||Fungi have been reported to be active producers of secondary metabolites. In this study, a fungal isolate (Aspergillus
sp) isolated from soil has been evaluated for its antimicrobial activity. The activity was studied under various
physio-chemical parameters, such as pH, temperature, incubation period, carbon and nitrogen sources. The best
antimicrobial activity was observed in the production medium having pH 5-7, on fifth day of incubation at 25 ºC
when grown as static culture. Starch was the most promising carbon source, while yeast extract and soyabean meal
acted as best nitrogen sources. Butanolic extract was comparable to standard antibiotics in contrast to aqueous
extract. Response surface analysis showed that the antimicrobial activity was enhanced by 1.25 folds in S.aureus,
1.28 folds (S.epidermidis), 1.6 folds (K.pneumoniae 1), 1.37 folds (C.albicans), 1.38 folds (MRSA). Characterization
of the purified compound responsible for antimicrobial activity was carried out by various analytical procedures i.e.
TLC, HPLC, NMR and IR. MIC of the butanolic extract ranged from (0.016mg/ml-18mg/ml) while purified
compound exhibited lower MIC value of 6µg/ml, 20 µg/ml and 20 µg/ml respectively for S.epidermidis, C.albicans
and MRSA. VCC (Viable cell count) studies revealed E.coli to be the most sensitive and demonstrated 100% killing
at 0 hr. Butanolic extract (crude) and the purified compound were found to be neither cytotoxic nor mutagenic.