Utilization of methoxylated benzoates and formation of intermediates by Desulfotomaculum thermobenzoicum in the presence or absence of sulfate

Abstract

Desulfotomaculum thermobenzoicum strain TSB (DSM 6193) was found to utilize some methoxylated benzoates as carbon and energy source with or without sulfate. 3- or 4-Methoxybenzoate, vanillate (4-hydroxy-3-methoxybenzoate), syringate (3,5-dimethoxy-4-hydroxybenzoate) and 3,4,5-trimethoxybenzoate were converted to corresponding hydroxybenzoates. However, neither 2-methoxybenzoate nor 2,6-dimethoxybenzoate was utilized. The organism grew acetogenically on each of the methoxylated benzoates in the absence of sulfate. 3,4-Dihydroxy-5-methoxybenzoate was detected during conversion of syringate, and syringate and 3,4-dihydroxy-5-methoxybenzoate were detected during conversion of 3,4,5-trimethoxybenzoate as intermediates. These findings indicate that 4-methoxyl-group is most readily cleaved, whereas 2-methoxyl-group is not utilized by the organism.

H 2 -CO 2 -Dependent Anaerobic O-Demethylation Activity in Subsurface Sediments and by an Isolated Bacterium

“…3 and 4). Sequential anaerobic 0 demethylation of syringate (8,38,39,41) and other multimethoxylated aromatic compounds (11,38) has been noted previously. It was hypothesized that a singleenzyme system with different affinities for syringate and methylgallate accounts for the sequential nature of the reaction (8).…”

Thermacetogenium phaeum gen. nov., sp. nov., a strictly anaerobic, thermophilic, syntrophic acetate-oxidizing bacterium.

“…These indicate that our isolate harbours a sulfate-respiration system. The other feature of such micro-organisms including our isolate is that they are also capable of growing acetogenically on pyruvate or methoxylated aromatics in the absence of sulfate (Min & Zinder, 1990 ;Tasaki et al, 1992Tasaki et al, , 1993Nilsen et al, 1996). Considering the fact that those Desulfotomaculum strains harbour the enzymes of the carbon monoxide dehydrogenase pathway that allows the microbes to convert methoxylated compounds to acetate, it is very likely that our isolate has a similar pathway.…”

Acetogenesis from pyruvate byDesulfotomaculum thermobenzoicumand differences in pyruvate metabolism among three sulfate-reducing bacteria in the absence of sulfate

“…The supernatant was used for the enzyme assay. Enzyme activities were measured by the methods previously described [3][4][5][6].…”