一株产NAD^+依赖型甘油脱氢酶嗜热杆菌的筛选

Screen Thermophilic Bacillus that Produce NAD^+ Depend Glycerol Dehydrogenase

将采集于清源山、华大后山果园、华大南浦果园、实验室附近等多处的高温堆肥样品在60℃、pH7.0条件下进行富集培养,其中南浦果园堆肥样品菌体长势较好,菌株呈暗绿色;逐步提高培养基中甘油浓度(0.5g/L^3g/L),进行菌株产甘油脱氢酶(GDH)的驯化培养与复筛,经8个批次的复筛,获得一株产GDH酶活达0.201U/mL的棕色菌株,编号TB8-5;经镜检分析同时结合菌落生长特性并经生理生化实验反应鉴定,初步判断筛选出的菌株属嗜热芽孢杆菌属;菌株发酵液中产物组分鉴定为二羟基丙酮(DHA),含量为0.597mg/mL,相应的GDH酶活也最高,其最适反应温度为50℃,最适反应条件pH为8.0,Zn2+对酶活有一定的促进作用.

Samples of high temperature compost collected from different point（named QYS, HS, NP, ZZ） were enrichment cultured at 60℃, pH7.0. Bacterium growed preferable was obtained from sample of NP and submit sap green; The strain was domesticationed for produce Glycerol Dehydrogenase （GDH） by improved glycerol from 0.5g/L to 3g/L and a Strain that produced GDH with 0.2 U/mL activity was acquired after 8 batchs screened, numbered TB8-5 and distinguished as Therrnophili Bacillus; Produce in ferment liquid was identified as Dihydroxyacetone （DHA） and it,s most content was 0.597 mg/mL, relevant GDH activity also highest and optimum temperature of the GDH was 50℃, optimum pH was 8.0, Zn^2＋ facilitated to enzyme activity.