【摘要】 为进一步探索高产褐藻胶裂解酶菌株,促进其工业化应用,以褐藻酸钠为唯一碳源筛选培养基,从鲍鱼内脏中筛选出一株高产褐藻胶裂解酶菌株B4,通过形态学观察和系统发育分析,鉴定为弧菌属细菌Vibrio sp.B4。通过单因素实验对B4菌株的发酵条件和发酵培养基进行优化,获得发酵培养基的最适碳源为褐藻酸钠10g/L,最适氮源为（NH4）2SO410g/L,最适发酵条件为温度30℃,接种量1%,培养基初始pH 6.0。在单因素实验的基础上,通过Plackett-Burman（PB）筛选出3个影响产酶活力的显著因素:（NH4）2SO4浓度、pH、接种量。通过响应面进一步分析优化,得到最佳的发酵培养基为褐藻酸钠10g/L,（NH₄）₂SO₄ 10.91g/L,NaCl 10g/L,KH₂PO₄ 1g/L,MgSO4·7H2O 0.5g/L,CaCl₂ 0.2g/L,FeSO₄·7H₂O 0.02g/L,最佳发酵条件为温度30℃,接种量1.1%,起始pH 6.07。在最佳培养条件下,褐藻胶裂解酶活力可达19.09U/mL,比基础培养条件下提高了3.67倍。该菌经过产酶发酵条件的优化,酶活力得到较大幅度的提高,且其发酵产酶时间短,可为褐藻胶裂解酶的进一步研究应用提供参考。更多还原

【Abstract】 In order to screen the alginate lyase-producing strain and promote its commercial application,a strain B4 producing high level alginate lyase was screened from the viscera of abalone using sodium alginate as sole carbon source on agar medium.The strain was identified as Vibrio sp.B4 according to morphological observation and phylogenetic analysis.Single factor experiments showed the optimum carbon source of its fermentation medium was 10 g/L sodium alginate and the optimum nitrogen source was 10 g/L（NH₄）₂ SO₄.The optimum fermentation conditions were temperature 30℃,initial pH 6.0,inoculation1%.On the basis of single factor experiment,3 significant factors affecting enzyme activity were screened out by Plackett-Burman（PB）design:（NH₄）₂ SO₄,pH and inoculation amount.The optimization by a response surface methodology revealed that the optimal fermentation medium of B4 was comprised of sodium alginate 10 g/L,（NH₄）₂ SO₄ 10.91 g/L,NaCl 10 g/L,KH2 PO41 g/L,MgSO₄·7 H₂ O 0.5 g/L,CaCl₂ 0.2 g/L,FeSO₄·7 H₂ O 0.02 g/L.The optimal fermentation conditions were temperature 30℃,inoculation amount1.1%,initial pH 6.07.The alginate lyase activity was 19.09 U/mL under the optimized condition,which was 3.67 times higher than that under basic medium and culture conditions.The enzyme activity of Vibrio sp.B4 in this work has been greatly improved by optimization,and its enzyme production time is short,which can provide reference for further research and application of alginate lyase.更多还原