Theanine is the most abundant non-protein amino acid in Camellia sinensis, but it is not known how a tea plant accumulates such high levels of theanine. The endophyte isolated from in vitro grown plantlets of C. sinensis cultivars was identified as Luteibacter spp., showing strong biocatalytic activity for converting both glutamine and ethylamine to theanine. Theanine was secreted outside of the bacteria. The endophyte isolated from in vitro plantlets of Camellia oleifera cultivar was identified as Bacillus safensis and did not convert glutamine and ethylamine to theanine. Enzymatic assays in vitro indicated that γ-glutamyltranspeptidases rCsEGGTs from the endophyte Luteibacter strains converted glutamine and ethylamine to theanine at higher rates than rCsGGTs from C. sinensis. This is the first report on theanine biosynthesis by an endophyte from C. sinensis, which provides a new pathway to explore the mechanism of theanine biosynthesis in C. sinensis and the interactions between an endophyte and tea plants.

中文翻译：

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内生细菌对茶树茶氨酸生产的贡献

茶氨酸是山茶中最丰富的非蛋白质氨基酸，但尚不知道茶树如何积累如此高水平的茶氨酸。从中华绒螯蟹的体外培养小植株中分离出的内生菌被鉴定为黄体杆菌属，显示出强大的生物催化活性，可将谷氨酰胺和乙胺均转化为茶氨酸。茶氨酸被分泌到细菌之外。从油茶（Camellia oleifera cultivar）的体外小植株中分离出的内生菌被鉴定为安全芽孢杆菌，并且不会将谷氨酰胺和乙胺转化为茶氨酸。体外酶法结果表明，内生细菌黄细菌菌株的γ-谷氨酰转肽酶rCsEGGT将谷氨酰胺和乙胺转化为茶氨酸的速率比中华C的rCsGGT高。这是由内生菌对茶氨酸生物合成的第一份报告山茶，它提供了一个新途径，探索茶氨酸的生物合成机理华支睾吸虫和内生菌和茶树之间的相互作用。