Degumming crude enzyme produced by Bacillus cereus HDYM-02 and its application in flax retting

A cellulase-free, degumming crude enzyme was produced by Bacillus cereus HDYM-02, using konjaku flour as an inexpensive substrate. After 48 h fermentation, this crude enzyme consisted of pectinase and mannanase, whose maximum activity was 756.7 U/mL and 2967.3 U/mL, respectively. This crude enzyme exhibited considerable stability under the conditions resembling industrial flax retting. After 120 h incubation, more than 50% of the maximum activity of both pectinase and mannanase was retained at pH value 4.0 to 7.0, and at least 70% of the maximum activity was detected at 25 °C to 40 °C. The degumming liquid retted by this crude enzyme contained more galacturonic acid and reducing sugar than those in the degumming liquid retted by commercial pectinase. The application of B. cereus HDYM-02 crude enzyme resulted in higher weight loss of flax stems, better properties, higher productivities, and smoother surfaces of flax fibres. This study showed promise for the use of B. cereus HDYM-02 crude enzyme for flax retting in the textile industry.