Chitosan Extraction from F.solani sps, Study of its Antibacterial and Dye Degradation Ability.

Recent advances in fermentation technology have led to new innovative techniques to obtain useful by-products from various soil microbes. F.solani CBNR KRRR, isolated from the marine soils of Pichavaram, Tamil Nadu was used for the economic production of Chitosan using Hesseltine and Anderson medium. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy. The highest growth rate was with Henderson and Anderson medium with a mycelial dry weight of 14 g/L. The best yield of the chitosan so obtained is (33.57 mg/g or 3.3%). The antimicrobial activity of Chitosan was tested against E.coli and S.aureus using Growth kinetics. It was found that the Extracted Chitosan have antimicrobial activity comparable to the Commercial Chitosan as well as the standard antibiotic used. Subsequently the extracted Chitosan was also tested for its photocatalytic ability to degrade dye-methylene blue and was found to exhibit 94.5% inhibition in 72 hours.

Phytoplankton diversity in Pichavaram mangrove waters from south-east coast of India.

The results of an investigation carried out during September 2002 to August 2003 on hydrography, composition and community structure of phytoplankton including chlorophyll ‘a’ (Chl-a) content and primary productivity (PP) of the Pichavaram mangrove (South-east coast of India) are reported. Atmospheric and surface water temperatures varied from 30.0 to 34.8oC and from 29.7 to 34.2oC respectively while the light extinction coefficient values (LEC) (K) ranged between 3.2 and 14.9. Salinity values varied from 9.6 to 35.4‰ and the pH ranged between 7.2 and 8.6. Variation in dissolved oxygen content was from 3.2 to 6.5 ml l-1. The ranges of inorganic nutrients viz., nitrate, nitrite, phosphate and silicate were: 7-36.23, 0.31-5.46, 0.28-3.70 and 12.26-56.64 μM respectively. Chlorophyll ‘a’ content ranged between 0.20 and 105.60 ;g l-1 and the ranges of gross and net primary productivities (PP) were: 16.54-826.8 and 11.52-610.2 mg C m-3 hr -1respectively. Presently a total of 94 species of phytoplankton were identified. Among these, the diatoms formed predominant group. Population density of phytoplankton varied from 400 to 3,21,000 cells-1. While the peak diversity (5.23 bits / ind.) of the phytoplankton was observed during summer season, the maximum population density was found during summer season coinciding with the stable hydrographical conditions.