代谢多种低聚糖乳酸菌的筛选鉴定及其部分益生特性研究

Screening and identification of lactic acid bacteria utilizing various oligosaccharides and their partial prebiotic properties

探究了110株乳酸菌对4种低聚糖(低聚木糖、低聚果糖、菊粉和低聚异麦芽糖)的广谱代谢能力,筛选获得3株对4种低聚糖代谢能力强的乳酸菌,对其进行系统鉴定和益生特性研究。结果表明,仅8株乳酸菌不能代谢低聚糖,其余菌株可代谢1~4种低聚糖,其中可代谢4种低聚糖的菌株SNR24为发酵乳杆菌(Lactobacillus fermentum)、菌株RP30和PC140为植物乳杆菌(Lactobacillus plantarum)。这3株菌能在以低聚糖为唯一碳源的培养基中良好生长,在11~13 h内进入稳定期,低聚糖添加量与生长量并非呈线性增长关系,菌株SNR24、RP30和PC140的最适宜低聚糖种类及添加质量浓度分别为50 g/L菊粉、30 g/L低聚异麦芽糖和50 g/L菊粉;对pH 3.0的低酸环境和质量浓度2 g/L胆盐环境耐受能力较好;在人工模拟胃肠液中的存活率为16%~70%;3株菌对多种抗生素敏感,对链霉素、环丙沙星耐药,菌株RP30和PC140对庆大霉素、四环素也耐药。综上所述,3株菌具有益生菌的潜质。

110 strains of suspected lactic acid bacteria were investigated for their broad-spectrum utilization to four oligosaccharides(xylo-oligosaccharides,fructo-oligosaccharides,inulin,isomalto-oligosaccharides).Of which,102 strains of lactic acid bacteria could use at least one oligosaccharide.Three strains,SNR24,RP30 and PC140 with maximum utilization of four oligosaccharides were screened out and identified as Lactobacillus fermentum,Lactobacillus plantarum and L.plantarum.Their prebiotic characteristics were also investigated.The results showed that the three strains grew well in the media with oligosaccharides as the only carbon source,and entered the stable period within 11-13 h.However,the oligosaccharide concentration was not linearly associated with the growth of lactic acid bacteria.The optimal oligosaccharides and concentrations for SNR24,RP30 and PC140 were 50 g/L of inulin,30 g/L of isomalto-oligosaccharides and 50 g/L of inulin,respectively.The three strains were tolerant to low-acid environment of pH 3.0 and bile salt environment of 2 g/L,and their survival rate in artificial simulated gastrointestinal fluid was 16%-70%.They were sensitive to multiple antibiotics,and resistant to streptomycin and ciprofloxacin.RP30 and PC140 were also resistant to gentamicin and tetracycline.In summary,they had the potential to become probiotics.