Constitutive high level expression of an endoxylanase gene from the newly isolated Bacillus subtilis AQ1 in Escherichia coli

An effective degumming enzyme from Bacillus sp. Y1 and synergistic action of hydrogen peroxide and protease on enzymatic degumming of ramie fibers

Enzymatic degumming, as an alternative to chemical processing, has attracted wide attention. However, to date, little information about other enzyme components with effective degumming except pectinase has been reported, and there is no report about the effect of bleaching agent (H₂O₂) on enzymatic degumming and combining enzymatic degumming and H₂O₂ bleaching process. In this study, we found that the crude enzyme of wild-type Bacillus sp. Y1 had a powerful and fast degumming ability. Its PGL activity was the highest at pH 9.6–10.0 and 60°C and stable at pH 7–10.5 and 30–50°C, having a wide scope of pH and temperature. Its PGL also had a high H₂O₂ tolerance, and the gum loss and brightness of fibers could be significantly improved when H₂O₂ was added into it for degumming. The synergistic action was also found between it and H₂O₂ on the degumming and bleaching of ramie fibers. All showed that it was very suitable for a joint process of enzymatic degumming and H₂O₂ bleaching. It also contained more proteins compared with a control pectinase, and its high protease content was further substantiated as a factor for effective degumming. Protease and pectinase also had a synergistic action on degumming.