表层蛋白对嗜酸乳杆菌NCFM生长代谢的影响

为评估表层蛋白对嗜酸乳杆菌自聚集、生长及代谢的影响,通过测定菌体自聚集率、菌体生长、GC-MS分析表层蛋白去除前后嗜酸乳杆菌胞内小分子代谢物的变化。结果表明,表层蛋白去除前后,嗜酸乳杆菌的胞内氨基酸类如组氨酸、酪氨酸、鸟氨酸,有机酸类如乳酸、苹果酸等代谢物具有显著差异,这些代谢物直接影响了表层蛋白相关的主要生化反应和关键代谢通路。经过代谢通路富集分析,主要影响了精氨酸和脯氨酸代谢、赖氨酸生物合成、精氨酸生物合成、氨基糖和核苷酸糖代谢、丙氨酸,天冬氨酸和谷氨酸代谢这5条代谢通路。总之,表层蛋白的剥离影响了氨基酸合成的代谢通路,氨基酸合成会竞争生长所需的能量,进而影响嗜酸乳杆菌的生长,该研究为进一步认识表层蛋白对嗜酸乳杆菌胞内小分子化合物代谢的影响提供了依据。

Effect of surface layer protein on the growth and metabolism of Lactobacillus acidophilus NCFM

In order to evaluate the effect of surface layer protein on the self-aggregation, growth and metabolism of Lactobacillus acidophilus NCFM, the self-aggregation rate and growth of L. acidophilus were measured, and GC-MS was used to analyze the changes of the intracellular small molecule metabolites of L. acidophilus before and after the removal of the surface layer protein. The intracellular amino acids and organic acids of L. acidophilus such as histidine, tyrosine, ornithine, lactic acid, malic acid and other metabolites changed significantly. These metabolites directly affected the major biochemical reactions and important metabolic pathways related with surface layer protein. Enrichment analysis of metabolic pathways showed that it mainly affected arginine and proline metabolism, lysine biosynthesis, arginine biosynthesis, amino sugar and nucleotide sugar metabolism, alanine, aspartate and glutamate metabolism. In conclusion, the removal of surface layer protein affected the metabolic pathways of amino acid synthesis. The synthesis of amino acids competed energy required for growth, and then affected the growth of L. acidophilus. This study provides a basis for further understanding the effects of surface layer protein on the metabolism of intracellular small molecule compounds in L. acidophilus.