caa a22 4500 605500045 CHVBK 20210128100554.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00253-014-6186-5 doi (NATIONALLICENCE)springer-10.1007/s00253-014-6186-5 Characterization of maltotriose production by hydrolyzing of soluble starch with α-amylase from Microbulbifer thermotolerans DAU221 [Elektronische Daten] [Yong-Suk Lee, Dong-Ju Park, Yong-Lark Choi] A maltotriose-producing α-amylase, AmyA, from a newly isolated bacterial strain Microbulbifer thermotolerans DAU221 was purified and characterized in the heterologous host, Escherichia coli, using the pCold I vector. The amyA gene encoded a 761-residue protein composed of a 33 amino acid secretion signal peptide. The purified α-amylase with a molecular mass of 80kDa, approximately, shared a sequence motif characteristic of the glycoside hydrolase family 13. The enzyme was optimally active, at 50°C in sodium phosphate buffer (pH 6.0), by the traditional one factor-at-a-time method. But the optimal conditions of time, temperature, and pH for production of maltotriose from soluble starch were 1.76h, 44.95°C, and pH 6.35 by response surface methodology, respectively. Maltotriose, as the major enzyme reaction product, was analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The enzyme was found to be inhibited by the addition of 10mM Cu2+, Fe3+, Hg2+, Zn2+, and EDTA, but exhibited extreme stability toward hexane. The K m and V max values for the hydrolysis of soluble starch were 1.08mg/mL and 1.736mmol maltotriose/mg protein/min, respectively. Springer-Verlag Berlin Heidelberg, 2014 Microbulbifer thermotolerans nationallicence Maltotriose nationallicence Maltotriose-producing α-amylase nationallicence Response surface methodology nationallicence Lee Yong-Suk Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut Park Dong-Ju Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut Choi Yong-Lark Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/9(2015-05-01), 3901-3911 0175-7598 99:9<3901 2015 99 253 https://doi.org/10.1007/s00253-014-6186-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6186-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lee Yong-Suk Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut NATIONALLICENCE 700 1- Park Dong-Ju Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut NATIONALLICENCE 700 1- Choi Yong-Lark Department of Biotechnology, Dong-A University, 604-714, Busan, Republic of Korea aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/9(2015-05-01), 3901-3911 0175-7598 99:9<3901 2015 99 253