Buß Oliver, Dold Sarah-Marie, Obermeier Pascal, Litty Dennis, Muller Delphine, Grüninger Jens, Rudat Jens
Section II: Technical Biology, Institute of Process Engineering in Life Sciences, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 3, 76131, Karlsruhe, Germany.
AMB Express. 2018 Sep 21;8(1):149. doi: 10.1186/s13568-018-0676-2.
Despite their key role in numerous natural compounds, β-amino acids have rarely been studied as substrates for microbial degradation. Fermentation of the newly isolated Paraburkholderia strain BS115 and the type strain P. phytofirmans PsJN with β-phenylalanine (β-PA) as sole nitrogen source revealed (S)-selective transamination of β-PA to the corresponding β-keto acid by both strains, accompanied by substantial formation of acetophenone (AP) from spontaneous decarboxylation of the emerging β-keto acid. While the PsJN culture became stationary after entire (S)-β-PA consumption, BS115 showed further growth at a considerably slower rate, consuming (R)-β-PA without generation of AP which points to a different degradation mechanism for this enantiomer. This is the first report on degradation of both enantiomers of any β-amino acid by one single bacterial strain.
尽管β-氨基酸在众多天然化合物中起着关键作用，但作为微生物降解的底物却很少被研究。以β-苯丙氨酸（β-PA）作为唯一氮源，对新分离的类伯克霍尔德氏菌菌株BS115和模式菌株植物类伯克霍尔德氏菌PsJN进行发酵，结果表明，这两种菌株都能将β-PA（S）选择性转氨生成相应的β-酮酸，同时新生成的β-酮酸自发脱羧会大量生成苯乙酮（AP）。当PsJN培养物消耗完所有（S）-β-PA后进入稳定期时，BS115仍以相当慢的速度继续生长，消耗（R）-β-PA且不产生AP，这表明该对映体的降解机制不同。这是关于单一细菌菌株对任何β-氨基酸的两种对映体进行降解的首次报道。
