Production and application of α-amylase from indigenous fungal strain Aspergillus luchuensis bs1

Abstract

Aim: The study aimed at isolation, screening, optimization and partial purification of α-amylase and evaluating its desizing efficiency in textile industry. Methodology and results: The AF01 showed the highest α-amylase activity of 128 KU. This isolate was identified as Aspergillus luchuensis strain bs1 using 18S rRNA gene sequencing. The process parameters were screened by employing Plackett-Burman Design (PBD) with seven variables and followed by Box-Behnken Design with three positively influencing factors. The investigation revealed that the maximum α-amylase production (192KU) at medium pH 5.6, starch 3% (w/v) and sodium nitrate 0.5% (w/v). The partial purification of α-amylase was done by acetone precipitation and it resulted in 6.1 fold purification. Partially purified α-amylase recorded optimum activity at pH 5.5, 60 min of contact time, temperature stability at 60 °C and 93% specificity to potato starch. The desized cotton fabric showed 9.5% weight loss, 5 sec of absorbency time and 8 rating in Tegewa analysis. Conclusion, significance and impact of study: The study proposes a novel indigenous fungal strain having ability to produce alpha amylase and an enzyme preparation for desizing sized cotton fabric in minimal concentration.