Microbial Production of L-Tyrosine by an n-Paraffin-grown Bacterium |
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Authors: | Ken Yamaguchi Yoh Tokoro Kazuo Oshima Katsunobu Tanaka Takeo Suzuki |
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Institution: | Tokyo Research Laboratory, Kyowa Hakko Kogyo Co., Ltd., Machida, Tokyo |
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Abstract: | Four mannanases (Mannanases I, II, III, and IV) were isolated from the culture filtrate of a Streptomyces sp. by ion exchange chromatography. Mannanase IV was the main component and accounted for 64.4% of the total activity of the four mannanases. Mannanase IV was further purified by gel filtration, and the purified Mannanase IV was homogeneous on disc-gel electrophoretic analysis.Optimum pH and temperature for the activity of Mannanase IV were 6.8 and 57°C, respectively. It was stable at temperatures up to 45°C when examined at pH 6.8 for 30min, and lost only 15% of its activity at 70°C for 30min at pH 6.8. The isoelectric point and molecular weight were pH 3.65 and 42,900, respectively. The enzyme was strongly inactivated by Al3+, Hg2+, Fe2+, Fe3+, Cd2+, Ag+, Sn2+, and Cu2+, and completely inhibited by iodoacetic acid and N-bromosuccinimide. The enzyme hydrolyzed mannotriose to mannose and mannobiose, but did not hydrolyze mannobiose. |
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