caa a22 4500 465823203 CHVBK 20180323112141.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1007/BF00170046 doi (NATIONALLICENCE)springer-10.1007/BF00170046 Efficient production of human α-amylase by a Bacillus brevis mutant [Elektronische Daten] [Hiroaki Konishi, Tasuhiko Sato, Hideo Yamagata, Shigezo Udaka] Summary: A cDNA for mature human salivary α-amylase was directly joined to a sequence encoding the signal peptide of the middle wall protein (MWP) gene of Bacillus brevis 47. This hybrid gene was placed downstream from the multiple promoter region of the MWP gene on a low copy-number plasmid vector, pHW1. B. brevis 47 carrying the plasmid produced 0.9 mg/l of active human α-amylase in the medium. A B. brevis 47 mutant obtained on mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine produced an increased amount of the α-amylase (6 mg/l). When the fused gene was inserted into a high copy-number expression vector, pNU200, and then introduced into the mutant, a large amount (60 mg/l) of the α-amylase was produced in the medium. The α-amylase showed approximately the same specific activity and molecular weight as those of the natural enzyme. The mutant showed higher sensitivity to various antibiotics than the original strain, and altered cell wall and cytoplasmic membrane protein compositions. The results of reversion analysis suggested that a single mutation is responsible for the above phenotypes and hyper-productivity of human α-amylase. Springer-Verlag, 1990 Konishi Hiroaki Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut Sato Tasuhiko Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut Yamagata Hideo Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut Udaka Shigezo Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut Applied Microbiology and Biotechnology Springer-Verlag 34/3(1990-12-01), 297-302 0175-7598 34:3<297 1990 34 253 https://doi.org/10.1007/BF00170046 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00170046 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Konishi Hiroaki Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut NATIONALLICENCE 700 1- Sato Tasuhiko Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut NATIONALLICENCE 700 1- Yamagata Hideo Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut NATIONALLICENCE 700 1- Udaka Shigezo Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Chikusa-ku, 464, Nagoya, Japan aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer-Verlag 34/3(1990-12-01), 297-302 0175-7598 34:3<297 1990 34 253 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer