Preliminary studies for a new antibiotic from the marine mollusk Melo melo(Lightfoot,1786)

Objective:To search for new bioactive compounds from marine mollusks Melo melo(M.melo). Methods:Preliminary work for bioactive compound was identified by using disc diffusion methods against human pathogens.Further analyses of compound were done by using TLC, SDS-PACE.And also estimate the amount of protein in the samples by following Biuret method.Results:In antibacterial activity the maximum diameter of 24 mm zone of inhibition was recorded against Klebsiella pneumoniae(K.pneumoniae) strain of the mucus extract and minimum zone of inhibition of 11 mm was observed in Salmonella typhi(S.typhi) strain of body tissue extract.The antifungal activity of the extraction shows maximum activity against Trichophyton mentagarophytes(T.mentagarophytes)(14 mm) and minimum activity was recorded in Aspergillus flavus(A.flavus)(11 mm).The extract of mucus,nerve tissue,body tissue and kidney that showed antimicrobial activity was subjected to TLC to determine the presence of the peptides and amide groups,and also subjected to SDS-PACE to estimate the molecular weight of proteins in a clear band were detected in the gel that represented kidney,body tissue,brain and mucus represent 14,17,22,45 kDa.Conclusions:The extracts from marine mollusks M.melo is the potential source of producing bioactive compounds against human pathogens and can be used for synthesis of new drugs.

Invasion of parasitic isopods in marine fishes

Objective:To carry out a detailed three-year observation study on isopod parasites infestation in fish.Methods:Fish samples were collected from different localities in various landing centers along the Tamil Nadu coastal area.The prevalence and mean intensity were calculated.The proximate composition of infestation and uninfestation were studied in different marine fishes.A comparative analysis of bacteria and fungi in the infected and uninfected regions of fishes were analysed.Results:Tweenty six species including 12 genera of isopods(Cymothoidae)distributed in 39 species of marine fishes along the Tamil Nadu coast.The isopod parasites were attached in three different microhabitats in host fishes viz.,buccal,branchial and body surfaces.They exhibited host and site specific occurrence.Maximum prevalence 17.11%was recorded in March 2010 and minimum 0.27%in Febuary 2010.The intensity ranged from 1 to 1.7 parasites per fish during the different months from Decmber 2008 to November 2011.There was a decrease in the protein,carbohydrate and lipid content in the infested fishes compared to uninfected fishes.A comparative analysis of bacteria and fungi in the infected and uninfected region of fishes were analysed.It revealed that infected portions had dense bacterial load as observed in the lesions of infected fishes than uninfected fishes.Conclusion:Factors which are able to induce parasitic manifestation are stock quality,stocking density,environmental conditions,biological and physiological characteristics of parasite,zoo technical measures,food quantity,feeding strategies,etc.