the product as to their toxicity and environmental risk and evaluate the effect of sediment on the bioavailability of the DFB in the water. The organisms-test were submitted to increasing concentrations of insecticide in air conditioned rooms of the Laboratory of Ecotoxicology FCAV-UNESP. Tests with D. magna were performed in volume of 10 mL at 20° C and five organisms neonates (6 and 24 hours of age) in each concentration, for 48 hours in the presence and absence of sediment. Fishes (P. reticulata) were exposed to concentrations of the DFB for 96 hours in tests in the presence and absence of sediment. The final volume was 3000 mL and five animals per concentration to 25° C. The plants of L. minor were exposed to the DFB for seven days in the presence and absence of sediment. The final volume was 100 mL and 12 fronds by concentration to 24° C. The tests were performed with three repetitions incluing the control. The EC50-48h estimeds for D. magna were 0.56 and 1.51 μg.L-1 in the absence and presence of sediment respectively; the LC50-96h for P. reticulata were 152.00 mg.L-1 and 277.83 mg.L-1 in the absence and presence of sediment respectively; and the EC50-7dias to L. minor were 459.50 mg.L-1 and 698.25 mg.L-1 in the absence and presence of sediment respectively...(Complete abstract, click electronic access below)

Orientador: Joaquim Gonçalves Machado Neto
Banca: Julio Vicente Lombardi
Banca: Robinson Antonio Pitelli
Resumo: Os agrotóxicos aplicados nas áreas agrícolas podem ser carreados, por diversos mecanismos, até os corpos d'água da rede hidrográfica. Além disso, estes produtos são comumente utilizados na aqüicultura para o controle de parasitoses. O teflubenzuron (TFB) é um inseticida registrado em alguns países da Europa para o controle de parasitas de peixes. Os possíveis efeitos tóxicos e risco ambiental do TFB podem ser avaliados inicialmente em condições de laboratório por meio de testes de toxicidade aguda com organismos-teste eleitos internacionalmente. Os objetivos deste trabalho foram avaliar a toxicidade aguda e o risco de intoxicação ambiental do uso agrícola e em aqüicultura do TFB, com base nos valores de CE50 e CL50 estimados em testes com Daphnia magna, Lemna minor e Poecilia reticulata, utilizados como organismos bioindicadores. Os testes de ecotoxicidade aguda foram realizados de acordo com normas nacionais e internacionais para estas espécies. A CE50-48h estimada para D. magna foi 0,00026 mg.L- 1, o que caracteriza este inseticida como altamente tóxico para esta espécie. Para L. minor, a CE50-7d estimada foi 1.176,16 mg.L-1, e para P. reticulata CL50-96h, 2.707,87 mg.L- 1, que classificam o TFB como praticamente não-tóxico para estas duas espécies. Devido à alta toxicidade do TFB para daphnídeos, mesmo em pequenas contaminações, pode causar desequilíbrio na cadeia alimentar aquática. Para minimizar o risco ambiental, o TFB pode ser utilizado de forma controlada e diluído em quantidades restritas de água.
Abstract: The pesticides used in agriculture areas can be transported to water bodies of the local hydrographic basin in several ways. Moreover, these chemicals are commonly used in aquaculture to fish parasite control. The teflubenzuron (TFB) is a registered insecticide in some European countries to this use. The possible effects of the TFB and environmental risk can be evaluated initially in laboratory conditions by tests of acute toxicity with internationally elected organisms. The objectives of this study were to evaluate the acute toxicity and the environmental risk due to agriculture and aquaculture use of TFB, based on the values of EC50 and LC50 estimated in tests with Daphnia magna, Lemna minor and Poecilia reticulata, internationally used as bioindicators organisms. The acute ecotoxicity tests were performed in accordance with national and international standards for these species. The EC50-48h estimated to D. magna was 0,00026 mg.L-1, which characterizes that as very highly toxic insecticide for this species. For L. minor, EC50-7d was estimated 1.176,16 mg.L-1, and P. reticulata LC50-96h, 2.707,87 mg.L-1, which classified the TFB as practically non-toxic to these species. Due to the high toxicity of the TFB to daphnids, even in little contamination, can cause a loss of equilibrium in the aquatic food chain. To minimize the environmental risk, the TFB can be used in a controlled way and diluted in limited quantities of water.
Mestre

Orientador: Joaquim Gonçalves Machado Neto
Banca: Julio Vicente Lombardi
Banca: Robinson Antonio Pitelli
Resumo: O inseticida diflubenzuron (DFB), comercializado como Dimilin®, é empregado em pisciculturas no tratamento de ecotoparasitoses em peixes. Este composto inibe a síntese de quitina, componente do exoesqueleto dos parasitas. A utilização deste inseticida se deve à sua baixa toxicidade aos peixes e eficácia no controle dos ectoparasitas. Porém, no ambiente aquático o DFB pode ser tóxico à espécies sensíveis e não-alvos, a concentração empregada no tratamento das ectoparasitoses é de 2 mg.L-1. Os objetivos deste estudo foram avaliar a toxicidade do DFB para as espécies de Daphnia magna, Poecilia reticulata e Lemna minor, classificar o produto quanto à sua toxicidade e risco ambiental e avaliar o efeito do sedimento na biodisponibilidade do DFB na água. Os organismos-teste foram submetidos a concentrações crescentes do inseticida em salas climatizadas do Laboratório de Ecotoxicologia da FCAV-UNESP. Os testes com D. magna foram realizados em volume de 10 mL a 20° C e cinco organismos neonatos por concentração, durante 48 horas na presença e ausência de sedimento. Os peixes (P. reticulata) foram expostos às concentrações do DFB por 96 horas em testes na presença e ausência de sedimento. O volume final foi de 3000 mL e cinco animais por concentração à 25° C. As plantas de L. minor foram expostas ao DFB por sete dias na presença e ausência de sedimento. O volume final foi de 100 mL e 12 frondes por concentração à 24° C. Os testes foram realizados com três réplicas incluindo o controle. As CE50-48h calculadas para D. magna foram de 0,56 μg.L-1 e 1,51 μg.L-1 na ausência e presença de sedimento respectivamente; as CL50-96h para P. reticulata foram 152,00 mg.L-1 e 277,83 mg.L-1 na ausência e presença de sedimento respectivamente; e as CE50-7dias para L. minor foram 459,50 mg.L-1 e 698,25 mg.L-1 na ausência e presença de sedimento respectivamente...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The insecticide diflubenzuron (DFB), marketed as Dimilin®, is used in fish farms to treat ectoparasites in fishes. This compound inhibits the chitin synthesis, exoskeleton component of the parasites. The use of this insecticide is due to its low toxicity for fish and effectiveness in the control of ectoparasites. However, the DFB in the aquatic environmental can be toxic to sensitive species and non-targed, the concentration used in the treatment of ectoparasites is 2 mg.L-1. The aims of this study were to evaluate the toxicity of the DFB for the species of Daphnia magna, Poecilia reticulata and Lemna minor, classify the product as to their toxicity and environmental risk and evaluate the effect of sediment on the bioavailability of the DFB in the water. The organisms-test were submitted to increasing concentrations of insecticide in air conditioned rooms of the Laboratory of Ecotoxicology FCAV-UNESP. Tests with D. magna were performed in volume of 10 mL at 20° C and five organisms neonates (6 and 24 hours of age) in each concentration, for 48 hours in the presence and absence of sediment. Fishes (P. reticulata) were exposed to concentrations of the DFB for 96 hours in tests in the presence and absence of sediment. The final volume was 3000 mL and five animals per concentration to 25° C. The plants of L. minor were exposed to the DFB for seven days in the presence and absence of sediment. The final volume was 100 mL and 12 fronds by concentration to 24° C. The tests were performed with three repetitions incluing the control. The EC50-48h estimeds for D. magna were 0.56 and 1.51 μg.L-1 in the absence and presence of sediment respectively; the LC50-96h for P. reticulata were 152.00 mg.L-1 and 277.83 mg.L-1 in the absence and presence of sediment respectively; and the EC50-7dias to L. minor were 459.50 mg.L-1 and 698.25 mg.L-1 in the absence and presence of sediment respectively...(Complete abstract, click electronic access below)
Mestre

Orientadores: Aline Vieira de Carvalho, Jansle Vieira Rocha
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas
Made available in DSpace on 2018-08-27T17:44:32Z (GMT). No. of bitstreams: 1 Gaissler_RubiaPereira_D.pdf: 5274430 bytes, checksum: d24c8d8f3ef14a2501b1e01a9e473735 (MD5) Previous issue date: 2015
Resumo: Esta tese de doutorado teve como objetivo analisar a cobertura midiática do pesticida DDT desde a sua primeira aparição na mídia, em 1944, até 2014. O objetivo estabelecido foi de identificar as principais narrativas usadas para falar sobre o DDT e as mudanças observadas no discurso referente ao mesmo durante todo o período de tempo acima mencionado. Isto foi atingido observando uma porção selecionada da mídia de dois países que têm um histórico relevante no que diz respeito ao DDT: os Estados Unidos e o Brasil. O primeiro foi escolhido por se tratar de um usuário intenso e um forte defensor da utilização do DDT entre as décadas de 1940 e 1960, e também por ter sido o vórtice de um debate que levou à proibição global do DDT, na década de 1970; o segundo foi incluído na análise para oferecer um contraponto ao primeiro, justificado por uma diferença muito distinta em aspectos culturais, geográficos, econômicos e demográficos. Foram analisadas as revistas Estadunidenses TIME, The New Yorker e Popular Science, e as revistas brasileiras Veja e Superinteressante. O estudo identificou uma virada discursiva única na cobertura da mídia, em 1967, quando DDT deixou de ser visto majoritariamente como benéfico e passou a ser principalmente visto como prejudicial. A análise quantitativa das 711 unidades midiáticas que fizeram parte do conjunto de dados mostrou oscilações na intensidade da cobertura ao longo dos 70 anos estudados, com destaque para um pico entre 1969 e 1971, sendo que tais variações foram interpretadas trazendo o contexto histórico-cultural de cada período abordado e considerando a trajetória do movimento ambientalista, do jornalismo científico e da própria ciência. Adicionalmente, a tese foi estruturada objetivando desmistificar o papel da bióloga norte-americana Rachel Carson na proibição de DDT, investigando sua influência na trajetória do discurso relacionado ao DDT tanto na época em que lançou a obra Primavera Silenciosa, em 1962, quanto observando de que maneiras o retrato da sua figura enquanto símbolo evoluiu nas décadas seguintes até chegar às representações oferecidas no presente
Abstract: This doctoral thesis aimed to analyze the media coverage of the pesticide DDT since its first appearance in the media, in 1944, until 2014. The established objective was to identify the main narratives used to talk about DDT and the observed discourse changes related to it throughout the period of time aforementioned. This was achieved by looking into selected media from two countries that have a relevant history concerning DDT: The United States and Brazil. The first was chosen because it was a heavy user and a strong advocate for DDT use from the 1940s to the 1960s, and also because it was the vortex of a debate that led to the DDT world ban in the 1970s; the second was included in the analysis to offer a counterpoint to the first, justified by a very distinct difference in cultural, geographic, economic and demographic aspects. The United States¿ magazines TIME, The New Yorker, and Popular Science were analyzed, and also the Brazilian magazines Veja and Superinteressante. The research identified a single discourse flip in the media coverage, in 1967, when DDT stopped being majorly seen as beneficial and started being predominantly faced as harmful. The quantitative analysis of the 711 media units that composed the data set showed oscillations in the coverage intensity during the 70 years studied, with a highlight to a peak between 1969 and 1971; such variations were interpreted bringing the historical and cultural context of each period and considering the trajectory of the environmental movement, the scientific journalism and of science itself. Additionally, the thesis was structured aiming to demystify the role of the North American biologist Rachel Carson in the DDT ban, investigating her influence in the DDT discourse trajectory not only when the Silent Spring was published, in 1962, but also observing in which ways her portraying as a symbol evolved in the following decades until reaching today¿s representations
Doutorado
Aspectos Biológicos de Sustentabilidade e Conservação
Doutora em Ambiente e Sociedade

This thesis presents a first ever extensive analysis of pesticides in water and sediments from the Okavango Delta, Botswana, employing green sample preparation techniques that require small volumes of organic solvents hence generating negligible volumes of organic solvent waste. Pesticides were extracted and pre-concentrated from water by solid phase extraction (SPE) and headspace solid phase microextraction (HS-SPME) while supercritical fluid extraction (SFE) and pressurized fluid extraction (PFE) were employed for sediments. Subsequent analysis was carried out on a gas chromatograph with electron capture detection and analytes were unequivocally confirmed by high resolution mass spectrometric detection. Hexachlorobenzene (HCB), trans-chlordane, 4,4′-DDD and 4,4′-DDE were detected after optimized HS-SPME in several water samples from the lower Delta at concentrations ranging from 2.4 to 61.4 μg L-1 that are much higher than the 0.1 μg L-1 maximum limit of individual organochlorine pesticides in drinking water set by the European Community Directive. The same samples were cleaned with ISOLUTE C18 SPE sorbent with an optimal acetone/n-hexane (1:1 v/v) mixture for the elution of analytes. No pesticides were detected after SPE clean-up and pre-concentration. HCB, aldrin and 4, 4‟-DDT were identified in sediments after SFE at concentration ranges of 1.1 - 30.3, 0.5 – 15.2 and 1.4 – 55.4 μg/g, respectively. There was an increase of pesticides concentrations in the direction of water flow from the Panhandle (point of entry) to the lower delta. DDE, fatty acids and phthalates were detected after PFE with optimized extraction solvent and temperature. The presence of DDT metabolites in the water and sediments from the Okavango Delta confirm historical exposure to the pesticide. However their cumulative concentration increase in the water-flow direction calls for further investigation of point sources for the long-term preservation of the Delta. The green sample preparation techniques and low toxicity solvents employed in this thesis are thus recommended for routine environmental monitoring exercises.

MgAl layered double hydroxides nanoparticles (LDHs) are known as the useful materials in agrochemsitry. LDHs can be used as a bio-insecticide carrier to enhance insecticide’s activity efficiency. In our study, to improve the insecticide activity of anacardic acid, an extract from cashew nut shell liquid, we intercalated it MgAl layered double hydroxides nanoparticles. Different hybridization between anacardic acid and LDHs (37, 74, 148, and 296μg/mL) (L-As) were made and tested on the survivals of cutworms (Spodoptera litura). L-As or free anacardic acid was sprayed directly on the leaves mustard to feed cutworms or directly on the skin of cutworms. Our results showed that in all L-As treatments, the worm killing efficiency was higher than the free anacardic acid treatment.
Hạt nano lớp đôi hydroxides MgAl (LDHs) được biết đến như là những vật liệu hữu ích trong nông ngành hóa học nông nghiệp. LDHs có thể được dùng như là một loại chất mang cho thuốc trừ sâu sinh học để tăng cường hiệu lực diệt sâu. Trong nghiên cứu này, để tăng cường hiệu lực diệt sâu của anacardic acid, một loại hoạt chất được chiết từ dầu vỏ hạt điều, chúng tôi đã gắn chèn nó lên hạt nano lớp đôi hydroxides MgAl. Các nồng độ khác nhau của dạng lai của anacardic và LDHs (37, 74, 148 và 296μg/mL) (L-As) đã được kiểm tra tỷ lệ sống của ấu trùng sâu khoang (Spodoptera litura). Các nghiệm thức L-As và dạng anacardic acid tự do đã được phun lên lá rau cải ngọt cho ấu trùng sâu ăn hoặc phun trực tiếp lên da ấu trùng sâu. Kết quả cho thấy, tất cả các công thức có xử lý bằng L-As, hiệu lực diệt ấu trùng sâu đều cao hơn so với dạng anacardic acid ở trạng thái tự do.

MgAl layered double hydroxides nanoparticles (LDHs) are known as the useful materials in agrochemsitry. LDHs can be used as a bio-insecticide carrier to enhance insecticide’s activity efficiency. In our study, to improve the insecticide activity of anacardic acid, an extract from cashew nut shell liquid, we intercalated it MgAl layered double hydroxides nanoparticles. Different hybridization between anacardic acid and LDHs (37, 74, 148, and 296μg/mL) (L-As) were made and tested on the survivals of cutworms (Spodoptera litura). L-As or free anacardic acid was sprayed directly on the leaves mustard to feed cutworms or directly on the skin of cutworms. Our results showed that in all L-As treatments, the worm killing efficiency was higher than the free anacardic acid treatment
Hạt nano lớp đôi hydroxides MgAl (LDHs) được biết đến như là những vật liệu hữu ích trong nông ngành hóa học nông nghiệp. LDHs có thể được dùng như là một loại chất mang cho thuốc trừ sâu sinh học để tăng cường hiệu lực diệt sâu. Trong nghiên cứu này, để tăng cường hiệu lực diệt sâu của anacardic acid, một loại hoạt chất được chiết từ dầu vỏ hạt điều, chúng tôi đã gắn chèn nó lên hạt nano lớp đôi hydroxides MgAl. Các nồng độ khác nhau của dạng lai của anacardic và LDHs (37, 74, 148 và 296μg/mL) (L-As) đã được kiểm tra tỷ lệ sống của ấu trùng sâu khoang (Spodoptera litura). Các nghiệm thức L-As và dạng anacardic acid tự do đã được phun lên lá rau cải ngọt cho ấu trùng sâu ăn hoặc phun trực tiếp lên da ấu trùng sâu. Kết quả cho thấy, tất cả các công thức có xử lý bằng L-As, hiệu lực diệt ấu trùng sâu đều cao hơn so với dạng anacardic acid ở trạng thái tự do

A utilização de pesticidas organoclorados é motivo de preocupação das entidades ligadas à área de saúde em todo o mundo. Apesar de as formas de contaminação serem bem conhecidas, não há um controle eficaz na fiscalização do seu uso no Brasil. Sabe-se que altos níveis séricos destes compostos nos organismos de seres humanos e animais acarretam sérios problemas de saúde. Tendo em vista essa realidade, foi realizado, em 2009, o Projeto Piloto do I Inquérito Nacional de Populações Expostas a Substâncias Químicas, cujo subprojeto \"doadores de sangue\" teve como objetivo mensurar as concentrações de substâncias químicas no sangue de 547 residentes da região metropolitana de São Paulo, dentre elas os pesticidas organoclorados. Este trabalho teve como objetivos avaliar as concentrações dos pesticidas hexaclorobenzeno (HCB), alfa-HCH, ?-HCH, beta-HCH, beta-HCH, heptacloro, heptacloro epóxido, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD nesta população e compará-las com as encontradas em outros países e determinar fatores associados aos níveis mais elevados destas substâncias. O método analítico utilizado foi de cromatografia a gás. Os resultados deste estudo indicam que a população adulta de São Paulo não está exposta a níveis preocupantes de pesticidas organoclorados, pois dentre os compostos analisados, apenas o beta-HCH e o p,p\'-DDE tiveram um número significante de amostras acima do limite de quantificação, 10,7% e 31,2% das amostras respectivamente. Quando utilizada a metade do limite de quantificação para substituir os valores abaixo do limite de quantificação do método, o valor médio encontrado para o beta-HCH foi de 0,028 ug/dL e para o p,p\'-DDE foi de 0,045 ug/dL. Este estudo propôs dois modelos multivariados para explicar os fatores associados aos compostos beta-HCH e p,p\'-DDE no sangue dos doadores. Segundo o modelo de Regressão Logística Ordinal Multivariado, os fatores associados a níveis mais altos de beta-HCH foram ter idade entre 26 e 45 anos e ser do sexo feminino. Para o p,p\'-DDE os fatores associados a níveis mais altos foram ter idade entre 26 e 45 anos, ser do sexo feminino e ter trabalhado com pesticidas, enquanto receber renda mensal de 3 a 5 salários mínimos e consumir derivados de origem animal uma ou mais vezes por semana foram associados a níveis mais baixos de p,p\'-DDE. Segundo o modelo de Regressão Linear Múltipla, os fatores associados a níveis mais altos de beta-HCH foram o sexo feminino, ter contato prévio com pesticidas na região agrícola, ter trabalhado com pesticidas em campanhas de saúde pública, ter trabalhado em empresas de capacitores ou transformadores, ter trabalhado em indústrias de solventes clorados, ter renda mensal de 3 a 5 salários mínimos, consumo de carnes uma ou duas vezes por semana e consumo de frutos do mar uma ou duas vezes por semana, enquanto consumo frequente de cerveja e ter renda mensal de 1 a 3 salários mínimos foram associado a níveis menores de beta-HCH. Já para o p,p\'-DDE, os fatores associados a níveis mais elevados foram ser do sexo feminino, ser não branco, ter trabalhado com pesticidas e consumir água de fontes que não sejam minerais ou de rede, enquanto o consumo frequente de bebidas alcoólicas foi associado a níveis mais baixos de p,p\'-DDE
The use of organochlorine pesticides is a cause of concern to the entities of the health field worldwide. Although the ways of contamination are well known, there is no effective surveillance of its use on Brazil. It\'s known that high levels of these compounds on human beings and animals entails serious health problems. Foreseeing this reality, a Pilot study of the 1st National Inquiry of Populations Exposed to Chemical Compounds was carried out in 2009, in a subproject called \"blood donors\" had the objective to measure the concentrations of chemical compounds on serum from 547 residents of the metropolitan area of São Paulo, among them, the organochlorine pesticides. This study had as objectives to evaluate the levels of the pesticides hexachlorobenzene (HCB), alfa-HCH, beta-HCH, beta-HCH, beta-HCH, heptachlor, heptachlor epoxide, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD on blood donors and compare these with the ones found on other countries and to find out factors associated with higher levels of those compounds in the population. The analytical method used was gas chromatography. The results of this study indicate that, overall, the population in São Paulo is not exposed to high levels of these compounds because of all compounds analyzed, only beta-HCH and p,p\'-DDE had a significative number of samples above the quantification limit, 10,7% and 31,2% of the samples respectively. Using the half of the quantification limit to substitute the values below the quantification limit, the beta-HCH mean level was 0.028 ug/dL and p,p\'-DDE mean level was 0.045 ug/dL. This study proposed two multivariate models to explain the factors associated with beta-HCH and p,p\'-DDE blood levels. According to the Multivariable Ordinal Logistic Regression model, the factors associated with higher levels of beta-HCH were age between 26 and 45 years and female gender. For the p,p\'-DDE, the associated factors with higher levels were age between 26 to 45 years, female gender and previous work with pesticides while having income of 3 to 5 minimum wages and consumption of derivates of animal origin at least once per week were associated to lower levels of p,p\'-DDE. According to the Multiple Linear Regression model, the factors associated with higher levels of beta-HCH were female gender, previous contact with pesticides on agricultural region, working with pesticides on campaigns of public health, in companies of capacitators or transformers, in companies of chlorinated solvents, having income of 3 to 5 minimum wages, consumption of meat once or twice per week, and consumption of seafood once or twice per week, while frequent consumption of beer and income of 1 to 3 minimum wages lead to lower levels of beta-HCH. Factors associated with higher levels of p,p\'-DDE were female gender, being non-white, previous work with pesticides and consumption of water from sources that not mineral or mains, while frequent consumption of alcohol were associated with lower levels of p,p\'-DDE

Das Ziel der vorliegenden Arbeit war es, die Wirksamkeit der beiden biologischen Präparate NeemAzal MD5 und TRF 002 MD auf das Entwicklungspotential der Larven der großen Stubenfliege (Musca domestica) und der Güllefliege (Hydrotaea aenescens) zu untersuchen. Bei den Präparaten handelte es sich um den Extrakt aus den Samen des tropischen Niembaumes (Azadirachta indica) mit dem Hauptwirkbestandteil Azadirachtin A in einer Konzentration von 5 % und um den Extrakt aus dem Bitterholz (Quassia amara) mit dem Hauptwirkstoff Quassin in einer Konzentration von 0,61 %. Die Larvenstadien 1 und 3 jeder Fliegenart wurden dem jeweiligen Präparat, das in verschiedenen Konzentrationen entweder eingemischt im Brutsubstrat (orale Aufnahme) oder in einem Tauchbad (topische Applikation) getestet wurde, ausgesetzt. Der Einfluss der Wirkstoffe auf die Parameter Verpuppungsrate, Schlupfrate, Entwicklungsdauer, Fliegengröße und Vorkommen von Asymmetrien wurde dabei ermittelt. NeemAzal MD5 in 5 % Lösung verhinderte, eingemischt ins Brutsubstrat, vollständig den Schlupf der Fliegen unabhängig vom Alter der verwendeten Larven. Das jüngste Larvenstadium wies dabei noch eine deutlich höhere Empfindlichkeit gegenüber dem Wirkstoff auf, hier reichte bereits eine 1 % Lösung aus, um die Entwicklung von Fliegen zu unterdrücken. Unterschiede in der Wirksamkeit auf die beiden verwendeten Fliegenarten waren gering. Hydrotaea aenescens erwies sich hierbei als etwas empfindlicher gegenüber NeemAzal MD5 als die Larven von Musca domestica. Die topische Applikation des Präparates auf das Larvenstadium 3 führte in den verwendeten hohen Konzentrationen (5 %, 10 %) nur zu einer Reduktion der Fliegenanzahl. Für eine vollständige Verhinderung der Fliegenentwicklung ist eine möglichst frühzeitige orale Aufnahme des Wirkstoffes durch die Larven notwendig. Es kommt dabei neben der Fraßhemmung zu einer Beeinflussung der Wachstums- und Häutungshormone, was die Metamorphose der Insekten unterdrückt. Die unter Laborbedingungen bewiesene insektizide Wirksamkeit von NeemAzal MD5 und seine Umweltverträglichkeit prädisponieren das Präparat für Feldversuche gegen Fliegenplagen in der ökologischen Tierhaltung. TRF 002 MD bewirkte auch in der höchsten verwendeten Konzentration (10 %), eingemischt in das Brutsubstrat der Larvenstadien 1 und 3 der beiden Fliegenarten, nur eine Reduktion der Schlupfrate um bis zu 30 % gegenüber den Kontrollgruppen. Die topische Anwendung dieser Substanz erwies sich in den durchgeführten Versuchen als nahezu wirkungslos auf die untersuchten Parameter. Damit war das Präparat nicht geeignet, das Schlüpfen von Fliegen vollständig zu verhindern.

An drei Standorten wurde die schädlingsregulierende Wirkung einer Raps-Rübsen-Mischsaat (Verhältnis 9:1) gegenüber einer Raps-Reinsaat bewertet. Des Weiteren wurden naturstoffliche und nach § 6a PflSchG selbst hergestellte Pflanzenschutzmittel als auch eine Käfersammelmaschine zur Regulierung der Stängelrüssler (Ceutorhynchus spp.) und des Rapsglanzkäfers (Meligethes aeneus F.) in Labor- und Freilandversuchen angewandt. In der Mischsaat war die Schaderregerabundanz gegenüber der Reinsaat zumeist erhöht. Diese führte zu einem teils signifikant stärkeren Schaderregerbefall der Rapspflanzen in der Mischsaat. Die Mischsaat erbrachte zudem einen teils signifikant geringeren Kornertrag. Natur-Pyrethrum und Spinosad führten im Labor zu deutlich erhöhten Mortalitäten bei den Stängelrüsslern. Im Freiland war kein Effekt erkennbar. Bei der Regulierung der Rapsglanzkäfer wies Spinosad in Feld- und Laborversuchen Wirkungsgrade bis zu 100 % auf. Gespritztes Gesteinsmehl und SiO2 zeigten einen nur geringen Effekt. Für die gleichmäßige Benetzung der Pflanzen mit diesen Präparaten kommt der Formulierung der Pflanzenschutzbrühe und der wiederholten Applikation eine hohe Bedeutung zu. Ökonomisch sind mehrfache Applikationen jedoch abzulehnen. Gestäubtes Gesteinsmehl und die Käfersammelmaschine sind aus Praktikabilitätsgründen nicht geeignet zur Regulierung der Rapsglanzkäfer. Ebenso wenig geeignet sind Quassin, Azadirachtin oder ein Bacillus thuringiensis-Präparat (B.t.t.). Mit Ausnahme einer Spinosad Applikation erzielte keine Pflanzenschutzmaßnahme einen wirtschaftlichen Mehrertrag. Stickstoffmangel und Unkrautkonkurrenz scheinen im ökologischen Rapsanbau häufig stärker auf die Limitierung der Kornerträge zu wirken als ein leichter bis mittlerer Schädlingsbefall. Je besser die Nährstoffversorgung und je geringer die Unkrautkonkurrenz, desto eher kann durch Pflanzenschutz ein wirtschaftlicher Mehrertrag realisiert werden. Die nötigen Pflanzenschutzkonzepte fehlen jedoch weiterhin.
On three sites the pest-regulating effect of a rape-turnip rape mixed cropping system (ratio 9:1) in comparison to rape in pure stand was assessed. Further, natural and self-produced natural insecticide solutions (§ 6a Plant Protection Act) and a beetle collecting machine to regulate the stem weevils (Ceutorhynchus spp.) and the pollen beetles (Meligethes aeneus F.) were applied in laboratory and field experiments. Compared to the fields in pure stand the mixed crop showed a significantly greater abundance of pests. This resulted in a sometimes significantly greater pest infestation of the rape plants in the mixed crop. Furthermore, the mixed crop often had a significantly lower grain yield. The use of natural pyrethrum and Spinosad resulted in significantly higher mortality rates of the stem weevils in laboratory tests. Under field conditions no effect could be detected. In the regulation of the pollen beetles, Spinosad demonstrated under field and laboratory conditions efficiencies of up to 100 %. Sprayed mineral powder or SiO2 had only a slight effect. For a uniform wetting of the plants with these compounds the formulation of the phytosanitary broth and its repeated application are important factors. From an economic perspective, however, repeated applications are inefficient. For reasons of practicality rock-dusted flour and the beetle-collecting machine are not suitable for pollen beetle regulation. Quassin is just as inappropriate as Azadirachtin, or Bacillus thuringiensis (B.t.t.) for the regulation of the pollen beetle. With the exception of one Spinosad application, no protection measure provided an economic surplus. Nitrogen deficiency and weeds seem to more frequently limit grain yield than slight to moderate pest infestation levels. The better the nutrient supply and the lower the weed competition, the more likely by crop protection can be realized an economic surplus. Adequate crop protection strategies, however, have not yet been developed.

In this thesis, we examined the effects of the exposures to anthropogenic pollutants on the fish, primarily juvenile chinook salmon, immune system using newly and recently developed immune assays. In addition, we developed a new assay for measuring immunocompetence of fish. In the first chapter, the Alamar Blue assay was developed to quantify the proliferation of chinook salmon (Oncorhynchus tshawytscha) leukocytes. Isolated splenic and pronephric leukocytes were stimulated with different concentration of mitogens (LPS, PWM, and ConA) for various incubation times. Optimum cell culture conditions (cell density, mitogen concentration, and incubation time) for the Alamar Blue assay were evaluated by comparison with flow cytometric analysis. The Alamar Blue dye was non-toxic for leukocytes, and the assay proved to be able to quantify the mitogenic responses using LPS, but PWM and ConA. In the second chapter, we determined the effects and mechanisms by which p,p'- DDE exposure might affect the immune system of chinook salmon (Oncorhynchus tshawytscha). Isolated salmon splenic and pronephric leucocytes were incubated with different concentrations of p,p'-DDE, and cell viability, induction of apoptosis, and mitogenic responses were measured by flow cytometry and Alamar Blue assay. p,p'- DDE significantly reduced cell viability and proliferation and increased apoptosis. The effect of p,p'-DDE on pronephric leukocytes was more severe than on splenic leukocytes, likely because pronephric leucocytes had a higher proportion of granulocytes, cells that appear more sensitive to p,p'-DDE. The effect of p,p'-DDE on leucocytes appeared to vary between developmental stages or season. The mitogenic response of leukocytes of chinook salmon exposed to p,p'-DDE in vivo exhibited a biphasic dose-response relationship. Only leukocytes isolated from salmon treated with 59 ppm p,p'-DDE had a significantly lower percentage of Ig+ blasting cells than controls. Our results support the theory that exposure to chemical contaminants could lead to an increase in disease susceptibility and mortality of fish due to immune suppression. In the third chapter, we evaluated the direct effects of in vitro exposures to tributyltin (TBT), widely used biocide, on the cell mediated immune system of chinook salmon (Oncorhynchus tshawytscha). Splenic and pronephric leukocytes isolated from juvenile chinook salmon were exposed for 6, 24, or 96 hr to a concentration range of 0.03 0.1 mg TBT 1����� in cell cultures. Effects of TBT on cell viability, induction of apoptosis, and mitogenic responses were measured by flow cytometry. Splenic and pronephric leukocytes in the presence of TBT experienced a concentration-dependent decrease in the viability in cell cultures following the induction of apoptosis. In addition, pronephric lymphocytes exhibited a greater sensitivity to TBT exposure than pronephric granulocytes. The functional ability of splenic B-cells to undergo blastogenesis upon LPS stimulation was also significantly inhibited in the presence of 0.05, 0.07, or 0.10 mg 1����� of TBT in the cell cultures. Flow cytometric assay with the fluorescent conjugated monoclonal antibody against salmon surface immunoglobulin was employed for the conclusive identification of B-cell in the chinook salmon leukocytes. Our findings suggest that adverse effects of TBT on the function or development of fish immune systems could lead to an increase in disease susceptibility and its subsequent ecological implications.
Graduation date: 2004

M.Sc.
The organochlorine insecticides were amongst the first pollutants shown to cause adverse population effects. The potential adverse effects of these pollutants on wildlife are a cause for great concern. Severities of their effects were sometimes surprising given the low levels of the compounds in environmental compartments such as surface waters and soils. High lipophilicity combined with chemical stability and very slow biodegradation are characteristic features of these toxic Persistent Organic Pollutants (POPs). Regional declines in fish, bird as well as invertebrate populations resulting from long term exposure to POPs such as 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane (DDT) and its stable metabolite 1,1-bis (4-chlorophenyl) -2,2-dichloroethene (DDE), could be related to some biochemical, endocrine and physiological effects in individuals. Some POPs have been suggested to have negative effects disrupting physiological processes and resulting in alterations of homeostasis, reproduction, development and behavior. Such adverse effects upon populations may be avoided if the potential of chemicals to cause them is recognized before problems arise. The aim of this study was to determine whether or not the ongoing spraying of DDT in the Limpopo Province is negatively affecting the health of aquatic species found in surface water of the area. Extensive research has shown that biomarkers have been very effective in the trace determination of a number of adverse effects caused by metals, and thus, are also being used for POPs. A battery of biomarkers (EROD, CAT and CEA) were used, both in the field and in a controlled laboratory environment, in order to try and determine the long term effects of exposure to low environmentally relevant levels of DDE in the selected area. DDT levels in the biota, water and sediment samples were also measured to determine the possible levels of exposure. Dose-response relationships were most successfully determined by the EROD and the CEA biomarkers in this study. In a controlled laboratory study, a definite effect was noted on the Mozambique Tilapia with increasing concentrations of DDE. In the natural environment, dose-response relationships to DDE exposure were more difficult to quantify as additional chemicals and natural environmental stressors also affect the results.

Chan Kam Che.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references (leaves 199-219).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstracts --- p.iii
摘要 --- p.v
Contents --- p.vii
List of figures --- p.xiv
List of tables --- p.xix
Abbreviations --- p.xxii
Chapter Chapter I --- Introduction --- p.1
Chapter 1.1 --- Persistent organic pollutants --- p.1
Chapter 1.2 --- DDT and DDE --- p.2
Chapter 1.2.1 --- Background --- p.2
Chapter 1.2.2 --- Health effects --- p.4
Chapter 1.2.3 --- Environmental exposure of DDE --- p.4
Chapter 1.2.4 --- Level of DDE in human --- p.9
Chapter 1.2.5 --- Biodegradation of DDE --- p.10
Chapter 1.3 --- Remediation methods --- p.11
Chapter 1.3.1 --- Physical/ chemical treatment --- p.11
Chapter 1.3.2 --- Bioremediation --- p.13
Chapter 1.4 --- Fungal Bioremediation --- p.14
Chapter 1.5 --- Ligninolytic enzymes --- p.15
Chapter 1.5.1 --- Laccase --- p.15
Chapter 1.5.2 --- Peroxidases --- p.20
Chapter 1.5.2.1 --- Manganese Peroxidase (MnP) --- p.20
Chapter 1.5.2.1 --- Lignin Peroxidase (LiP) --- p.24
Chapter 1.6 --- Cultivation of Pleurotus pulmonarius --- p.27
Chapter 1.7 --- Enzyme technology on environmental cleanup and its limitation --- p.28
Chapter 1.8 --- Aims and objectives of this study --- p.29
Chapter Chapter II --- Materials and Methods --- p.30
Chapter 2.1 --- Organism and growth conditions --- p.30
Chapter 2.2 --- Cultivation and the expression of the ligninolytic enzyme-coding genes during solid-state-fermentation of edible mushroom Pleurotus pulmonarius --- p.30
Chapter 2.3 --- Treatment of DDE by living P. pulmonarius --- p.31
Chapter 2.3.1 --- Optimization of DDE removal in broth system --- p.31
Chapter 2.3.1.1 --- Effects of initial DDE concentration on the removal of DDE --- p.32
Chapter 2.3.1.2 --- Effects of inoculum size on the removal of DDE --- p.33
Chapter 2.3.1.3 --- Effects of incubation time on the removal of DDE and transcriptional profiles of the ligninolytic enzyme-coding genes --- p.33
Chapter 2.3.2 --- Optimization of DDE removal in soil system --- p.34
Chapter 2.3.2.1 --- Effects of initial DDE concentration on the removal of DDE --- p.34
Chapter 2.3.2.2 --- Effects of inoculum size on the removal of DDE --- p.35
Chapter 2.3.2.3 --- Effects of incubation time on the removal of DDE --- p.35
Chapter 2.3.2.4 --- Transcription of the ligninolytic enzyme-coding genes --- p.35
Chapter 2.4 --- Treatment of DDE by 1st SMC of p. pulmonarius grown on straw-based compost --- p.36
Chapter 2.4.1 --- Optimization of DDE removal in soil system --- p.36
Chapter 2.5 --- Treatment of DDE by crude enzyme preparations of P. pulmonarius grown on straw-based compost --- p.36
Chapter 2.5.1 --- Optimization of DDE removal in broth system --- p.36
Chapter 2.5.1.1 --- Effects of initial DDE concentration on the removal of DDE --- p.37
Chapter 2.5.1.2 --- Effects of amounts of crude enzyme preparations on the removal of DDE --- p.37
Chapter 2.5.1.3 --- Effects of incubation time on the removal of DDE --- p.37
Chapter 2.5.2 --- Optimization of DDE removal in soil system --- p.37
Chapter 2.5.2.1 --- Effects of initial DDE concentration on the removal of DDE --- p.38
Chapter 2.5.2.2 --- Effects of amount of crude enzyme preparations on the removal of DDE --- p.38
Chapter 2.5.2.3 --- Effects of incubation time on the removal of DDE --- p.38
Chapter 2.6 --- Soil characterization --- p.39
Chapter 2.6.1 --- Identification of organic contaminants in soil sample from Gene Garden using Gas Chromatography/Mass Spectrometry (GC/MS) --- p.39
Chapter 2.6.2 --- Determination of soil texture --- p.42
Chapter 2.6.3 --- Fresh soil/air-dried sample moisture --- p.44
Chapter 2.6.4 --- "Soil pH, electrical conductivity & salinity" --- p.44
Chapter 2.6.5 --- Total organic carbon contents --- p.44
Chapter 2.6.6 --- Total nitrogen and total phosphorus --- p.44
Chapter 2.6.7 --- Available nitrogen --- p.45
Chapter 2.6.8 --- Available phosphorus --- p.45
Chapter 2.6.9 --- Potassium value --- p.46
Chapter 2.7 --- Quantification of residual DDE level --- p.47
Chapter 2.7.1 --- Preparation of DDE stock solution --- p.47
Chapter 2.7.2 --- Extraction and quantification of DDE using Gas Chromatography with Electron Capture Detector (GC/μECD) --- p.47
Chapter 2.7.3 --- Identification of DDE breakdown products by GC/MS --- p.50
Chapter 2.8 --- Extraction of protein and ligninolytic enzymes --- p.53
Chapter 2.8.1 --- Protein assay --- p.53
Chapter 2.8.2 --- Laccase assay --- p.53
Chapter 2.8.3 --- Manganese peroxidase assay --- p.54
Chapter 2.8.4 --- Calculation of activity and specific activity of laccase and manganese peroxidase --- p.54
Chapter 2.9 --- Estimation of fungal biomass --- p.55
Chapter 2.9.1 --- Preparation of ergosterol standard solution --- p.56
Chapter 2.9.2 --- Analysis of ergosterol content --- p.56
Chapter 2.10 --- Expression of the ligninolytic enzyme-coding genes --- p.58
Chapter 2.10.1 --- Preparation of ribonuclease free reagents and apparatus --- p.58
Chapter 2.10.2 --- RNA isolation and purification --- p.58
Chapter 2.10.3 --- cDNA synthesis --- p.59
Chapter 2.10.4 --- Semi-quantification of ligninolytic enzyme-coding gene expression by RT-PCR --- p.59
Chapter 2.11 --- Preparation of crude enzyme preparations from P. pulmonarius compost --- p.63
Chapter 2.12 --- "Assessment criteria: removal efficiency, RE, and removal capacity, RC" --- p.63
Chapter 2.13 --- Statistical analysis “ --- p.64
Chapter Chapter III --- Results --- p.65
Chapter 3.1 --- Soil characterization --- p.65
Chapter 3.2 --- Cultivation and the expression of the ligninolytic enzyme-coding genes during solid-state-fermentation of edible mushroom Pleurotus pulmonarius --- p.66
Chapter 3.2.1 --- Mushroom yield --- p.66
Chapter 3.2.2 --- Protein content --- p.66
Chapter 3.2.3 --- Specific ligninolytic enzymes activities --- p.66
Chapter 3.2.4 --- Ergosterol content --- p.69
Chapter 3.2.5 --- Ligninolytic enzymes productivities --- p.69
Chapter 3.2.6 --- Expression of the ligninolytic enzyme-coding genes during solid-state-fermentation --- p.72
Chapter 3.3 --- Treatment of DDE by living P. pulmonaruis --- p.78
Chapter 3.3.1 --- Optimization of DDE removal in broth system --- p.78
Chapter 3.3.1.1 --- Effects of initial DDE concentration on the removal of DDE --- p.78
Chapter 3.3.1.1.1 --- Effects of DDE on biomass development --- p.78
Chapter 3.3.1.1.2 --- Protein content --- p.78
Chapter 3.3.1.1.3 --- Specific ligninolytic enzyme activities --- p.78
Chapter 3.3.1.1.4 --- Ligninolytic enzyme productivities --- p.79
Chapter 3.3.1.1.5 --- DDE removal and removal capacity --- p.79
Chapter 3.3.1.2 --- Effects of inoculum sizes on the removal of DDE --- p.84
Chapter 3.3.1.2.1 --- Effects of DDE on biomass development --- p.84
Chapter 3.3.1.2.2 --- Protein content --- p.84
Chapter 3.3.1.2.3 --- Specific ligninolytic enzyme activities --- p.85
Chapter 3.3.1.2.4 --- Ligninolytic enzyme productivities --- p.85
Chapter 3.3.1.2.5 --- DDE removal and removal capacity --- p.85
Chapter 3.3.1.3 --- Effects of incubation time on the removal of 4.0 mM DDE/g biomass --- p.89
Chapter 3.3.1.3.1 --- Effects of DDE on biomass development --- p.89
Chapter 3.3.1.3.2 --- Protein content --- p.89
Chapter 3.3.1.3.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.89
Chapter 3.3.1.3.4 --- DDE removal and removal capacity --- p.90
Chapter 3.3.1.3.5 --- Putative degradation derivatives --- p.90
Chapter 3.3.1.3.6 --- Expression of the ligninolytic enzyme-coding genes during the removal of 4.0 mM DDE/g biomass --- p.94
Chapter 3.3.1.4 --- Effects of incubation time on the removal of 10.0 mM DDE/g biomass --- p.100
Chapter 3.3.1.4.1 --- Effects of DDE on biomass development --- p.100
Chapter 3.3.1.4.2 --- Protein content --- p.100
Chapter 3.3.1.4.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.100
Chapter 3.3.1.4.4 --- Expression of the ligninolytic enzyme-coding genes during the removal of 10.0 mM DDE/g biomass --- p.102
Chapter 3.3.2 --- Optimization of DDE removal in soil system --- p.107
Chapter 3.3.2.1 --- Effects of initial DDE concentration on the removal of DDE --- p.107
Chapter 3.3.2.1.1 --- Ergosterol content --- p.107
Chapter 3.3.2.1.2 --- Protein content --- p.107
Chapter 3.3.2.1.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.107
Chapter 3.3.2.1.4 --- DDE removal and removal capacity --- p.108
Chapter 3.3.2.2 --- Effects of inoculum sizes on the removal of DDE --- p.111
Chapter 3.3.2.2.1 --- Ergosterol content --- p.111
Chapter 3.3.2.2.2 --- Protein content --- p.111
Chapter 3.3.2.2.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.111
Chapter 3.3.2.2.4 --- DDE removal and removal capacity --- p.112
Chapter 3.3.2.3 --- Effects of incubation time on the removal of DDE --- p.115
Chapter 3.3.2.3.1 --- Ergosterol content --- p.115
Chapter 3.3.2.3.2 --- Protein content --- p.115
Chapter 3.3.2.3.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.115
Chapter 3.3.2.3.4 --- DDE removal and removal capacity --- p.116
Chapter 3.3.2.3.5 --- Putative degradation derivatives --- p.116
Chapter 3.3.2.4 --- Transcription of the ligninolytic enzyme-coding genes --- p.121
Chapter 3.4 --- Treatment of DDE by 1st SMC of p. pulmonarius grown on straw-based compost --- p.127
Chapter 3.4.1 --- Optimization of DDE removal in soil system --- p.127
Chapter 3.4.1.1 --- Effects of initial DDE concentration on the removal of DDE --- p.127
Chapter 3.4.1.1.1 --- Ergosterol content --- p.127
Chapter 3.4.1.1.2 --- Protein content --- p.127
Chapter 3.4.1.1.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.127
Chapter 3.4.1.1.4 --- DDE removal and removal capacity --- p.128
Chapter 3.4.1.2 --- Effects of inoculum sizes on the removal of DDE --- p.132
Chapter 3.4.1.2.1 --- Ergosterol content --- p.132
Chapter 3.4.1.2.2 --- Protein content --- p.132
Chapter 3.4.1.2.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.132
Chapter 3.4.1.2.4 --- DDE removal and removal capacity --- p.133
Chapter 3.4.1.3 --- Effects of incubation time on the removal of DDE --- p.136
Chapter 3.4.1.3.1 --- Ergosterol content --- p.136
Chapter 3.4.1.3.2 --- Protein content --- p.136
Chapter 3.4.1.3.3 --- Specific ligninolytic enzyme activities and ligninolytic enzyme productivities --- p.136
Chapter 3.4.1.3.4 --- DDE removal and removal capacity --- p.137
Chapter 3.4.1.3.5 --- Putative degradation derivatives --- p.137
Chapter 3.5 --- Treatment of DDE by crude enzyme preparations of P. pulmonarius grown on straw-based compost --- p.142
Chapter 3.5.1 --- The crude enzyme preparations of P. pulmonarius grown on straw-based compost --- p.142
Chapter 3.5.2 --- Optimization of DDE removal in broth system --- p.143
Chapter 3.5.2.1 --- Effects of initial DDE concentration on the removal of DDE --- p.143
Chapter 3.5.2.2 --- Effects of amounts of crude enzyme preparations on the removal of DDE --- p.145
Chapter 3.5.2.3 --- Effects of incubation time on the removal of DDE --- p.147
Chapter 3.5.2.4 --- Putative degradation derivatives --- p.147
Chapter 3.5.3 --- Optimization of DDE removal in soil system --- p.151
Chapter 3.5.3.1 --- Effects of initial DDE concentration on the removal of DDE --- p.151
Chapter 3.5.3.2 --- Effects of amounts of crude enzyme preparations on the removal of DDE --- p.151
Chapter 3.5.3.3 --- Effects of incubation time on the removal of DDE --- p.154
Chapter 3.5.3.4 --- Putative degradation derivatives --- p.154
Chapter Chapter IV --- Discussions --- p.158
Chapter 4.1 --- Quantification of the expression of the ligninolytic enzyme-coding genes --- p.158
Chapter 4.2 --- Artificial cultivation and the expression of the ligninolytic enzyme-coding genes during solid-state-fermentation of edible mushroom Pleurotus pulmonarius --- p.164
Chapter 4.3 --- Treatment of DDE by living P. pulmonarius --- p.166
Chapter 4.3.1 --- Optimization of DDE removal in broth system --- p.166
Chapter 4.3.2 --- Optimization of DDE removal in soil system --- p.169
Chapter 4.3.3 --- Phylogeny of the ligninolytic enzyme-coding genes --- p.170
Chapter 4.3.3.1 --- Laccase coding genes --- p.170
Chapter 4.3.3.2 --- MnP coding genes --- p.175
Chapter 4.3.4 --- Transcription of the ligninolytic enzyme-coding genes --- p.178
Chapter 4.4 --- Treatment of DDE by 1st SMC of P. pulmonarius grown on straw-based compost --- p.183
Chapter 4.4.1 --- Optimization of DDE removal in soil system --- p.183
Chapter 4.5 --- Treatment of DDE by crude enzyme preparations of P. pulmonarius grown on straw-based compost --- p.184
Chapter 4.6 --- Cost-effectiveness of the bioremediation method --- p.185
Chapter 4.7 --- Further investigations --- p.194
Chapter Chapter V --- Conclusions --- p.197
References --- p.199

Ph.D.
This study consisted of a two-tiered approach to assessment of the effects of EDCs on aquatic organisms, and heavy metal accumulation in the aquatic environment, by integrating field work and laboratory-based experiments. In the last three decades a considerable portion of research in aquatic health and aquatic toxicology has been largely focused on endocrine disruptors, aiming to establish how certain chemicals discharged into the environment, especially organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), surfactants and plasticisers, can mimic endogenous hormones and thereby induce reproductive abnormalities. The rationale behind the present study was the growing interest in the study of endocrine disrupting chemicals (EDCs) internationally and the aspects of this field of research that are relevant to South Africa’s aquatic environment and its endemic aquatic organisms. The field work was carried out in the Rietvlei Wetland System and consisted of a combination of plant root analysis and application of the South African Scoring System 5 (SASS5) macroinvertebrate index. Three characteristic wetland macrophytes used in the study were Typha capensis, Phragmites australis and Persicaria lapathifolia. Samples of plants, sediment and water were taken from predetermined locations along the wetland system in the Rietvlei Nature Reserve and analyzed for heavy metals by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The heavy metals analyzed in this study; lead, arsenic and cadmium, have also been implicated as endocrine disruptors. The results of heavy metal accumulation in the plant roots reflected a pollution trend along the wetland, suggesting that plant roots are useful bioindicators of contamination in freshwater systems.

PhD
An important component of fish health is an optimally functioning reproductive system. The Luvuvhu River Catchment in the Limpopo Province, South Africa, is a tropical, high-risk malaria area where 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), an endocrine disrupting chemical (EDC), has been used annually since 1945 as a malaria vector control. DDT is known to affect testes morphology and motility of fish sperm. As such, testicular histology and sperm motility (kinematic) parameters were studied as reproductive indicators of the reproductive capacity for two wild, indigenous fish species (Oreochromis mossambicus and Clarias gariepinus) from the currently DDT sprayed area. Three field studies were carried out over two years (2007 – 2008), including two high flow (HF) periods and one low flow (LF) period [HF 1 (March 07), LF (October 07), HF 2 (February 08)]. Both species were sampled from three sites on the Luvuvhu River for testicular histology and computer assisted sperm analysis (CASA), during all three field studies. The sites included a reference site outside the DDT sprayed area, Albasini Dam (AD), and two exposed sites within the DDT sprayed area, Xikundu Weir (XW) and Nandoni Dam (ND). CASA, based on open-source software, was used for the first time in South Africa to assess sperm kinematic parameters of indigenous fish species in field conditions. These included percent motile sperm (% MOT), curvilinear velocity (VCL μm s-1), velocity of an average path (VAP μm s-1), straight line velocity (VSL μm s-1), linearity (LIN %), progression (PROG μm), and average efficiency (AVE. EFF.). Water and sediment samples were collected during all field studies from the three sites for metal and EDC analysis. Controlled laboratory studies were also carried out on the sperm of both species, externally sourced from aquaculture farms equipped to breed and raise fish in toxicant free water. The laboratory studies involved in vitro exposure of spermatozoa to two different, but environmentally relevant, concentrations of both DDT (DDT 1: 0.27 μg L-1; DDT 2: 0.5 μg L-1) and 1,1-dihloro-2,2-bis(p-chlorophenyl)ethylene (DDE) (DDE 1: 0.11 μg L-1; DDE 2: 1.0 μg L-1) with the aim to provide data to support the possible outcomes found in the field studies using CASA. Furthermore, peroxidation of sperm lipids was assayed by production of malondialdehyde (MDA) after in vitro exposure of spermatozoa to DDT and DDE. DDT and its metabolites were found in varying concentrations in the water from all three sites (0.1 μg L-1 – 1.2 μg L-1). Levels of dieldrin (3.5 μg L-1) and lindane (9.4 μg L-1) residues were also found at XW in HF 2. The histological results revealed alterations to testis tissue of both species at all three sites. The testes were assessed through the identification of alterations and an organ index was calculated: Testes Index (IT). The index is indicative of the histological response in the respective tissue type. O. mossambicus at XW had the highest mean IT value during LF (7.45 ± 5.73) and for all field studies combined (5.47 ± 4.63), primarily due to the occurrence of testicular oocytes (intersex), where the frequency of prevalence was 72.73% and 58.82% respectively. These results were statistically higher than the laboratory control (C) group. The CASA results showed statistical differences primarily for O. mossambicus, where motility parameters were lower at XW when compared to AD. Laboratory exposures found a decrease in sperm motility (% MOT) between the control (C) group and the DDT 1, DDE 1 and DDE 2 exposed groups for C. gariepinus. No significant differences were seen for lipid peroxidation (MDA). On the other hand, no significant differences were seen in CASA parameters between the control and exposed laboratory groups for O. mossambicus, but there was an increase in MDA production from the control to the DDT 1 exposure group.

Ph.D.
The toxicant dichlorodiphenyl-trichloroethane, commonly known as DDT, is a broad spectrum insecticide and is currently banned in most countries due to its toxic effects. However, in some countries restricted use of DDT has been authorized as an effective vector control within malarial control programmes. South Africa is one such country, where spraying of DDT occurs in three provinces including the Limpopo Province, KwaZulu Natal and Mpumalanga. Specifically in the Limpopo Province, spraying of DDT has been ongoing for almost 56 years within the eastern malaria belt of the province. Despite this long term spraying there is still a scarcity of data regarding DDT and its effects on indigenous aquatic organisms in South Africa. Any research regarding DDT will therefore be of the utmost value. It was in this context that the present study was initiated, which primarily aimed to assess the extent of contamination within DDT sprayed areas in South Africa and the associated effects on indigenous species, whilst identifying techniques that could be used in future monitoring of these areas. This assessment was done in the Luvuvhu River catchment at three reference sites and four exposure sites situated within the areas where indoor residual spraying of DDT is done annually. At these sites the extent of DDT contamination within the water, sediment and biota (using the bioindicator pecies C. gariepinus from only the lentic sites) in the Luvuvhu river was evaluated. The results showed that DDT concentrations were well above recommended levels in all three of the measured phases, with the highest concentrations predominantly observed at the Xikundu weir. This site was particularly impacted by DDT due to a combination of its close proximity to the DDT sprayed areas, concentration accumulation from upstream sources and environmental conditions that accentuated contamination. These elevated levels of DDT did, however, not induce significant quantifiable effects in the bioindicator C. gariepinus or in the fish and macro-invertebrate community structures. Specifically, the effects in the catfish, C. gariepinus, were assessed using a range of biomarkers specific to the endocrine disrupting effects of DDT, including indirect measures of vitellogenin (calcium, zinc, magnesium and alkali-labile phosphate (ALP) that are all present on the VTG molecule in high abundances), gonad-somatic index (GSI), condition factor (CF), analysis of covariance (ANCOVA) manipulated gonads, protein carbonyls (PC) and intersex. Although none of these biomarkers could be significantly correlated with the DDT contaminations, DDT was shown to induce a slight sub-organismal effect by slightly inducing the synthesis of ALP and Ca as well as reducing the gonad mass (shown by GSI and adjusted gonad mass biomarkers) and body condition. In contrast, the fish and macroinvertebrate communities showed no conclusive relationship with DDT contamination, using a variety of methodologies, including informal assessments, univariate diversity indices, multivariate statistics, abundance models, fish response assessment index (FRAI) as well as average score per taxon (ASPT) and Ephemeroptera, Plecoptera and Trichoptera (EPT) richness. In conclusion, it was shown that DDT concentrations within the Luvuvhu River only induced effects at the lower levels of complexity, which highlights the importance of the utilisation of biomarkers to measure more subtle long-term effects as compared to the usage of community level effects.

Gong Jun.
"March 2004."
Thesis (Ph.D.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (p. 254-294)
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.
Abstracts in English and Chinese.

Qin, Jing.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 162-218).
Abstract also in Chinese.
Acknowledgment --- p.i
Abstract --- p.ii
摘要 --- p.iv
Table of Content --- p.vi
List of Figures --- p.x
List of Tables --- p.xv
Abbreviations --- p.xvii
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Ganoderma spp --- p.1
Chapter 1.1.1 --- Introduction of Ganoderma spp --- p.1
Chapter 1.1.2 --- Bioactivities of Ganoderma spp --- p.3
Chapter 1.1.3 --- Endocrine system and breast cancer --- p.11
Chapter 1.1.3.1 --- Estrogen --- p.11
Chapter 1.1.3.2 --- Estrogen receptors --- p.12
Chapter 1.1.3.3 --- Estrogen responsive genes --- p.15
Chapter 1.1.3.3.1 --- pS2 --- p.15
Chapter 1.1.3.3.2 --- Progesterone receptor --- p.18
Chapter 1.1.3.4 --- Androgen --- p.21
Chapter 1.1.3.5 --- Androgen receptor --- p.23
Chapter 1.1.3.6 --- Androgen responsive gene --- p.24
Chapter 1.1.3.6.1 --- Transmembrane prostate androgen-induced RNA --- p.24
Chapter 1.1.3.6.2 --- Uridine diphosphate glucose dehydrogenase --- p.26
Chapter 1.1.3.7 --- Breast cancer --- p.26
Chapter 1.2 --- "Endocrine Disruption of p,p '-DDE" --- p.28
Chapter 1.2.1 --- Introduction of p´ةp '-DDE --- p.28
Chapter 1.2.2 --- "p,p '-DDE in environments" --- p.29
Chapter 1.2.3 --- "p,p '-DDE in human body" --- p.32
Chapter 1.2.4 --- "p,p '-DDE and reproductive system" --- p.33
Chapter 1.2.5 --- Endocrine disruptor --- p.35
Chapter 1.2.6 --- "Action mechanism of p,p '-DDE on endocrine system" --- p.37
Chapter 1.2.7 --- Apoptosis --- p.39
Chapter 1.3 --- Food therapy against endocrine disruption --- p.41
Chapter 1.3.1 --- Food therapy and functional food --- p.41
Chapter 1.3.2 --- Ganoderma as a Functional food --- p.47
Chapter 1.3.3 --- Cancer prevention by dietary agents --- p.47
Chapter 1.3.4 --- Hormone therapy --- p.48
Chapter 1.3.5 --- Hormone-related properties of Ganoderma spp --- p.50
Chapter 1.4 --- The aim of the study --- p.51
Chapter Chapter 2 --- Materials and Methods --- p.52
Chapter 2.1 --- Ganoderma samples --- p.52
Chapter 2.2 --- Artificial cultivation of Ganoderma spp --- p.54
Chapter 2.3 --- Molecular identification of Ganoderma spp --- p.55
Chapter 2.3.1 --- Extraction of genomic DNA --- p.55
Chapter 2.3.2 --- Gene-specific polymerase chain reaction (PCR) --- p.56
Chapter 2.3.3 --- Gel electrophoresis --- p.56
Chapter 2.3.4 --- Purification of PCR amplified product for sequencing --- p.57
Chapter 2.3.5 --- Cycle-sequencing --- p.57
Chapter 2.3.6 --- Sequencing --- p.58
Chapter 2.3.7 --- Sequence analysis --- p.58
Chapter 2.4 --- Chemical analyses of Ganoderma spp --- p.59
Chapter 2.4.1 --- Polysaccharide preparations --- p.59
Chapter 2.4.2 --- Terpene profile --- p.60
Chapter 2.4.3 --- Fatty acid profile --- p.60
Chapter 2.5 --- Anti-oxidation activities --- p.61
Chapter 2.5.1 --- Superoxide radical scavenging assay --- p.61
Chapter 2.5.2 --- DPPH radical scavenging assay --- p.62
Chapter 2.6 --- Anti-proliferation effect on human breast cancer cells --- p.62
Chapter 2.7 --- Hormone-like effects --- p.63
Chapter 2.7.1 --- E-screen test --- p.63
Chapter 2.7.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.64
Chapter 2.7.3 --- "Recombinant yeast cell based ER-, AR- and PGR-responsible promoter assays" --- p.65
Chapter 2.7.3.1 --- Recombinant yeasts --- p.65
Chapter 2.7.3.2 --- Growth medium for recombinant yeasts --- p.66
Chapter 2.7.3.3 --- "ER, AR and PGR assays" --- p.67
Chapter 2.7.3.4 --- β-Galactosidase assay --- p.67
Chapter 2.7.4 --- Real time PCR --- p.68
Chapter 2.8 --- Flow cytometry --- p.71
Chapter 2.9 --- Comet assay --- p.71
Chapter 2.10 --- DNA microarray --- p.73
Chapter 2.10.1 --- Total RNA isolation --- p.73
Chapter 2.10.2 --- cDNA synthesis --- p.73
Chapter 2.10.3 --- Preparation of labelled cDNA --- p.74
Chapter 2.10.4 --- cDNA purification --- p.74
Chapter 2.10.5 --- Oligo GEArray hybridization --- p.75
Chapter 2.10.6 --- Chemiluminescent detection --- p.76
Chapter 2.10.7 --- Data analysis --- p.77
Chapter Chapter 3 --- Results --- p.78
Chapter 3.1 --- Analysis of Ganderma spp --- p.78
Chapter 3.1.1 --- Mycelia and fruiting bodies --- p.78
Chapter 3.1.2 --- Identification of Ganoderma spp --- p.79
Chapter 3.1.3 --- Chemical properties of samples --- p.80
Chapter 3.1.4 --- Anti-oxidation activities --- p.90
Chapter 3.1.5 --- Anti-proliferation effect on human breast cancer cells --- p.90
Chapter 3.1.6 --- Hormone-like bioactivities --- p.93
Chapter 3.1.6.1 --- E-screen test --- p.93
Chapter 3.1.6.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.94
Chapter 3.1.6.3 --- "Recombinant yeast cell-based ER-, AR- and PGR-responsible promoter assays" --- p.95
Chapter 3.1.6.4 --- ER- and AR-pathway gene expression by real time PCR --- p.97
Chapter 3.2 --- "Action mechanism of p,p' -DDE" --- p.99
Chapter 3.2.1 --- E-screen --- p.99
Chapter 3.2.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.101
Chapter 3.2.3 --- Recombinant yeast cell based ER- and AR-responsible promoter assays --- p.103
Chapter 3.2.4 --- ER- and AR-pathway gene expression by real time PCR --- p.106
Chapter 3.3 --- Ganoderma tsugae mycelia extract against p.p' -DDE --- p.109
Chapter 3.3.1 --- E-screen test --- p.109
Chapter 3.3.2 --- ER- and AR-pathway gene expression by real time PCR --- p.110
Chapter 3.3.3 --- Analysis of cell cycle --- p.112
Chapter 3.3.4 --- Analysis of DNA damage --- p.114
Chapter 3.3.5 --- Analysis of sub-G1 peak --- p.117
Chapter 3.3.6 --- DNA damage and apoptosis relative gene expression by real time PCR --- p.120
Chapter 3.3.7 --- DNA microarray --- p.121
Chapter Chapter 4 --- Discussion --- p.131
Chapter 4.1 --- Analysis of Ganoderma spp --- p.131
Chapter 4.2 --- Effects of p.p´ة-DDE --- p.144
Chapter 4.3 --- Protective effects of G. tsugae against p.p' -DDE --- p.151
Chapter 4.4 --- Further investigation --- p.159
Chapter 4.5 --- Conclusion --- p.160
References --- p.162

Environmental factors such as chemical contamination can have immunomodulatory effects on the immune response of fish and may be contributing to the decline in salmonid populations by augmenting disease susceptibility. Xenobiotics can interfere with the immune system at several levels of complexity, and different immune cells and processes have variable sensitivity to pollutants. For this reason, a suite of tests is required to evaluate immunomodulatory mechanisms. In this thesis, I formulated and calibrated an assay for the detection of humoral immunity for chinook salmon (Oncorhynchus tshawvtscha). Subsequently, I used this technique in conjunction with other immune and endocrine assays to detect effects of embryonic exposure to o,p'-DDE, a known environmental estrogen. The technique combines exposure of whole animals or leukocyte cultures to immunomodulatory agents/conditions with in vitro mitogenic activation of B-lymphocytes. The proportion of leukocytes undergoing blastogenesis following in vitro stimulation with lipopolysaccaride (LPS) was quantified by flow cytometric analysis of forward and side scatter properties. In addition, I used a fluorescein isothiocyanate labeled anti-rainbow trout surface immunoglobin monoclonal antibody (anti-RBT SIgM-FITC) to determine the ability of the lymphoblasts to express surface immunoglobin (SIgM) through flow cytometry. I used the assay to evaluate the effects of short-term exposures to o,p'-DDE during early life history stages on the long-term immune competence of fall chinook salmon. Immersion of chinook salmon eggs in 10 ppm o,p'-DDE for 1 h at fertilization followed by 2 h at hatch caused significant reductions in the ability of splenic leukocytes to undergo blastogenesis and express SIgM upon in vitro stimulation with LPS one year after treatment (ANOVA, P<0.05). The concentration of o,p'-DDE in fry treated with 10 ppm o,p'-DDE was 0.92 ��g g����� lipid one month post first feeding. The chemical persisted through development and, one year after exposure, levels in juvenile muscle tissue were 0.94 ��g g����� lipid. Mortality rate, time to hatch, fish size, sex ratios, gonadal development, plasma estradiol and 11-ketotestosterone concentrations were not affected by treatment with o,p'-DDE. In addition, neither plasma lysozyme concentration, nor mitogenic response of splenic leukocytes to concanavallin A or polyinosinic-polycytidylic acid were influenced by the treatment. A short period of exposure to an estrogenic chemical during early periods of development induced long term effects on humoral immune competence of chinook salmon. I discuss the possibility that the xenobiotic is exerting its activity through steroid-mediated pathways.
Graduation date: 2002

Das Ziel der vorliegenden Arbeit war es, die Wirksamkeit der beiden biologischen Präparate NeemAzal MD5 und TRF 002 MD auf das Entwicklungspotential der Larven der großen Stubenfliege (Musca domestica) und der Güllefliege (Hydrotaea aenescens) zu untersuchen. Bei den Präparaten handelte es sich um den Extrakt aus den Samen des tropischen Niembaumes (Azadirachta indica) mit dem Hauptwirkbestandteil Azadirachtin A in einer Konzentration von 5 % und um den Extrakt aus dem Bitterholz (Quassia amara) mit dem Hauptwirkstoff Quassin in einer Konzentration von 0,61 %. Die Larvenstadien 1 und 3 jeder Fliegenart wurden dem jeweiligen Präparat, das in verschiedenen Konzentrationen entweder eingemischt im Brutsubstrat (orale Aufnahme) oder in einem Tauchbad (topische Applikation) getestet wurde, ausgesetzt. Der Einfluss der Wirkstoffe auf die Parameter Verpuppungsrate, Schlupfrate, Entwicklungsdauer, Fliegengröße und Vorkommen von Asymmetrien wurde dabei ermittelt. NeemAzal MD5 in 5 % Lösung verhinderte, eingemischt ins Brutsubstrat, vollständig den Schlupf der Fliegen unabhängig vom Alter der verwendeten Larven. Das jüngste Larvenstadium wies dabei noch eine deutlich höhere Empfindlichkeit gegenüber dem Wirkstoff auf, hier reichte bereits eine 1 % Lösung aus, um die Entwicklung von Fliegen zu unterdrücken. Unterschiede in der Wirksamkeit auf die beiden verwendeten Fliegenarten waren gering. Hydrotaea aenescens erwies sich hierbei als etwas empfindlicher gegenüber NeemAzal MD5 als die Larven von Musca domestica. Die topische Applikation des Präparates auf das Larvenstadium 3 führte in den verwendeten hohen Konzentrationen (5 %, 10 %) nur zu einer Reduktion der Fliegenanzahl. Für eine vollständige Verhinderung der Fliegenentwicklung ist eine möglichst frühzeitige orale Aufnahme des Wirkstoffes durch die Larven notwendig. Es kommt dabei neben der Fraßhemmung zu einer Beeinflussung der Wachstums- und Häutungshormone, was die Metamorphose der Insekten unterdrückt. Die unter Laborbedingungen bewiesene insektizide Wirksamkeit von NeemAzal MD5 und seine Umweltverträglichkeit prädisponieren das Präparat für Feldversuche gegen Fliegenplagen in der ökologischen Tierhaltung. TRF 002 MD bewirkte auch in der höchsten verwendeten Konzentration (10 %), eingemischt in das Brutsubstrat der Larvenstadien 1 und 3 der beiden Fliegenarten, nur eine Reduktion der Schlupfrate um bis zu 30 % gegenüber den Kontrollgruppen. Die topische Anwendung dieser Substanz erwies sich in den durchgeführten Versuchen als nahezu wirkungslos auf die untersuchten Parameter. Damit war das Präparat nicht geeignet, das Schlüpfen von Fliegen vollständig zu verhindern.