scholarly journals Isolation of ammonium- and nitrite-oxidizing bacterial strains from soil, and their potential use in the reduction of nitrogen in household waste water

2017 ◽  
Vol 65 (4) ◽  
pp. 1527 ◽  
Author(s):  
Abad Rodríguez Rodríguez ◽  
Silvia Mau Inchaustegui ◽  
Lilliana Piedra Castro ◽  
Ricardo Jiménez Montealegre ◽  
Juan Pablo Herrera Vargas
Keyword(s):  
Domestic Wastewater ◽  
Household Waste ◽  
Nitrifying Bacteria ◽  
Main Element ◽  
Future Research ◽  
Bacterial Strains ◽  
Genetic Sequencing ◽  
Removal Capacity ◽  
Nitrite Oxidizing Bacteria ◽  
Potential Use

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.

Structure and function of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes

2000 ◽  
Vol 42 (12) ◽  
pp. 21-32 ◽  
Author(s):  
S. Okabe ◽  
Y. Watanabe
Keyword(s):  
In Situ Hybridization ◽  
Spatial Organization ◽  
Settling Tank ◽  
Outer Part ◽  
Domestic Wastewater ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Bacterial Populations ◽  
Nitrite Oxidizing Bacteria

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.

scholarly journals Isolation and characterization of bacterial strains with a hydrolytic profile with potential use in bioconversion of agroindustial by-products and waste

2013 ◽  
Vol 33 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Cintia Anabela Mazzucotelli ◽  
Alejandra Graciela Ponce ◽  
Catalina Elena Kotlar ◽  
María del Rosario Moreira
Keyword(s):  
Bacterial Strains ◽  
Isolation And Characterization ◽  
By Products ◽  
Potential Use

scholarly journals Operational modifications for the development of nitrifying bacteria in a large-scale biological aerated filter and its impact on wastewater treatment

2018 ◽  
Vol 78 (8) ◽  
pp. 1704-1714 ◽  
Author(s):  
François-René Bourgeois ◽  
Frédéric Monette ◽  
Daniel G. Cyr
Keyword(s):  
Large Scale ◽  
Oxygen Demand ◽  
Bacterial Biofilm ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Total Biomass ◽  
Ammonia Oxidizing Bacteria ◽  
Operational Conditions ◽  
Nitrite Oxidizing Bacteria ◽  
Aerated Filter

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.

scholarly journals Investigating the chemolithoautotrophic and formate metabolism of Nitrospira moscoviensis by constraint-based metabolic modeling and 13C-tracer analysis

2021 ◽  
Author(s):  
Christopher E. Lawson ◽  
Aniela B. Mundinger ◽  
Hanna Koch ◽  
Tyler B. Jacobson ◽  
Coty A. Weathersby ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Metabolic Networks ◽  
Metabolic Model ◽  
Scale Model ◽  
Nitrifying Bacteria ◽  
Metabolomic Analysis ◽  
A Genome ◽  
Nitrite Oxidizing Bacteria ◽  
Genome Scale ◽  
Nitrospira Moscoviensis

AbstractNitrite-oxidizing bacteria belonging to the genus Nitrospira mediate a key step in nitrification and play important roles in the biogeochemical nitrogen cycle and wastewater treatment. While these organisms have recently been shown to exhibit metabolic flexibility beyond their chemolithoautotrophic lifestyle, including the use of simple organic compounds to fuel their energy metabolism, the metabolic networks controlling their autotrophic and mixotrophic growth remain poorly understood. Here, we reconstructed a genome-scale metabolic model for Nitrospira moscoviensis (iNmo686) and used constraint-based analysis to evaluate the metabolic networks controlling autotrophic and formatotrophic growth on nitrite and formate, respectively. Subsequently, proteomic analysis and 13C-tracer experiments with bicarbonate and formate coupled to metabolomic analysis were performed to experimentally validate model predictions. Our findings support that N. moscoviensis uses the reductive tricarboxylic acid cycle for CO2 fixation. We also show that N. moscoviensis can indirectly use formate as a carbon source by oxidizing it first to CO2 followed by reassimilation, rather than direct incorporation via the reductive glycine pathway. Our study offers the first measurements of Nitrospira’s in vivo central carbon metabolism and provides a quantitative tool that can be used for understanding and predicting their metabolic processes.ImportanceNitrospira are globally abundant nitrifying bacteria in soil and aquatic ecosystems and wastewater treatment plants, where they control the oxidation of nitrite to nitrate. Despite their critical contribution to nitrogen cycling across diverse environments, detailed understanding of their metabolic network and prediction of their function under different environmental conditions remains a major challenge. Here, we provide the first constraint-based metabolic model of N. moscoviensis representing the ubiquitous Nitrospira lineage II and subsequently validate this model using proteomics and 13C-tracers combined with intracellular metabolomic analysis. The resulting genome-scale model will serve as a knowledge base of Nitrospira metabolism and lays the foundation for quantitative systems biology studies of these globally important nitrite- oxidizing bacteria.

scholarly journals Performance and Energy Consumption Evaluation of Rotating Biological Contactor for Domestic Wastewater Treatment

2021 ◽  
Vol 6 (1) ◽  
pp. 101-112
Author(s):  
Sharjeel Waqas ◽  
Muhammad Roil Bilad ◽  
Zakaria B Man
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Operating Cost ◽  
Domestic Wastewater ◽  
Nitrifying Bacteria ◽  
Organic Loading Rate ◽  
Treatment Efficiency ◽  
Domestic Wastewater Treatment ◽  
Rotating Biological Contactors ◽  
Biological Performance

Biological processes are extensively used for wastewater treatment because of low organic footprint, economically feasible, and high treatment efficiency. Rotating biological contactors (RBC), an attached growth biological process offers advantage of low operating cost, simple configuration and structure, reduced bionomical footprint and thus has been extensively employed for organics and nitrogen removal. In this study, RBC was used for the treatment of synthetic domestic wastewater operating at high hydraulic and organic loading rate to demonstrate the biological performance. The results showed that the RBC achieved a treatment efficiency for COD, ammonium, TN and turbidity of 70.2%, 95.2%, 70%, and 78.9 %, respectively. The efficient nitrogen removal and increased nitrate concentration signify the presence of nitrifying bacteria which actively degrade the nitrogen compounds through the nitrification process. Thus, this system is a sound alternative for both domestic and industrial wastewater treatment for decentralized applications.

Enzyme inhibitors of microbial origin

1980 ◽  
Vol 290 (1040) ◽  
pp. 291-301 ◽  
Keyword(s):  
Enzyme Inhibitors ◽  
Future Research ◽  
Main Interest ◽  
Porcine Pancreas ◽  
The Past ◽  
Microbial Origin ◽  
Irreversible Inhibitors ◽  
Antibiotic Agents ◽  
Potential Use ◽  
New Metabolites

The screening for enzyme inhibitors of microbial origin in the past decades has been a prosperous area to find new metabolites that are of potential importance as therapeutic or antibiotic agents. This review attempts a survey of recent achievements in this type of screening. Special emphasis is given to enzyme inhibitors and screening systems in fields where industry has a main interest in development. This includes some notes on the improved methodology for the detection of reversible and irreversible inhibitors of β-lactamases and the presentation of a unique inhibitor of α-amylase from porcine pancreas isolated from a strain of Streptomyces tendae . This inhibitor (HOE 467) may be of potential use in the treatment of diabetic conditions, obesity and adipositas. The results show that the screening for enzyme inhibitors from microorganisms still provides one of the central challenges for future research.

Robots and Autism Spectrum Disorder

2016 ◽  
pp. 905-924
Author(s):  
Amie Senland
Keyword(s):  
Autism Spectrum Disorder ◽  
Critical Review ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Future Research ◽  
Future Directions ◽  
Children With Asd ◽  
Technological Intervention ◽  
Educational Applications ◽  
Potential Use

Technology featuring robots is a promising innovative technological intervention for treating and educating children with Autism Spectrum Disorder (ASD). This chapter reviews, critiques, and presents future directions for research on clinical and educational applications of robots for these children. Specifically, this chapter reviews current research on: (1) robots that act as social mediators for children with ASD and (2) robots that assist them in developing social skills such as joint attention and imitation. A critical review of the research suggests that robots may have the capacity to assist some of these children, but additional rigorous studies are necessary to demonstrate their efficacy and effectiveness. Future research must (1) examine whether robots have differential effects for specific subgroups of children with ASD and (2) contribute to a deeper understanding of robots' potential use in educational settings.

scholarly journals High cadmium uptake ability of Bacillus cereus strains isolated from rhizosphere of Tagetes minuta L. growing in cadmium-polluted soil

2018 ◽  
Vol 47 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Kulsoom Akhter ◽  
Tahseen Ghous ◽  
Muhammad Siddique Awan ◽  
Zain Ul-Abdin ◽  
Basharat Hussain
Keyword(s):  
Bacillus Cereus ◽  
Inhibitory Concentration ◽  
Polluted Soil ◽  
Maximum Adsorption Capacity ◽  
Bacterial Strains ◽  
Removal Capacity ◽  
Tagetes Minuta ◽  
Uncontaminated Soil ◽  
Langmuir And Freundlich Models ◽  
Percent Removal

Microbes resistant to heavy metals develop mechanisms to accumulate Cd(II) in their cells. Two bacterial strains, Bacillus cereus AVP12 and B. cereus NC7401 which grew at high Cd(II) concentration were isolated from roots of Tagetes minuta L. growing in Cd(II) contaminated and uncontaminated soil. Minimum inhibitory concentration (MIC) and percent removal capacity were determined as function of pH, contact time and initial Cd(II) concentration. Bioaccumulation capacity was determined to observe possible effect of two different rhizospheres on Cd(II) removal capacity of both strains. Both strains were resistant up to 300 mg/l Cd(II) concentration. The percent removal capacity of both strains was maximum at pH 7 and incubation time of 24 hrs. High bioaccumulation capacity was observed with increasing Cd(II) concentration. Both Langmuir and Freundlich models fitted well to data of Cd(II) bioaccumulation. Though, maximum adsorption capacity (Qo) was observed for strains isolated from both types of rhizospheres, however remarkable Qo values of 434.0 and 212.7 mg/g were observed for Bacillus cereus AVP12 and NC7401, respectively isolated from polluted rhizosphere. Bacillus cereus strains growing in polluted rhizosphere can develop high Cd(II) uptake ability in comparison to non-polluted rhizosphere.

scholarly journals Sweet Immunity: The Effect of Exogenous Fructans on the Susceptibility of Apple (Malus × domestica Borkh.) to Venturia inaequalis

2020 ◽  
Vol 21 (16) ◽  
pp. 5885 ◽  
Author(s):  
Anze Svara ◽  
Łukasz Paweł Tarkowski ◽  
Henry Christopher Janse van Rensburg ◽  
Evelien Deleye ◽  
Jarl Vaerten ◽  
...  
Keyword(s):  
Complex Dynamics ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Fungal Growth ◽  
Production Costs ◽  
Future Research ◽  
Leaf Ontogeny ◽  
Disease Symptoms ◽  
Potential Use

There is an urgent need for novel, efficient and environmentally friendly strategies to control apple scab (Venturia inaequalis), for the purpose of reducing overall pesticide use. Fructans are recently emerging as promising “priming” compounds, standing out for their safety and low production costs. The objective of this work was to test a fructan-triggered defense in the leaves of apple seedlings. It was demonstrated that exogenous leaf spraying can reduce the development of apple scab disease symptoms. When evaluated macroscopically and by V. inaequalis-specific qPCR, levan-treated leaves showed a significant reduction of sporulation and V. inaequalis DNA in comparison to mock- and inulin-treated leaves, comparable to the levels in fosetyl-aluminum-treated leaves. Furthermore, we observed a significant reduction of in vitro mycelial growth of V. inaequalis on plates supplemented with levans when compared to controls, indicating a direct inhibition of fungal growth. Variations in endogenous sugar contents in the leaves were followed during priming and subsequent infection, revealing complex dynamics as a function of time and leaf ontogeny. Our data are discussed in view of the present theories on sugar signaling and fructan-based immunity, identifying areas for future research and highlighting the potential use of fructans in apple scab management in orchards.

Biodegradation of aniline

1997 ◽  
Vol 36 (10) ◽  
pp. 53-63 ◽  
Author(s):  
Shabbir H. Gheewala ◽  
Ajit P. Annachhatre
Keyword(s):  
Activated Sludge ◽  
Ammonia Oxidation ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Inhibitory Effect ◽  
Synthetic Wastewater ◽  
Nitrifying Bacteria ◽  
Aquatic Life ◽  
Oxidation Rates ◽  
Batch Tests

Discharge of aniline to the environment must be controlled as aniline is toxic to aquatic life and also exerts additional oxygen demand due to nitrification reaction involved during its biodegradation. Organic carbonaceous removal by heterotrophs during aniline biodegradation releases NH4+ which is the substrate for autotrophic nitrifying bacteria. However, aniline is toxic to nitrifying bacteria and severely inhibits their activity. Accordingly, batch and continuous studies were conducted to assess the biodegradation of aniline and its inhibitory effect on nitrification. Synthetic wastewater was used as feed with aniline as sole carbon source for mixed microbial population. Experiments were conducted at ambient temperatures of 30–32°C. An aerobic activated sludge Unit was operated at an HRT of about 13 hours and SRT of about 12 days. Biomass from aerobic activated sludge process treating domestic wastewater was acclimatized to synthetic wastewater Containing aniline. Removal efficiencies more than 95% were obtained for feed aniline concentrations upto 350 mg/l with insignificant inhibition of nitrification due to aniline. Ammonia oxidation rates of about 20–115 mgNH4N/l/d were observed. Batch tests were carried out to test the inhibitory effects of high initial aniline concentrations on nitritication. Carbonaceous removal by heterotrophs proceeded rapidly within 4–6 hours with nitrification picking up as soon as aniline concentration dropped below 3–4 mg/l. For higher initial aniline concentration more than 250 mg/l, complete nitrification did not take place even after aniline Concentration dropped below 3–4 mg/l.

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