Mutation of Alternaria tenuissima FCBP-252 for hyper-active alpha-amylase.

Production of extracellular alpha-amylase enzyme by a filamentous fungus, Alternaria tenuissima was studied in solid-state fermentation (SSF) as well as submerged fermentation (SmF). The potential strain was successfully mutated by UV and ethyl methanesulfonate (EMS). High-level of alpha-amylase activity was obtained by the mutant At-Ch-5.6 (76.75 Units mL(-1)) after chemical treatment followed by UV mutant At-UV-2.8 (63.12 Units mL(-1)) which was significantly higher than parental A. tenuissima FCBP-252 (32 Units mL(-1)). These mutants with high levels of activity were genetically characterized using RAPD-PCR. Expression pattern of mutants exhibited that the mutants were isogenic variants of parent strain and out-performance of the mutants could be attributed to change in genetic make up. This work represented the first report of strain improvement in Alternaria for hyper activity of alpha-amylase enzyme and suggested that this fungus could be used to extract purified enzyme.