Desulfitibacter alkalitolerans gen. nov., sp. nov., an anaerobic, alkalitolerant, sulfite-reducing bacterium isolated from a district heating plant

Abstract

A novel alkalitolerant, anaerobic bacterium, designated strain sk.kt5T, was isolated from a metal coupon retrieved from a corrosion-monitoring reactor of a Danish district heating plant (Skanderborg, Jutland). The cells of strain sk.kt5T were motile, rod-shaped (0.4–0.6×2.5–9.6 μm), stained Gram-positive and formed endospores. Strain sk.kt5T grew at pH 7.6–10.5 (with optimum growth at pH 8.0–9.5), at temperatures in the range 23–44 °C (with optimum growth at 35–37 °C), at NaCl concentrations in the range 0–5 % (w/v) (with optimum growth at 0–0.5 %) and required yeast extract for growth. Only a limited number of substrates were utilized as electron donors, including betaine, formate, lactate, methanol, choline and pyruvate. Elemental sulfur, sulfite, thiosulfate, nitrate and nitrite, but not sulfate or Fe(III) citrate, were used as electron acceptors. The G+C content of the DNA was 41.6 mol%. Phylogenetic analyses of the sequence data for the dsrAB genes [encoding the major subunits of dissimilatory (bi)sulfite reductase] and the 16S rRNA gene placed strain sk.kt5T within a novel lineage in the class Clostridia of the phylum Firmicutes. Taken together, the physiological and genotypic data suggest that strain sk.kt5T represents a novel species within a novel genus, for which the name Desulfitibacter alkalitolerans gen. nov., sp. nov. is proposed. The type strain of Desulfitibacter alkalitolerans is sk.kt5T (=JCM 12761T=DSM 16504T).

Dethiobacter alkaliphilus gen. nov. sp. nov., and Desulfurivibrio alkaliphilus gen. nov. sp. nov.: two novel representatives of reductive sulfur cycle from soda lakes

“…In contrast to them, AHT 1 seems to move further into the direction of secondary sulfidogenic anaerobes. Other examples of such specialization in clostridia are represented by recently described alkalitolerant Desulfitibacter alkalitolerans from communal heating system (Nielsen et al 2006) and haloalkaliphilic thermophile Natrananaerobius thermophilus from alkaline Wadi Natrun lakes (Mesbach et al 2007). In contrast to AHT 2, however, strain AHT 1 was not able to use acetate and butyrate as electron donor, since there was no growth with these compounds without H 2 .…”

“…Desulfitibacter alkalitolerans from commune water heating plant can use sulfur, thiosulfate and sulfite as electron acceptors and belongs to the Clostridia (Nielsen et al 2006). Desulfurispirillum alkaliphilum is a moderately alkaliphilic deep-lineage bacterium (Chrysiogenetes) from sulphide-removing bioreactor utilizing sulfur/polysulfide, nitrate and fumarate as electron acceptors .…”

Haloalkaliphilic spore-forming sulfidogens from soda lake sediments and description of Desulfitispora alkaliphila gen. nov., sp. nov.

“… Natronincola peptidovorans (Zhilina et al 2009); Desulfitibacter alkalitolerans (Nielsen et al 2006); Desulfitobacterium hafniense (Christiansen and Ahring 1996) n.d. no data…”

“…The latter, together with the alkali-tolerant clostridium Desulfitibacter alkalitolerans isolated from an anthropogenic habitat (Nielsen et al 2006) are the only known culturable haloalkaliphilic Gram-positive sulfidogens.…”

Biogeochemical activity of microbial biofilms in the water column overlying uranium mine tailings

“…Similarly, Desulfitibacter and Dethiobacter, found at 41 m, are spore‐forming obligate anaerobes capable of growth at high pH and capable of using sulphur, thio‐sulphate and sulphite as electron acceptor (Nielsen et al . ; Sorokin et al . ).…”