Enhancement of β-1，3-Endoglucanase Production by Trichoderma harzianum Using Two-Stage pH and Agitation Speed Control Strategy

Abstract:

Beta-1，3-endoglucanase has important applications in food，agriculture and biotechnology. To enhance the productivity of β-1，3-endoglucanase and its ratio in total β-1，3-glucanase activity by Trichoderma harzianum Rifai GIM 3.442，the effects of pH and agitation speeds were investigated in a 7 L fermentator. It was shown that the mono-control of pH or agitation speed could not satisfactorily offer higher biomass and β-1，3-endoglucanase production simultaneously. A two-stage pH and agitation speed control strategy was therefore employed，i.e.，pH and agitation speed were controlled at 7.0 and 100 r/min in the first stage of fermentation（0~24 h） and then switched to pH 5.0 and 200 r/min in the second stage（24~168 h）. On account of this， β-1，3-endoglucanase activity and its productivity reached 407.8 U/mL and 3.09 U/（mL?h），320.0 % and 398.4 % higher than that of uncontrolled condition，respectively. The ratio of β-1，3-endoglucanase to total β-glucanases activity was 0.71，increasing 65.1 % than that of uncontrolled condition.