谷氨酰胺合成酶产酶菌株的筛选及酶学性质

Screening and Enzyme Property of Enzyme-producing Strains

通过对枯草杆菌、黑曲霉、米曲霉3种菌株的筛选,得到3种菌株具有产谷氨酰胺合成酶(GS)的能力,其中米曲霉产酶能力较高,对米曲霉菌株进行紫外线诱变使其产酶能力提高了15.6%。确定了米曲霉最佳超声波破碎条件为:功率400W,工作1s,间歇3s,超声20min。谷氨酰胺合成酶的最佳酶促反应时间为30min,最适pH值为6.5,最适温度为60℃,并且得出了Mg2+和Mn2+对维持酶活至关重要。

By screening Bacillus subtilis, Aspergillus niger and Aspergillus oryzae, three kinds of strains have producted the ability of glutamine synthetase （GS）, in which Aspergillus oryzae has the higher production ability of enzyme, its production capacity of enzyme is improved 15.6% by ultraviolet mutagenesis of Aspergillus oryzae strains. The best ultrasonic fragmentation conditions of Aspergillus oryzae are determined： the power 400 W, the work time 1 s, the intervale time 3 s, the ultrasound time 20 min. The best enzyme reaction time of GS is 30 min, pH 6.5, the temperature 60 ℃, Mg2＋ and Mn2＋are essential to maintain enzymic activity.