title: Clostridium hungatei sp. nov., a mesophilic, N2-fixing cellulolytic bacterium isolated from soil.
abstract: Two strains of obligately anaerobic, mesophilic, cellulolytic, N2-fixing, spore-forming bacteria were isolated from soil samples collected at two different locations near Amherst, MA, USA. Single cells of both strains were slightly curved rods that measured between 2 and 6 microm in length and approximately 0.5 microm in diameter. The spores were spherical, terminally located, distended the sporangium and measured 0.8-1.0 microm in diameter. The cells of both isolates (designated strain ADT and strain B3B) stained Gram-negative, but did not have a typical Gram-negative cell wall structure as demonstrated by transmission electron microscope analysis. The cells of both strains were motile with subpolarly inserted flagella and exhibited chemotactic behaviour towards cellobiose and D-glucose. Both strains fermented cellulose, xylan, cellobiose, cellodextrins, D-glucose, D-xylose, D-fructose, D-mannose and gentiobiose. In addition, strain B3B fermented L-arabinose. For both strains, fermentation products from cellulose were acetate, ethanol, H2 and CO2, as well as small amounts of lactate and formate. The G+C content of strain AD was 40 mol% and that of strain B3B was 42 mol%. Based on their morphological, physiological and phylogenetic characteristics, it was concluded that the two isolates are representatives of a novel species of Clostridium. The name Clostridium hungatei is proposed for the new species. The type strain of Clostridium hungatei sp. nov. is strain ADT (= ATCC 700212T).
authors.forename: E
authors.initials: E
authors.lastname: Monserrate
authors.forename: S B
authors.initials: SB
authors.lastname: Leschine
authors.forename: E
authors.initials: E
authors.lastname: Canale-Parola
mesh_terms: D000693:Anaerobiosis; D001482:Base Composition; D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D003013:Clostridium / Q000145:classification* / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D003470:Culture Media; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D002482:Cellulose; D002480:Cellulase