Truncated α-amylase: an improved candidate for textile processing

Enzymes are indispensable biocatalysts required in various steps of textile processing to minimize various chemical-induced hazards. The present work focuses on the applications of the truncated α-amylase in textile industry for desizing of fabrics by starch hydrolysis. The multiple sequence alignment was performed to find homology and the possible truncation region in Bacillus subtilis MTCC 121 α-amylase with same bacilli family α-amylase. Two constructs were generated for α-amylase gene of Bacillus subtilis MTCC 121 (Amy_F, full-length and Amy_T, C-terminal truncated) were cloned, overexpressed, purified, and characterized. Results revealed that activity of Amy_T was found to be 2.87-fold better than Amy_F. Further, the optimum temperature of Amy_F and Amy_T was obtained at 45 °C and 55 °C, respectively, whereas optimum pH was recorded at pH 7 and pH 8, respectively. Improved thermostability of Amy_T was further confirmed through thermal shift assay. Subsequently, starch-coated fabrics were tested for starch removal using the α-amylases. Comparative analysis revealed that Amy_T performed better in starch removal from polystyrene (85%), silk (75%), and cotton (70%) fabrics. The removal of starch from the fabrics was further confirmed by FESEM. Conclusively, this work presents one truncated α-amylase as an improved candidate over its full-length counterpart for textile desizing.