Abstract:Fermentation conditions of xylanase production by Streptomyces F0107 were optimized. More than 80 actinomycetes obtained by isolating from dozens of decaying wood, debris and soil samples of different parts of China with corncob xylan as the sole carbon source, all degraded xylan and produced evident xylan hydrolyzed circles. Xylanase production by a newly isolated Streptomyces strain F0107 was studied by using submerged fermentation under shaking. Production of xylanase by F0107 on corncobs xylan was enhanced by optimizing the carbon source, nitrogen source, initial pH value of the culture medium, rotation rate and temperature. The results of single-factor experiment showed that insoluble corncob xylan was the best carbon source, a combination of yeast extract and peptone was the best nitrogen source, and the optimal initial pH value was 5.0. The optimal cultivation temperature and rotation rate were 32℃ and 140r/min, respectively. The maximum increase in xylanase production (41%) was observed in the presence of Tween 80 at a concentration of 0.4%. After optimization of various production parameters, the maximum xylanase yield (332.17U/mL) was obtained with no carboxymethy cellulase activity in 8 days of cultivation. In addition, SDS-PAGE and zymography analysis of culture supernatant under denaturing conditions revealed the presence of two xylanases with the molecular mass of approximately 38.9ku and 24.4ku, respectively.
