kre1Δ酿酒酵母孢子固定肌酐酶体系的构建及其酶学分析

Construction and analysis of creatininase encapsulated in kre1Δ Saccharomyces cerevisiae yeast spores

酵母孢子固定化酶是一种利用酵母孢子对酶进行包埋固定的新型酶固定化技术。研究表明,利用有孢子壁缺陷的osw2Δ酿酒酵母孢子作为酶固定化载体,不仅能大幅提高酶活,而且具有较强的抗逆性及较好的可重复利用性。为了研究新发现的kre1Δ孢子是否具有类似的性能,将肌酐酶转入酵母孢子,并对其酶学性能进行分析。实验结果表明,kre1Δ孢子固定的肌酐酶活性与osw2Δ孢子相近,都显著高于野生型孢子。与游离酶相比,kre1Δ孢子固定的肌酐酶与osw2Δ一样,都有较好的可重复利用性和较强的抗逆性。同时,kre1Δ孢子与osw2Δ孢子肌酐酶活的最适温度均为60℃,最适pH值均为6.0,且kre1Δ孢子与osw2Δ孢子一样都表现出较好的耐高温性及较广范围的pH耐受性。因此,kre1Δ孢子也是综合性能较好的酶固定化载体。

Using yeast spores to encapsulate enzymes is a new enzyme-immobilized technology. It was reported that the activity of encapsulated enzymes was largely improved by Saccharomyces cerevisiae spores of osw2Δ with mild deficiency of spore wall and the osw2Δ spore-encapsulate enzymes also exhibited resistance to environmental stresses and had a good reusability. To investigate whether kre1Δ spores had similar ability,the creatininase gene was transformed into yeast cells and the properties of encapsulated enzymes were examined. The results suggested that the activity of the creatininase encapsulated in kre1Δ spores was similar to osw2Δ spores but was significantly higher than that of wild type spores. Compared with free enzymes,like osw2Δ,encapsulated creatininase in kre1Δ spores exhibited resistance to environmental stresses and had a good reusability. The spore-encapsulated creatininase in kre1Δ and osw2Δ showed highest activity at 60 ℃,pH 6. 0. Moreover,the kre1Δ spore-encapsulated enzymes were resistant to high temperature and exhibited a wide range of pH tolerance as that of osw2Δ spores. Therefore,kre1Δ spores could be used as a superior carrier of enzyme capsules.