Biovalorizing agro-waste 'de-oiled rice bran' for thermostable, alkalophilic and detergent stable α-amylase production with its application as laundry detergent additive and textile desizer.

ABSTRACT

The current research was concerned with the use of abundant agro-waste 'de-oiled rice bran (DORB)' as a sustainable substrate to produce α-amylase followed by several targets like process parameter optimization for augmented production and immobilization. In addition, we have also focused on investigating the application of DORB_amy as an efficient laundry detergent additive and textile desizer. The best production was recorded at pH 8.0 at 37 °C after 96 h incubation with 1.5 % (w/v) maltose. The DORB_amy has optimum activity at pH 9.0 at 60 °C with a Km and Vmax of 0.31 mg/mL and 222.22 mg/mL/min respectively. The catalytic performance of DORB_amy was further enhanced after immobilization in 3.0 % calcium alginate beads with 61.95 ± 0.17 % of operational stability after five continuous reaction cycles. The findings showed excellent performance of DORB_amy in cleaning starchy stains. The washing performance of enzyme and detergent together was better than their individual performance which increases the application of α-amylase as a laundry detergent additive. About 17.34 % weight loss or desizing was done by DORB_amy with an 8-9 TEGEWA rating. The reported biochemical features like thermostability, alkalophilic and detergent-stable nature of the DORB_amy make it industrially fit with great significance.