The Role of the Terminal and Subterminal Oxidation Pathways in Propane Metabolism by Bacteria

Abstract

Several strains of propane-utilizing bacteria were isolated from samples of pond and river water. They could be classified into three groups according to their ability to grow on acetone, and a representative strain from each group was selected for detailed study. All three strains belonged to the genus Arthrobacter. Strain B3aP could not grow on acetone and could not oxidize acetone after growth on propane. Strain PrI03 grew slowly on acetone but could not oxidize acetone after growth on propane. Both strains excreted acetone during growth on propane. Simultaneous adaptation experiments demonstrated that, whilst propane was oxidized to both propan-1-01 and propan-2-01, only propan-l-ol was metabolized completely suggesting that only the terminal oxidation pathway was involved in propane dissimilation. The third strain, B2, grew rapidly on acetone and was induced for acetone oxidation after growth on propane, suggesting that both propan-l-ol and propan-2-01 were produced and metabolized completely since no products of propane oxidation could be detected in culture supernatants. We compare these findings with previous reports concerning pathways of propane oxidation.

Origin and fate of deep-sea seeping methane bubbles at Kuroshima Knoll, Ryukyu forearc region, Japan

“…5, δ 13 C values for the hydrocarbons in the bubbles are plotted as a function of the reciprocal of each carbon number, together with values for the Sirus-1 Exmouth Plateau, offshore Australia, for which significant secondary alteration has been suggested (James and Burns, 1984). The alteration would probably be due to anaerobic microorganisms (Perry, 1980;Stephens and Dalton, 1986;Ashraf et al, 1994;Head et al, 2003). The two sets of results coincide strikingly well.…”

Evidence for metabolism of o-xylene by simultaneous ring and methyl group oxidation in a new soil isolate

“…Although the mutant produced small quantities of both dimethylphenol isomers, it is probable that the 3,4-isomer was formed by a side reaction during the initial oxygenase-catalysed reaction. There are precedents for such side reactions in monooxygenase-catalysed reactions, since a number of micro-organisms can hydroxylate aliphatic and aromatic hydrocarbons at more than one carbon atom, even though only one of the hydroxylated products is metabolized fully (Fredricks, 1967;Klein & Henning, 1969;Grossebuter et a/., 1979;Stephens & Dalton, 1986;Shields et al, 1989).…”

“…Strain B3 (NCIMB 13447), identified as a Rhodococcus species (T. Dando, NCIMB, Aberdeen, personal communication), was isolated from garden soil. The isolation procedure, growth conditions and apparatus were essentially as described by Stephens & Dalton (1986) except that MS medium pH 6.8 was used, with o-xylene (O.lo/0 v/v) as the carbon and energy source. When required, other carbon and energy sources were substituted for o-xylene.…”

“…Oxygen uptake rates were measured as described by Stephens & Dalton (1986) except that the reaction mixture contained 100 pl cell suspension, the required volume of the substrate solution and sufficient KPB to adjust the total volume to 3 ml. Toluene cis-glycol and benzene cis-glycol were supplied by ICI Fine Chemicals (now Zeneca Lifescience Molecules) and were prepared as stock solutions (150 mM) in KPB.…”

Molecular analysis of the soluble butane monooxygenase from ‘Pseudomonas butanovora’ a aThe GenBank accession number for the bmoXYBZDC sequence is AY093933.

“…Propane-oxidizing bacteria which utilize terminal and subterminal oxidation pathways have been identified (Ashraf et al, 1994 ;Stephens & Dalton, 1986), but the propane monooxygenases have not been further characterized. Bacteria capable of metabolizing liquid alkanes do so by a terminal oxidation pathway and utilize three-component systems containing an integral membrane alkane hydroxylase, rubredoxin and rubredoxin reductase.…”