中文摘要：

通过传统分离培养法从动物肠道分离得到112株芽胞杆菌,其培养物通过离心过滤后采用氨基酸全自动分析仪对分离得到的100多株芽胞杆菌进行上清氨基酸分析,采用打孔法测定芽胞杆菌对大肠杆菌O8株的抑制效果,通过紫外诱变和S-（2-氨乙基）-L-半胱氨酸筛选对菌株进行选育。结果发现,不同芽胞杆菌菌株产赖氨酸能力相差较大,其中产赖氨酸水平高、抑菌性好的菌株枯草芽胞杆菌PA105,上清赖氨酸水平超过0.3g/L。将枯草芽胞杆菌PA105进行紫外诱变和AEC筛选,获得产赖氨酸高且抗菌的突变菌株枯草芽胞杆菌PL83,上清赖氨酸水平达到0.582g/L,几乎比常规菌株提高了1倍。

英文摘要：

The present research aimed to develop a new probiotic product with functions of both lysine high-yielding and strong inhibition on the growth of E.coli O8 by screening and mutation breeding of the Bacillus strains.A total of 112 Bacillus strains were isolated from pig intestine in the present study by traditional culture-based method.The lysine content in the culture supernatant of Bacillus strains was determined by Automatic Amino Acid Analyzer.The inhibition effects of Bacillus strains on the growth of E.coli O8 were determined using an inhibition zone assay.The UV-mutagenesis and s-（2-aminoethyl）-L-cysyeine hydrochloride（AEC）screening was conducted on bacterial strain.The results indicated that there existed large differences for the lysine content of the culture supernatant among different Bacillus strains.The Bacillus subtilis PA105 can effectively inhibit the growth of E.coli O8 and its lysine content in the culture supernatant was up to 0.3g/L.The UV-mutagenesis and S-（2-aminoethyl）-L-cysyeine hydrochloride（AEC）screening was conducted on B.subtilis PA105.The lysine content in the culture supernatant of the resulting mutant strain B.subtilis PL83 was up to 0.582g/L.The lysine content in the culture supernatant of the resulting bacterial strain in the present research is increased by almost 100 percent compared with conventional strains.