Anaerobic Degradation of α-resorcylate by a Nitrate-reducing Bacterium, Thauera aromatica Strain AR-1

Two distinct pathways for anaerobic degradation of aromatic compounds in the denitrifying bacterium Thauera aromatica strain AR-1

“…Here, we report on our work on 3,5-DHB degradation by this T. aromatica strain which differs from the type strain K-172 only by its ability to degrade 3,5-DHB (Gallus et al 1997). We checked for the presence of the HHQdehydrogenating activity and performed comparative physiological studies with cells grown with either 3,5-DHB or benzoate in order to assess the presence of a second, mechanistically distinct pathway for anaerobic degradation of aromatic compounds in addition to the welldescribed benzoyl-CoA pathway.…”

“…These suspensions were kept on ice and used for experiments within 1-2 h. For degradation experiments, cells were added to 50 mM anoxic potassium phosphate buffer (pH 7.0) containing 4 mM nitrate, to a final optical density of 2.0 [equivalent to ca. 0.7 mg dry weight per ml (Gallus et al 1997)]. Experiments were performed under nitrogen gas in butyl rubber-sealed Hungate tubes, and reactions were started by addition of the aromatic substrates.…”

“…During incubation, no significant lag phases were observed in both cases. The cells commenced to grow with the respective other substrate as fast as with their original growth substrate (not Table 1 Hydroxyhydroquinone-dehydrogenating activity in cellfree extract fractions of Thauera aromatica strain AR-1 after ultracentrifugation (100,000×g, 1 h); in vivo activity of T. aromatica strain AR-1 for degradation of 3,5-dihydroxybenzoate: 22.6 nmol min -1 (mg protein) -1 (Gallus et al 1997 shown). When cells were transferred to a medium containing a mixture of benzoate and 3,5-DHB, growth was biphasic (Fig.…”

Characterization of halobenzoate-degrading, denitrifying Azoarcus and Thauera isolates and description of Thauera chlorobenzoica sp. nov.

“…Several bacterial strains capable of growing at the expense of aromatic compounds under denitrifying conditions have been assigned to the genera Azoarcus and Thauera (Anders et al, 1995 ;Gallus et al, 1997 ;Harms et al, 1999 ;Ha$ ggblom & Young, 1999 ;Rabus & Widdel, 1995 ;van Schie & Young, 1998 ;Song et al, 1998Song et al, , 1999Song et al, , 2000aSpringer et al, 1998 ;Zhou et al, 1995). These closely related genera seem to constitute a major group of denitrifying bacteria capable of degrading aromatic compounds.…”

Description of strain 3CB-1, a genomovar of Thauera aromatica, capable of degrading 3-chlorobenzoate coupled to nitrate reduction.

“…These are strain K172 T , the type strain of the species (Anders et al, 1995), strain AR-1, capable of degrading α-resorcylate with nitrate as electron acceptor (Gallus et al, 1997), and strain T1, which, as strain K172 T , was examined for its capacity for toluene degradation coupled to nitrate reduction (Evans et al, 1991 ;Song et al, 1998 T. terpenica are of interest because of their capacity to degrade linalool (strain 47Lol T ) and monoterpenes (strains 21Mol and 58Eu T ), respectively (Foss & Harder, 1998). We propose to add strain 3CB-1 to Thauera aromatica as a genomovar, Thauera aromatica genomovar chlorobenzoica, on the basis of a polyphasic analysis.…”