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1
Okabe, Satoshi, Tomonori Kindaichi e Tsukasa Ito. "Fate of 14C-Labeled Microbial Products Derived from Nitrifying Bacteria in Autotrophic Nitrifying Biofilms". Applied and Environmental Microbiology 71, n. 7 (luglio 2005): 3987–94. http://dx.doi.org/10.1128/aem.71.7.3987-3994.2005.
Testo completoAbstract (sommario):
ABSTRACT The cross-feeding of microbial products derived from 14C-labeled nitrifying bacteria to heterotrophic bacteria coexisting in an autotrophic nitrifying biofilm was quantitatively analyzed by using microautoradiography combined with fluorescence in situ hybridization (MAR-FISH). After only nitrifying bacteria were labeled with [14C]bicarbonate, biofilm samples were incubated with and without NH4 + as a sole energy source for 10 days. The transfer of 14C originally incorporated into nitrifying bacterial cells to heterotrophic bacteria was monitored with time by using MAR-FISH. The MAR-FISH analysis revealed that most phylogenetic groups of heterotrophic bacteria except the β-Proteobacteria showed significant uptake of 14C-labeled microbial products. In particular, the members of the Chloroflexi were strongly MAR positive in the culture without NH4 + addition, in which nitrifying bacteria tended to decay. This indicated that the members of the Chloroflexi preferentially utilized microbial products derived from mainly biomass decay. On the other hand, the members of the Cytophaga-Flavobacterium cluster gradually utilized 14C-labeled products in the culture with NH4 + addition in which nitrifying bacteria grew. This result suggested that these bacteria preferentially utilized substrate utilization-associated products of nitrifying bacteria and/or secondary metabolites of 14C-labeled structural cell components. Our results clearly demonstrated that the coexisting heterotrophic bacteria efficiently degraded and utilized dead biomass and metabolites of nitrifying bacteria, which consequently prevented accumulation of organic waste products in the biofilm.
2
Ikuta, H., N. Noda, Y. Ebie, A. Hirata, S. Tsuneda, M. Matsumura e Y. Inamori. "The rapid quantification and detection of nitrifying bacteria by using monoclonal antibody method". Water Science and Technology 42, n. 3-4 (1 agosto 2000): 1–7. http://dx.doi.org/10.2166/wst.2000.0351.
Testo completoAbstract (sommario):
Monoclonal antibodies against the two kinds of nitrifying bacteria Nitrosomonas europaea (IFO14298) and Nitrobacter winogradskyi (IFO14297) were raised and isotypes of these monoclonal antibodies, IgM and IgG1, were successfully obtained. Cross reactivities of these monoclonal antibodies against various kinds of representative heterotrophic bacteria turned out to be relatively low by competitive ELISA. In contrast, these monoclonal antibodies were very specific for nitrifying bacteria used as antigens. By means of sandwich ELISA using different isotype monoclonal antibodies such as IgM and IgG1, calibration curves were successfully developed for quantification of nitrifying bacteria. It was shown that the obtainable lower limit of quantification of N. europaea and N. winogradskyi were 7.0 × 106 N/ml and were 6.0 × 105 N/ml, respectively. Nitrifying bacteria in activated sludge of advanced domestic wastewater treatment johkaso were counted by sandwich ELISA and MPN methods. The bacterial number estimated by MPN method was lower than that estimated by sandwich ELISA. It was indicated that this monoclonal antibody method could be used as a quick and powerful tool for estimating and controlling the population of nitrifying bacteria in the advanced domestic wastewater treatment processes.
3
Ayiti, Oluwatobi Esther, Ayansina Segun Ayangbenro e Olubukola Oluranti Babalola. "16S Amplicon Sequencing of Nitrifying Bacteria and Archaea Inhabiting Maize Rhizosphere and the Influencing Environmental Factors". Agriculture 12, n. 9 (28 agosto 2022): 1328. http://dx.doi.org/10.3390/agriculture12091328.
Testo completoAbstract (sommario):
Nitrifying bacteria and archaea are ubiquitous and can transform ammonia locked up in soil or manure into nitrate, a more soluble form of nitrogen. However, nitrifying bacteria and archaea inhabiting maize rhizosphere have not been fully explored. This study evaluates the diversity and abundance of nitrifying bacteria and archaea across different growth stages of maize using 16S amplicon sequencing. Moreover, the influence of environmental factors (soil physical and chemical properties) on the nitrifying communities was evaluated. Rhizosphere soil DNA was extracted using Nucleospin Soil DNA extraction kit and sequenced on Illumina Miseq platform. MG-RAST was used to analyze the raw sequences. The physical and chemical properties of the soil were measured using standard procedure. The results revealed 9 genera of nitrifying bacteria; Nitrospira, Nitrosospira, Nitrobacter, Nitrosovibrio, Nitrosomonas, Nitrosococcus, Nitrococcus, unclassified (derived from Nitrosomonadales), unclassified (derived from Nitrosomonadaceae) and 1 archaeon Candidatus Nitrososphaera. The Nitrospirae phyla group, which had the most nitrifying bacteria, was more abundant at the tasselling stage (67.94%). Alpha diversity showed no significant difference. However, the Beta diversity showed significant difference (p = 0.01, R = 0.58) across the growth stages. The growth stages had no significant effect on the diversity of nitrifying bacteria and archaea, but the tasselling stage had the most abundant nitrifying bacteria. A correlation was observed between some of the chemical properties and some nitrifying bacteria. The research outcome can be put into consideration while carrying out a biotechnological process that involves nitrifying bacteria and archaea.
4
Inamori, Yuhei, Tomotake Takai, Naohiro Noda, Akira Hirata, Hiroshi Niioka, Gao YueHua e Masatoshi Matsumura. "Development of a rapid quantification method for nitrosomonas and nitrobacter using elisa for wastewater treatment facilities". Water Science and Technology 36, n. 12 (1 dicembre 1997): 169–74. http://dx.doi.org/10.2166/wst.1997.0444.
Testo completoAbstract (sommario):
Enzyme-linked immunosorbent assay (ELISA) by use of monoclonal antibodies (MAbs) is very useful and helpful for the detection and quantification of the specific bacteria like nitrifiers in a mixed bacterial habitat. In this study, seven monoclonal antibodies were raised from splenocytes of mice(BALB/c) that are specific for the surface antigen of the two kinds of nitrifying bacteria. Three were directed against Nitrosomonas europaea (IFO 14298) and four were directed against Nitrobacter winogradskyi (IFO 14297). Cross-reactivities of MAbs against other strains of nitrifying bacteria as well as some kinds of representative heterotrophic bacteria in activated sludge and biofilm were checked to determine the usefulness of MAbs. It was found that there were some strain specificities between the same genera of IFO and ATCC strain. By means of a competitive ELISA, correlation curves for quantifying nitrifying bacteria were developed in a pure culture. It was found that this monoclonal antibody method could be used as a quick and powerful tool for estimating and controlling the population of nitrifying bacteria.
5
Alfisah, R. K., I. Rusmana, T. Widiyanto e R. Affandi. "The Abundance and Potential Activity of Nitrifying, Denitrifying, and Nitrate-ammonifying Bacteria in the Vanamae Shrimp Culture in Karawang". IOP Conference Series: Earth and Environmental Science 1062, n. 1 (1 luglio 2022): 012011. http://dx.doi.org/10.1088/1755-1315/1062/1/012011.
Testo completoAbstract (sommario):
Abstract The existence of inorganic nitrogen in the shrimp pond ecosystem will not be separated from the nitrogen cycle and microbiological processes including the activity of microbes. This study aimed to analyze the abundance and potential rate of nitrifying, denitrifying, and nitrate-ammonifying bacteria in Vanamae shrimp cultivation. Water samples were collected on a shrimp pond in Karawang, West Java. Water sampling was carried out at the age of shrimp rearing 0 days, 21 days, 65 days, and 89 days. Water sampling was conducted at four points representing an area of the pond. The bacterial abundances were analyzed using Most Probable Number (MPN) method. The potential rates of bacteria were calculated by Michaelis-Menten kinetics. The highest abundance of nitrifying bacteria was 3.690 log cells ml-1 on 65 days, denitrifying bacteria was 3.415 log cells mL-1 on 89 days, and nitrate-ammonifying bacteria was 3.079 log cells mL-1 on 65 days of shrimp cultivation. The affinity of enzymes related to ammonia oxidation from nitrifying bacteria was higher than nitrate reduction from denitrifying and nitrate-ammonifying bacteria. Generally, nitrifying bacteria were the most abundant and dominant activity over shrimp cultivation.
6
Okabe, S., T. Kindaichi, Y. Nakamura e T. Ito. "Eco-physiology of autotrophic nitrifying biofilms". Water Science and Technology 52, n. 7 (1 ottobre 2005): 225–32. http://dx.doi.org/10.2166/wst.2005.0205.
Testo completoAbstract (sommario):
Microautoradiography combined with fluorescent in situ hybridization (MAR-FISH), a powerful tool for linking physiology with identification of individual cells, was applied to investigate microbial interactions between nitrifying bacteria and coexisting heterotrophic bacteria in an autotrophic nitrifying biofilm community fed with only ammonia as the sole energy source and bicarbonate as the sole carbon source. First, nitrifying bacteria were radiolabeled by culturing the biofilm samples with [14C]bicarbonate for 6 h, and then the transfer of radioactivity from nitrifying bacteria to heterotrophic bacteria was monitored by using MAR-FISH. MAR-FISH revealed that the heterotrophic bacterial community was composed of bacteria that were phylogenetically and metabolically diverse. We could obtain direct evidence that organic matter derived from nitrifiers was subsequently utilized by mainly filamentous bacteria belonging to the Chloroflexi (green non-sulfur bacteria) group or CFB group in the biofilm, which was clearly visualized by MAR-FISH at single cell resolution for the first time. On the other hand, the members of the α- and γ-Proteobacteria were specialized to utilize low-molecular-weight organic matter. This community represents functionally integrated units that assure maximum access to and utilization of metabolites of nitrifiers.
7
Han, Dengfeng, Zhenyi Hu, Dapeng Li e Rong Tang. "Nitrogen Removal of Water and Sediment in Grass Carp Aquaculture Ponds by Mixed Nitrifying and Denitrifying Bacteria and Its Effects on Bacterial Community". Water 14, n. 12 (9 giugno 2022): 1855. http://dx.doi.org/10.3390/w14121855.
Testo completoAbstract (sommario):
Nitrification and denitrification are important for nitrogen (N) cycling in fish ponds culture, but the effects of nitrifying and denitrifying bacteria concentrations on pond water and sediments remain largely unknown. Here, we used 0, 0.15, 0.30, 0.60 mg/L different concentrations of mixed nitrifying and denitrifying bacteria to repair the pond substrate through an enclosure experiment lasting 15 days. The results showed that the purification effect of nitrifying and denitrifying bacteria was most obvious on pond nitrogen from day 4 to day 7. The optimal relative concentration was 0.60 mg/L for nitrifying and denitrifying bacteria; NH4+-N (ammonia nitrogen) decreased by 75.83%, NO2−-N (nitrite) by 93.09%, NO3−-N (nitrate) by 38.02%, and TN (total nitrogen) by 45.16% in this concentration group on pond water. In one cycle, C/N (carbon/nitrogen) ratio of both water body and bottom sediment significantly increased, but C/N ratio of water body increased more significantly than that of sediment. Water C/N ratio increased by 76.00%, and sediment C/N ratio increased by 51.96% in the 0.60 mg/L concentration group. Amplicon sequencing of pond sediment showed that the change in nitrifying and denitrifying bacterium diversity was consistent with that in water quality index. Dominant nitrifying bacteria had a relatively high percentage, with significant differences in dominant bacterium percentage across different bacterial addition groups, while dominant denitrifying bacterium percentage was not high without significant differences among different groups. The dominant species of nitrifying bacteria were, respectively, Nitrosomonas, Nitrosovibrio, Nitrosospira, and Aeromonas, and the dominant species of denitrifying bacteria were Thauera, Azoarcus, Magnetospirillum, Azospira, and Idiomarina. The correlation analyses showed an aerobic nitrification and facultative anaerobic denitrification in pond sediments. Research shows that the addition of exogenous nitrifying and denitrifying bacteria can effectively reduce the nitrogen load of pond water and sediment. At the concentration of 0.6 mg/L, the nitrogen load of pond water and sediment decreased most obviously, which had the best effect on pond purification.
8
Lai, Zi Ni, Ying De Cui, Peng Gao e Xun Jun Chen. "Modified PLA Carrier Material and its Performance in Immobilization of Nitrifying Bacteria". Materials Science Forum 610-613 (gennaio 2009): 198–201. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.198.
Testo completoAbstract (sommario):
To prepare the renewable carrier materials for immobilization of nitrifying bacteria, polylactic acid (PLA) dichloromethane solution was added to chitosan aqueous solution, mixed by agitation at a speed of 150 rpm / min. The resultant PLA microspheres were fund to have diameter of 100 ~ 300 μm, thus underwent ammonolysis by a 6 % hexamethylenediamine / n-propanol solution for 8 min, hydroformylation by a 1% glutaraldehyde solution for 3 h, and grafted with 1% chitosan for 24 h, to improve the surface hydrophilic property. The static adsorption was applied for adhesion of nitrifying bacteria to the surface of the carrier, i.e. immobilization of nitrifying bacteria. The removal efficiency of ammonia by the immobilized nitrifying bacteria in wastewater treatment was tested. The results showed that the surface of the microsphere carrier was rough and osteoporosis, therefore it can adhere more nitrifying bacteria. When it was immersed in the suspension of nitrifying bacteria for 8 h, the rate of nitrification by the immobilized nitrifying bacteria reached the highest level and tended to be stable afterwards.
9
Yosmaniar, Y., T. Sumiati e M. Mulyasari. "Growth Performance and Survival Rate of Catfish (Pangasius sp) with the Application of the Nitrifying and Denitrifying Bacteria". IOP Conference Series: Earth and Environmental Science 934, n. 1 (1 novembre 2021): 012004. http://dx.doi.org/10.1088/1755-1315/934/1/012004.
Testo completoAbstract (sommario):
Abstract Nitrifying and denitrifying bacteria can be used as a bioremediation agents in aquaculture. The purpose of this experiment is to evaluate the optimal growth and survival performances of catfish rearing with the application of nitrifying and denitrifying bacteria. A completely randomized design was performed with the following treatments: A) nitrifying and denitrifying bacteria NP2-DP1; B) nitrifying and denitrifying bacteria NP2-DP2; C) commercial bacteria and D) without bacterial isolate (control), each with 3 replications. Twelve containers (34 x 34 x 45 cm) were used with a volume of 20 L equipped with aeration. The catfish used (Pangasius sp) has a body weight of 8.33 g ± 0.1 and stocking density of 20 fish / container reared within 30 days. Feed was applied to the fish at 3% of their body weight for three times a day at 08.00 am, 12.00 and 15.00 pm . . Inoculation of bacteria on day 10th and; 20th, that is 108 cfu / mL. The parameters measured were growth rate, survival rate, and water quality. Sampling was carried out every 10 days. The results showed that the application of NP2 and DP1 was the optimal to increase the growth and survival of catfish.
10
Sheng, Xiaolin, Rui Liu, Lujun Chen, Zihua Yin e Jianfeng Zhu. "Enrichment and application of nitrifying activated sludge in membrane bioreactors". Water Science and Technology 76, n. 11 (14 agosto 2017): 2888–94. http://dx.doi.org/10.2166/wst.2017.421.
Testo completoAbstract (sommario):
Abstract In this study, nitrifying bacteria were enriched in a membrane bioreactor (MBR, R1) and their bioaugmentation effectiveness was evaluated in another two MBRs (R2 and R3). Nitrifying activated sludge (NAS) with high nitrification activity of up to 3,000 mg-N/(L·d)−1 was successfully enriched in R1. The results showed that chemical oxygen demand concentration of 100–200 mg/L had no negative effect on NAS enrichment but reduced the ratio of bacterial nitrifiers. Moreover, the cell concentration of nitrifying bacteria in NAS, which was 3.1 × 1011 cells/L, was similar to that of the commercial bacterium agent. For the bioaugmentation test, the reactor inoculated with 14% NAS achieved a 23% higher NH4+-N removal efficiency than that of the uninoculated reactor. Along with the improvement of nitrification performance, the bacterial nitrifiers abundance and microbial richness remarkably increased after bioaugmentation. These results suggested that the MBR system could efficiently enrich nitrifying bacteria using organic carbon containing culture medium, and potentially act as a side-stream reactor to enhance the nitrification function of the wastewater treatment plant.
11
Bai, Xue, Haixin Gu e Yulong Li. "Coimmobilized Microalgae and Nitrifying Bacteria for Ammonium Removal". International Journal of Environmental Science and Development 7, n. 6 (2016): 406–9. http://dx.doi.org/10.7763/ijesd.2016.v7.809.
Testo completo
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Schramm, Andreas, Dirk de Beer, Johan C. van den Heuvel, Simon Ottengraf e Rudolf Amann. "Microscale Distribution of Populations and Activities ofNitrosospira and Nitrospira spp. along a Macroscale Gradient in a Nitrifying Bioreactor: Quantification by In Situ Hybridization and the Use of Microsensors". Applied and Environmental Microbiology 65, n. 8 (1 agosto 1999): 3690–96. http://dx.doi.org/10.1128/aem.65.8.3690-3696.1999.
Testo completoAbstract (sommario):
ABSTRACT The change of activity and abundance of Nitrosospiraand Nitrospira spp. along a bulk water gradient in a nitrifying fluidized bed reactor was analyzed by a combination of microsensor measurements and fluorescence in situ hybridization. Nitrifying bacteria were immobilized in bacterial aggregates that remained in fixed positions within the reactor column due to the flow regimen. Nitrification occurred in a narrow zone of 100 to 150 μm on the surface of these aggregates, the same layer that contained an extremely dense community of nitrifying bacteria. The central part of the aggregates was inactive, and significantly fewer nitrifiers were found there. Under conditions prevailing in the reactor, i.e., when ammonium was limiting, ammonium was completely oxidized to nitrate within the active layer of the aggregates, the rates decreasing with increasing reactor height. To analyze the nitrification potential, profiles were also recorded in aggregates subjected to a short-term incubation under elevated substrate concentrations. This led to a shift in activity from ammonium to nitrite oxidation along the reactor and correlated well with the distribution of the nitrifying population. Along the whole reactor, the numbers of ammonia-oxidizing bacteria decreased, while the numbers of nitrite-oxidizing bacteria increased. Finally, volumetric reaction rates were calculated from microprofiles and related to cell numbers of nitrifying bacteria in the active shell. Therefore, it was possible for the first time to estimate the cell-specific activity of Nitrosospira spp. and hitherto-uncultured Nitrospira-like bacteria in situ.
13
Bourgeois, François-René, Frédéric Monette e Daniel G. Cyr. "Operational modifications for the development of nitrifying bacteria in a large-scale biological aerated filter and its impact on wastewater treatment". Water Science and Technology 78, n. 8 (25 ottobre 2018): 1704–14. http://dx.doi.org/10.2166/wst.2018.447.
Testo completoAbstract (sommario):
Abstract To develop a better understanding for fixed biomass processes, the development of a nitrifying bacterial biofilm, as well as the performance of treatment during modifications to operational conditions of a full-scale submerged biological filter were examined. The development of the nitrifying biofilm was investigated at four depth levels (1, 2, 4 and 5 feet). The result of bacterial subpopulations analyzed by qPCR relative to the physico-chemical parameters of the wastewater during the various tests (sustained aeration, modified backwash parameters and inflow restriction) revealed an increase of the relative presence of nitrifying microorganisms throughout the biofilm (especially for nitrite oxidizing bacteria (NOB)), but this was not necessarily accompanied by a better nitrification rate. The highest observed nitrification rate was 49% of removal in the test cell during backwashing conditions, whereas the relative ammonia oxidizing bacteria (AOB) population was 0.032% and NOB was 0.008% of the total biomass collected. The highest percentage of nitrifying bacteria observed (0.034% AOB and 0.18% NOB) resulted in a nitrification rate of 21%. The treatment of organic matter determined by measuring the chemical and biochemical oxygen demand (COD, CBOD5) was improved.
14
Abeliovich, Aharon. "Nitrifying Bacteria in Wastewater Reservoirs". Applied and Environmental Microbiology 53, n. 4 (1987): 754–60. http://dx.doi.org/10.1128/aem.53.4.754-760.1987.
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Hill, Dennis R., e Terry Webster. "High pH Inhibits Nitrifying Bacteria". Opflow 34, n. 7 (luglio 2008): 20–22. http://dx.doi.org/10.1002/j.1551-8701.2008.tb02000.x.
Testo completo
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Cébron, Aurélie, Thierry Berthe e Josette Garnier. "Nitrification and Nitrifying Bacteria in the Lower Seine River and Estuary (France)". Applied and Environmental Microbiology 69, n. 12 (dicembre 2003): 7091–100. http://dx.doi.org/10.1128/aem.69.12.7091-7100.2003.
Testo completoAbstract (sommario):
ABSTRACT The Achères wastewater treatment plant, located just downstream of Paris, discharges its effluents into the lower Seine River. The effluents contain large numbers of heterotrophic bacteria, organic matter, and ammonium and are a source of nitrifying bacteria. As a result, degradation of organic matter by heterotrophic bacteria and subsequent oxygen depletion occur immediately downstream of the effluent outlet, whereas nitrifying bacteria apparently need to build up a significant biomass before ammonium oxidation significantly depletes the oxygen. We quantified the potential total nitrifying activity and the potential activities of the ammonia- and nitrite-oxidizing communities along the Seine River. In the summer, the maximum nitrifying activity occurs in the upper freshwater estuary,∼ 200 km downstream of Achères. The quantities of nitrifying bacteria, based on amoA gene copy numbers, and of Nitrobacter organisms, based on 16S rRNA gene copy numbers, were correlated with the potential nitrifying activities. The species composition of ammonia-oxidizing bacteria was investigated at two sites: the Triel station just downstream from Achères (km 84) and the Seine freshwater estuary at the Duclair station (km 278). By means of PCR primers targeting the amoA gene, a gene library was created. Phylogenetic analysis revealed that the majority of the analyzed clones at both sites were affiliated with the genus Nitrosomonas. The Nitrosomonas oligotropha- and Nitrosomonas urea-related clones represented nearly 81% of the community of ammonia-oxidizing bacteria at Triel and 60% at Duclair. Two other ammonia-oxidizing clusters of the β subclass of the Proteobacteria, i.e., Nitrosomonas europaea- and Nitrosospira-like bacteria, were found in smaller numbers. The major change in the ammonia-oxidizing community between the two stations along the Seine River-upper estuary continuum was the replacement of the N. oligotropha- and N. urea-related bacteria by the Nitrosospira-affiliated bacteria. Although the diversities of the ammonia oxidizers appear to be similar for the two sites, only half of the restriction patterns are common to both sites, which could be explained by the differences in ammonium concentrations, which are much lower in the upper estuary than in the river at the effluent outlet. These results imply a significant immigration and/or selection of the ammonia-oxidizing bacterial population along the continuum of the Seine River from Paris to the estuary.
17
Tsuneda, S., Y. Ejiri, T. Nagano e A. Hirata. "Formation mechanism of nitrifying granules observed in an aerobic upflow fluidized bed (AUFB) reactor". Water Science and Technology 49, n. 11-12 (1 giugno 2004): 27–34. http://dx.doi.org/10.2166/wst.2004.0796.
Testo completoAbstract (sommario):
The influences of trace metals in the wastewater and shear stress by aeration were particularly examined to clarify the formation mechanism of nitrifying granules in an aerobic upflow fluidized bed (AUFB) reactor. It was found that Fe added as a trace element to the inorganic wastewater accumulated at the central part of the nitrifying granules. Another result obtained was that suitable shear stress by moderate aeration (0.07-0.20 L/min/L-bed) promoted granulation. Furthermore, it was successfully demonstrated that pre-aggregation of seed sludge using hematite promoted core formation, leading to rapid production of nitrifying granules. From these results, a nitrifying granulation mechanism is proposed: 1) as a first step, nitrifying bacteria aggregate along with Fe precipitation, and then the cores of granules are formed; 2) as a second step, the aggregates grow to be spherical or elliptical in form due to multiplication of the nitrifying bacteria and moderate shear stress in the reactor, and then mature nitrifying granules are produced. Fluorescence in situ hybridization (FISH) analysis successfully visualized the change in the spatial distribution of nitrifying bacteria in the granules, which supports the proposed granulation mechanism.
18
Ding, Yuan Hong, Qing Wang, Hong Qiang Ren e Jian Lu. "Effects of Trichloroethylene on the Wastewater Treatment in Membrane Bioreactors". Advanced Materials Research 588-589 (novembre 2012): 34–38. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.34.
Testo completoAbstract (sommario):
The activities of nitrifying bacteria and organic utilizing bacteria against TCE in sludge was investigated using three series of Membrane bioreactors, and the results indicated that, the removal efficiencies of COD decreased gradually, but was not affected severely with TCE inhibition, good organics removal efficiencies was possibly realized, while the ammonia removal efficiencies dropped sharply due to the severe inhibition of TCE against nitrifying bacteria, the degree of TCE inhibition against nitrifying bacteria increased with the TCE concentration, but low-concentration TCE addition seems act as a chronic toxicity to the sludge activity, However, the nitrifying bacteria was gradually adapted to the TCE inhibition and its activities could be entirely resumed, and the ability of the nitrifying sludge to tolerate TCE could be satisfactory maintained either after the stop of TCE addition, therefore, TCE could be degradated partly by the nitrification processes, when the TCE was added intermittently and continuously into the Membrane reactors, simultaneously, a good performance of nitrification and organic utilization processes was possibly maintained stably.
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Kindaichi, Tomonori, Tsukasa Ito e Satoshi Okabe. "Ecophysiological Interaction between Nitrifying Bacteria and Heterotrophic Bacteria in Autotrophic Nitrifying Biofilms as Determined by Microautoradiography-Fluorescence In Situ Hybridization". Applied and Environmental Microbiology 70, n. 3 (marzo 2004): 1641–50. http://dx.doi.org/10.1128/aem.70.3.1641-1650.2004.
Testo completoAbstract (sommario):
ABSTRACT Ecophysiological interactions between the community members (i.e., nitrifiers and heterotrophic bacteria) in a carbon-limited autotrophic nitrifying biofilm fed only NH4 + as an energy source were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescence in situ hybridization (FISH). Phylogenetic differentiation (identification) of heterotrophic bacteria was performed by 16S rRNA gene sequence analysis, and FISH probes were designed to determine the community structure and the spatial organization (i.e., niche differentiation) in the biofilm. FISH analysis showed that this autotrophic nitrifying biofilm was composed of 50% nitrifying bacteria (ammonia-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) and 50% heterotrophic bacteria, and the distribution was as follows: members of the alpha subclass of the class Proteobacteria (α-Proteobacteria), 23%; γ-Proteobacteria, 13%; green nonsulfur bacteria (GNSB), 9%; Cytophaga-Flavobacterium-Bacteroides (CFB) division, 2%; and unidentified (organisms that could not be hybridized with any probe except EUB338), 3%. These results indicated that a pair of nitrifiers (AOB and NOB) supported a heterotrophic bacterium via production of soluble microbial products (SMP). MAR-FISH revealed that the heterotrophic bacterial community was composed of bacteria that were phylogenetically and metabolically diverse and to some extent metabolically redundant, which ensured the stability of the ecosystem as a biofilm. α- and γ-Proteobacteria dominated the utilization of [14C]acetic acid and 14C-amino acids in this biofilm. Despite their low abundance (ca. 2%) in the biofilm community, members of the CFB cluster accounted for the largest fraction (ca. 64%) of the bacterial community consuming N-acetyl-d-[1-14C]glucosamine (NAG). The GNSB accounted for 9% of the 14C-amino acid-consuming bacteria and 27% of the [14C]NAG-consuming bacteria but did not utilize [14C]acetic acid. Bacteria classified in the unidentified group accounted for 6% of the total heterotrophic bacteria and could utilize all organic substrates, including NAG. This showed that there was an efficient food web (carbon metabolism) in the autotrophic nitrifying biofilm community, which ensured maximum utilization of SMP produced by nitrifiers and prevented buildup of metabolites or waste materials of nitrifiers to significant levels.
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Okabe, S., e Y. Watanabe. "Structure and function of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes". Water Science and Technology 42, n. 12 (1 dicembre 2000): 21–32. http://dx.doi.org/10.2166/wst.2000.0232.
Testo completoAbstract (sommario):
Time dependent development of the spatial organization of NH4+- and NO2−-oxidizing bacterial populations in a domestic wastewater biofilm and in an autotrophic nitrifying biofilm were investigated by fluorescent in situ hybridization (FISH) with a set of 16S rRNA-targeted oligonucleotide probes. Population dynamics of nitrifying bacteria in the biofilms were correlated with the biofilm performance. In situ hybridization indicated that Nitrosomonas spp. (excluding probe NEU stained NH4+-oxidizing bacteria: i.e., N. marina-lineage, N. europaea-lineage, N. eutropha, and N. halophila) and Nitrospira-like bacteria were the numerically dominant nitrifying species in the domestic wastewater biofilm. However, probe NEU stained NH4+-inoxidizing bacteria became dominant populations in the autotrophic nitrifying biofilm (which were initially cultured with the primary settling tank effluent) after switching to the synthetic media. This population shift might be attributed to the effect of NO2−-–N accumulation and higher growth rates of N. europaea-lineage and N. eutropha, outcompeting other Nitrosomonas spp. in the synthetic medium. This evidence indirectly supports that N. europhaea has been most commonly isolated and studied in most of the previous researches. For the spatial organization of NH4+- and NO2−-oxidizing bacterial populations, bacteria of the genus Nitrobacter could not be detected, instead Nitrospira-like bacteria were found as the main nitrite-oxidizing bacteria in both biofilms. Whereas most of the ammonia-oxidizing bacteria were found throughout the biofilms, the location of nitrite-oxidizing bacteria was restricted to the active nitrite-oxidizing zone, which was detected in the inner part of the biofilms. Microelectrode measurements showed that the active ammonia-oxidizing zone was located in the outer part of a biofilm, whereas the active nitrite-oxidizing zone was located just below the ammonia-oxidizing zone and overlapped the location of NO2−-oxidizing bacteria, as determined with FISH. These observations have considerable significance to our understanding of microbial nitrification occurring in wastewater treatment processes and in the natural environment.
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Wang, Zhu, Bo Liu e Ai Min Li. "Effects of Adding Nitrifying Bacteria on Microbial Communities and Nitrification in a Laboratory-Scale a/O Reactor Treating Leather-Tanning Wastewater". Advanced Materials Research 599 (novembre 2012): 289–94. http://dx.doi.org/10.4028/www.scientific.net/amr.599.289.
Testo completoAbstract (sommario):
A laboratory-scale anoxic/oxic reactor was used to analyze the effects of adding nitrifying bacteria on microbial communities in the treatment of leather-tanning wastewater. The reactor was operated in series in continuous flow mode for 25 d after an acclimation period of 45 d, and the nitrifying bacteria were added after the acclimation period. The addition of nitrifying bacteria into the wastewater significantly enhanced NH4+-N removal efficiency. The Arrhenius and Jacob-Monod models were applied to determine the optimum and acceptable operating conditions for this process. The optimum temperature range and concentration of dissolved oxygen were 15-30 oC and 5 mg L-1, respectively. Use of Nitrosomonas europaea and Nitrobacter were considered reliable for leather-tanning wastewater treatment due to their dominant status as nitrifying bacteria. Substrate half-saturation constants for ammonia oxidizing bacteria and nitrite oxidizing bacteria were 24.13 mg L-1 and 5.43 mg L-1, respectively.
22
Daims, H., P. H. Nielsen, J. L. Nielsen, S. Juretschko e M. Wagner. "Novel Nitrospira-like bacteria as dominant nitrite-oxidizers in biofilms from wastewater treatment plants: diversity and in situ physiology". Water Science and Technology 41, n. 4-5 (1 febbraio 2000): 85–90. http://dx.doi.org/10.2166/wst.2000.0430.
Testo completoAbstract (sommario):
The frequency and distribution of putatively nitrite-oxidizing, Nitrospira- like bacteria in nitrifying biofilms from two reactors receiving wastewater with different ammonia and salt concentrations were observed by fluorescent in situ hybridization. For this purpose, new 16S rRNA-directed oligonucleotide probes targeting the bacterial phylum Nitrospira and the three main lineages within this phylum were developed and evaluated. The diversity of Nitrospira-like bacteria in the reactors was additionally investigated by retrieval and comparative analysis of full 16S rRNA sequences from the biofilms. We found that, despite of the differences in the influent composition, Nitrospira-like bacteria form dominant populations in both reactors. In addition, first insights into the physiology of these still unculturable bacteria were obtained by the incubation of active biofilm samples with radioactively labeled substrates followed by the combined application of fluorescent in situ hybridization and microautoradiography. The results are discussed in consideration of the frequently observed dominance of Nitrospira-like bacteria in nitrifying bioreactors. Consequently, high priority should be assigned to future studies on the ecology and physiology of these organisms in order to increase our fundamental understanding of nitrogen cycling and to enable knowledge-driven future improvements of nitrifying wastewater treatment plants.
23
Dong, Ziyi, Changhao Xiao, Weihua Zeng e Jinbo Zhao. "Impact of 17β-Estradiol on Natural Water’s Heterotrophic Nitrifying Bacteria". International Journal of Environmental Science and Development 12, n. 1 (2021): 17–22. http://dx.doi.org/10.18178/ijesd.2021.12.1.1312.
Testo completoAbstract (sommario):
In this research, bottom water samples were collected from nature water. After cultivating and selecting, bacteria which could use (NH4)2SO4 as the only nitrogen source had been selected. The bacteria in different cultures with different concentration of 17β-estradiol (E2) were cultivated, and every group’s concentration of N-NH4 +, N-NO3 - and OD600 were measured. The result shows that compare with the control group, in which no E2 was added, the growth of heterotrophic nitrifying bacteria had been promoted when the concentration of E2 was in range of 1-100 ng/L. In addition, heterotrophic nitrifying bacteria’s growing speed has a positive correlation between the E2’s concentration. However, low concentration of E2 (like 0.1 ng/L), could inhibit the growth of heterotrophic nitrifying bacteria. Considering the impact of E2 on heterotrophic nitrifying bacteria, it is necessary to intensify the detection to E2 in the future.
24
Hasebe, Yoshiaki, Hiroaki Meguro, Yuuki Kanai, Masahiro Eguchi, Toshifumi Osaka e Satoshi Tsuneda. "High-rate nitrification of electronic industry wastewater by using nitrifying granules". Water Science and Technology 76, n. 11 (7 settembre 2017): 3171–80. http://dx.doi.org/10.2166/wst.2017.431.
Testo completoAbstract (sommario):
Abstract Nitrifying granules have a high sedimentation property and an ability to maintain a large amount of nitrifying bacteria in a reaction tank. Our group has examined the formation process of nitrifying granules and achieved high-rate nitrification for an inorganic synthetic wastewater using these granules. In this research, a pilot-scale test plant with an 850-liter reaction tank was assembled in a semiconductor manufacturing factory in order to conduct a continuous water conduction test using real electronics industry wastewater. The aim was to observe the formation of nitrifying granules and determine the maximum ammonia removal rate. The average granule diameter formed during the experiment was 780 μm and the maximum ammonia removal rate was observed to be 1.5 kgN·m−3·day−1 at 20 °C, which is 2.5–5 times faster than traditional activated sludge methods. A fluorescence in situ hybridization analysis showed that β-proteobacterial ammonia oxidizing bacteria and the Nitrospira-like nitrite-oxidizing bacteria dominate the bacteria population in the granules, and their strong aggregation capacity might confer some benefits to the formation of these nitrifying granules.
25
Aswiyanti, I., I. Istiqomah e A. Isnansetyo. "Isolation and identification of nitrifying bacteria from tilapia (Oreochromis sp.) pond in Sleman Yogyakarta Indonesia". IOP Conference Series: Earth and Environmental Science 919, n. 1 (1 novembre 2021): 012054. http://dx.doi.org/10.1088/1755-1315/919/1/012054.
Testo completoAbstract (sommario):
Abstract This research aims to isolate and identify autochtonous nitrifying bacteria from tilapia pond in Sleman Yogyakarta Indonesia for future application in aquaculture practices in the region. Bacteria were isolated using a nitrification medium. Bacterial characterization was carried out by non-pathogenic test to tilapia (Oreochromis sp.), and nitrification activity test in a single bacterial fermentation medium for 9 days. Bacterial identification was carried out based on the colony and cell morphologies, biochemical tests, and molecular analysis using the 16S rRNA and gyrB genes. A total of 15 isolates of nitrifying bacteria were obtained. Four non-pathogenic isolates obtained the highest nitrification activity on the sixth day of incubation, with nitrate production of 17.26-21.54 ppm. Two selected bacteria, isolates A2 and A3, have colony morphology that is milky white, smooth surface, circular shape, entire edge, and convex elevation. Both bacteria are short rods, Gram-negative, non-motile, produce catalase, fermenting glucose, sucrose, and lactose, and do not produce oxidase, ornithine decarboxylase, indole, and H2S. Molecular analysis showed that the two isolates had the highest similarity (99.28% and 99.34%) to Klebsiella spp.
26
Rodríguez Rodríguez, Abad, Silvia Mau Inchaustegui, Lilliana Piedra Castro, Ricardo Jiménez Montealegre e Juan Pablo Herrera Vargas. "Isolation of ammonium- and nitrite-oxidizing bacterial strains from soil, and their potential use in the reduction of nitrogen in household waste water". Revista de Biología Tropical 65, n. 4 (19 settembre 2017): 1527. http://dx.doi.org/10.15517/rbt.v65i4.26509.
Testo completoAbstract (sommario):
Currently, nitrogen has become the main element of water pollution, causing riverine, lacustrine and coastal eutrophication. The continuous contamination of aquifers and the absence of planned water resource utilization, boost its scarcity, and has been the only way in which our societies become aware of the urgent need to process the generated wastewater. The objective of this research was to evaluate the nitrifying capacity of different autochthonous bacterial isolates from soils from nearby sources of domestic wastewater drainage. For this, bacteria were isolated from Pirro River, contaminated with nitrogen of domestic sewage. Nitrifying bacteria were counted by serial dilution and agar plates, and were isolated until obtaining axenic colonies. These were identified by biochemical batteries or genetic sequencing, and the quantification of their nitrifying capacity was obtained by the methods 4500- NH4 + -F and 4500-NO-2-B, all between September 26, 2011 and March 16, 2014. A total of seven strains of nitrifying microorganisms were isolated and purified, including four Streptomyces sp., one Pseudomonas putida, one Sphingomonas sp. and one Aeromonas sp. We found that there were 2.23 x 105 UFC/g of soil of ammonium oxidizing bacteria and 2.2 x 104 CFU/g of soil of nitrite oxidizing bacteria in the samples. The quantification of the nitrifying capacity of the strains by colorimetric methods, determined that the maximum ammonium removal capacity was 0.050 mg N/L/day and 0.903 mg N/L/day of nitrite. The collection of few strains of nitrifying organisms and a low CFU count, can be attributed to the technique used, since this only recovers 1 % of the microorganisms present in a sample, which, however, is acceptable for studies which main purpose is to obtain cultivable microorganisms. Future research should consider removal tests with higher ammonium and nitrite levels, to find the maximum capacity of the isolated microorganisms, and evaluate their potential use in wastewater treatment systems.
27
Fdz-Polanco, F., S. Villaverde e P. A. García. "Temperature effect on nitrifying bacteria activity in biofilters: activation and free ammonia inhibition". Water Science and Technology 30, n. 11 (1 dicembre 1994): 121–30. http://dx.doi.org/10.2166/wst.1994.0552.
Testo completoAbstract (sommario):
Nitrifying bacteria activity and concentrations depend on specific free ammonia concentration (ratio NH3/biomass), that is a function of temperature, pH, ammonium concentration and nitrifying biomass concentration. So, temperature is a key parameter in the nitrification process producing two opposite effects: bacteria activation and free ammonia inhibition. These phenomena are studied in an up-flow biological aerated filter (UBAF) settled by a nitrifying biofilm (measured as Volatile Attached Solids, VAS). The plug flow allows to disclosure of both effects, activation and inhibition. For Nitrosomonas bacteria only an activation effect was observed; their activity reaches a maximum at 28-29 °C. For Nitrobacter the free ammonia inhibition prevails against the activation effect for values greater than 1 mg N-NH3/mg VAS allowing nitrite accumulation of 80%; this inhibition threshold value for nitrifying biofilm is obtained measuring the specific rate of utilization of substratum per unit of biomass (μmax/Y) by activity test. The knowledge of this threshold in a biofilm process is fundamental in order to control the nitrite accumulation in nitrifying biofilm reactors.
28
Sirotkin, A. S., J. V. Kobeleva e E. S. Gorshkova. "Bio-Augmentation of Nitrifying Microorganisms to Increase the Efficiency of Oxidation of Nitrogen Compounds during Wastewater Biofiltration". Biotekhnologiya 36, n. 2 (2020): 99–107. http://dx.doi.org/10.21519/0234-2758-2020-36-2-99-107.
Testo completoAbstract (sommario):
The efficiency of nitrifying bacteria bio-augmentation into biofilm microbiocenosis during 30-day continuous biofiltration of municipal wastewater model solution has been assessed. The laboratory setup consisted of two parallel operating biofilters, in one of which, after start-up period, cultures of ammonium-oxidizing and nitrite-oxidizing bacteria of the Nitrobacter genus were sequentially introduced. It was established that the bio-augmentation of ammonium-oxidizing bacteria into the biofilm microbiocenosis led to an increase in the efficiency of ammonium nitrogen removal by an average of 1.6 times compared to the control biofilter. The subsequent bio-augmentation of nitrite-oxidizing bacteria caused an increase in the amount of nitrates in purified water by 2 times on average. As a result of bio-augmentation of nitrifying bacteria into the biofilm microbiocenosis, the nitrification process was intensified. Quantitative and qualitative identification of microorganisms via fluorescence in situ hybridization showed an increase in the number of nitrifying microorganisms in the biofilm of experimental biofilter, which confirms the efficiency of introduction of microorganisms and correlates with the data on biotransformation of nitrogen compounds. nitrifying microorganisms, wastewater biofiltration, biofilms, bio-augmentation, fluorescence in situ hybridization.
29
Jancarkova, Ivana, Tove A. Larsen e Willi Gujer. "Distribution of nitrifying bacteria in a shallow stream". Water Science and Technology 36, n. 8-9 (1 ottobre 1997): 161–66. http://dx.doi.org/10.2166/wst.1997.0660.
Testo completoAbstract (sommario):
A project investigating the dynamics of self-purification processes in a shallow stream is carried out. Effects of the concentration gradient due to the distance to the pollution source, of hydraulic conditions in the river bed and of storm floods on the distribution of nitrifying bacteria were studied with the help of laboratory and field experiments. Nitrifiers density on the surface of the stream bed increased rapidly up to a distance of 300 m from the WWTP indicating possible competition of the nitrifiers with the heterotrophic bacteria close to the WWTP. Afterwards a slight decrease in the downstream direction was observed. In vertical profiles, higher bacterial densities were found at sites with rapid infiltration of channel water to the stream bed than at sites with no exchange between channel water and stream bed water or where stream bed water exfiltrated. A major flood event scoured the nitrifiers nearly totally from the surface of the river bed. Major floods belong so to the most dominant processes controlling self-purification in shallow streams. Minor floods, however, don't scour bacteria in the depth of the stream bed that could then be important for the self-purification processes.
30
Tarre, S., M. Beliavski, N. Denekamp, A. Gieseke, D. de Beer e M. Green. "High nitrification rate at low pH in a fluidized bed reactor with chalk as the biofilm carrier". Water Science and Technology 49, n. 11-12 (1 giugno 2004): 99–105. http://dx.doi.org/10.2166/wst.2004.0814.
Testo completoAbstract (sommario):
A typical steady state bulk pH of about 5 was established in a nitrifying fluidized bed with chalk as the only buffer agent. In spite of the low pH, high rate nitrification was observed with the nitrification kinetic parameters in the chalk reactor similar to those of biological reactors operating at pH>7. Various methods were used to determine the reasons for high rate nitrification at such low pH including (i) determination of bacterial species, (ii) microsensor measurements in the biofilm, and (iii) comparison of nitrification performance at low pH with a non-chalk fluidized bed reactor. Fluorescence in situ hybridization (FISH) using existing 16S rRNA-targeted oligonucleotide probes showed common nitrifying bacteria in the low pH chalk reactor. The prevalent nitrifying bacteria were identified in the Nitrosomonas oligotropha, Nitrosomonas europeae/eutropha, Nitrosospira and Nitrospira related groups, all well known nitrifiers. Microelectrode measurements showed that the pH in the biofilm was low and similar to that of the bulk pH. Finally, reactor performance using a non-chalk biofilm carrier (sintered glass) with the same bacterial inoculum also showed high rate nitrification below pH 5. The results suggest that inhibition of nitrification at low pH is highly overestimated.
31
Acevedo, Juan Diego, e Jenny Dussán. "Ammonium Cycling and Nitrification Stimulation during Oil Sludge Remediation by Gram-Positive Bacteria Lysinibacillus sphaericus Using Red Wiggler Earthworm Eisenia fetida". AgriEngineering 2, n. 4 (13 novembre 2020): 544–55. http://dx.doi.org/10.3390/agriengineering2040036.
Testo completoAbstract (sommario):
The performance of a mixture between L. sphaericus and E. fetida was evaluated for ammonium cycling and nitrifying bacteria stimulation during oil sludge remediation. The addition of E. fetida significantly increased ammonium concentration (p = 0.0218) and total Colony-forming units (CFU) count p = 0.02848). However, oil sludge with worms and L. sphaericus reached lower ammonium concentrations and CFU counts than sludge with worms alone. Sludge inoculated only with L. sphaericus presented higher ammonium concentration than sludge without inoculum, but the bacterial population reached a lower density during the final days. Final DNA and RNA extractions from all treatments amplified for L. sphaericus putative amoA and Gram-negative nitrifying bacteria amoA genes correlated with diminished ammonium concentrations during the final days of the experiment. Final RNA extractions for L. sphaericus amplified for Molybdenum transporter gene suggesting possible nitrogen fixation by L. sphaericus. The addition of Red Wiggler Earthworm to oil sludge remediation systems may provide better conditions for bacterial populations to carry out hydrocarbon degradation. The addition of E. fetida to a L. sphaericus crude oil biodegradation system may improve soil ammonium concentrations and nitrifying activity, and this could be crucial in oil sludge remediation because of bacterial inhibition due to high C:N ratios. The final product of this process may be used for soil enhancement due to its richness in nutrients and beneficial bacterial populations.
32
Okabe, Satoshi, Hisashi Satoh e Yoshimasa Watanabe. "In Situ Analysis of Nitrifying Biofilms as Determined by In Situ Hybridization and the Use of Microelectrodes". Applied and Environmental Microbiology 65, n. 7 (1 luglio 1999): 3182–91. http://dx.doi.org/10.1128/aem.65.7.3182-3191.1999.
Testo completoAbstract (sommario):
ABSTRACT We investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in domestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (FISH) performed with 16S rRNA-targeted oligonucleotide probes. The combination of these techniques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. In situ hybridization revealed that bacteria belonging to the genus Nitrosomonas were the numerically dominant ammonia-oxidizing bacteria in both types of biofilms. Bacteria belonging to the genus Nitrobacter were not detected; instead, Nitrospira-like bacteria were the main nitrite-oxidizing bacteria in both types of biofilms. Nitrospira-like cells formed irregularly shaped aggregates consisting of small microcolonies, which clustered around the clusters of ammonia oxidizers. Whereas most of the ammonia-oxidizing bacteria were present throughout the biofilms, the nitrite-oxidizing bacteria were restricted to the active nitrite-oxidizing zones, which were in the inner parts of the biofilms. Microelectrode measurements showed that the active ammonia-oxidizing zone was located in the outer part of a biofilm, whereas the active nitrite-oxidizing zone was located just below the ammonia-oxidizing zone and overlapped the location of nitrite-oxidizing bacteria, as determined by FISH.
33
Gnida, Anna, Sebastian Żabczyński e Joanna Surmacz-Górska. "Filamentous bacteria in the nitrifying activated sludge". Water Science and Technology 77, n. 11 (14 maggio 2018): 2709–13. http://dx.doi.org/10.2166/wst.2018.215.
Testo completoAbstract (sommario):
Abstract Filamentous bacteria in addition to wastewater treatment are responsible for the shape of flocs and sedimentation properties of activated sludge. Their dynamics in activated sludge influences the performance of the whole sewage treatment plant. Therefore the composition of activated sludge biocenosis and its dynamics in the nitrification process were investigated. Four laboratory-scale activated sludge membrane bioreactors fed with wastewater highly concentrated with ammonium (synthetic wastewater imitating landfill leachate) were operated to obtain a high rate of nitrification. The sludge age was 8, 12, 24 and 32 days. An additional fifth reactor was conventionally ammonium loaded at 12-day sludge age and served as the reference. A shift in filamentous bacteria population was observed in all operated reactors. There was no influence of sludge age on composition or abundance of filamentous biocenosis. In high ammonium loaded activated sludge Nostocoida limicola, Haliscomenobacter hydrossis and also Type 021N were the most abundant filamentous bacteria. In the reference reactor Type 021N and Sphaerotilus natans dominated the activated sludge.
34
Umiyati, Uum. "Allelopathic Inhibition of Nitrifying Bacteria by Legumes". Journal of Tropical Soils 22, n. 2 (1 maggio 2017): 125–30. http://dx.doi.org/10.5400/jts.2017.v22i2.125-130.
Testo completoAbstract (sommario):
The study aimed at understanding the competitive ability of legumes Vigna radiata L. and Mucuna pruriens with weeds and their effects on the activity of nitrifying bacteria in soils and the contents of organic-N in legumes and weeds. The experiment was arranged in a randomized block design with three factors and four replications. The first factor was soil order, i.e. Inceptisol and Vertisol; the second factor was types of legumes, i.e. Vigna radiata L. cultivar Sriti and Mucuna pruriens; and the third factor was weed management, i.e. with weed management and without weed management. The results showed that Vigna radiata L. and Mucuna pruriens indirectly influence the supply of available nitrogen in soils that can be taken up by the coexisted plants or weeds via the inhibition of the growth of Nitrosomonas and Nitrobacter in soils. As a results, the organic-N content in weeds decreases, which is in contrast to the increasing amount of organic-N in Vigna radiata L. and Mucuna pruriens. The results indicated that Vigna radiata L. and Mucuna pruriens are considered as allelophatic legumes, resulting in low organic-N content in weeds. Keywords: Allelopathic, Mucuna pruriens, Nitrosomonas, Nitrobacter, Vigna radiata
35
Lee, Yong-Woo, Say-Kee Ong e Chikashi Sato. "Effects of heavy metals on nitrifying bacteria". Water Science and Technology 36, n. 12 (1 dicembre 1997): 69–74. http://dx.doi.org/10.2166/wst.1997.0432.
Testo completoAbstract (sommario):
Laboratory evaluations were conducted to study the toxic responses of heavy metals such as copper and nickel of an autotrophic culture of strict nitrifiers (Nitrosomonas sp. and Nitrobacter sp.) in continuous flow stirred tank reactors (CSTR). One of the CSTRs was operated as a suspended growth (SG) system while the other was operated as an attached & suspended growth (A&SG) system. Nitrification inhibition in a SG and A&SG systems was investigated with the emphasis on the effect of shock loading of copper and nickel. As a result of the copper and nickel test, Nitrosomonas sp. was found to be equally or more sensitive than Nitrobacter sp. However, a higher influent nickel concentration of 50 mg/L was needed to cause a similar percent inhibition of ammonium oxidation than the copper concentration of 5 mg/L. A geochemical equilibrium speciation model, MINTEQA2/PRODEFA2, was used to compute the concentrations of various chemical species present in the wastewater for both systems. The high correlations of Cu(NH3)4+2 and Ni(NH3)4+2 with percent inhibition were found and it was thought that they were probably the species responsible for the inhibition of ammonia oxidation.
36
Stein, Lisa Y., e Martin G. Klotz. "Nitrifying and denitrifying pathways of methanotrophic bacteria". Biochemical Society Transactions 39, n. 6 (21 novembre 2011): 1826–31. http://dx.doi.org/10.1042/bst20110712.
Testo completoAbstract (sommario):
Nitrous oxide, a potent greenhouse gas and ozone-depleting molecule, continues to accumulate in the atmosphere as a product of anthropogenic activities and land-use change. Nitrogen oxides are intermediates of nitrification and denitrification and are released as terminal products under conditions such as high nitrogen load and low oxygen tension among other factors. The rapid completion and public availability of microbial genome sequences has revealed a high level of enzymatic redundancy in pathways terminating in nitrogen oxide metabolites, with few enzymes involved in returning nitrogen oxides to dinitrogen. The aerobic methanotrophic bacteria are particularly useful for discovering and analysing diverse mechanisms for nitrogen oxide production, as these microbes both nitrify (oxidize ammonia to nitrite) and denitrify (reduce nitrate/nitrite to nitrous oxide via nitric oxide), and yet do not rely on these pathways for growth. The fact that methanotrophs have a rich inventory for nitrogen oxide metabolism is, in part, a consequence of their evolutionary relatedness to ammonia-oxidizing bacteria. Furthermore, the ability of individual methanotrophic taxa to resist toxic intermediates of nitrogen metabolism affects the relative abundance of nitrogen oxides released into the environment, the composition of their community, and the balance between nitrogen and methane cycling.
37
Naghdi, Mitra, Maximiliano Cledon, Satinder Kaur Brar e Antonio Avalos Ramirez. "Nitrification of vegetable waste using nitrifying bacteria". Ecological Engineering 121 (ottobre 2018): 83–88. http://dx.doi.org/10.1016/j.ecoleng.2017.07.003.
Testo completo
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Wang, Guangyu, Lei Chen, Fang Ma, Zhong Xu e Weiguo Li. "Screening and identification of marine nitrifying bacteria". Journal of Biotechnology 136 (ottobre 2008): S550. http://dx.doi.org/10.1016/j.jbiotec.2008.07.1293.
Testo completo
39
Manser, R., W. Gujer e H. Siegrist. "Membrane bioreactor versus conventional activated sludge system: population dynamics of nitrifiers". Water Science and Technology 52, n. 10-11 (1 novembre 2005): 417–25. http://dx.doi.org/10.2166/wst.2005.0719.
Testo completoAbstract (sommario):
Although membrane bioreactors have attracted increasing attention in recent years, little research has been undertaken on the influence of the membrane separation on the microbial community composition. This paper compares the startup behaviour and the performance of the subsequent eight months of a membrane bioreactor with a conventional activated sludge pilot plant. Both plants were operated in parallel at the same sludge age and treated the same domestic wastewater. The identification of the nitrifying community composition using fluorescent in situ hybridization revealed only minor differences between the two reactors for both ammonia-oxidizing bacteria and nitrite-oxidizing bacteria. Accordingly, both systems exhibited the same maximum nitrification rates. Confocal laser scanning microscopy showed that the aggregates formed by nitrifying bacteria were located mostly in the inner part of the flocs and were overgrown by heterotrophic bacteria. It is concluded that the membrane separation itself does affect neither the nitrifying community composition nor the nitrification performance. However, impacts on kinetic parameters are emphasized.
40
Jiao, Y., W. B. Jin, Q. L. Zhao, G. D. Zhang, Y. Yan e J. Wan. "Transformation of nitrogen and distribution of nitrogen-related bacteria in a polluted urban stream". Water Science and Technology 60, n. 6 (1 settembre 2009): 1597–605. http://dx.doi.org/10.2166/wst.2009.502.
Testo completoAbstract (sommario):
Most researchers focused on either nitrogen species or microbial community for polluted urban stream while ignoring the interaction between them and its effect on nitrogen transformation, which restricted the rational selection of an effective and feasible remediation technology. Taking Buji stream in Shenzhen (China) as target stream, the distribution of nitrogen-related bacteria was investigated by most probable number (MPN) besides analysis of nitrogen species etc. The nitrogen-related bacteria in sediment were 102 times richer than those in water. Owing to their faster growth, the MPN of ammonifying bacteria and denitrifying bacteria were 105 and 102 times higher than those of nitrifying bacteria, respectively. The ammonifying bacteria numbers were significantly related to BOD5 in water, while nitrifying bacteria in sediment correlated well with nitrate in water. Thus, nitrification occurred mainly in sediment surface and was limited by low proportion of nitrifying bacteria. The denitrifying bacteria in sediment had good relationship with BOD5 and nitrite and nitrate in water. Low DO and rich organic compounds were beneficial to denitrification but unfavourable to nitrification. Denitrification was restricted by low nitrite and nitrate concentration. These results could be served as a reference for implementing the remediation scheme of nitrogen polluted urban stream.
41
Hu, T. L., e K. T. Kung. "Study of heterotrophic nitrifying bacteria from wastewater treatment systems treating acrylonitrile, butadiene and styrene resin wastewater". Water Science and Technology 42, n. 3-4 (1 agosto 2000): 315–21. http://dx.doi.org/10.2166/wst.2000.0397.
Testo completoAbstract (sommario):
In this study we investigated the population of heterotrophic nitrifying bacteria in three biological wastewater treatment systems treating acrylonitrile, butadiene and styrene (ABS) resin wastewater. In addition to isolating and identifying these bacteria, we examined the physiological properties of the isolates, particularly utilization of acrylonitrile and its derivatives. An enrichment process was employed to isolate heterotrophic nitrifying bacteria from sludge samples taken from three biological wastewater treatment systems. Thirteen isolates were obtained and four strains were identified as Alcaligenes sp., Acinetobacter sp., Xanthomonas sp. and Corynebacterium sp. Alcaligenes sp. and Corynebacterium sp. have already been reported as heterotrophic nitrifiers. To our knowledge, this is the first time Acinetobacter sp. and Xanthomonas sp. have been reported as heterotrophic nitrifiers. The heterotrophic nitrifying isolates used acrylonitrile and acrylamide as the sole carbon and nitrogen sources. Moreover, adding an extra carbon source enhanced the nitrification rate.
42
Tanaka, Kazuhiro, Minoru Tada, Takashi Kimata, Shouji Harada, Yuhko Fujii, Tamotu Mizuguchi, Naomichi Mori e Hiroyoshi Emori. "Development of New Nitrogen Removal System Using Nitrifying Bacteria Immobilized in Synthetic Resin Pellets". Water Science and Technology 23, n. 4-6 (1 febbraio 1991): 681–90. http://dx.doi.org/10.2166/wst.1991.0518.
Testo completoAbstract (sommario):
A newly developed process applying a technique of microorganism immobilization to biological nitrogen removal is reported. Nitrifiers immobilized in 2 to 3 mm diameter polyethylene-glycol resin (Nitrifying pellets) are mixed with activated sludge in the nitrification tanks to promote quick nitrification. Due to the high nitrifying activity of the pellets, nitrification of municipal wastewaters is completed within a few hours. This paper introduces the synthetic polymer and immobilization method suited to nitrifiers, the conditions for pellet fluidization, the activity of nitrifying pellets and its treatment performance as a nitrogen removal process.
43
Xu, Jinlan, Haiyang Zhang, Rong Zhao e Fanxing Kong. "Enhanced bacterial quorum aggregation on a zeolite capping layer for sustainable inhibition of ammonium release from contaminated sediment". Water Science and Technology 76, n. 12 (27 settembre 2017): 3428–40. http://dx.doi.org/10.2166/wst.2017.507.
Testo completoAbstract (sommario):
Abstract The main objective of this study was to investigate how signal molecules enhance bacterial quorum aggregation on a zeolite capping layer for sustainable inhibition of ammonium release from contaminated sediment. Sediment remediation experiments were carried out by using nitrifying bacteria (WGX10, WGX18), denitrifying bacteria (HF3, HF7) and two kinds of signal molecules (OHHL, C8-HSL). The results showed that nitrifying bacteria and denitrifying bacteria could significantly aggregate on zeolite after adding 1.0 μM OHHL at a C/N ratio of 7. The maximum ammonium removal of five times the amount of ammonium adsorbed was achieved when 1.0 μM OHHL was added at the C/N ratio of 7 (the bio-regeneration rate was up to 88.32%), which was 1.24–2.02 times the ammonium removal amount at C/N ratios of 3, 5, 9. The concentration of total nitrogen in the overlying water was no more than 0.8 mg/L during four rounds of sediment remediation experiments. In addition, the bio-regeneration rate was up to 71.20%, which achieved sustainable inhibition of ammonium release from contaminated sediment.
44
Ikuesan, Felix Adeleke, Iyanu Ehuwa e Bartholomew Saanu Adeleke. "‘Petroleum derivatives’ toxicity: influence on the growth of soil nitrifying bacteria". Dutse Journal of Pure and Applied Sciences 8, n. 3b (14 ottobre 2022): 44–54. http://dx.doi.org/10.4314/dujopas.v8i3b.5.
Testo completoAbstract (sommario):
Over dependence on crude oil and its derivatives to drive our daily activities for energy and economy results in frequent discharge of petrochemicals into the environment causing pollution of varying magnitude with worrisome ecological and environmental impact of global concern. This study aimed to determine the toxicity of petroleum derivatives on soil nitrifying bacteria. Soil samples were collected into sterile polythene bag and transported to the laboratory for analyses. Microbiological analyses of the soil samples were performed using conventional and standard microbiological techniques. Kerosene, diesel and petrol at 1%, 3%, 5% and 10% concentrations were used as toxicants on nitrogen-fixing bacteria. Results revealed the mean counts of 2.7 x 107 (CFU/g), 4.3 x 106 (CFU/g), 8.7 x 104 (CFU/g) and 1.2 x 103 CFU/g of total heterotrophic bacteria, bacterial growth on Okon red, Ashby medium and Yeast extract mannitol agar respectively. The identities of nitrifying bacteria were Azospirillum spp., Azotobacter spp. and Rhizobium spp. Toxicity results revealed that while Azospirillum spp. exhibited complete cell death to petrol from 3%, all the other bacteria showed log survival of 70.29 – 86% to the toxicants and Azospirillum, spp., Azotobacter spp. and Rhizobium spp. had 76.63%, 79.63% and 86% log survival to diesel and 77.76%, 79.63 and 77.6% respectively to kerosene. Significant difference (p-value = 0.000) was observed among the three toxicants across all concentration levels. Therefore, this study concludes that petroleum derivatives are toxic to nitrifying bacteria at any concentration and the microbial response is dependent on concentration and hydrocarbon types. Soil contaminated with petroleum derivatives should of necessity be treated in order to ameliorate the consequences of pollution and restore soil productive capacity.
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Yosmaniar, Yosmaniar, Hessy Novita e Eri Setiadi. "ISOLASI DAN KARAKTERISASI BAKTERI NITRIFIKASI DAN DENITRIFIKASI SEBAGAI KANDIDAT PROBIOTIK". Jurnal Riset Akuakultur 12, n. 4 (18 gennaio 2018): 369. http://dx.doi.org/10.15578/jra.12.4.2017.369-378.
Testo completoAbstract (sommario):
Senyawa nitrogen yang tinggi pada limbah budidaya perikanan intensif dapat memperburuk kualitas air, sehingga perlu diatasi dengan penambahan probiotik untuk proses bioremediasi. Tujuan penelitian ini adalah untuk mendapatkan bakteri nitrifikasi dan denitrifikasi yang berpotensi sebagai kandidat probiotik pengendali senyawa nitrogen pada budidaya ikan air tawar. Tahap penelitian terdiri atas: 1) koleksi sampel air dan sedimen dari kolam budidaya ikan patin di kawasan minapolitan Desa Pudak Kecamatan Kumpeh Kabupaten Muaro Jambi Provinsi Jambi dan Desa Koto Mesjid Kecamatan XIII Koto Kampar Kabupaten Kampar Provinsi Riau; 2) pengujian sampel secara in vitro yang meliputi: a) Isolasi dan seleksi bakteri nitrifikasi dan denitrifikasi; b) Karakterisasi morfologis bakteri terpilih; c) Karakterisasi fisiologi/biokimia isolat bakteri terpilih; d) Karakterisasi genetika isolat bakteri terpilih dengan sekuensing 16S-rRNA. Analisis data dilakukan secara deskriptif. Berdasarkan hasil penelitian diperoleh empat isolat bakteri nitrifikasi dan empat isolate bakteri denitrifikasi. Isolat bakteri nitrifikasi Pandoraea pnomenusa strain 1318 (NP1); Pseudomonas aeruginosa strain PSE12 (NP2); Pseudomonas aeruginosa strain PSE12 (NP3); Burkholderia vietnamiensis strain NE 7 (NP4); dan denitrifikasi Achromobacter xylosoxidans strain TPL14 (DP1); Stenotrophomonas acidaminiphila strain BTY (DP2); Stenotrophomonas maltophilia strain BHWSL2 (DP3); Ochrobactrum intermedium strain: SQ 20 (DP4) Achromobacter xylosoxidans strain TPL14 (DP1); Stenotrophomonas acidaminiphila strain BTY (DP2); Stenotrophomonas maltophilia strain BHWSL2 (DP3); Ochrobactrum intermedium strain: SQ 20 (DP4); yang berpotensi digunakan sebagai kandidat probiotik pengendali senyawa nitrogen pada budidaya ikan air tawar. Wastes from an intensive aquaculture contain nitrogen compounds which, if untreated, could rapidly reduce water quality condition within the system. The addition of probiotics as bioremediation to aquaculture system has been used to improve water quality with promising results. The aim of this study was to obtain potential nitrifying and denitrifying bacteria that could be used as probiotic candidates to control excessive nitrogen compounds in freshwater culture. This study consisted of two steps, 1) the collection of water samples and sediments from catfish ponds at ‘Minapolitan Area” in Pudak Village, Jambi Province and Koto Mesjid Village, Riau Province; 2) in vitro tests consisting of isolation and selection of nitrifying and denitrifying bacteria; morphological characterization of the selected nitrifying and denitrifying bacteria; characterization of physiological/biochemical selected nitrifying and denitrifying bacteria; genetic characterization of the selected nitrifying and denitrifying bacteria with 16SrRNA sequencing. All data were analyzed descriptively. The study had found four nitrifying bacteria isolates: Pandoraea pnomenusa strain 1318 (NP1); Pseudomonas aeruginosa strain PSE 12 (NP2); Pseudomonas aeruginosa strain PSE12 (NP3); Burkholderia vietnamiensis strain NE 7 (NP4). The study also found four isolates of denitrifying bacteria isolates: Achromobacter xylosoxidans strain TPL14 (DP1); Stenotrophomonas acidaminiphila strain BTY (DP2); Stenotrophomonas maltophilia strain BHWSL2 (DP3); Ochrobactrum intermedium strain: SQ 20 (DP4). All the identified nitrifying and denitrifying bacteria isolates have the potential to be used as probiotic candidates to control nitrogen compound in freshwater aquaculture.
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Placella, Sarah A., e Mary K. Firestone. "Transcriptional Response of Nitrifying Communities to Wetting of Dry Soil". Applied and Environmental Microbiology 79, n. 10 (22 marzo 2013): 3294–302. http://dx.doi.org/10.1128/aem.00404-13.
Testo completoAbstract (sommario):
ABSTRACTThe first rainfall following a severe dry period provides an abrupt water potential change that is both an acute physiological stress and a defined stimulus for the reawakening of soil microbial communities. We followed the responses of indigenous communities of ammonia-oxidizing bacteria, ammonia-oxidizing archaea, and nitrite-oxidizing bacteria to the addition of water to laboratory incubations of soils taken from two California annual grasslands following a typically dry Mediterranean summer. By quantifying transcripts for a subunit of bacterial and archaeal ammonia monooxygenases (amoA) and a bacterial nitrite oxidoreductase (nxrA) in soil from 15 min to 72 h after water addition, we identified transcriptional response patterns for each of these three groups of nitrifiers. An increase in quantity of bacterialamoAtranscripts was detectable within 1 h of wet-up and continued until the size of the ammonium pool began to decrease, reflecting a possible role of transcription in upregulation of nitrification after drought-induced stasis. In one soil, the pulse ofamoAtranscription lasted for less than 24 h, demonstrating the transience of transcriptional pools and the tight coupling of transcription to the local soil environment. Analysis of 16S rRNA using a high-density microarray suggested that nitrite-oxidizingNitrobacterspp. respond in tandem with ammonia-oxidizing bacteria while nitrite-oxidizingNitrospinaspp. andNitrospirabacteria may not. Archaeal ammonia oxidizers may respond slightly later than bacterial ammonia oxidizers but may maintain elevated transcription longer. Despite months of desiccation-induced inactivation, we found rapid transcriptional response by all three groups of soil nitrifiers.
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Tanaka, Y., K. Taguchi e H. Utsumi. "Toxicity assessment of 255 chemicals to pure cultured nitrifying bacteria using biosensor". Water Science and Technology 46, n. 11-12 (1 dicembre 2002): 331–35. http://dx.doi.org/10.2166/wst.2002.0758.
Testo completoAbstract (sommario):
The bioassay has been attracting attention as a method of toxicity assessments of micropollutants in the environment. In this study, we report the characteristics (selectivity and sensitivity) of the nitrifying bacteria biosensor for 255 kinds of chemicals as a model of chemical contaminant in the environment and the results of evaluation of mixed samples of several substances. In the nitrifying bacteria respiration inhibition test using the biosensor, 56 chemicals were detected. It was found that this biosensor is especially sensitive to seven chemicals that have a thiocarbonyl functional group (>C=S), such as a thioamide group of thiocarbamate group. These chemicals are considered to specifically inhibit AMO by chelation of copper. The samples consisted of a mixture of seven types of anilines that inhibit respiration in the bacteria, a mixture of five types of chlorophenols, and a mixture of eight types of substances that contain thiocarbonyl groups were examined. All of the mixed samples inhibited the respiration of the nitrifying bacteria more than 10% by the inhibition rate, and observed a synergistic effects of the substances in the samples.
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Fu, Jinxiang, Zhe Zhang e Jinghai Zhu. "Study on the diversity of denitrification bacteria treating with wastewater by using PPGC filler on SBMBBR at low temperature". E3S Web of Conferences 158 (2020): 04002. http://dx.doi.org/10.1051/e3sconf/202015804002.
Testo completoAbstract (sommario):
Aiming at the problem of the low removal efficiency of biological nitrogen-removing of low temperature waste-water, using Polyurethane Porous Gel Carrier (PPGC)-SBMBBR treated low temperature sewage, in compared with conventional SBR,and viaing Miseq high-throughput sequencing technology in analysis of the differences of microbial diversity and abundance of structure on the two reactors of activated sludge, revealed dominant nitrogen-removing bacterium improving the treatment efficiency of low temperature sewage. The results shows that the removal efficiency of the effluent nitrogen and the sludge sedimentation rate of (PPGC)-SBMBBR reactor are significantly improved under the water temperature (6.5±1℃). Adding the filler can contribute to improvement of bacterial diversity and relative abundance of nitrification and denitrification bacterium in the activated sludge system. The main relative abundance of ammonia oxidizing bacteria (AOB),nitrite oxidizing bacteria (NOB),anaerobic denitrifying bacteria, and aerobic denitrifying bacteria in (PPGC)-SBMBBR(R2) are significantly better than SBR (R1),and the R2 reactor can independently enrich the nitrifying bacteria and the aerobic denitrifying bacteria, such as Nitrospira, Hydrogens, Pseudomonas, and Zoogloea. The total relative abundance of dominant and nitrifying denitrifying bacterium increases from 28.65% of R1 to 60.23% of R2, providing a microbiological reference for improving the efficiency of biological nitrogen removal in low temperature waste-water.
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Zhang, Ji Ku, Hui Ting Shao, Yue Ming e Hui Ye Wang. "Study on Biofortification in Vertical Flow Constructed Wetland". Advanced Materials Research 955-959 (giugno 2014): 2570–73. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2570.
Testo completoAbstract (sommario):
The methods of dosing composite microbial inoculants are used in vertical flow constructed wetlands for biofortification. The removal of the main pollution indicators by substrate microorganisms was studied. The results show that compared with the blank system, the number of bacteria and nitrifying bacteria was higher in the substrate of constructed wetland by biofortification. At the hydraulic loading rate (HLR) of about 0.8 m3/(m2·d), relationship between total number of bacteria and the removal rate of COD was significant in Device A and Device B. Relationship with TP removal rate is not evident. Correlation between the number of nitrifying bacteria and TN removal rate was obvious. The biofortification is feasible on technology and economy.
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Prastowo, Bambang Widyo, Manja Meyky Bond e Betutu Senggagau. "Perbandingan Sistem Resirkulasi dan Air Mengalir Untuk Pembesaran Lobster Pasir (Panulirus Homarus): Kajian Dinamika Kualitas Air". Barakuda 45: Jurnal Ilmu Perikanan dan Kelautan 4, n. 1 (28 aprile 2022): 12–23. http://dx.doi.org/10.47685/barakuda45.v4i1.205.
Testo completoAbstract (sommario):
Aquaculture with the Recirculation Aquaculture System (RAS) is a unique engineered ecosystem that minimizes environmental disturbances by reducing the discharge of nutrient pollution through reuse of water used in fish farming. This activity was conducted at LP2IL Serang field test facility starting in June-November 2020. In this test, the RAS system used for growing of sand lobster uses the stages of purification: sedimentation, physical filtration, biological filtration, water disinfection with UV irradiation, removal of CO2, clean water reservoirs and sand lobster rearing tanks. Water quality parameters tested: a) physics: DO, pH, temperature and salinity are measured every day; b) chemistry: ammonia (TAN and UIA), nitrite, nitrate and phosphate are measured every two weeks. If from the UIA value calculation, the value is above the quality standard (> 0.05 mg / L) then added molasses (26.02% organic C) with a concentration of 64 gr / gr TAN; c) microbiology: total bacteria and Vibrio sp. counting. From the results of this study it is known that RAS can maintain stable water quality for a relatively long time. High availability of organic matter (from leftover feed, feces and addition of molasses) can promote the growth of nitrifying bacteria. The "maturation" of the nitrifying bacteria in the biofilter compartment takes about 6 weeks. These bacteria are able to reduce levels of ammonium nitrogen, where the accumulation of nitrate nitrogen (NO3-) which is produced from the overhaul of nitrite nitrogen (NO2-) by nitrifying bacteria, is a signal that the maturation process of nitrifying bacteria has been achieved. The nitrification process consumes alkalis, hence lowers the pH value in the water, besides it also consumes a large amount of oxygen. The low number of bacteria and vibrio in the RAS system was affected by the use of a UV-sterilizer with a wavelength of 254 nm.