枯草芽孢杆菌B2的生长及其对仿刺参的益生特性

从大连湾地区健康的仿刺参养殖池塘沉积物中分离得到一株芽孢杆菌菌株B2,经16SrDNA鉴定以及形态学分析确定其为枯草芽孢杆菌。该菌株生长适宜温度为15~35℃,适宜pH为6~8,适宜盐度为30~50。电镜观察发现,枯草芽孢杆菌B2周围有明显可见的芽孢。枯草芽孢杆菌B2可产淀粉酶和蛋白酶,但不具有产脂肪酶的能力。将枯草芽孢杆菌B2按照仿刺参体质量的0.1%、0.2%和0.3%配成不同密度的菌液,添加至饲料中,投喂7d后发现,该菌株可有效提高仿刺参肠道内的消化酶以及体腔液中多种非特异性免疫酶的活性。结果表明,枯草芽孢杆菌B2可作为益生菌剂的基础菌株添加至仿刺参饲料中。

Growth and Probiotic Characteristics of Bacillus subtilis B2 in Sea Cucumber Apostichopus j aponicus

A bacterial strain B2 isolated from sediment in healthy sea cucumber A postichopus j aponicus farm in Dalian was identified as Bacillus subtilis by morphological and 16S rDNA sequence analysis .It was found that the optimal grow th of strain B2 was observed at temperature of 15—35 ℃ ,pH of 6—8 and a sa‐linity of 30—50 .The electron microscopy revealed that there was visible gemma around strain B 2 obvious‐ly .The strain B2 produced both amylase and protease ,but did not secreate lipase .The different doses of the strain B2 was added into the diets according to the weight of sea cucumber by 0 .1% ,0 .2% and 0 .3% , and it was found that the strain B2 effectively improved the activities of digestive enzymes in the intestine and nonspecific immune enzymes in the coelomic fluids .The findings indicate that B. subtilis B2 can be used as basis strain of probiotics and added into the sea cucumber feed ,w hich can provide more resources for the further sea cucumber probiotics .