Trace metals in water, sediment and bivalves of a tropical estuary, west coast of India.

Trace metal pollution was studied in water, sediment and three selected bivalves in Mandovi and Chapora estuaries of Goa. The trace metal in water and sediment of Mandovi was higher than in Chapora. The concentration in the tissues was in the range of 1205.2-2506.7 ppm for Paphia malabarica, 1906.2-2802.6 ppm for Perna viridis and 778.7-1607.5 ppm for Saccostrea cucullata in Mandovi estuary. Tha values for Chapora were 199.4-625.8 ppm for P. malabarica, 812.6-1220.2 for P. viridis and 392.5-418.6 ppm for S. cucullata. The anthropogenic input of metal in Mandovi estuary appears to be mainly responsible for the high accumulation of trace metals. These bivalves have potential to serve as indicator for metal contamination in seafood of Goa.

Active pharmaceutical ingredient (api) from an estuarine fungus, Microdochium nivale (Fr.).

Various marine habitats sustain variety of bio-sources of ecological and biotech potentials. Pharmaceutical potential compound Cyclosporine A was reported from marine fungus Microdochium nivale associated with Porteresia coarctata, a marine salt marsh grass from mangrove environment distributed along the Central West Coast (CWC) of India. This study involves association of M. nivale with P. coarctata plant, fermentation conditions, purification of Cyclosporine A, chemical characterization etc. Its antifungal inhibition and MIC (Minimum inhibitory concentration) against Aspergillus strains (A. niger, A. japonicus, A. fresenii), yeasts and dermatophytes (Candida sp., Cryptococcus neoformans, Trichophyton mentagrophytes, T. tonsurans, T. violaceum, Microsporium gypsum and Fusarium sp.) were evaluated. However, the MIC against A. japonicus, C. neoformans, Candida sp. and T. tonsurans were confirmed to be as low as 12.5-25 mg disc(-1). The antifungal properties of Cyclosporine A against Aspergillus species, yeast and dermatophytes revealed that CyclosporineAwould be a potential compound for life threatening diseases caused by above fungi in both human and animals. Furthermore, we have reported herewith another source of Cyclosporin Aderived from filamentous fungus, M. nivale. occurring in marine environment.

Evaluation of genotoxic responses of Chaetoceros tenuissimus and Skeletonema costatum to water accommodated fraction of petroleum hydrocarbons as biomarker of exposure.

Genotoxic responses towards chronic exposure of Chaetoceros tenuissimus and Skeletonema costatum to water accommodated fraction of petroleum hydrocarbons (WAF-P) were evaluated as biomarkers of petroleum hydrocarbons pollution. The DNA damage caused by water accommodated fraction of petroleum hydrocarbons was assessed in terms of the DNA integrity measured by alkaline unwinding assay. The comparative study of the growth pattern of C. tenuissimus with respect to DNA integrity and the DNA strand breaks in different concentrations of WAF-P showed sufficient tolerance. However, its toxicity increased proportionately with exposure to elevated levels of WAF-P. Although DNA damage in S. costatum was similar to C. tenuissimus, its tolerance level to WAF-P was at least 5 times lower than that of C. tenuissimus indicating its high sensitivity to petroleum hydrocarbons. Active growth was exhibited by C. tenuissimus between 10 and 20% WAF-P (ranging from 0.59 to 1.18mg/L petroleum hydrocarbons) which can be related to the polluted regions only, suggesting the tolerant nature of this organism. Considering the degree of sensitivity to petroleum products and good growth under laboratory conditions, these two diatoms could be recommended as model species for evaluating ecogenotoxic effects of wide range of petroleum hydrocarbon pollutants using alkaline unwinding assays.

Evaluation of significant sources influencing the variation of water quality of Kandla creek, Gulf of Katchchh, using PCA.

To evaluate the significant sources contributing to water quality parameters, we used principal component analysis (PCA) for the interpretation of a large complex data matrix obtained from the Kandla creek environmental monitoring program. The data set consists of analytical results of a seasonal sampling survey conducted over 2 years at four stations. PCA indicates five principal components to be responsible for the data structure and explains 76% of the total variance of the data set. The study stresses the need to include new parameters in the analysis in order to make the interpretation of principal components more meaningful. The PCA could be applied as a useful tool to eliminate multi-collinearity problems and to remove the indirect effect of parameters.

Antifouling potential of some marine organisms from India against species of Bacillus and Pseudomonas.

Crude methanolic extracts of 37 marine organisms (16 species of flora, 21 species of fauna) were screened for antibacterial properties against 5 strains of bacteria isolated from marine environments. Of these, 10 plant and 9 animal extracts exhibited antibacterial activity against at least one bacterial strain. The extracts of 6 species were active against all the strains: i.e., Stoechospermum marginatum (brown algae), Cymodocea rotundata (seagrass), Petrosia sp. and Psammaplysilla purpurea (sponges), Sinularia compressa (soft coral), and Cassiopeia sp. (jellyfish). Among the plants, Padina tetrastromatica (brown algae) extract exhibited significant activity (9-11-mm inhibition zone at 500 microg per 6-mm disc) against Bacillus pumilus and Pseudomonas vesicularis, while the extracts of Petrosia, Psammaplysilla, and Cassiopeia were strongly active (11-13-mm inhibition zone at 500 microg per 6-mm disc) against B. circulans and P. putida. It was further confirmed that the attachment of bacterial strains on glass slides was inhibited remarkably with increasing concentrations of bioextracts of Petrosia sp. and Psammaplysilla purpurea. The present findings could form the basis for exploring the antibacterial potential of bioactive molecules from some of the marine organisms that exhibited moderate to strong antibacterial properties.

Antifungal activity of some marine organisms from India, against food spoilage Aspergillus strains.

Crude aqueous methanol extracts obtained from 31 species of various marine organisms (including floral and faunal), were screened for their antifungal activity against food poisoning strains of Aspergillus. Seventeen species exhibited mild (+ = zone of inhibition 1-2 mm) to significant (+3 = zone of inhibition 3-5 mm) activity against one or the other strain under experiment. However, extracts of 12 species were active against all the three strains. Organisms like Salicornia brachiata (obligate halophyte), Sinularia leptocladus (Soft coral), Elysia grandifolia (Mollusks), Gorgonian sp. 2 and Haliclona sp. exhibited significant (inhibition zone of 3-5 mm) antifungal activity against one or the other strains. However, extracts of A. ilicifolius, Amphiroa sp., Poryphyra sp., Unidentified sponge, Suberites vestigium, Sinularia compressa, Sinularia sp., Sinularia maxima, Subergorgia suberosa, Echinogorgia pseudorassopo and Sabellaria cementifera were mild (inhibition zone of 1-2 mm) to moderate (inhibition zone of 2-3 mm) active against the respective strains. The growth of A. japonicus was significantly inhibited by the extracts of S. leptocladus (r = 0.992, p < 0.0001) and E. grandifolia (r = 0.989, p < 0.0001).