一株广温性大菱鲆肠道益生菌的筛选与鉴定

Screening and identification of a eurythermal probiotic bacterium in the intestine of cultured Scophthalmus maximus

从健康的大菱鲆肠道内分离细菌,以大菱鲆致病菌鲨鱼弧菌Vibrio archariae和大菱鲆弧菌Vibrio scophthalmi为指示菌,根据拮抗作用原则,分离得到一株菌TYTG-1。根据菌株的形态、生理生化特征和16S rDNA序列分析,菌株被鉴定为枯草芽孢杆菌Bacillus subtilis。从养殖大菱鲆肠道中分离获得枯草芽孢杆菌在国内属首次报道。该株菌在4~42℃均能生长,属广温性。经过28d的投喂添加浓度为107和109CFU/g枯草芽孢杆菌的饲料,大菱鲆生长正常,未产生不良反应。该株枯草芽孢杆菌对引起大菱鲆腹水病和肠炎病的两株致病弧菌具有良好的拮抗作用,其具有较大潜力作为肠道益生菌应用于大菱鲆的养殖。

One potential probiotic bacterium TYTG-1 screened from the intestine of cultured Scophthalmus maximus was obtained.The antagonism of bacterium TYTG-1 to turbot pathogens Vibrio archariae and V.scophthalmi was evaluated.Based on the morphological observations,physiological and biochemical characteristics and 16S rDNA sequence analysis,the bacterium was identified as Bacillus subtilis.This is the first report on B.subtilis being found in the intestine of cultured S.maximus in China.The TYTG-1 is a eurythermal bacterium that can grow at 4~42 ℃.S.maximus could grow without any abnormal phenomenon as they were fed with the TYTG-1 bacterial cells at densities of 107 or 109 CFU/g for 4 weeks.The bacterium exhibited an excellent antagonism to the pathogens V.archariae and V.scophthalmi which could cause ascetic and enteric diseases in turbots.Therefore this probiotic bacterium is a potential candidate to be applied in turbot culture.