Academic literature on the topic 'Algae Biological control'

With the increasing of water pollution, water eutrophication is seriously affecting people’s daily life and production. Therefore, it is particularly important to explore safe and efficient algae control technology. In the current algal bloom treatment methods, the physical method is not complete in algae dissolving, and the cost of algal control is high. The chemical method is easy to produce secondary pollution and toxic by-products, and the safety is not high. However, the biological method has the advantages of low cost, high ecological security and good ecological compatibility. It is considered to be a more promising method to remove algae and biological toxins, and it is also an inevitable trend to control water eutrophication in the future.

At present, there are few studies on known bacterial species and even less on fungi in biological algae control technology. In this paper, the green eutrophic shallow water lake Scenedesmus quadricauda (Turpin) was used as the research object, and white rot fungi, which has a high removal effect on water pollutants, algae and biological toxins, was used for algae control. The extent of the removal effect, physiological characteristics and the internal functional groups of the algae cells in the white rot fungi solution, the supernatant of the white rot fungi solution after centrifugation and the sterilized white rot fungi solution were investigated. The results showed that the best algae solubilization effect of the algae control system was achieved at 250 mg/L, with 8 mg/L of dissolved oxygen and a hydraulic retention time of 48 h. The average algae lysis rate was 85.48%, the average dehydrogenase activity reduction rate was 59.23%, the average soluble protein reduction rate was 65.16% and the average malondialdehyde content increased to 0.128 umol/L. After treatment with the white rot algae control system, the spatial structure of the Turpin cells was severely disrupted, and significant lysis occurred within the algal cells, forcing the release of intracellularly soluble substances, and reducing the dehydrogenase activity of the Turpin cells, thus inhibiting the growth activity of the algae cells. A further reduction in the soluble protein content reduces the nutrients required for the growth of Turpin, exacerbating the rate of reduction in the physiological metabolic activity of the Turpin cells and, ultimately, the inhibition or killing of the algal cells. The results of this research may provide theoretical guidance for the microbial control of water eutrophication; however, whether there will be secondary pollution after the algae dissolution of this process is worthy of further study.

The study aims to demonstrate the efficiency of the synergy between types of fungi and algae for wastewater treatment. Samples are collected from the waters of Wadi al-Kharazi inside the University of Mosul. Four genera of organisms, two sexes of fungi, and two sexes of algae are used for the purpose of reacting. Examinations are conducted for water treated with fungi and algae, as 8 treatments are used compared to the control treatment that contains water alone. The pH function, bicarbonate ions, and sulfates with the two elements iron and copper are measured. The results of the bicarbonate examination show that the best biological treatment is in the mixed culturing of the alga Spirogyra maxima and the fungus Trichoderma asperallum. The average concentration during the incubation periods is 162.8 mg.l-1 compared to the average control treatment ranging 204.9 mg.l-1. The results of the sulfate examination show a decrease in concentration for all treatments compared to the control treatment. The best biological treatment in the mixed culturing is between the alga Spirogyra maxima and the fungus Mucor racemosus, as the removal rate reached 48% compared to the average of the control treatment. Examinations have demonstrated the synergy between fungi and algae in increasing the efficiency of pollutant removal rather than using both separately.

We propose an algae-fish semicontinuous system for the Zeya Reservoir to study the control of algae, including biological and chemical controls. The bifurcation and periodic solutions of the system were studied using a Poincaré map and a geometric method. The existence of order-1 periodic solution of the system is discussed. Based on previous analysis, we investigated the change in the location of the order-1 periodic solution with variable parameters and we described the transcritical bifurcation of the system. Finally, we provided a series of numerical results to illustrate the feasibility of the theoretical results. These results may help to facilitate a better understanding of algal control in the Zeya Reservoir.

A method is proposed to control phytoplankton biomass in aquacultural ponds, using both zooplankton and filter-feeding silver carp (Hypophthalmichthys molitrix). The technique maintains co-existence of zooplankton and filter-feeding fish by excluding the fish from part of the water column. Zooplankton, which feed on smaller algal species, and silver carp, which feed on large algae and zooplankton, together can consume all sizes of phytoplankton, thus controlling algal biomass. This technique was tested in 1000-L tanks, some containing channel catfish (Ictalurus punctatus) alone, some both catfish and silver carp, and others catfish and silver carp with a zooplankton refuge. The refuge permitted coexistence of high densities of large zooplankters with the filter-feeding fish. This combination of filter-feeders reduced algal biomass by as much as 99%, increased phytoplankton diversity, and showed a trend toward improved silver carp growth compared with treatments without a refuge. The proposed technique could be applied to both intensive and extensive aquacultural systems.

Abstract Microcystis aeruginosa is a globally important cyanobacterial species that poses a threat to human health and development. The use of bacteria to control algal blooms has become an important research topic in recent years. In the present work, the algicidal strain G1 was isolated from sediments of a reservoir in Xi'an, China, identified by 16S ribosomal DNA (rDNA), and its algicidal effects were investigated. The rDNA sequence of G1 (GenBank accession number MW205793) is 99.86% similar to that of Chitinimonas sp., and the strain indirectly solubilised algae. Algae removal by G1 was optimal during the decay phase (algae solubilisation rate = 65.85%). Temperature (5–120 °C) did not significantly affect algae removal, pH 5–9 was tolerated, and pH 7 achieved the highest algae lysis rate (63.56%). Ultrasonic treatment of G1 destroyed the algae-solubilising effect. An injection ratio of 15% achieved the highest algae lysis rate (67.64%) under 12 h:12 h light:dark conditions, and full darkness achieved the highest algae lysis rate (68.21%). Thus, G1 can effectively inhibit the reproduction of M. aeruginosa, making it a promising biological agent for controlling algal growth.

The relationship between algae and their zooplanktonic predators typically involves consumption of nutrients by algae, grazing of the algae by zooplankton which in turn enhances predator biomass, controls algal growth and regenerates nutrients. Eutrophication raises nutrient levels, but does not simply increase normal predator–prey activity; rather, harmful algal bloom (HAB) events develop often with serious ecological and aesthetic implications. Generally, HAB species are outwardly poor competitors for nutrients, while their development of grazing deterrents during nutrient stress ostensibly occurs too late, after the nutrients have largely been consumed already by fast-growing non-HAB species. A new mechanism is presented to explain HAB dynamics under these circumstances. Using a multi-nutrient predator–prey model, it is demonstrated that these blooms can develop through the self-propagating failure of normal predator–prey activity, resulting in the transfer of nutrients into HAB growth at the expense of competing algal species. Rate limitation of this transfer provides a continual level of nutrient stress that results in HAB species exhibiting grazing deterrents protecting them from top-down control. This process is self-stabilizing as long as nutrient demand exceeds supply, maintaining the unpalatable status of HABs; such events are most likely under eutrophic conditions with skewed nutrient ratios.

Salvinia molesta D.S. Mitchell (Salviniaceae) is a damaging free-floating invasive alien macrophyte native to South America. The biological control programme against S. molesta by the weevil Cyrtobagous salviniae Calder and Sands (Erirhinidae) has been successful in controlling S. molesta infestations in the introduced range, however, there is some debate as to how biological control success is measured. This study measured the response of epilithic algae and aquatic macroinvertebrate communities in a S. molesta-dominated state and subsequently where the weed had been cleared by biological control, as a proxy for ecosystem recovery in a before–after control–impact mesocosm experiment. The restored treatment (S. molesta and C. salviniae) demonstrated epilithic algae and aquatic macroinvertebrate recovery during the “after” biological control phase, defined as similar to the control treatment. Comparatively, the impacted treatment (100% S. molesta) showed a drastic decline in biodiversity and shifts in community assemblages. We conclude that the biological control effort by C. salviniae facilitated biodiversity recovery of the impacted treatment. Furthermore, epilithic algae and aquatic macroinvertebrate communities were reliable biological indicators for measuring ecological impacts of invasion and ecosystem recovery following biological control, and thus represent potential tools for evaluating biological control success and ecological restoration.

Eukaryotic algae represent a highly heterogeneous group in terms of organization, lifestyle, and metabolic capabilities. Unicellular green microalgae are capable of biohydrogen production through direct and indirect photolysis as well as dark fermentation. Most algae hydrogen studies focus on axenic algal cultures, although these are difficult and expensive to maintain for continuous operation. Moreover, the complex interplays and metabolic fluxes between algae and bacteria in natural ecosystems provide a number of clear biological and technological benefits to large-scale functional algae-based systems. Two green algae species from the Chlamydomonas and Chlorella genera were used to engineer stable synthetic communities by incorporating a starch-degrading bacterium from the Bacillus genus into the inter-kingdom consortium. Continuous photoheterotrophic biohydrogen production was achieved by elaborating an appropriate algal–bacterial ratio and fine-tuning the culture conditions for the synthetic consortia. Medium with starch as only carbon source served as a simple model of cheap substrate for algal hydrogen generation. The engineered pairwise algal–bacterial associations showed increased biomass and biohydrogen yield compared to the axenic control conditions. Chlorella sp. MACC-360 produced a significantly higher amount of hydrogen when both the bacterium partner and starch were added to the media compared to the axenic algae. Continuous, elevated algal hydrogen production was achieved in media supplemented with 8 g L−1 starch as sole carbon source when carefully selected initial cell number values were used for the Chlorella sp. MACC-360–B. amlyloliquefaciens co-cultures.

This paper proposes and analyzes a nonlinear model for the biological control of algal bloom in a lake. Algal bloom often occurs in a lake due to excessive flow of nutrients from domestic drainage, industrial and agricultural waste, and this causes the decrease in the concentration of dissolved oxygen in the lake. Hence, it threatens the survival of other species of the ecosystem indirectly, and it is also responsible for the degradation of water quality in the lake because of less oxygen content. In this work we study biological control which means the introduction of predatory fish, i.e. the release of algae-eating fish into the lake to control the rapid growth of algae. We formulate our model by assuming Michaelis-Menten type ratio-dependent prey-predator interaction. The equilibrium of the mathematical model is found and also the stability is discussed in detail. It is observed that the positive equilibria is locally asymptotically stable under certain conditions on the parameters. Also the system is simulated for various sets of parameters and it is found that system may oscillate for some realistic set of parameters. In fact we found that the parameter m, which is the half saturation constant, is very sensitive and with the decrease in this parameter steady state solution of the system changes to stable oscillation. On the practical side, it means that the method of biological control by introducing predatory fish is not always beneficial because outcome of this method depends upon the actual value of the parameter. Here we get the paradox of biological control, which says that it is not possible to have low level of steady state equilibrium of prey population.

Chromophoric Dissolved Organic Matter (CDOM) is a substance produced by the planktonic community that naturally blocks biologically damaging, ultraviolet radiation (UV; wavelengths = 280 to 400 nm). While a variety of planktonic species produce CDOM, investigations into the quality and quantity of their CDOM production are few. The purpose of this study was to investigate the properties of CDOM produced by phytoplankton versus zooplankton. Typically, UV radiation breaks down CDOM. However, marine organisms sometimes produce CDOM that, when exposed to sunlight, increases its absorbance of UV radiation. The reasons for this anomaly and the source of this unusual CDOM are unclear. To test for distinctions among sources, filtered water samples from cultures of two marine phytoplankton, Gymnodinium sp. and Dunaliella sp., and a marine copepod, Tigriopus californicus were exposed to sunlight for intervals of 0, 0.5, 1, 2, and 4 hours. The maximal UVB radiation (wavelengths; λ = 280 to 320 nm) was 0.1699 J cm-2. Before and after sunlight exposures, CDOM sources were assessed by comparing absorbance spectra from 184 to 730 nm with detailed comparisons at wavelengths of 254, 305, 320, and 350 nm. Results are expressed as "absorption", which is the raw absorbance converted to the natural log. Before exposure to sunlight, CDOM from algal species had 5- to 8-times higher average absorption values across UV wavelengths than CDOM produced by Tigriopus. CDOM samples produced by phytoplankton were more susceptible to photochemical change than CDOM from Tigriopus. In response to sunlight, CDOM from Gymnodinium varied greatly, increasing in UV absorption in 2 out of 5 replicates but decreasing in absorption in the other replicates. In contrast, peak absorption at λ = 260 nm of CDOM from Dunaliella decreased directionally by an average of 76% in absorption and 75% in specific absorption, and this decrease in absorption was significant (p = 0.03). CDOM from Tigriopus significantly decreased in both absorption (all UV wavelengths, p < 0.01) and "specific absorption", which is absorption standardized per mg of dissolved organic carbon (λ = 320 nm; p < 0.03), but the magnitude of change was only 17%. Thus, photochemical responses of CDOM from the three planktonic sources demonstrated more, consistently less, and unchanged UV absorption. Phytoplankton biomass, which is greater than that of copepods at the next trophic level, likely produce more CDOM but because of greater variability in CDOM absorbance of UV both within and between algal sources, copepods may offer a more stable source of UV protection depending on sunlight exposure and their relative abundance. Definitive conclusions depend on future laboratory studies expanded to more planktonic organisms as well as in situ studies during oceanographic cruises to test the relative contributions of planktonic species.

A bacterial-based algal control product, Environ-8®/BI-CHEM®Pondclear by Novozymes, was tested in a series of microcosm and tank experiments between October 2008 and March 2009 to evaluate if the product was suitable as a short-term intervention technique for algal bloom management in the Swan-Canning River system. Results from the microcosms did not suggest that “Pondclear” bacteria significantly reduced nutrient concentrations and “Pondclear‘s” ability to suppress algal growth could not be verified. Results from fibreglass tank experiments (1200L) suggested that “Pondclear” did not actively attack and lyse algal cells. However, in “Pondclear” treated tanks, both aerated and non-aerated, “Pondclear” accelerated NH4 and NOx reduction. “Pondclear” application resulted in PO4 reduction in “pondclear” no aeration tanks. Furthermore, Pondclear” appeared to suppress algal growth in nonaerated tanks over short periods (several days). Algal growth regularly diminished after “Pondclear” application but reappeared shortly afterwards. Aeration had a negative effect on bacterial proliferation in the tanks, possibly through alteration of environmental conditions. As a consequence of the environmental conditions in the tanks being counterproductive to the development of a representative microbial composition, several aspects regarding ”Pondclear‘s” effectiveness could not be assessed satisfactorily in the tank experiments.

[EN] ABSTRACT This PhD thesis is based on a collaboration between Professor Dr. Ramon Serrano's laboratory and the fertilizer company Fertinagro Nutrientes and it's motivated by the increasing need in agriculture to increase crop productivity while minimizing its impact on the environment. Fertinagro Nutrientes supplied the following six bioestimulants for analyzing its effects on tolerance to abiotic stress in the yeast Saccharomyces cerevisiae, providing no (or very limited in some cases) information about its composition: Seaweed extract, Vinacillas, Phosphite, Humic Acid, Amino22 and Potassium fulvate. The broad conservation of metabolic pathways and the molecular mechanisms involved in abiotic stress response between yeast and plants allows the use of S. cerevisiae as a suitable model system for this study. All bioestimulants showed, to a greater or lesser extent, positive effects on yeast tolerance against at least one of the abiotic stresses in study. Seaweed extract improves growth under salt stress. Phosphite and Vinacillas protect against salt stress and heat shock. Humic acid increases tolerance to oxidative stress and heat shock. The two most versatile bioestimulants, Amino22 and Potassium fulvate, were further investigated in order to identify their mechanisms of action. Amino22, which is the most effective biostimulant, considerably improves growth in the absence of stress and under osmotic stress and, to a lesser extent, it also enhances growth under salt stress conditions. Amino22 also provides tolerance against oxidative stress and heat shock. By comparison with an acid casein peptone it was confirmed that the active substance in Amino22 are amino acids. Analysis of global gene expression using DNA microarrays showed that Amino22 treatment represses both Gcn4 regulated genes (which are involved in amino acid and vitamin biosynthesis) and Aft1 regulated genes (which are involved in iron homeostasis). The positive effect of amino acids on growth and stress tolerance is related, at least in part, to the activation of TORC1 pathway and it also requires a partial inhibition of GAAC pathway. By contrast, this positive effect is independent of the Aft1 regulon repression. Following the observation that amino acid treatment represses iron regulon expression, we studied more in depth the relationship between amino acid and iron homeostasis in S. cerevisiae. We suggest a regulation model according to which the activation of GAAC pathway induces nuclear localization of Aft1 and subsequent expression of its target genes, whereas inhibition of this pathway by amino acids may have the opposite effect. Aft1 activity may be controlled through eIF2a phosphorylation and, hypothetically, it would involve regulation Fe/S biosynthesis. Potassium fulvate improves tolerance to osmotic, oxidative and heat stress. Microarray and qRT-PCR expression analysis indicate that Potassium fulvate represses Aft1 regulon. This repression can be explained by an increase in intracellular iron content, whose absorption depends on an oxidoreductase encoded by the FET3 gene. Tolerance to abiotic stress by Potassium fulvate also depends on FET3, therefore it is concluded that the mechanism of action of this biostimulant is based on an increased iron availability, which is accumulated in yeast cells without causing oxidative damage.
[ES] RESUMEN Este trabajo se basa en una colaboración entre el laboratorio del profesor doctor Ramón Serrano y la empresa de fertilizantes Fertinagro Nutrientes y está motivado por la necesidad creciente de incrementar la productividad de los cultivos agrícolas al mismo tiempo que se minimiza el impacto que la agricultura tiene sobre el medio ambiente. Fertinagro Nutrientes facilitó los siguientes seis bioestimulantes para el análisis de sus efectos sobre la tolerancia a estrés abiótico en la levadura Saccharomyces cerevisiae, aportando escasa (o nula en algunos casos) información acerca de su composición: Extracto de algas, Vinacillas, Fosfito, Ácido húmico, Amino22 y Fulvato potásico. La amplia conservación de rutas las metabólicas y de los mecanismos moleculares de defensa frente a estrés abiótico entre levadura y plantas justifican el uso de S. cerevisiae como sistema modelo para este estudio. Todos los bioestimulantes tienen, en mayor o menor medida, efectos positivos sobre la tolerancia de la levadura frente a al menos uno de los tipos de estrés abiótico estudiados. El Extracto de algas mejora el crecimiento en condiciones de estrés salino. El Vinacillas y el Fosfito protegen frente a estrés salino y choque térmico. El Ácido húmico incrementa la tolerancia a estrés oxidativo y choque térmico. Los dos bioestimulantes más polivalentes, el Amino22 y el Fulvato potásico, fueron estudiados en mayor profundidad con el objetivo de identificar sus mecanismos de acción. El Amino22, que es el bioestimulante más efectivo de los estudiados, mejora considerablemente el crecimiento en ausencia de estrés y bajo estrés osmótico y, en menor medida, también resulta beneficioso para el crecimiento en condiciones de estrés salino. Asimismo, el Amino22 proporciona tolerancia frente a estrés oxidativo y choque térmico. Mediante la comparación con una peptona de caseína ácida se comprobó que el principio activo responsable del efecto del Amino22 son los aminoácidos que contiene. El análisis del efecto del Amino22 sobre la expresión global de genes empleando micromatrices de DNA muestra que el bioestimulante reprime tanto genes regulados por Gcn4 e involucrados en la biosíntesis de aminoácidos y vitaminas como genes regulados por Aft1, implicados en la homeostasis de hierro. El efecto positivo de los aminoácidos sobre el crecimiento y tolerancia a estrés está relacionado, en parte al menos, con la activación de la ruta TORC1 y, además, requiere la inhibición parcial de la ruta GAAC. En cambio, dicho efecto positivo es independiente de la represión del regulón de Aft1. A raíz de la observación de que los aminoácidos reprimen el regulón de hierro, se profundizó en el estudio de la relación entre la homeostasis de aminoácidos y la de hierro en S. cerevisiae llegando a un modelo de regulación según el cual la activación de la ruta GAAC induciría la localización nuclear de Aft1 y la consiguiente expresión de sus genes diana, mientras que la inhibición de dicha ruta por la presencia de aminoácidos tendría el efecto contrario. La actividad de Aft1 sería controlada a través del estado de fosforilación de eIF2a e, hipotéticamente, implicaría la regulación de la formación de complejos Fe/S. El Fulvato potásico mejora la tolerancia a estrés osmótico, oxidativo y térmico. Los análisis de expresión mediante micromatrices y qRT-PCR indican que el tratamiento con Fulvato potásico reprime el regulón de Aft1. Esta represión se puede explicar por un aumento en el contenido intracelular de hierro, cuya entrada depende de la oxidorreductasa codificada por el gen FET3. La tolerancia a estrés abiótico que proporciona el Fulvato potásico también depende de FET3, por lo que se concluye que el mecanismo de acción de este bioestimulante se basa en un incremento de la disponibilidad de hierro, el cual se acumula en las células sin producir daño oxidativo extra.
[CAT] RESUM Aquest treball es basa en una col·laboració entre el laboratori del professor doctor Ramón Serrano i l'empresa de fertilitzants Fertinagro Nutrientes i està motivat per la necessitat creixent d'incrementar la productivitat dels cultius agrícoles al mateix temps que es minimitza l'impacte de l'agricultura sobre el medi ambient. Fertinagro Nutrientes va facilitar els següents sis bioestimulants per a l'anàlisi dels seus efectes sobre la tolerància a estrés abiòtic en el llevat Saccharomyces cerevisiae, aportant escassa (o nul·la en alguns casos) informació sobre la seua composició: Extracte d'algues, Vinacillas, Fosfit, Àcid húmic, Amino22 i Fulvat potàssic. L'àmplia conservació de les rutes metabòliques i dels mecanismes moleculars de defensa front a l'estrés abiòtic entre llevat i plantes justifiquen l'ús de S. cerevisiae com a sistema model per a este estudi. Tots els bioestimulants tenen, en major o menor mesura, efectes positius sobre la tolerància del llevat front a almenys un dels tipus d'estrés abiòtic estudiats. L'Extracte d'algues millora el creixement en condicions d'estrés salí. El Vinacillas i el Fosfit protegeixen front a l'estrés salí i xoc tèrmic. L'Àcid húmic incrementa la tolerància a estrés oxidatiu i xoc tèrmic. Els dos bioestimulants més polivalents, l'Amino22 i el Fulvat potàssic, van ser estudiats en major profunditat amb l'objectiu d'identificar els seus mecanismes d'acció. L'Amino22, que és el bioestimulant més efectiu dels estudiats, millora considerablement el creixement en absència d'estrés i baix estrés osmòtic i, en menor mesura, també resulta beneficiós per al creixement en condicions d'estrés salí. Així mateix, l'Amino22 proporciona tolerància front a l'estrés oxidatiu i xoc tèrmic. Mitjançant la comparació amb una peptona de caseïna àcida es va comprovar que el principi actiu responsable de l'efecte de l'Amino22 són els aminoàcids que conté. L'anàlisi de l'efecte de l'Amino22 sobre l'expressió global de gens emprant micromatrius de DNA mostra que el bioestimulant reprimeix tant gens regulats per Gcn4 i involucrats en la biosíntesi d'aminoàcids i vitamines com gens regulats per Aft1, implicats en l'homeòstasi del ferro. L'efecte positiu dels aminoàcids sobre el creixement i tolerància a estrés està relacionat, en part almenys, amb l'activació de la ruta TORC1 i, a més, requereix la inhibició parcial de la ruta GAAC. En canvi, aquest efecte positiu és independent de la repressió del reguló de Aft1. Arran de l'observació que els aminoàcids reprimeixen el reguló de ferro, es va aprofundir en l'estudi de la relació entre l'homeòstasi d'aminoàcids i la de ferro en S. cerevisiae arribant a un model de regulació segons el qual l'activació de la ruta GAAC induiria la localització nuclear de Aft1 i la consegüent expressió dels seus gens diana, mentre que la inhibició d'aquesta ruta per la presència d'aminoàcids tindria l'efecte contrari. L'activitat de Aft1 seria controlada a través de l'estat de fosforilació d' eIF2a i, hipotèticament, implicaria la regulació de la formació de complexos Fe/S. El Fulvat potàssic millora la tolerància a estrés osmòtic, oxidatiu i tèrmic. Les anàlisis d'expressió mitjançant micromatrius i qRT-PCR indiquen que el tractament amb Fulvat potàssic reprimeix el reguló de Aft1. Aquesta repressió es pot explicar per un augment en el contingut intracel·lular de ferro, l'entrada del qual depén de la oxidorreductasa codificada pel gen FET3. La tolerància a estrés abiòtic que proporciona el Fulvat potàssic també depén de FET3, per la qual cosa es conclou que el mecanisme d'acció d'aquest bioestimulant es basa en un increment de la disponibilitat de ferro, el qual s'acumula en les cèl·lules sense produir dany oxidatiu extra.
Caballero Molada, M. (2016). Estudio de efectos protectores y mecanismos de acción frente a estrés abiótico de bioestimulantes de fertilizantes en Saccharomyces cerevisiae [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/67390
TESIS

AbstractThe microbiota present in cultural heritage objects, made by diverse inorganic and organic materials and inserted into particular environment, represents a complex and dynamic ecosystem composed by bacteria, cyanobacteria, fungi, algae and lichens, which can induce decay by biological mechanisms. To control the microbial growth several methods are being applied such as mechanical and physical processes and chemical biocides. However, these methods have several weaknesses like be dangerous to handle, material incompatibility or produce environmental and health hazards. Therefore, the identification of effectively biodeteriogenic agents and the design of mitigation strategies directed to these agents without prejudice to historical materials, to the environment and to operators, taking into account the microbial community’s dynamics, is an important challenge to control biodeterioration of cultural heritage. Bacteria, in particular Bacillus spp. are worth for the creation of new green biocides solutions because they produce a great variety of secondary metabolites including ribosomally and non-ribosomally synthesized antimicrobial peptides, known to possess antagonistic activities against many biodeteriogenic fungi and bacteria. The discovery of new safe active compounds and green nanotechnology for direct application in cultural heritage safeguard can in a close future contribute to potentiate a new generation of biocides and safe sustainable methods for cultural heritage.

Upgradation and advancement in every field related to mankind leads to the origin of a contaminated environment. Development in science and technology enabled humans to combat the rate of contaminants by using biological agents, commonly known as bioremediation. The chapter deals with the different species of bioremediation agents viz. bacteria, fungi, algae, plants, animals and organic wastes to treat diverse environmental pollution. The extent of environmental bioremediation encompasses inorganic viz. arsenic, chromium, mercury, cyanide etc. and organics viz. Hydrocarbons, petroleum, pesticides etc. Thus, the reasons for the control of water and soil by considering bioremediation are concern on public health, protection of environment, and cost reduction of decontamination. Different case studies have been demonstrated herein to understand the enigmatic process and evaluate practical efficacy of the environment to decontaminate itself by the presence of various biological organisms.

Upgradation and advancement in every field related to mankind leads to the origin of a contaminated environment. Development in science and technology enabled humans to combat the rate of contaminants by using biological agents, commonly known as bioremediation. The chapter deals with the different species of bioremediation agents viz. bacteria, fungi, algae, plants, animals and organic wastes to treat diverse environmental pollution. The extent of environmental bioremediation encompasses inorganic viz. arsenic, chromium, mercury, cyanide etc. and organics viz. Hydrocarbons, petroleum, pesticides etc. Thus, the reasons for the control of water and soil by considering bioremediation are concern on public health, protection of environment, and cost reduction of decontamination. Different case studies have been demonstrated herein to understand the enigmatic process and evaluate practical efficacy of the environment to decontaminate itself by the presence of various biological organisms.

Pollution is one of the biggest challenges of current times. For control of environmental pollutants, degradation of these contaminants is need of times. Degradation of pollutants can be achieved by various physical and chemical or by physicochemical approaches. Since these methods are in efficient, hence development of biological methods began. Bioremediation is the approach of using bacteria, fungi, plants, algae, etc. to degrade wide range of environmental pollutants. Nano-bioremediation is one of such method which has received lot of attention in past few years. Nano-sized particles have large surface area relative to their volumes and thus have enhanced chemical and biological reactivity. Nano-bioremediation aims at reducing the contaminant concentrations to low risk-based levels and alleviating environmental impacts simultaneously. It brings the benefits to both nanotechnology and bioremediation together to achieve remediation which is more efficient, less time taking and eco-friendly.

Blue green algae (BGA) are prokaryotic phototrophic organisms that can fix the atmospheric nitrogen biologically, and were directly applied as a biofertilizers in agricultural fields specifically Paddy field. Since they are having the ability to fix nitrogen, they are formulated with various adsorbents for the purpose of enhancing the crop growth along with maintaining the soil fertility and other soil factors responsible for productivity. The present study revealed that the formulations of blue green algae isolated from paddy fields of southern districts with different adsorbents like alluvial soil, sand, charcoal, and powdered paddy straw. All the adsorbents mixed with blue green algae showed significant growth when compared to the control plant. This determined that the adsorbent formulated mixed blue green algae enhanced the paddy plant growth under greenhouse condition.

Quantitative data quality descriptors are important for evaluating and communicating acceptability of information used in environmental monitoring and assessment. In this chapter, we present (1) the rationale for establishing and using performance measures and MQOs in routine quality control planning and analysis, (2) field and laboratory methods for capturing input data required for performance calculations, and (3) approaches for setting data acceptability thresholds and determining the need for corrective actions. Relevant examples are available from local, regional, and national programs in the U.S. charged with monitoring and assessing aquatic biological condition, physical habitat, contaminants, and toxicity testing. We will describe techniques for calculating and determining acceptability of performance measures, such as, among other data quality indicators, precision, accuracy, sensitivity, representativeness, and completeness of field sampling, laboratory processing, and data management and analysis. Data types on which these examples will be based include benthic macroinvertebrates, fish assemblage, tissue body burden, laboratory analytical and toxicity testing, physical habitat, selected geomorphic characteristics, and algal toxins.

The Llucmajor platform on southern Mallorca Island (Spain) is one of the best-exposed Miocene shallow-water carbonate platforms known in the world. Up to 90 m vertical sea cliffs provide a clean, continuous and detailed 3D view of the facies architecture and continuous cores from fifty-two water wells, affording information to interpret the 3D architecture of this 20 km-wide and only slightly deformed carbonate platform. Forty years of research on the Llucmajor platform provided insights into how the mutual interaction of biological and physical processes control the type of carbonate production and sediment dynamics which, along with changes in sea-level, determine the facies stacking patterns and the distribution of internal heterogeneities. Moreover, the ‘modern character’ of the carbonate-producing biota permits to capture the response of the carbonate system to changing ecological and oceanographic conditions. Although learnings from the Llucmajor platform do not apply to older platforms, it is this process-product type of analysis that can be applied to carbonate systems of all ages. Thus through this field guide, two carbonate factories working out of phase and with a non-linear response to sea-level changes are identified. A shallow-water euphotic (well lit) production (corals, red and green calcareous algae and associated heterozoan biota) predominated during rising sea-level when linear reefal rims grading to broad lagoons expanded and increased production and the sediment shed-off from these reef-lagoon systems built-out thick slopes. A deeper oligophotic (low light) factory expanded during the lowstands of sea-level when the light reached the basin floor; red algae, larger benthic foraminifers and molluscs were the prime producers. The Llucmajor platform grew up during the late Miocene, through the transition from greenhouse to icehouse climate that characterised the late Cenozoic. Its building blocks occur hierarchically stacked in response to the sea-level cyclicity. At the bed scale, the sigmoids consist of a lagoonal bed passing successively into sigmoidal reef core and then into slope clinobed and basinal deposits and bounded by an erosion surface onto the lagoon and reef and its correlative conformity basinward. Sigmoids stack in sets of sigmoids, these in cosets of sigmoids and these last in megasets, all of them fitting the characteristics of a depositional sequence when the genetic processes are analysed. Departures from the sequence model rely on the inter-dependence between depth gradient, the type of carbonate-producing biota and the ranges of sea-level cyclicity. Through the visit to a series of selected outcrops, this field guide offers a comprehensive assessment of the Llucmajor reef-rimmed shelf from the basin to the coral-dominated reefal margin and across the open-lagoon to restricted lagoon that defined the shelf top. The itinerary focusses on numerous topics and at different scales, from the study of discrete rock bodies to km-wide outcrop windows resembling high-resolution seismic profiles. The field guide integrates facies analysis, stratal architecture and distinct diagenetic features such as extensive secondary porosity after the dissolution of aragonitic components and pervasive dolomitization. Impressive sub-vertical collapse structures were produced by karstic dissolution during lowstands of sea-level and gravitational collapse of the roof complete the suite of diagenetic overprint. Altogether, the depositional and diagenetic attributes of the Llucmajor platform reveal a complex and highly heterogeneous carbonate system that is used as outcrop analogue for numerous Miocene carbonate reservoirs across the world.

This paper describes a unique analytical model created to assess the maximum potential for algae production in Texas. The model, which merges engineering, biology and geosciences into a singular analysis, aims to identify suitable growth locations and estimate the quantity of algae-based oils that can be potentially produced in Texas. The model incorporates geographically- and temporally-resolved data on sunlight, anthropogenic CO2 emissions, and saline or brackish water availability. These data are then overlaid with first-order biological approximations for algae growth calculations in order to create maps of algae growth potential. Solar insolation data were obtained from measurement locations throughout the state for varying time scales spanning many years from the Texas Solar Radiation Database (TSRDB). CO2 emissions were compiled from area and point sources (such as natural gas and coal-fired power plants) from the Energy Information Administration and Environmental Protection Agency. Water data for wastewater treatment plants and saline aquifers were obtained from the Texas Commission on Environmental Quality and the Texas Water Development Board. A home-built MATLAB code uses these data, along with engineering approximations and the ability to manipulate different assumptions to calculate algae growth by location and time period. For each location, the model calculates potential oil yield, biomass produced, growth rates, water and CO2 consumed and land used. Standard pond and tubular photobioreactor dimensions have been used to model real world production facilities. Realistic limits for growth rates, photosynthetic efficiencies, photosynthetic flux tolerances and oil content are also incorporated. These parameters can be varied to approximate different algae strains and growth conditions. The model assumes reactors to have ideal mixing, optimal pH and temperature controls in place. This preliminary resource assessment estimates that Texas receives an average of 375 W/m2 annually, produces 409 million tons per year of CO2 from the industrial and electrical power sectors and has approximately 1.4 trillion gallons per year of available water on a sustainable basis. The computational model estimates that between 44 and 167 million tons of algal biomass and 3.1 to 12 billion gallons of lipids can be produced annually in Texas based on the combination and availability of these resources.

Microalgae are believed to be a promising source of different high value products (HVP). HVP are metabolites which are produced during the growth of microalgae and their production is triggered by the physiochemical growth conditions of the microalgae. The present project is aimed at exploring the presence of bioactive compounds in desert microalgae Desmodesmus sp. and to assess its ability to support and improve health care in Qatar. The isolate was cultivated under conventional conditions as a control, and under 3 different stress conditions to enhance the production of high value products. Then crude algal extracts were used to assess the biological activity. Results of the study suggest that Desmodesmus sp. produces high value products that exhibit great anti-oxidant, anti-proliferative and anti-bacterial activity when cultivated under conventional conditions and under continuous light stress.

Stormwater management is an ongoing challenge in the United States and the world at-large. As state and municipal agencies grapple with conflicting interests like encouraging land development, complying with permits to control stormwater discharges, “urban stream syndrome” effects, and charges to steward natural resources for the long-term, some agencies may turn to constructed wetlands (CWs) as aesthetically pleasing and functional natural analogs for attenuating pollution delivered by stormwater runoff to rivers and streams. Constructed wetlands retain pollutants via common physical, physicochemical, and biological principles such as settling, adsorption, or plant and algae uptake. The efficacy of constructed wetlands for pollutant attenuation varies depending on many factors such as flow rate, pollutant loading, maintenance practices, and design features. In 2018, the culmination of efforts by Clackamas Water Environment Services and others led to the opening of the Carli Creek Water Quality Project, a 15-acre constructed wetland adjacent to Carli Creek, a small, 3500-ft tributary of the Clackamas River in Clackamas County, OR. The combined creek and constructed wetland drain an industrialized, 438-acre, impervious catchment. The wetland consists of a linear series of a detention pond and three bioretention treatment cells, contributing a combined 1.8 acres of treatment area (a 1:243 ratio with the catchment) and 3.3 acre-feet of total runoff storage. In this study, raw pollutant concentrations in runoff were evaluated against International Stormwater BMP database benchmarks and Oregon Water Quality Criteria. Concentration and mass-based reductions were calculated for 10 specific pollutants and compared to daily precipitation totals from a nearby precipitation station. Mass-based reductions were generally higher for all pollutants, largely due to runoff volume reduction on the treatment terrace. Concentration-based reductions were highly variable, and suggested export of certain pollutants (e.g., ammonia), even when reporting on a mass-basis. Mass load reductions on the terrace for total dissolved solids, nitrate+nitrite, dissolved lead, and dissolved copper were 43.3 ± 10%, 41.9 ± 10%, 36.6 ± 13%, and 43.2 ± 16%, respectively. E. coli saw log-reductions ranging from -1.3 — 3.0 on the terrace, and -1.0 — 1.8 in the creek. Oregon Water Quality Criteria were consistently met at the two in-stream sites on Carli Creek for E. coli with one exception, and for dissolved cadmium, lead, zinc, and copper (with one exception for copper). However, dissolved total solids at the downstream Carli Creek site was above the Willamette River guidance value 100 mg/L roughly 71% of the time. The precipitation record during the study was useful for explaining certain pollutant reductions, as several mechanisms are driven by physical processes, however it was not definitive. The historic rain/snow/ice event in mid-February 2021 appeared to impact mass-based reductions for all metals. Qualitatively, precipitation seemed to have the largest effect on nutrient dynamics, specifically ammonia-nitrogen. Determining exact mechanisms of pollutant removals was outside the scope of this study. An improved flow record, more targeted storm sampling, or more comprehensive nutrient profiles could aid in answering important questions on dominant mechanisms of this new constructed wetland. This study is useful in establishing a framework and baseline for understanding this one-of-a-kind regional stormwater treatment project and pursuing further questions in the future.