具有分解嘌呤核苷能力的益生菌菌株筛选

在不同的肠道菌群及奶制品样品中筛选益生菌菌株，对其耐酸和耐胆盐能力、分解嘌呤核苷能力进行评价，为后续研发治疗高尿酸血症益生菌制剂提供依据。

采集内蒙古地区及巴马长寿村的健康婴儿肠道菌群或奶豆腐、奶疙瘩制品，通过选择性培养基划线培养、镜检及16S rDNA测序的方式筛选益生菌菌株。通过耐酸、耐胆盐试验，模拟胃液和模拟肠液筛选出对胃肠道环境耐受能力强的菌株并通过电镜观察其形态。再进一步通过分解嘌呤核苷能力检测确定分解能力最优的菌株。

在8个样本中筛选出23株益生菌，对其胃肠耐受能力进行检测后发现筛选出了8株耐受能力较强的益生菌菌株，分别为鼠李糖乳酪杆菌RH01103，罗伊氏粘液乳杆菌HCS02-001，植物乳植杆菌RH03010，动物双歧杆菌乳亚种RH04020，发酵粘液乳杆菌RH08050，副干酪乳酪杆菌HCS17-040，乳酸片球菌RH27102和戊糖片球菌RH34011。通过对分解嘌呤核苷能力检测，发现与未接种益生菌的空白对照组相比，罗伊氏粘液乳杆菌HCS02-001和副干酪乳酪杆菌HCS17-040对肌苷和鸟苷的分解能力最显著（P = 0.0002, P＜0.0001）。

8个样本筛选出的23株益生菌中罗伊氏乳杆菌HCS02-001和副干酪乳杆菌HCS17-040的胃肠耐受能力最强，分解嘌呤核苷效率最高。

Isolation of probiotic strains capable of decomposing purine nucleosides

ObjectiveTo screen probiotic strains from different gut microbiota and dairy samples, evaluate their acid and bile salt tolerance and purine nucleoside decomposition ability, and provide basis for further research and development of probiotics for the treatment of hyperuricemia. MethodsThe gut microbiota of healthy infants or milk curd and milk products from Inner Mongolia and Bama longevity village were collected, and the probiotic strains were screened by means of selective medium streak culture, microscopic examination and 16S rDNA sequencing. The strains with strong tolerance to gastrointestinal environment were screened by using acid and bile salt tests, simulated gastric fluid and simulated intestinal fluid, and their morphology was observed with electron microscopy. Then, the strain with the best decomposition ability was determined by detecting the ability to decompose purine nucleoside. ResultsTwenty-three strains of probiotics were selected from 8 samples. After testing their gastrointestinal tolerance, 8 strains of probiotics with strong tolerance were selected, namely, Lacticaseibacillus rhamnosus RH01103, Limosilactobacillus reuteri HCS02-001, Lactiplantibacillus plantarum RH03010, Bifidobacterium animalis subsp. lactis RH04020, Limosilactobacillus fermentans RH08050, Lacticaseibacillus paracasei HCS17-040, Pediococcus acidilactici RH27102 and Pediococcus pentosaceus RH34011. Compared with the blank control, it was found through the detection of purine nucleoside decomposition ability that Lactobacillus reuteri HCS02-001 and Lactobacillus paracasei HCS17-040 had the most significant ability of decomposing inosine and guanosine (P＜0.001). ConclusionAmong the 23 strains of probiotics, Limosilactobacillus reuteri HCS02-001 and Lacticaseibacillus paracasei HCS17-040 had the strongest gastrointestinal tolerance and the highest efficiency of purine nucleoside decomposition.