一株泡叶藻降解菌的筛选及其发酵条件优化 (1).pdfVIP

山东农业大学学报(自然科学版),2014,45(4):515-521 VOL.45 NO.4 2014 Journal of Shandong Agricultural University (Natural Science Edition ) doi:10.3969/j.issn.1000-2324.2014.04.007 一株泡叶藻降解菌的筛选及其发酵条件优化 刘 露,公春艳,赵宏涛,王 鹏,李园园* 青岛明月蓝海生物科技有限公司, 山东 青岛 266400 摘 要: 为了利用微生物降解泡叶藻，本研究以泡叶藻为唯一营养物质从土壤中筛选到一株对泡叶藻有明显降解效果 的菌株，编号 2-2。根据其形态学特征、生理生化特性和 16S rDNA 序列分析鉴定该菌株为巨大芽孢杆菌（Bacillus megaterium）。对菌株的发酵条件进行了优化，最优发酵培养基为：泡叶藻 30 g/L、酵母粉 6 g/L 和葡萄糖 4 g/L。摇 瓶最佳培养条件为：250 mL 三角瓶装液量 50 mL，起始 pH 7.5，发酵温度 32 ℃，发酵 48 h 有效活菌数为 2.4×109 CFU/mL。并对发酵液酶活进行了测定，其中纤维素酶活为 47.7 U/mL，蛋白酶活为 3.4 U/mL，海藻胶裂解酶活为 0.721 U/mL。研究结果表明巨大芽孢杆菌 2-2 同时具有海藻胶裂解酶、蛋白酶和纤维素酶活性，具有良好的应用前景。 关键词: 泡叶藻降解菌; 巨大芽孢杆菌; 海藻胶裂解酶; 发酵条件 中图法分类号: Q936 文献标识码: A 文章编号: 1000-2324(2014)04-0515-07 Isolation and Fermentation Optimization of an Ascophyllum Nodosum Degrading Strain LIU Lu, GONG Chun-yan, ZHAO Hong-tao, WANG Peng, LI Yuan-yuan* Qingdao Mingyue BlueOcean Bio-technology Co. Ltd., Qingdao 266400, China Abstract: To study ascophyllum nodosum degradated by microorganism, a high efficient microorganism was isolated from soil using ascophyllum nodosum as the sole nutrient. Based on the morphological, physiological characteristics and 16S rDNA sequence, the strain was identified as Bacillus megaterium. The optimized fermentation medium was composed of ascophyllum nodosum 30 g/L, yeast extract 6 g/L and glucose 4 g/L. The optimal culture condition was that the strain was cultured in 250 mL shake flakes containing 25 mL medium with initial pH 7.5 at 32 ℃. After 48 h fermentation, the effect