M. Srinivasan

Antimicrobial activities of the tissue extracts of Babylonia spirata Linnaeus, 1758 (Mollusca: Gastropoda) from Thazhanguda, southeast coast of India

OBJECTIVE To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata (B. spirata) against nine bacterial and three fungal pathogens. METHODS Crude extract of gastropod was tested for inhibition of bacterial and fungal growth. Antibacterial assay was carried out by disc diffusion method and in vitro antifungal activity was determined against Czapex Dox agar. The antimicrobial activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract. Molecular size of muscle protein was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). And fourier transform infrared spectroscopy (FTIR) spectro photometry analysis was also studied. RESULTS The maximum inhibition zone (12 mm) was observed against Pseudomonas aeruginosa in the crude ethanol extract of B. spirata and the minimum inhibition zone (2 mm) was noticed against Staphylococcus aureus in the crude methanol extract of B. spirata. Water extract of B. spirata showed the highest activity against Vibrio parahaemolyticus, Staphylococcus aureus and Candida albicans. Ethanol, acetone, methanol, chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus. Compared with water extracts, ethanol and methanol extracts showed higher activity against all pathogens. The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE. FTIR analysis revealed the presence of bioactive compounds signals at different ranges. CONCLUSIONS The research shows that the great medicinal value of the gastropod muscle of B. spirata may be due to high quality of antimicrobial compounds.

Nutritional quality of processed head and bone flours of Tilapia (Oreochromis mossambicus, Peters 1852) from Parangipettai estuary, South East Coast of India

Objective To analyze the proximate composition, fatty acids, amino acids and nutritional composition of flour made from Tilapia (Oreochromis mossambicus) head and bones.

Nutritional value of gastropod Babylonia spirata (Linnaeus, 1758) from Thazhanguda, Southeast coast of India

Abstract Objective To study the biochemical composition, i.e. , protein, carbohydrate, lipid, and amino acids from Babylonia spirata ( B. spirata ). Methods The gastropod ( B. spirata ) were collected from the Thazhanguda, Southeast coast of India. The animal shell was broken and body muscles (expected digestive gland) were dried at 60 °C in an oven and used for biochemical analysis, such as protein, carbohydrate, lipid, amino acid and molecular size of muscle protein. Results The results of proximate composition showed that the percentage of protein in the tissue was (53.86%), followed by the carbohydrate content (16.85%). The amount of lipid was 9.30%, and totally 10 essential and nonessential amino acids were analyzed in B. spirata and the content was 9.911 mg/g. The molecular weight of the gastropod sample was low as 2 kDa on SDS-PAGE. FT-IR analysis revealed the presence of amino acids signals at different ranges. Conclusions The results of this research showed that B. spirata meat is a valuable food with high quality protein and well-balanced amino acids.

Real time PCR quantification of WSSV infection in specific pathogen free (SPF) Litopenaeus vannamei (Boone, 1931) exposed to antiviral nucleotide

Abstract Objective To investigate the level of WSSV transmission from the infected tiger prawn Penaeus monodon ( P. monodon ) to specific pathogen free Litopenaeus vannamei ( L. vannamei ) in laboratory captivity condition in relation to PCR detection, histopathological observation and viral genome sequence. Methods Viral DNA was isolated from purified virions by treatment with proteinase K (0.2 mg/mL) and Sarkosyl (1%). The purity and concentration of the DNA were determined by agarose gel electrophoresis. Moribund and dead shrimp were removed and processed for indirect immunofluorescence (IIF) analysis. Histological observation of infected L. vannamei shrimps were revealed by the degenerated cells which were characterized by intranuclear inclusions in the tissues of WSSV infected mid-gut gland, lymphoid organ, gill lamellae and gut epithelium. Total DNA was extracted, from shrimp hemolymph and tissues, with a High Puree PCR template preparation kit. WSSV-DNA was detected using a commercial 2-step PCR detection kit. Results The present study compares the real-time PCR results with SYBR Green I concentration ranging from 0.2 to 0.7×. The positive standard was used in the range of 10 2 , 10 4 10 6 , 10 8 and 10 10 copies/ng of DNA in general. The PCR analysis showed the appearance of a prominent band from the PCR amplified product of WSSV-DNA at internal control band of 848 bp. Moderate and severe levels were observed as 650 bp and 910 bp (200 & 2 000 copies) in various transmission routes. The WSSV content in moribund shrimp of all the experimental species ( L. vannamei ) approximately ranged in nucleotide application by quantification method from 0.000 001 WSSV copies/μg of total DNA. In whole moribund infection animal, approximately 0.02 WSSV copies/μg of DNA was detected in nucleotide applied animal. Conclusion These results indicate that wild brood stock and native culture shrimp P. monodon may be infected with WSSV and can get transferred into the SPF L. vannamei farming environment. Based on the studies, we made in captivity condition in different WSSV transmission route in dissimilar infection range with the use of nucleotide for antiviral drugs. There is an urgent need to address and develop antiviral drugs and molecular based viral genome technique for control measures to salt away the aquaculture environments.