PDF(Pubmed)
Abstract：
The D-amino acid content of Ishizuchi-kurocha, a post-fermented tea produced in Ehime, Japan, was measured. Ishizuchi-kurocha mainly contains D-glutamic acid and D-alanine, but it also contains a small amount of D-aspartic acid. Two types of lactic acid bacteria, Lactiplantibacillus plantarum and Levilactobacillus brevis, are the main species involved in lactic acid fermentation during the tea fermentation process. Therefore, the D-amino acid-producing abilities of strains of these two species isolated from Ishizuchi-kurocha were examined. Specifically, the production of D-aspartic acid, D-alanine, and D-glutamic acid by L. brevis and L. plantarum strains was observed. The amount of D-aspartic acid produced by L. plantarum was low. D-glutamine was detected in culture supernatant but not in bacterial cells. D-arginine was detected in bacterial cells of the L. plantarum strains but not in the culture supernatant. Both the L. brevis and L. plantarum strains possessed at least three kinds of putative racemase genes: alanine racemase, glutamate racemase, and aspartate racemase. However, their expression and enzyme activity remain unknown. L. plantarum and L. brevis could play an important role in the production of D-amino acids in Ishizuchi-kurocha. In fact, Ishizuchi-kurocha is expected to possess the effective physiological activities of D-amino acids.
摘要：
石口-黑茶的D-氨基酸含量，爱媛生产的后发酵茶，Japan,是测量的。石口黑茶主要含有D-谷氨酸和D-丙氨酸，但它也含有少量的D-天冬氨酸。两种类型的乳酸菌，植物乳杆菌和短左杆菌，是茶叶发酵过程中参与乳酸发酵的主要菌种。因此,检查了从石口-黑茶中分离出的这两个物种的菌株的D-氨基酸生产能力。具体来说,D-天冬氨酸的生产,D-丙氨酸,观察到短乳杆菌和植物乳杆菌菌株的D-谷氨酸。植物乳杆菌产生的D-天冬氨酸的量较低。在培养上清液中检测到D-谷氨酰胺，但在细菌细胞中未检测到。在植物乳杆菌菌株的细菌细胞中检测到D-精氨酸，但在培养上清液中检测不到。短乳杆菌和植物乳杆菌菌株都具有至少三种推定的消旋酶基因：丙氨酸消旋酶，谷氨酸消旋酶，和天冬氨酸消旋酶.然而,它们的表达和酶活性仍然未知。植物乳杆菌和短乳杆菌可能在石口苦茶中D-氨基酸的产生中起重要作用。事实上,石口苦茶有望具有D-氨基酸的有效生理活性。
