具有抑菌活性植物乳杆菌的筛选及抑菌物质特性的研究

Screening of Lactiplantibacillus plantarum with bacteriostaticactivity and study on properties of bacteriostatic substances

该研究通过牛津杯双层平板法,从分离自四川泡菜的114株植物乳杆菌中筛选对大肠杆菌O157:H7具有较强拮抗活性的菌株,并对其所产抑菌物质的特性进行了初步的研究。结果表明:114株植物乳杆菌的上清液均可抑制大肠杆菌,其中16株菌的上清液经排酸后仍有抑菌作用,并且抑菌作用不受过氧化氢酶影响,经蛋白酶处理后大幅降低甚至消失;在进一步筛选中发现植物乳杆菌IMAU80122所产抑菌物质具有耐酸(pH 3)、耐弱碱(pH 8)的特性,在80℃具有一定的稳定性,对不同的表面活性剂、有机溶剂、金属离子、盐浓度、紫外照射时间都具有良好的耐受性;对G^(-)菌株的抑菌活性强于G^(+)菌株,但对供试的乳酸菌没有作用。综上所述,植物乳杆菌IMAU80122所产抑菌物质具有蛋白性质,不仅抑菌活性强,而且具有良好的稳定性和广谱抑菌效果,在食品加工和医药行业中具有一定的开发应用潜能。

In this study,114 strains of Lactiplantibacillus plantarum isolated from Sichuan pickles were screened by Oxford cup double-layer plate method,which had strong antagonistic activity against Escherichia coli O157∶H7,and the characteristics of protein antibacterial substances produced by L.plantarum were studied.The results showed that the supernatant of 114 strains of L.plantarum could inhibit E.coli,and 16 strains of L.plantarum could still inhibit E.coli after acid drainage,and the inhibitory effect was not affected by catalase,but was significantly reduced or even disappeared after protease treatment.Further screening showed that the antibacterial substances produced by L.plantarum IMAU80122 had the characteristics of acid resistance(pH 3)and weak alkali resistance(pH 8),had certain stability at 80℃,and had good resistance to different surfactants,organic solvents,metal ions,salt concentration and UV irradiation time.The antibacterial activity against G^(-)strain was stronger than G^(+)strain,but it had no antibacterial activity against tested lactic acid bacteria.In conclusion,the bacteriostatic substances produced by L.plantarum IMAU80122 have protein properties,which not only have strong bacteriostatic activity,but also have good stability and broad-spectrum bacteriostatic effect,and have certain development and application potential in food processing and pharmaceutical industry.