Hechtman P, Scriver C R, Middleton R B
J Bacteriol. 1970 Nov;104(2):851-6. doi: 10.1128/jb.104.2.851-856.1970.
beta-Alanine catabolism in Pseudomonas fluorescens is initiated by the enzyme beta-alanine transaminase. We have isolated mutants which fail to produce this enzyme and thus cannot grow on beta-alanine as the sole nitrogen source. The accumulation of beta-alanine-1-(14)C has been studied in one of these mutants, strain 67, and in the wild type. In the mutant, beta-alanine remains in a stable intracellular pool, whereas in the wild type conversion of beta-alanine to an intermediate, presumably malonate semialdehyde, and to CO(2) can be detected. The membrane transport system for beta-alanine can be conveniently studied in this transaminaseless mutant.
荧光假单胞菌中的β-丙氨酸分解代谢由β-丙氨酸转氨酶启动。我们分离出了无法产生这种酶的突变体，因此它们不能以β-丙氨酸作为唯一氮源生长。已经在其中一个突变体菌株67和野生型中研究了β-丙氨酸-1-(14)C的积累情况。在突变体中，β-丙氨酸保留在稳定的细胞内池中，而在野生型中，可以检测到β-丙氨酸转化为一种中间体（推测为丙二酸半醛）并进一步转化为CO₂。在这个无转氨酶的突变体中，可以方便地研究β-丙氨酸的膜转运系统。
