降解嘌呤核苷乳酸菌的筛选及益生特性探索

Screening of purine nucleoside-degrading lactic acid bacteria and exploration of its probiotic properties

摘要:

【背景】高尿酸血症是人体内嘌呤代谢紊乱导致的一种慢性代谢疾病，利用乳酸菌降解嘌呤类物质是辅助治疗高尿酸血症的新方法。【目的】筛选高效降解嘌呤核苷的乳酸菌并对其益生特性进行研究。【方法】利用HPLC法评价乳酸菌对肌苷、鸟苷的降解效果。通过药敏性试验、体外耐受性试验及细胞黏附试验研究目标菌株的益生特性。【结果】筛选出一株发酵乳杆菌(Lactobacillus fermentum) SR2-6，对肌苷和鸟苷的降解率分别为99.26%和98.85%。该菌株对青霉素、氯霉素等5种常见抗生素不具备耐药性，在pH 2.0环境下处理4 h后菌株的存活率为76.51%，在饱腹状态下的人工肠液模拟消化4 h后活菌数仍能达到6.85 lg (CFU/mL)，对Caco-2细胞的黏附数为(52.29±15.14) CFU/cell。【结论】发酵乳杆菌SR2-6能够高效降解肌苷和鸟苷且具有优良的益生特性，是预防和治疗高尿酸血症的潜在优势菌株，可作为优势菌种资源应用于相关功能产品的开发。

Abstract:

[Background] Hyperuricemia is a chronic metabolic disease caused by the disorder of purine metabolism and lactic acid bacteria can degrade purines. [Objective] To screen lactic acid bacteria that efficiently degrade purine nucleoside and analyze the probiotic properties. [Methods] High performance liquid chromatography was used to determine the strain with the strongest ability to degrade inosine and guanosine. What’s more, probiotic properties of the target strain were studied by drug sensitivity test, in vitro tolerance tests, and cell adhesion test. [Results] Lactobacillus fermentum SR2-6 was screened out, which had the highest degradation rates of inosine and guanosine (99.26% and 98.85%, respectively). This strain showed no resistance to five common antibiotics such as penicillin and chloramphenicol. The survival rate of the strain was 76.51% after treatment under pH 2.0 for 4 h. The count of the viable bacteria was up to 6.85 lg (CFU/mL) after 4 h treatment in artificial satiety intestinal juice. The number bacteria adhered to Caco-2 cells was (52.29±15.14) CFU/cell. [Conclusion] SR2-6 can efficiently degrade inosine and guanosine, with excellent probiotic properties. It is a potential superior strain for the prevention and adjuvant treatment of hyperuricemia and can be applied into the development of related functional products.