Hammann R, Kutzner H J
Institut für Mikrobiologie und Genetik der Technischen Universität Darmstadt, Germany.
J Basic Microbiol. 1998;38(3):207-20.
A preliminary screening of numerous species of the order Actinomycetales, especially of the genera Mycobacterium, Nocardia, Rhodococcus, Pseudonocardia, and Streptomyces, showed that many of them are able to metabolize benzoate (B) and p-hydroxybenzoate (pHB) as indicated by growth and change of color of the pH-indicator of an agar medium. Subsequent experiments with liquid cultures which allowed the analysis of substrate utilization by thin layer chromatography confirmed these results. The study of the degradative pathway proved that B was metabolized via catechol (C), pHB via protocatechuate (P) and m-hydroxybenzoate (mHB) via gentisate (G). The aromatic ring of C and P was subjected to an ortho-cleavage; only one strain of Noc. asteroides degraded C via a meta-cleavage, but P via an ortho-cleavage. Cell free extracts of four selected organisms exhibited activity of C-1,2-dioxygenase (C-1,2-O) and/or P-3,4-dioxygenase (P-3,4-O), depending on the growth substrate used for precultivation. In Streptomyces C-1,2-O was only found in cells grown on B, and P-3,4-O only in cells grown on pHB. On the contrary, in Rhodococcus rhodochrous B-cells oxidized C as well as P, while P-cells possessed only P-3,4-O-activity.
对放线菌目众多菌种，特别是分枝杆菌属、诺卡氏菌属、红球菌属、假诺卡氏菌属和链霉菌属进行的初步筛选表明，如琼脂培养基上的生长情况及pH指示剂颜色变化所示，其中许多菌种能够代谢苯甲酸盐（B）和对羟基苯甲酸盐（pHB）。随后对液体培养物进行的实验，通过薄层色谱法分析底物利用情况，证实了这些结果。对降解途径的研究证明，B通过儿茶酚（C）进行代谢，pHB通过原儿茶酸（P）进行代谢，间羟基苯甲酸盐（mHB）通过龙胆酸（G）进行代谢。C和P的芳香环进行邻位裂解；只有一株星形诺卡氏菌通过间位裂解降解C，但通过邻位裂解降解P。根据用于预培养的生长底物，四种选定生物体的无细胞提取物表现出C-1,2-双加氧酶（C-1,2-O）和/或P-3,4-双加氧酶（P-3,4-O）的活性。在链霉菌中，C-1,2-O仅在以B为生长底物培养的细胞中发现，P-3,4-O仅在以pHB为生长底物培养的细胞中发现。相反，在红平红球菌中，以B为底物培养的细胞能够氧化C和P，而以P为底物培养的细胞仅具有P-3,4-O活性。
