High-level expression of Humicola insolens cutinase in Pichia pastoris without carbon starvation and its use in cotton fabric bioscouring

摘要

Huimcola insolens cutinase (HiC) was heterologously expressed in Pichia pastoris. To avoid a carbon starvation step, fermentation was conducted using combinations of sorbitol with glycerol and methanol in the cell growth and induction phases, respectively. The cutinase productivity (27.71 U mL(-1) h(-1)) was 9.93 U mL(-1) h(-1) greater than that achieved using traditional two-phase methods, and a cutinase activity of 2660 U mL(-1), using pnitrophenyl butyrate as substrate, was achieved after only 96 h in a 3-L bioreactor. Subsequently, the combination of HiC with Thermobifida fusca cutinase (TfC) in cotton fabric bioscouring was evaluated by monitoring the wettability and dyeability of the fabric. Treatment with 20 U mL(-1) of HiC at 80 degrees C for 5 min followed by 30 U mL(-1) of TfC at 50 degrees C for 1 h gave the best results. The total treatment time was shorter and performance was better than those seen with the alkali method.