Proteus mirabilis could convert l-phenylalanine into 2-phenylethanol (2-PE) via the Ehrlich pathway, the amino acid deaminase pathway, and the aromatic amino acid decarboxylase pathway. The aromatic amino acid decarboxylase pathway was proved for the first time in P. mirabilis. In this pathway, l-aromatic amino acid transferase demonstrated a unique catalytic property, transforming 2-penylethylamine into phenylacetaldehyde. Eleven enzymes were supposed to involve in 2-phenylethanol synthesis. The mRNA expression levels of 11 genes were assessed over time by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in vivo. As a result, the expression of 11 genes was significantly increased, suggesting that P. mirabilis could transform l-phenylalanine into 2-phenylethanol via three pathways under aerobic conditions; nine genes were significantly overexpressed, suggesting that P. mirabilis could synthesize 2-phenylethanol via the Ehrlich pathway under anaerobic conditions. This study reveals the multipath synthetic metabolism for 2-phenylethanol in P. mirabilis and will enrich the new ideas for natural (2-PE) synthesis.

中文翻译：

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揭示了变形菌中2-苯基乙醇的多径生物合成机理。

奇异变形杆菌可以通过Ehrlich途径，氨基酸脱氨酶途径和芳族氨基酸脱羧酶途径将1-苯丙氨酸转化为2-苯乙醇（2-PE）。芳香氨基酸脱羧酶途径首次在奇异疟原虫中得到证实。在该途径中，1-芳族氨基酸转移酶表现出独特的催化性质，将2-苯基乙胺转化为苯基乙醛。据推测有11种酶参与了2-苯基乙醇的合成。通过体内逆转录定量聚合酶链反应（RT-qPCR）评估了11个基因的mRNA表达水平。结果，11个基因的表达显着增加，表明奇异假单胞菌在有氧条件下可通过三种途径将1-苯丙氨酸转化为2-苯乙醇；9个基因明显过表达，这表明在厌氧条件下，奇异疟原虫可以通过Ehrlich途径合成2-苯基乙醇。这项研究揭示了P. mirabilis中2-苯基乙醇的多径合成代谢，并将丰富天然（2-PE）合成的新思路。