Ilyobacter insuetus sp. nov., a fermentative bacterium specialized in the degradation of hydroaromatic compounds.

Abstract

NOTEThe mesophilic, anaerobic bacterium strain VenChi2 T was isolated with quinic acid (1,3,4,5-tetrahydroxy-cyclohexane-1-carboxylic acid) as the sole source of carbon and energy. Of more than 30 substrates tested, only quinic acid and shikimic acid (3,4,5-trihydroxy-1-cyclohexene-1-carboxylic acid) were utilized, yielding acetate, propionate, butyrate, H 2 and CO 2 as fermentation products. Sugars, alcohols, (di-)carboxylic acids, amino acids and aromatic compounds were not fermented and no external electron acceptors were used. Strain VenChi2T is a Gram-negative, strictly anaerobic, coccoid rod ; it does not employ the classical hydroaromatic pathway of aerobic bacteria for the degradation of hydroaromatic compounds (no aromatic intermediates involved). Comparative 16S and 23S rDNA sequence analyses placed strain VenChi2 T in the fusobacteria phylum, with the closest relatives among species of the genera Ilyobacter and Propionigenium. The results indicate that, disregarding the taxonomically misplaced Ilyobacter delafieldii, which is a member of the clostridia, the validly described Ilyobacter and Propionigenium species are phylogenetically intermixed. Based on its phenotypic properties, strain VenChi2 T (l DSM 6831 T l ATCC BAA-291 T ) is assigned to the genus Ilyobacter as the type strain of a novel species, Ilyobacter insuetus sp. nov.

Psychrilyobacter atlanticus gen. nov., sp. nov., a marine member of the phylum Fusobacteria that produces H2 and degrades nitramine explosives under low temperature conditions

“…When temperatures for growth were determined (Tables 1 and 2), strain HAW-EB21 T was found to be a psychrotrophic bacterium with a growth temperature optimum of 18.5 u C (Zhao et al, 2004b), whereas members of the genera Ilyobacter, Propionigenium and Fusobacterium are all mesophilic bacteria with temperature optima of 28-37 u C (Moore et al, 1984;Schink & Pfennig, 1982;Stieb & Schink, 1984;Schink, 1984;Janssen & Liesack, 1995;Brune et al, 2002). As regards requirement for NaCl, strain HAW-EB21…”

“…For example, strain HAW-EB21 T did not grow on succinate, the carbon source for the isolation of members of the genus Propionigenium (Schink & Pfennig, 1982;Janssen & Liesack, 1995;Schink, 1992), or on L-tartrate, 3-hydroxybutyrate or quinate (and shikimate) which have been used for the isolation of Ilyobacter tartaricus (Schink, 1984), Ilyobacter polytropus (Stieb & Schink, 1984) and Ilyobacter insuetus (Brune & Schink, 1992;Brune et al, 2002), respectively. T different from the most closely related species of the genera Ilyobacter and Propionigenium Taxa: 1, strain HAW-EB21 T ; 2, I. tartaricus (data from Schink, 1984); 3, I. insuetus (Brune & Schink, 1992); 4, I. polytropus (Stieb & Schink, 1984); 5, Propionigenium modestum (Schink & Pfennig, 1982); 6, Propionigenium maris (Janssen & Liesack, 1995;Watson et al, 2000).…”

Complete genome sequence of Ilyobacter polytropus type strain (CuHbu1T)

“…No further isolates have been obtained for I. polytropus . Members of the genus Ilyobacter were isolated from anoxic marine sediments in Germany [2], Italy [3,4] and of estuarine origin [5]. Here we present a summary classification and a set of features for I. polytropus CuHbu1 T , together with the description of the complete genomic sequencing and annotation.…”

Hypnocyclicus thermotrophus gen. nov., sp. nov. isolated from a microbial mat in a hydrothermal vent field

“…The phylum Fusobacteria includes pathogens isolated from both human and animal sources, in addition to non-pathogenic free-living species. The majority of the free-living members of Fusobacteriaceae, isolated from marine sediments and mud, seem to have a limited metabolic range where a few specific substrates are fermented such as succinate, hydroxybuturate, hydroaromatic componds and tartrate (Brune et al, 2002;Janssen & Harfoot, 1990;Janssen & Liesack, 1995;Schink, 1984;Stieb & Schink, 1984). In this study we describe a novel bacterium, designated strain IR-2 T , isolated from a microbial mat.…”

“…The strain could only utilize sugars by fermentation, and we thereby suggest that the in situ metabolism of strain IR-2 T is degradation of polysaccharides from exopolymeric substances (EPS) or of intracellular origin. Other free-living species within Fusobacteriaceae, such as Ilyobacter insuetus, Ilyobacter delafieldii and Propionigenium modestum, could not ferment sugars, probably as a result of a lifestyle in environments depleted of sugars (Both et al, 1991, Brune et al, 2002, Janssen & Harfoot, 1990. Strain IR-2 T was isolated from a microbial mat situated in a hydrothermal vent field at the Northern Kolbeinsey Ridge, 166 km west of Jan Mayen in the Greenland Sea.…”