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为研究刺参养殖中海带饲料原料存在的高黏度、低消化率等问题,本试验以褐藻酸钠为唯一碳源的选择性培养基从海泥中筛选出一株能降解海带中褐藻胶且对刺参无致病性的细菌。经16S rDNA鉴定,该菌为芽孢杆菌。通过单因素试验及正交试验对影响菌株生长和褐藻胶降解的7个因素:发酵时间、发酵温度、诱导物褐藻酸钠浓度、补充氮源种类、氯化钠浓度、发酵初始pH和装液量进行了优化。确定的褐藻胶降解菌株的最佳发酵条件为:发酵时间96 h,褐藻酸钠0.2%,发酵起始pH 7.5,发酵温度30℃,硫酸铵0.3%,氯化钠2.5%,装液量40 mL(200 mL摇瓶体系,料液比为1∶30),在最优化的条件下,菌株W16的褐藻胶降解能力比优化前提高了3.29倍。
In order to study the high viscosity and low digestibility of seaweed feedstuffs in sea cucumber breeding, we selected a seaweed gel that can degrade alginate in kelp, and selected the seaweed as selective medium with sodium alginate as sole carbon source Non-pathogenic bacteria on the sea cucumber. The 16S rDNA identification, the bacteria Bacillus. Seven factors influencing the growth of strains and the degradation of alginate were investigated by single factor test and orthogonal test: fermentation time, fermentation temperature, inducer sodium alginate concentration, supplemental nitrogen source, sodium chloride concentration, initial fermentation pH and liquid volume Optimized. The optimum conditions for the degradation of alginate were as follows: fermentation time 96 h, sodium alginate 0.2%, fermentation pH 7.5, fermentation temperature 30 ℃, ammonium sulfate 0.3%, sodium chloride 2.5%, liquid 40 mL (200 mL shake flask system, the ratio of material to liquid was 1:30). Under the optimized conditions, the degradation ability of alginate of strain W16 was 3.29 times higher than that before optimization.