Waste water fed fisheries are a common feature in different parts of the world. Yet not all work as efficiently as those operating at East Calcutta Wetland for more than 70 years now. The objective of this study is to unravel the reason for the markedly greater efficiency of the Bheris in fish production compared to other water bodies like rain water ponds or sewage fed fish ponds elsewhere. The study indicates that plankton growth could be an important factor responsible for greater fish production in the Bheris. The architecture of the Bheri itself acts as a facilitator in the process. It is proposed that planktons can act as biomarker for water quality assessment in fish production

Extracellular protease from a novel bacterial isolate showing maximum similarity of 98.22% with Microbacterium luteolum was obtained from East Calcutta Wetland, India. It showed compatibility with commercial detergents. The enzyme retains more than 60% of its activity between 6.0 to 10.5 pH. The maximum activity is at pH 7.5 with 71% activity at pH 10.0 and 10.5. The protease retained its activity between 4 to 60°C with maximum activity at 30°C and a residual activity of 74.4% at 60°C after overnight incubation. It was completely inhibited by 5mM PMSF pointing towards the presence of serine group of protease. Its inhibition by EDTA indicates the involvement of metal cations in its catalytic activity. It is not effected by Cu +2 , partially inhibited by Pb +2 and Ni +2 , while completely inhibited by Co +1 , Cr +6 , Zn +1 , Al +3 , Ag +3 and Hg +2 . Strong reducing agents like β-merceptoethanol and oxidants like bleach and hydrogen peroxide inactivate the enzyme. The enzyme retains 88% of its activity on being mixed with commercially available detergents while it is inactivated by non-ionic Triton X 100. Its efficiency as an additive with detergent in terms of cleaning stains like grease, burnt mobil, vegetable curry and blood was found to be satisfactory. It could enhance the quality of washing as additive in case of all the ten detergents that were tried. The protease alone was also capable of cleaning but the detergent additive mixture could work better. The enzyme was found to work efficiently on different colors as well as on fabric. On mixing with detergent it was found to retain activity up to 2 months and there after, there was a drop in efficiency of washing. The bacterial cells were immobilized in calcium alginate and the released enzyme was found to be equally effective. Market surveys were carried out and the satisfactory result prompted the use of another additive (extracellular lipase) obtained from yet another bacterial strain from East Calcutta Wetland. The lipase activity was confirmed through degradation of coconut oil analyzed by Gas Chromatography. Thus the combination was observed to be more successful as indicated through the market survey. These observations suggest the suitability of the protease and lipase combination as additive to commercially available detergents.

Protease secreting microbe was isolated and characterized on the basis of their morphological, biochemical, physiological and 16S rDNA based molecular properties. The extracellular protease was quantified and characterized. Protease was used for different time (4, 8, 12 and 24 h) at different temperature (RT and 37°C) for optimization of the degumming process for raw silk fabric with enzyme dosage (0.2-1 unit/cm 2 of fabric). Post-enzymatic treatment, the fabric quality and texture was compared with conventionally treated as well as untreated fabric in terms of degumming loss, tensile strength and yarn count and colour fastness to light/water. The isolate SM1 (Bacillus thuringensis) was able to grow in Carbon Minimal Salt Medium (CMSM) with jaggery or tamarind as the carbon source (0.3% w/v). Energy Dispersive X-Ray Fluorescense (EDXRF) data showed intracellular accumulation of heavy metal by the isolate. Extracellular protease was able to degum silk fabric within 4 h at RT with enzyme concentration of 0.8unit/cm 2 and the maximum degumming loss was 21.72%. Post enzymatic degumming, a shiny texture was observed under Environmental Scanning Electron Microscope (ESEM) and the yarn volume also increased. Utilization of CMSM made the process cost effective during large scale application. Intracellular metal accumulation and growth in a wide range of temperature and pH made the isolate a potential candidate for bioremediation. Extracellular protease with significant degumming property could be used as an eco friendly approach as compared to the conventional chemical treatment.