Williams P A, Murray K
J Bacteriol. 1974 Oct;120(1):416-23. doi: 10.1128/jb.120.1.416-423.1974.
Mutant strains of Pseudomonas putida (arvilla) mt-2 which have lost the ability to grow at the expense of m- or p-toluate (methylbenzoate) but retain the ability to grow with benzoate arise spontaneously during growth on benzoate; this genetic loss occurs to a lesser extent during growth on nonaromatic carbon sources in the presence of mitomycin C. The mutants have totally lost the activity of the enzymes of the divergent meta pathway with the possible exception of 2-oxopent-4-enoate hydratase and 4-hydroxy-2-oxovalerate aldolase; unlike the wild type they utilize benzoate by the ortho pathway. Evidence is presented that these mutants have lost a plasmid coding for the enzymes of the meta pathway, which may be transmitted back to them or into other P. putida strains. Preliminary results from these mutants and from a mutant defective in the regulation of the plasmid-carried pathway suggest that the wild type contains two benzoate oxidase systems, one on the plasmid which is nonspecific in both its catalysis and its induction and one on the chromosome which is more specific to benzoate as substrate and is specifically induced by benzoate.
恶臭假单胞菌（ arvilla ） mt-2的突变菌株在以苯甲酸盐为碳源生长时会自发出现，这些菌株失去了以间甲苯酸盐或对甲苯酸盐（甲基苯甲酸酯）为代价进行生长的能力，但保留了以苯甲酸盐生长的能力；在丝裂霉素C存在的情况下，在非芳香族碳源上生长时，这种遗传损失的发生程度较小。除了2-氧代戊-4-烯酸水合酶和4-羟基-2-氧代戊酸醛缩酶可能例外，这些突变体已经完全丧失了发散性间位途径中酶的活性；与野生型不同，它们通过邻位途径利用苯甲酸盐。有证据表明，这些突变体已经丢失了一个编码间位途径酶的质粒，该质粒可以传递回它们或其他恶臭假单胞菌菌株中。来自这些突变体和一个在质粒携带途径调控方面有缺陷的突变体的初步结果表明，野生型含有两个苯甲酸氧化酶系统，一个在质粒上，其催化和诱导都是非特异性的，另一个在染色体上，它对苯甲酸作为底物更具特异性，并由苯甲酸特异性诱导。
