Characterization of Novel Amylase from Amylolytic Lactic Acid Bacteria Pediococcus ethanolidurans Isolated from Japanese Pickles (Nuka-zuke)

摘要

In this study, Pediococcus ethanolidurans A4-27 was isolated from Japanese pickles (nuka-zuke). The bacteria produce high molecular weight amylase. Sodium dodecyl sulfate-polyacrylamide gel electropho-resis and zymogram activity staining showed a single band at around 150 kDa. The enzyme was purified by disc preparative native-poly aery lamide gel electrophoresis, and ion chromatograph analysis of reaction products of P. ethanolidurans amylase on starch showed that glucose and maltose are the main final products. The appearance of maltose and glucose as major hydrolysis products suggests that the amylase produced by this organism is of α-type. Optimal temperature and pH for the enzyme activity were 60℃ and pH 4.0 - 6.0, respectively. Enzyme activity was not affected by the presence of 10 mM calcium chloride (Ca~(2+)) or the presence of 1000 mM and 2000 mM NaCl. These results indicate that the amylase from P. ethanolidurans is a useful enzyme for fermentation of rice bran-bed (nuka-doko) containing more than 15% NaCl.