紫色红曲霉中新型酯酶ESM1的纯化及其酶学特性研究

该研究以白酒大曲中筛选出的一株高产酯酶菌株HQ为研究对象，采用分子生物学对其进行菌种鉴定。通过硫酸铵二级沉淀、丁基琼脂糖凝胶柱和Superdex G-200柱对其所产的酯酶进行纯化，并进行N-端序列、质谱和酶学性质分析。结果表明，菌株HQ被鉴定为紫红曲霉（Monascus purpureus），经纯化获得一个分子质量为60 kDa的酯酶，命名为ESM1。酯酶ESM1具有一段酸性蛋白酶的肽段序列，最适温度为60 ℃、最适pH值为7.0，在温度为50 ℃的环境和中性环境中表现出良好的稳定性。Zn2+、Ca2+和Na+对ESM1有促进作用，其中Zn2+促进作用最高，Cu2+、Mg2+、Fe2+和Mn2+有抑制作用，其中Cu2+的抑制作用最强。

Purification and characterization of a new esterase ESM1 from Monascus purpureus

Using a strain HQ with high-yield esterase screened from Baijiu (Chinese liquor) Daqu as the research object, the strain was identified by molecular biology. The esterase produced by the strain HQ was purified by ammonium sulfate two-stage precipitation, butyl agarose gel column and Superdex G-200 column, and analyzed by N-terminal sequence, mass spectrometry and enzymatic properties. The results showed that the strain HQ was identified as Monascus purpureus, and the esterase with a molecular weight of 60 kDa was obtained by purification, named ESM1. The esterase ESM1 had a peptide sequence of an acid protease, and the optimum temperature and pH of the esterase ESM1 were 60 ℃, 7.0, respectively. The esterase ESM1 had good stability in the environments of 50 ℃ and neutral environments. The esterase ESM1 could be promoted by Zn2+, Ca2+ and Na+, among which the promoting effect of Zn2+ was the strongest, and be inhibited by Cu2+, Mg2+, Fe2+ and Mn2+, among which the inhibiting effect of Cu2+ was the strongest.