Ethanedisulfonate is degraded via sulfoacetaldehyde in Ralstonia sp. strain EDS1

Abstract

Aerobic enrichment cultures (11) yielded three cultures able to utilise ethane-1,2-disulfonate as sole source of carbon and energy in salts medium. Two pure cultures were obtained and we worked with strain EDS1, which was assigned to the genus Ralstonia on the basis of its 16S rDNA sequence and simple taxonomic tests. Strain EDS1 utilised at least seven alkane(di)sulfonates, ethane-1,2-disulfonate, taurine, isethionate, sulfoacetate, sulfoacetaldehyde and propane-1,3-disulfonate, as well as methanesulfonate and formate. Growth with ethanedisulfonate was concomitant with substrate disappearance and the formation of 2 mol sulfate per mol substrate. The growth yield, 7 g protein (mol C) -1 , indicated quantitative utilisation of the substrate. Ethanedisulfonate-dependent oxygen uptake of whole cells during growth rose to a maximum before the end of growth and then sank rapidly; this was interpreted as evidence for an inducible desulfonative oxygenase that was not active in cell extracts. Inducible sulfoacetaldehyde sulfo-lyase was detected at high activity. Inducible degradation of taurine or isethionate or sulfoacetate via sulfoacetaldehyde sulfo-lyase is interpreted from the data.

The DUF81 protein TauE in Cupriavidus necator H16, a sulfite exporter in the metabolism of C2 sulfonates

“…This confirmed the previous observations that both isethionate and sulfoacetate are degraded via sulfoacetaldehyde ( Fig. 1a; Brüggemann et Denger & Cook, 2001;S. Weinitschke, unpublished data).…”

“…The current hypotheses (Fig. 1a) of cytochrome c-dependent isethionate dehydrogenase (Brüggemann et al, 2004) and sulfoacetate reduction to sulfoacetaldehyde involving CoA, ATP and NADH (Denger & Cook, 2001) have new experimental support (S. Weinitschke, unpublished data). The enzymes (Xsc, Pta) necessary to transform sulfoacetaldehyde to an amphibolic intermediate (acetyl-CoA), and those for sulfite excretion and oxidation (TauE and sulfite dehydrogenase; see below) were induced in all relevant cultures (Table 2).…”

“…Isethionate and sulfoacetate were determined by ion chromatography Styp von Rekowski et al, 2005). Sulfite was quantified as the fuchsin derivative (Denger & Cook, 2001). Sulfate was determined turbidimetrically as a suspension of BaSO 4 (Sörbo, 1987).…”

Dissimilation of the C2 sulfonates

“…Propane-1,3-disulfonate is utilized as a sole source of carbon and energy by Ralstonia sp. strain EDS1; here again, the sulfonate moiety is recovered as sulfate (Denger and Cook 2001). Utilization of homotaurine as a sole source of carbon or of nitrogen for growth has recently been detected in this laboratory (J. Mayer et al, unpublished).…”

“…strains EDS1 or EDS2 when they utilize propane-1,3-disulfonate (Fig. 4) (Denger and Cook 2001). It is further hypothesized that a transaminase (or a dehydrogenase) could attack homotaurine and make propanal-3-sulfonate a point of convergence in the degradation of C 3 -sulfonates (Fig.…”