7株鸡源肠球菌的分离、鉴定及益生性能比较

Isolation,Identification and Comparison of Probiotic Characteristics of Seven Kinds of Chicken Enterococcocci

对从健康6日龄AA肉仔鸡肠道中分离出的7株肠球菌进行了体外生物学特性研究。利用肠球菌选择性培养基进行分离,采用16S rRNA和Biolog两种方法进行菌种鉴定,并测定其生长、产乳酸、抑制病原菌、耐人工胃肠液等益生性能指标。研究发现,从小鸡肠道中分离得到的7株菌,经鉴定为粪肠球菌(Entero-coccus faecalis)或屎肠球菌(Enterococcus faecium),通过对7株菌的益生性能进行综合评价比较后,筛得菌株Enterococcus faecium GJ01013,其具有生长速度快(代时<30 min)、延滞期短、产L-乳酸能力强(达6.5 g/L)、对致病型大肠杆菌K88/K99、多杀性巴氏杆菌、鸡白痢沙门氏菌及金黄色葡萄球菌有较强的抑制作用(最大抑菌圈直径可达21.5 mm)、人工胃肠液中存活率高(最高达93.5%)等优良特点,为饲用益生菌产品开发提供了菌种来源。

This article studies the biological characteristics in vitro of seven enterococcocci which are isolated from the guts of 6 - day - old AA broiler chickens. Selective medium is used to isolate enterococcocci and two methods that are 16S rRNA and Biolog are used to identify these strains, and the probiotic characteristics index such as growth, lactic acid production, inhibiting pathogens and tolerance of artificial gastrointestinal fluid are determined. This research finds that the seven strains are either Enterococcus faecalis or Enterococcus faecium. After comparing the per- formances of probiotics, an excellent strain named Enterococcusfaecium GJ01013 can be obtained. It has the following characteristics ： faster growth （ generation time 〈 30 min）, shorter lag phase, better capacity of L - lactic acid produc- tion（ up to 6.5 g/L）, stronger inhibitory of Escherichia coli K88/K99, Pasteurella multocida, Salmonella pullorum and Staphyloccocus aureus Rosenbach （the maximum antibacterial diameter can be up to 21.5 mm）, and higher survival rate of artificial gastrointestinal fluid（the highest survival rate is 93.5% ）. Enterococcus faecium GJ01013 shows excellent performance for the exploitation of new feed probiotic products.