Investigation on natural Ammonia oxidizing microorganisms in various aquaculture systems
Published by : KUFOS (Panangad) Physical details: 90 Year: 2020| Item type | Current library | Collection | Call number | Status | Notes | Date due | Barcode |
|---|---|---|---|---|---|---|---|
Thesis
|
KUFOS Central Library Thesis Shelf | Reference | 639.3 NAJ/IN (Browse shelf(Opens below)) | Available | Abstract :- Accumulation of toxic nitrogenous metabolites derived from excess, uneaten feed and excreta poses the major problem in intensive aquaculture systems. Therefore, maintaining ammonia nitrogen below threshold level forms the major key limiting factor in successful aquaculture practices. Microbial oxidation of ammonia to nitrite through ammonia oxidizing microbes (AOM) is the central and rate limiting step in ammonia detoxification. Ecological significance in nitrogen cycle within aquaculture systems, toxic implications of ammonia deposition and possible applications for improving water quality characteristics has propelled the research in AOMs of aquatic environments worldwide. However, slowness of their growth and the difficulties in culturing of AOMs has impeded achieving the knowledge of this microbial group necessitating molecular marker based studies. Thus, as the initial step in investigations of AOMs in aquaculture environments, a molecular marker guided approach for detection of the two major groups of AOMs namely, β-Ammonia Oxidizing Bacteria (β-AOB) and Ammonia-oxidizing Archaea (AOA) was optimized through the present study. After optimizing the methodology, the same was applied in a limited number of commercially available water probiotics to check the reliability of these products and in different aquaculture systems. It was found that both β-AOB and AOA microbes were present in marine aquaculture facility. Further, among the five commercial water probiotics screened, only two products were containing the AOMs screened, suggesting the need for establishing a quality criteria to assure their effective use. Additionally, one of the positive sample obtained during the screening process from aquaculture systems was enriched through batch culture experiments. Molecular characterization based on amoA gene showed that the enriched culture belonged to order Nitrosomonadales. In the attempt for checking effect of antibiotics on activity of this enriched culture ampicillin was found to have no effect on ammonia oxidizing capability, while oxytetracycline and streptomycin had a small and maximum inhibitory effect respectively. Studies on activity kinetics of the enriched culture demonstrated its potential to be used for reducing ammonium pollution. Altogether, the results of present investigation will provide the essential guidelines for future research on microbial ecological and water quality management in aquaculture systems. 90 | TH310 |
There are no comments on this title.