关键词: Bispora sp. MEY-1, 酸性海藻糖酶, 异源表达, 酶学性质鉴定

Abstract: As a biocatalystase, acid trehalase is widely used in biological industry. It is very important to exploit new acid trehalase with excellent enzymatic properties. In this study, an acid trehalase gene (TreA) from Bispora sp. MEY-1 was successfully cloned and expressed in Pichia pastoris GS115. The enzymatic properties of purified trehalase TreA were identified. The optimum pH was 4.0, and the relative activity maintained over 60% under the range of pH 2.2~5.0. The relative activity of purified enzyme was more than 88% after treated for 1 h under pH 1.0~4.0, which exhibited the good acid stability. The optimum temperature of purified enzyme was 60 ℃, which was enzyme with medium-high temperature resistance. The specific activity of purified enzyme was 1 913 U·mg^-1, and its Km and Vmax were 0.67 mg·mL^-1 and 119 μmol·min^-1·mg^-1, respectively. Moreover, the effects of different mental ions or chemical reagents, and the protease resistances on the purified enzyme activity were also evaluated.

Key words: Bispora sp. MEY-1, acid trehalase, heterologous expression, characterization