猪源乳酸杆菌的安全性及抗逆性评价

对本实验室自行分离自猪肠道的3株乳酸杆菌进行安全性和抗逆性检测,采用体外法对分离自不同生理阶段猪(仔猪、生长肥育猪、母猪)肠黏膜和食糜的罗伊乳杆菌(Lactobacillus reuteri)L45、植物乳杆菌(L.plantarum)L47和约氏乳杆菌(L.johnsonii)L63进行生长特性、溶血性、有害代谢产物、抗生素敏感性试验以及模拟胃肠道消化试验。结果:3株乳酸杆菌无溶血现象,不产生有害代谢产物。植物乳杆菌L47在37℃培养24 h时活菌数达到8.07lg CFU/mL,OD600值达到0.80,乳酸产量达到135.21 mmol/L,为3株菌中最高;对试验所用抗生素敏感性最高,且其在模拟胃液中消化4 h存活率依然高达99.11%,显著高于罗伊乳杆菌L45和约氏乳杆菌L63(P<0.05)。研究表明:植物乳杆菌L47益生特性良好且不是溶血菌株,发酵过程中不产生有害代谢产物,耐药性较低,在肠道中存活率高,具有潜在饲用价值。

Evaluation of safety and stress resistance of Lactobacilli isolated from swine

The safety and stress resistance of three Lactobacillus strains isolated from swine intestinal tract in our laboratory were tested to lay foundation for production application and promotion.The three Lactobacillus strains(L.reuteri L45,L.plantarum L47 and L.johnsonii L63)isolated from the intestinal mucosa and digesta of swine at different stages of growth(piglets,growth-finishing pigs,sows)were tested in vitro for probiotic properties,hemolysis,harmful metabolites,antibiotic sensitivity and simulated gastrointestinal digestion.The results showed that these Lactobacillus strains had no hemolysis and did not produce harmful metabolites.When Lactobacilli were cultured at 37℃for 24 hours,the viable count reached 8.07 lg CFU/mL,the OD600 value reached 0.80,the lactic acid yield reached 135.21 mmol/L and its sensitivity to the antibiotics of L.plantarum L47 was the best of the three strains.Meanwhile,the survival rate of the strain was as high as 99.11%after 4 h digestion in simulated gastric fluid,which was significantly higher than that of L.reuteri L45 and L.johnsonii L63(P<0.05).The present study indicated that L.plantarum L47 possessed good probiotic properties and was not a hemolytic strain.It did not produce harmful metabolites during fermentation,but had low drug resistance,and had a high survival rate in the intestinal tract.It would be a probiotic with a potential of feeding value.