Potential of soil fungi to produce penicillin V acylase and its optimization conditions

Fifty fungal isolates representing 31 species, related to 8 genera, were isolated from soil and screened for their abilities to produce endo- and exocellular penicillin V acylase enzymes. For endocellular enzyme, eleven isolates (represent 22% of total isolates) exhibited high enzyme activity and 9 isolates (18%) had moderate ability. However, twenty isolates (40%) were low producers and ten isolates (20%) had no ability to produce the enzyme. For exocellular enzyme, four isolates only (representing 8% of total isolates) exhibited high enzyme activity, and fifteen isolates (30%) were found to be moderate. However, twenty two isolates (44%) were low producers and nine isolates (18%) had no activity. The most active fungal isolates were Aspergillus terreus and Penicillium chrysogenum , producing 325 and 280 U/ml, respectively. Maximum activity of penicillin V acylase produced by A. terreus and P. chrysogenum were obtained after 7 and 6 days of incubation, respectively at 35°C and initial pH 6. Dextrin or glucose was the best carbon source for penicillin V acylase produced by A. terreus and P. chrysogenum , respectively. However, peptone was the best nitrogen source. Inoculation of cultures by 3 discs of fungi and incubation of cultures at 180 rpm shaking condition improved the enzyme production.