Eaton R W, Chapman P J
Gulf Ecology Division, U.S. Environmental Protection Agency, Gulf Breeze, Florida 32561, USA.
J Bacteriol. 1995 Dec;177(23):6983-8. doi: 10.1128/jb.177.23.6983-6988.1995.
The p-cumate-degrading strain Pseudomonas putida F1 and the m- and p-toluate-degrading strain P. putida mt-2 transform indole-2-carboxylate and indole-3-carboxylate to colored products identified here as indigo, indirubin, and isatin. A mechanism by which these products could be formed spontaneously following dioxygenase-catalyzed dihydroxylation of the indolecarboxylates is proposed. Indolecarboxylates were employed as chromogenic substrates for identifying recombinant bacteria carrying genes encoding p-cumate dioxygenase and toluate dioxygenase. Dioxygenase gene-carrying bacteria could be readily distinguished as dark green-blue colonies among other colorless recombinant Escherichia coli colonies on selective agar plates containing either indole-2-carboxylate or indole-3-carboxylate.
对异丙基苯甲酸降解菌株恶臭假单胞菌F1以及间甲苯甲酸和对甲苯甲酸降解菌株恶臭假单胞菌mt-2可将吲哚-2-羧酸酯和吲哚-3-羧酸酯转化为在此鉴定为靛蓝、靛玉红和异吲哚酮的有色产物。本文提出了一种机制,即吲哚羧酸酯经双加氧酶催化二羟基化后可自发形成这些产物。吲哚羧酸酯被用作显色底物,用于鉴定携带对异丙基苯甲酸双加氧酶和甲苯甲酸双加氧酶编码基因的重组细菌。在含有吲哚-2-羧酸酯或吲哚-3-羧酸酯的选择性琼脂平板上,携带双加氧酶基因的细菌很容易在其他无色的重组大肠杆菌菌落中被区分出来,呈现为深绿蓝色菌落。