Efficacy of commercial shrimp farm bioremediators in removing ammonia in microcosm experiments

The efficacy of two commercial aquaculture bioremediators to remove ammonia was tested under laboratory conditions. The bioremediators were capable of removal of total ammoniacal nitrogen (TAN) to the tune of 86 - 90% (max) at 1-3 ppm initial level of ammonia (NH3) and the removal rate decreased thereafter. Significant differences in nitrite (NO2) levels in treated and control tanks were observed probably due to the differences in the levels of resident nitrifying bacteria that utilize NH3 and oxidize it to NO2. The nitrate levels increased in all the treatment tanks, but showed a general decreasing trend in control tanks. Among the tanks with varied NH3 concentrations, the levels of NO3 between the control and treatment tanks differed insignificantly (P>0.05). The results of the present study revealed that the commercial bioremediators failed to remove majority of the total ammoniacal nitrogen when the NH3 level is high initially

Microcosm evaluation of indigenous microflora of traditional shrimp farming system as bioremediators

The ability of indigenous microflora of traditional shrimp farming system to remove ammonia was evaluated under laboratory conditions. The indigenous microflora in combination were capable of removal of total ammoniacal nitrogen (TAN) to the tune of 85 - 99% within a week. The activity of nitrifying bacteria was observed to be substrate dependent. The results revealed that the TAN removal rate was affected by high initial TAN concentration and varied microbial activity. The results of the present study would release new avenues for future research and refinement of techniques on bioremediation in shrim

Assessment of nitrogen and sulphur cycle bacteria and shrimp production in ponds treated with biological products

Objective: To study the influence of biological products on the levels of nitrogen and sulphur cycle bacteria in shrimp culture systems of West Bengal, India. Methods: The pond water and sediment samples were analyzed for physico-chemical parameters as per standard methods. The bacteria involved in ammonification, nitrification, denitrification, sulphate reduction and sulphur oxidation were enumerated by most probable number technique. Results: The semi-intensive and modified extensive shrimp farms used a variety of biological products during various stages of production. No biological products were used in traditional farms. The water and sediment samples of modified extensive system recorded significantly higher mean heterotrophic bacterial counts. The counts of ammonia, nitrite and sulphur oxidizers, and nitrate and sulphate reducers varied among the systems. The cycling of nitrogen and sulphur appeared to be affected with the intensification of culture practices. Conclusions: The application of biological products in certain systems helped to maintain the bacteria involved in nitrogen and sulphur cycles and safe levels of ammonia, nitrite and nitrate. An assessment of these metabolically active bacteria in shrimp culture ponds and the application of right kind microbial products would help ameliorate the organic pollution in shrimp aquaculture

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Not AvailableThe ability of indigenous microflora of traditional shrimp farming system to remove ammonia was evaluated under laboratory conditions. The indigenous microflora in combination were capable of removal of total ammoniacal nitrogen (TAN) to the tune of 85 - 99% within a week. The activity of nitrifying bacteria was observed to be substrate dependent. The results revealed that the TAN removal rate was affected by high initial TAN concentration and varied microbial activity. The results of the present study would release new avenues for future research and refinement of techniques on bioremediation in shrimpNot Availabl

Antibiotic susceptibility of luminous bacteria from shrimp farm environs of West Bengal

334-336 Sensitivity of 175 isolates of luminous bacteria from various shrimp farming systems of West Bengal was tested against six antibiotics, viz., chloramphenicol (30µg), ciprofloxacin (5µg), co-trimoxazole (25µg), gentamycin (10µg), nitrofurantoin (300µg) and oxytetracycline (30µg). Besides, the minimum inhibitory concentration (MIC) of the antibiotics was determined against 60 isolates of Vibrio harveyi. The isolates were least susceptible to oxytetracycline followed by ciprofloxacin and nirofurantoin, and highly susceptible to chloramphenicol. Vibrio harveyi was the most resistant species. About 56% of the luminous isolates exhibited multiple antibiotic resistance. The MIC of oxytetracycline was observed to be in the range of 1.56->200 µg/ml. Majority of the isolates were inhibited at a concentration of 0.10-0.78 µg/ml of ciprofloxacin and 0.20-6.25 µg/ml of chloramphenicol. The observations on the antibiotic resistance did not indicate that the luminous bacteria of certain shrimp culture systems of West Bengal is developing resistance to broad-spectrum antibiotics. </smarttagtype

Distribution of bacteria involved in nitrogen and sulphur cycles in shrimp culture systems of West Bengal, India

The bacteria involved in nitrogen and sulphur cycles and physicochemical characteristics of water and sediment in traditional, modified extensive and semi-intensive shrimp culture systems of West Bengal, India were monitored. The physicochemical parameters, except salinity and sediment pH, were observed to be well within the optimum levels recommended for shrimp culture. The levels of ammonia (NH3; PV0.05) and nitrite (NO2; Pb0.03) differed significantly among systems. The mean heterotroph counts were always close to or above 106/ml pond water and 106/g sediment. The counts of total heterotrophs and nitrate reducing bacteria (NRB) of the pond water of different culture systems differed significantly ( Pb0.01). While the counts of nitrite oxidizing bacteria (NOB; Pb0.001), nitrate reducing bacteria ( Pb0.01) and sulphate reducing bacteria (SRB; Pb0.03) in pond sediment of the three culture systems differed significantly. The mean counts of ammonia oxidizers increased with days of culture (DOC) in traditional and modified extensive systems, but they remained constant in semi-intensive pond sediment. The mean counts of nitrite oxidizers were generally high in water and sediment samples of modified extensive system. The mean sulphur oxidizing bacterial counts of pond water were higher in semi-intensive and modified extensive systems, which generally decreased with increasing DOC. The sulphate reducing bacterial counts of sediment increased with DOC in modified extensive and semi-intensive systems and vice versa i

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Not AvailableRole of ICT Interventions in Promotion of Horticultural Crops in Arunachal PradeshNot AvailablePromotion of Horticultural CropsArunachal Prades

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Not AvailableThe bacteria involved in nitrogen and sulphur cycles and physicochemical characteristics of water and sediment in traditional, modified extensive and semi-intensive shrimp culture systems of West Bengal, India were monitored. The physicochemical parameters, except salinity and sediment pH, were observed to be well within the optimum levels recommended for shrimp culture. The levels of ammonia (NH3; PV0.05) and nitrite (NO2; Pb0.03) differed significantly among systems. The mean heterotroph counts were always close to or above 106/ml pond water and 106/g sediment. The counts of total heterotrophs and nitrate reducing bacteria (NRB) of the pond water of different culture systems differed significantly ( Pb0.01). While the counts of nitrite oxidizing bacteria (NOB; Pb0.001), nitrate reducing bacteria ( Pb0.01) and sulphate reducing bacteria (SRB; Pb0.03) in pond sediment of the three culture systems differed significantly. The mean counts of ammonia oxidizers increased with days of culture (DOC) in traditional and modified extensive systems, but they remained constant in semi-intensive pond sediment. The mean counts of nitrite oxidizers were generally high in water and sediment samples of modified extensive system. The mean sulphur oxidizing bacterial counts of pond water were higher in semi-intensive and modified extensive systems, which generally decreased with increasing DOC. The sulphate reducing bacterial counts of sediment increased with DOC in modified extensive and semi-intensive systems and vice versa inNot Availabl