Acidic bacterial proteases fromBacillusspecies as an alternative agent for scouring of cotton fabrics

Abstract

Protease production by Bacillus licheniformis and Bacillus cerus sources follows similar profiles with marginal differences in activity levels (690, 648 U/mL/min, respectively). Optimum pH values of proteases were closer to the neutral at 60°C. Lower scouring efficiency was observed in proteases produced by B. cerus compared to that of B. licheniformis, in terms of weight loss (4.0 and 3.34%), drop absorbency (1.59 and 3.28 s), extractable impurities (2.03 and 2.82%) and Ruthenium red binding (35 and 43%). Reduction in the tear strength was observed in protease-scoured samples compared to the alkali-scoured samples. FTIR results showed the elimination of nitrogen-containing compounds related to proteins, while the peaks related to wax, pectin were present in the scoured cotton samples.