The study aimed at isolation and screening of fungal amylase producer, optimization of solid state fermentation conditions for maximum amylase production by the best amylase producer, and characterization of the crude amylases, so produced. Aspergillus fumigatus NTCC1222 showed the highest amylase activity (164.1 U/mL) in secondary screening under SSF conditions and was selected for further studies. The test strain showed maximum amylase production (341.7 U/mL) and supernatant protein concentration (9.7 mg/mL) for incubation period (6 days), temperature (35°C), initial pH (6.0), nutrient salt solution as moistening agent, and beef extract as nitrogen source. Pomegranate peel produced maximum amylase activity, but wheat bran (only slightly lesser amylase activity as compared to that of pomegranate peel) was chosen for further studies, keeping in mind the seasonal availability of pomegranate peel. TLC confirmed the amylase produced to be α-type and 60 kDa was the molecular weight of the partially purified amylase. The enzyme showed maximum enzyme activity at pH 6.0, temperature of 55°C, and incubation time of 60 minutes. UV (616.0 U/mL) and chemical (814.2 U/mL) mutation enhanced amylase activity as compared to wild test strain. The study indicates that Aspergillus fumigatus NTCC1222 can be an important source of amylase and the crude enzyme, hence obtained, can be cost effectively applied in multiple sections of textile wet processing.

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The search for better microbial sources of enzymes has long been an area of active research owing to the clear and distinct importance in todays' world where exploration and application of environment friendly products has become a necessity. Though the natural, wild microbial strains, are continuously be searched and explored for their potential for amylase production yet, simultaneous attempts for improved enzyme production are necessary too. In the present study, a comparison between the influence of different mutational treatments (UV treatment and EMS-EtBr treatment) on amylase production was studied. Aspergillus fumigatus NTCC1222, an indigenously isolated amylase producer, which has shown an amylase activity of 341.7 U/mL under optimized conditions of SSF in our previous study, was subjected to UV-and EMS-EtBr-treatment for possible improved amylase production under optimized solid state fermentation conditions. The UV mutated strains yielded an amylase production of 614.2 U/mL while the chemically (EMS-EtBr) mutated strain produced 814.1 U/mL of amylase activity thereby indicating the successful enhancement in amylase activity for the test fungal strain.