Cellulase is widely used in food industries, but most of the cellulase currently used are not resistant to high temperatures. Clostridium thermocellum is a thermophilic anaerobic bacterium that produces cellulosome with high cellulase activity and hyperthermophilic property. The fermentation conditions of the cellulase production by the bacteria were studied in anaerobic bottles and fermenters. During the anaerobic flask fermentation, the optimum conditions for enzyme production were 55 ℃, pH 7, and 60 h of fermentation . The enzyme activity reached 5.12 U/mL under the above conditions. The growth curve and sugar consumption of the bacteria were studied in 5 L fermenter. Under batch fermentation, the feeding time and addition of carbon source were studied. The results indicated the growth of C. thermocellum turned in to the exponential growth phase after 16 h. Furthermore, optimal feeding time for carbon source was determinated at 16-48 h. Different carbon sources were studied under fed-batch fermentation conditions, cellobiose supplementation led to a significant increase in enzyme activity and reached to 16.56 U/mL, which was significantly higher than that of flask fermentation. The results provide the theoretical basis for industrial production of hyperthermophilic cellulase by C. thermocellum.
ZHANG Tingzhou
,
ZHU Tingheng
,
WANG Tenghao
,
ZHAO Yan
,
SHEN Wei
. Optimization of fermentation conditions for cellulase production ofClostridium thermocellum[J]. Food and Fermentation Industries, 2019
, 45(22)
: 185
-189
.
DOI: 10.13995/j.cnki.11-1802/ts.020951
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