Manju, N J; Dr.Bright Singh,I S(Cochin University of Science and Technology, October , 2007)
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Abstract:
This thesis entitled Development of nitrifying ans photosynthetic sulfur bacteria based bioaugmentation systems for the bioremediation of ammonia and hydregen sulphide in shrimp culture.
the thesis is to propose a sustainable, low cost option for the mitigation of toxic ammonia and hydrogen sulphide in shrimp culture systems. Use of ‘bioaugmentors’ as pond additives is an emerging field in aquaculture. Understanding the role of organisms involved in the ‘bioaugmentor’ will obviously help to optimize conditions for their activity.The thesis describes the use of wood powder immobilization of nitrifying consortia.Shrimp grow out systems are specialized and highly dynamic aquaculture production units which when operated under zero exchange mode require bioremediation of ammonia, nitrite nitrogen and hydrogen sulphide to protect the crop. The research conducted here is to develop an economically viable and user friendly technology for addressing the above problem. The nitrifying bacterial consortia (NBC) generated earlier (Achuthan et al., 2006) were used for developing the technology.Clear demonstration of better quality of immobilized nitrifiers generated in this study for field application.
Description:
National Centre for Aquatic Animal Health, School of Environmental
Studies, Cochin University of Science and Technology
Bright Singh, I S; Cini, Achuthan; Rosamma, Philip; Manju, N J(Elsevier, May 11, 2009)
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Abstract:
Shrimp grow out systems under zero water exchange mode demand constant remediation of total ammonia
nitrogen (TAN) andNO2
−–Nto protect the crop. To address this issue, aninexpensive and user-friendly technology
using immobilized nitrifying bacterial consortia (NBC) as bioaugmentors has been developed and proposed for
adoption in shrimp culture systems. Indigenous NBC stored at 4 °C were activated at room temperature (28 °C)
and cultured in a 2 L bench top fermentor. The consortia, after enumeration by epifluorescence microscopy,were
immobilized on delignifiedwood particles of a soft wood tree Ailantus altissima (300–1500 μm) having a surface
area of 1.87m2 g−1. Selection of wood particle as substratumwas based on adsorption of NBC on to the particles,
biofilm formation, and their subsequent nitrification potential. The immobilization could be achievedwithin 72 h
with an initial cell density of 1×105 cells mL−1. On experimenting with the lowest dosage of 0.2 g (wet weight)
immobilized NBC in 20 L seawater, a TAN removal rate of 2.4 mg L−1 within three days was observed. An NBC
immobilization device could be developed for on site generation of the bioaugmentor preparation as per
requirement. The product of immobilization never exhibited lag phase when transferred to fresh medium. The
extent of nitrification in a simulated systemwas two times the rate observed in the control systems suggesting the
efficacy in real life situations. The products of nitrification in all experiments were undetectable due to
denitrifying potency, whichmade the NBC an ideal option for biological nitrogen removal. The immobilized NBC
thus generated has been named TANOX (Total Ammonia Nitrogen Oxidizer)