Isolation from oil reservoirs of novel thermophilic anaerobes phylogenetically related to Thermoanaerobacter subterraneus: reassignment of T. subterraneus, Thermoanaerobacter yonseiensis, Thermoanaerobacter tengcongensis and Carboxydibrachium pacificum to Caldanaerobacter subterraneus gen. nov., sp. nov., comb. nov. as four novel subspecies

Abstract

Novel thermophilic, anaerobic, Gram-positive, rod-shaped bacteria, strains SL9 and OCA1, were isolated from oilfields in France and Australia, respectively. Both strains, together with Thermoanaerobacter yonseiensis KB-1T (=DSM 13777T), Thermoanaerobacter tengcongensis MB4T (=DSM 15242T) and Carboxydibrachium pacificum JMT (=DSM 12653T), possessed genomic (DNA–DNA hybridization studies) and phylogenetic similarities with Thermoanaerobacter subterraneus SEBR 7858T (=DSM 13054T), which was isolated recently from an oilfield reservoir in south-west France. Marked phenotypic differences exist between the three oilfield isolates (T. subterraneus, strain OCA1 and strain SL9): they include temperature range for growth and substrates used. Differences were also observed in the DNA G+C contents of all organisms. Similarly to T. subterraneus, strains SL9 and OCA1, and also T. yonseiensis, T. tengcongensis and Carboxydibrachium pacificum, produced acetate and l-alanine as major end products of glucose metabolism [0·8–1·0 mol l-alanine produced (mol glucose consumed)−1] and reduced thiosulfate, but not sulfate, to sulfide. Because of these significant metabolic and phylogenetic differences between the oilfield isolates (T. subterraneus, strain OCA1 and strain SL9), T. yonseiensis, T. tengcongensis and Carboxydibrachium pacificum and other Thermoanaerobacter species, it is proposed to reassign them as a novel genus and species, Caldanaerobacter subterraneus gen. nov., sp. nov., comb. nov., with the creation of four novel subspecies, Caldanaerobacter subterraneus subsp. subterraneus subsp. nov., comb. nov., Caldanaerobacter subterraneus subsp. yonseiensis subsp. nov., comb. nov., Caldanaerobacter subterraneus subsp. tengcongensis subsp. nov., comb. nov. and Caldanaerobacter subterraneus subsp. pacificus subsp. nov., comb. nov.

Carbon monoxide conversion by thermophilic sulfate-reducing bacteria in pure culture and in co-culture with Carboxydothermus hydrogenoformans

“…Conversion of CO to H 2 by thermophilic anaerobes may provide additional means to avoid CO inhibition. An increasing number of anaerobes grow by the conversion of CO to H 2 but do not reduce SO 4 (Fardeau 2004;Sokolova et al 2001Sokolova et al , 2002Sokolova et al , 2004aSvetlichnyi et al 1991Svetlichnyi et al , 1994. Formation of H 2 and removal of CO by these bacteria may remove inhibition and thus stimulate SO 4 reduction.…”

Molecular characterization of mesophilic and thermophilic sulfate reducing microbial communities in expanded granular sludge bed (EGSB) reactors

“…lienii in the TR might have thrived on products from cell decay. Three of the OTUs were most closely related to the thermophilic, fermentative bacteria, Thermoanaerobacter tengcongensis and Thermoanaerobacter subterraneus, both species which have been proposed to be reassigned a novel genus and species, Caldanaerobacter subterraneus (Fardeau et al 2004). Within the Nitrospirae division, three OTUs were most closely related to Thermodesulfovibrio yellowstonii (AB231858), a thermophilic sulfate reducer that does not grow on acetate or ethanol (Henry et al 1994).…”

Biofuel From Cellulosic Mass with Incentive for Feed Industry Employing Thermophilic Microbes

“…Wide variety of organic compounds in a water body can be photoassimilated by purple non-sulfur bacteria (Cooper et al, 1975;Holm & Vennes, 1970;Sunita & Mitra, 1993). Thermophilic nature, however, is limited to only among few genera of anoxygenic phototrophic bacteria (Fardeau et al, 2004;Hanada, 2003). However, thermotolerant or mildly thermophilic PPNS bacteria, having optimum growth temperature, are well documented around 40°C (Ahn et al, 2005;Fang et al, 2002b;Hisada et al, 2007;Madigan, 2003;Shin et al, 2005;Ueno et al, 2001b;.…”