Yeast strain 10 with high yield of protease was isolated from sediments of saltern near Qingdao, China. The protease had the highest activity at pH 9.0 and 45 ℃. The optimal medium for the maximum alkaline protease p...Yeast strain 10 with high yield of protease was isolated from sediments of saltern near Qingdao, China. The protease had the highest activity at pH 9.0 and 45 ℃. The optimal medium for the maximum alkaline protease production of strain 10 was 2.5 g soluble starch and 2.0 g NaNO3 in 100 mL seawater with initial pH 6.0. The optimal cultivation conditions for the maximum protease production were temperature 24.5 ℃, aeration rate 8.0 L min -1 and agitation speed 150 r min -1. Under the optimal conditions, 623.1 U mg -1 protein of alkaline protease was reached in the culture within 30 h of fermentation.展开更多
[目的]筛选产蛋白酶的海洋细菌资源。[方法]分别采用2216E培养基和酪蛋白固体培养基,对采自宁波洋沙山和象山海域的海水进行微生物的分离与纯化,采用平板透明圈法初筛和酶活力测定法复筛,采用16S r DNA序列分析进行菌株鉴定,并进行产酶...[目的]筛选产蛋白酶的海洋细菌资源。[方法]分别采用2216E培养基和酪蛋白固体培养基,对采自宁波洋沙山和象山海域的海水进行微生物的分离与纯化,采用平板透明圈法初筛和酶活力测定法复筛,采用16S r DNA序列分析进行菌株鉴定,并进行产酶工艺优化研究。[结果]纯化出15株产蛋白酶海洋细菌,从中筛选出1株产蛋白酶活力最高的菌株PB02,经鉴定为交替假单胞菌(Pseudoalteromonas sp.)。该菌株最适培养温度为20℃,最适装液量为10%,最适接种量为0.5%,最适转速为100 r/min,最适培养基pH为7。酶促反应最适温度为40℃,最适pH为10。[结论]该研究为蛋白酶高产菌株的改造和定向进化奠定了资源基础。展开更多
基金The authors would like to thank the National Natural Science Foundation of China for providing the financial support for the study （No. 30328021）.
文摘Yeast strain 10 with high yield of protease was isolated from sediments of saltern near Qingdao, China. The protease had the highest activity at pH 9.0 and 45 ℃. The optimal medium for the maximum alkaline protease production of strain 10 was 2.5 g soluble starch and 2.0 g NaNO3 in 100 mL seawater with initial pH 6.0. The optimal cultivation conditions for the maximum protease production were temperature 24.5 ℃, aeration rate 8.0 L min -1 and agitation speed 150 r min -1. Under the optimal conditions, 623.1 U mg -1 protein of alkaline protease was reached in the culture within 30 h of fermentation.
文摘[目的]筛选产蛋白酶的海洋细菌资源。[方法]分别采用2216E培养基和酪蛋白固体培养基,对采自宁波洋沙山和象山海域的海水进行微生物的分离与纯化,采用平板透明圈法初筛和酶活力测定法复筛,采用16S r DNA序列分析进行菌株鉴定,并进行产酶工艺优化研究。[结果]纯化出15株产蛋白酶海洋细菌,从中筛选出1株产蛋白酶活力最高的菌株PB02,经鉴定为交替假单胞菌(Pseudoalteromonas sp.)。该菌株最适培养温度为20℃,最适装液量为10%,最适接种量为0.5%,最适转速为100 r/min,最适培养基pH为7。酶促反应最适温度为40℃,最适pH为10。[结论]该研究为蛋白酶高产菌株的改造和定向进化奠定了资源基础。
