The presentstudy was carried out to validate the sensitivity and precision of an invitro assay for evaluating the efficiency against antiphytopathogenic fungiby bacterial species viz. Lactobacillus sp, Corynebacterium sp,and Aeromonas sp. isolated from Mandapam, Gulf of Mannar. The bacterialprotein was extracted from the isolated bacteria and screened against tenphytopathogenic fungi. Among the three bacterial isolates only Corynebacteriumsp. exhibited antagonism against phytopathogenic fungi. The minimuminhibition was observed with Aspergillus niger (2 mm) and the maximuminhibition against Alternaria alternata (20mm). The optimized growthparameters of Corynebacterium sp. was carried out for mass scale production.The antiphytopathogenic protein was partially purified by subjecting toammonium sulphate precipitation followed by TLC and gel electrophoresis. SDS –PAGE analysis reported two protein bands corresponding to 34 kDa and 71 kDa.