具有沙门氏菌拮抗能力的植物乳杆菌益生特性评价

Probiotic Properties Assessment of Lactobacillus plantarum with Salmonella Antagonistic Ability

对筛选出的具有较强沙门氏菌拮抗能力的植物乳杆菌进行生物学特性研究,评价其作为饲用益生菌的可行性和安全性。通过牛津杯法抑菌试验对乳酸菌进行抑菌性能的初筛,选择抑菌性能最强的菌株与沙门氏菌共培养,测定其对沙门氏菌的拮抗能力。随后研究其生长性能、对不良环境耐受能力、对肠黏膜的黏附性、安全性、传代稳定性等。结果显示,植物乳杆菌BLCC2-0410细菌培养液对鸡白痢沙门氏菌抑制效果最好,与对照组相比,植物乳杆菌BLCC2-0410和鸡白痢沙门氏菌CVCC533共培养24 h,鸡白痢沙门氏菌数量降低了约3个对数值。植物乳杆菌BLCC2-0410接种后2 h即进入对数生长期,最高活菌数可达4.7×109 cfu/mL,发酵液最低pH值为3.74,耐受pH值2.5和3.0的环境,对0.1%~0.3%的禽胆盐环境具有一定的耐受性,在胃蛋白酶液和胰蛋白酶液中处理4 h存活率分别为34.3%和77.8%,对肠黏膜的黏附率为18.2%。安全性试验结果表明,灌喂植物乳杆菌BLCC2-0410未对雏鸡饮食造成影响,剖检未发现肺脏、脾脏、肝脏、肾脏等有肉眼可见病变;植物乳杆菌BLCC2-0410连续传5、15、25代,培养物在活菌含量、细菌形态、发酵液pH值、对鸡白痢沙门氏菌的抑菌圈直径方面均无明显变化。由此可见,植物乳杆菌BLCC2-0410的抑菌特性明显,生长特性优良,产酸能力强,对酸、胆盐和消化酶等不良环境的耐受能力强,具有一定的黏附于肠黏膜的能力,且对雏鸡无毒副作用,传代稳定性良好,可作为潜在鸡用益生菌进行进一步研究。

The aim of this study was to investigate the biological characteristics of a strain of Lactobacillus plantarum with strong ability to antagonize Salmonella,and to evaluate the feasibility and safety of Lactobacillus plantarum as feed probiotics.The strains were screened by Oxford cup antimicrobial test,and the strain with the strongest antibacterial property was co-cultured with Salmonella to determine its antagonistic ability to Salmonella.Then the growth performance,tolerance to adverse environment,adhesion to intestinal mucosa,safety and passage stability were studied.The results showed that Lactobacillus plantarum BLCC2-0410 had the best inhibitory effect on Salmonella pullorum.Lactobacillus plantarum reduced the growth of Salmonella pullorum by approximately 3 logs after co-culture for 24 h compared to the control.The growth of Lactobacillus plantarum entered logarithmic growth phase at 2 h after inoculation,and the highest viable count was 4.7×109 cfu/mL.The minimum pH value of the culture medium was 3.74.It was tolerant to pH values of 2.5 and 3.0,and had certain tolerance to 0.1%—0.3%avian bile salt environment.The survival rate was 34.3%in pepsin solution and 77.8%in trypsin solution after 4 h,and the adhesion rate to intestinal mucosa was 18.2%.The security test results showed that feeding Lactobacillus plantarum BLCC2-0410 did not affect the feed intake of chicks and there were no visible lesions in the lung,spleen,liver,kidney,etc..The strain of Lactobacillus plantarum BLCC2-0410 was continuously passed for 5,15,25 generations,and there was no significant difference in the viable count,bacterial morphology,pH value of fermentation broth and the diameter of inhibition zone to Salmonella pullorum.In conclusion,the strain of Lactobacillus plantarum BLCC2-0410 has obvious antimicrobial properties,excellent growth characteristics,strong acid production capacity,strong tolerance to acids,bile salts and digestive enzymes,certain adhesion ability,no side effects on chickens and good passage stability,which can be used as a potential probiotic for further study.