Microbiological dissimilation of tricarballylate and trans-aconitate

Abstract

Two fluorescent pseudomonads capable of metabolizing tricarballylate and trans-aconitate were isolated by the soil-enrichment culture technique. These and some other species of bacteria were tested for their ability to utilize for growth the salts of many di- and tricarboxylic acids. Alloisocitrate and mesaconate were not utilized by any of the ten strains tested; only two strains grew on tricarballylate and itaconate. trans-Aconitate was utilized by many strains which had not been previously exposed to this compound. The resting cells of two strains could adapt to oxidize two acids (tricarballylate and trans-aconitate), and this induction was chloramphenicol-sensitive. The tricarballylate-grown cells were simultaneously induced to oxidize trans-aconitate and other tricarboxylates, whereas the trans-aconitate-grown cells were not induced to oxidize tricarballylate, and their subsequent induction was inhibited by chloramphenicol. This trans-aconitate or tricarballylate. But tricarballylate dehydrogenase was present only in tricarballylate-grown cells. The cell-free extracts of the two organisms contained the enzymes of the Krebs cycle and isocitritase. These enzymes are most probably operative during growth on and oxidation of these two acids as sole carbon sources.