Department of Food Management, Miyagi University, Sendai, Japan.
Methods Mol Biol. 2024;2851:185-192. doi: 10.1007/978-1-0716-4096-8_16.
Gram-negative bacteria such as Escherichia coli, among intestinal bacteria, have lipopolysaccharide (LPS), which induces inflammation of human intestines. However, lactic acid bacteria (LAB) can improve human intraintestinal conditions. One reason is that ingestion of LAB prevents bacterial diarrhea. This chapter describes a method of LPS elimination using lactic acid bacteria (LAB). First, the LPS concentration is assayed using an LPS assay kit with the limulus cascade reaction made by limulus amebocyte lysate. Some LABs, four bacillus strains and one coccus strain, have LPS-elimination activity. Particularly, the coccus strain Pediococcus pentosaceus eliminates LPS to 43%. The cells fractionate and eliminate four fractions: the extracellular fraction, cell membrane fraction, cytoplasm fraction, and cell wall fraction. Only the cell wall digesting fraction eliminates LPS to 45%. Results confirm that the LAB eliminates all LPS having O-antigen under a low-sugar medium condition at temperatures of 15-30 °C. This method can be used for assay of LPS elimination by LABs exactly and easily for the probiotics field.
革兰氏阴性菌，如肠道细菌中的大肠杆菌，具有脂多糖（LPS），会引起人类肠道炎症。然而，乳酸菌（LAB）可以改善人体肠道内环境。原因之一是摄入乳酸菌可以预防细菌性腹泻。本章介绍了一种使用乳酸菌（LAB）去除 LPS 的方法。首先，使用鲎试剂的鲎血阿米巴细胞溶解物进行脂多糖检测试剂盒来检测 LPS 浓度。一些 LAB，四种芽孢杆菌菌株和一种球菌菌株，具有 LPS 消除活性。特别是，戊糖片球菌（Pediococcus pentosaceus）菌株可将 LPS 消除至 43%。细胞分级并消除四个部分：细胞外部分、细胞膜部分、细胞质部分和细胞壁部分。只有细胞壁消化部分可将 LPS 消除至 45%。结果证实，LAB 在 15-30°C 的低糖培养基条件下可完全消除具有 O-抗原的 LPS。该方法可用于准确、轻松地检测 LAB 消除 LPS 的能力，适用于益生菌领域。
