title: Caloramator coolhaasii sp. nov., a glutamate-degrading, moderately thermophilic anaerobe.
abstract: An obligately anaerobic, moderately thermophilic, glutamate-degrading bacterium (strain ZT) was isolated from an enrichment culture obtained from anaerobic thermophilic granular sludge. The cells were rod-shaped to filamentous and showed no motility or spore formation. The cell wall had a Gram-positive structure, which was revealed by electron microscopy. Optimum growth of the strain was observed under neutrophilic conditions at 50-55 degrees C. The doubling time of strain ZT grown in rich medium was approximately 1 h at optimal pH and temperature. Strain ZT was able to grow on a variety of organic compounds. Most carbon sources were converted to acetate, CO2, H2, and traces of propionate and lactate. Strain ZT oxidized glutamate to acetate, CO2, NH4+, traces of propionate and H2. The doubling time on this substrate was 1-6 d. The strain fermented glutamate syntrophically in co-culture with Methanobacterium thermoautotrophicum Z-245T to the same products, but the co-culture had a fourfold higher growth rate. 16S rDNA sequence analysis revealed a relationship with Thermobrachium celere, Caloramator indicus and Caloramator proteoclasticus. The G+C content was 31.7 mol%. Based on its morphological, phylogenetic and physiological characteristics, it is proposed that strain ZT should be classified in the genus Caloramator as a new species, Caloramator coolhaasii.
authors.forename: C M
authors.initials: CM
authors.lastname: Plugge
authors.forename: E G
authors.initials: EG
authors.lastname: Zoetendal
authors.forename: A J
authors.initials: AJ
authors.lastname: Stams
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification* / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D001482:Base Composition; D001673:Biodegradation, Environmental; D003470:Culture Media; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019605:Euryarchaeota / Q000254:growth & development / Q000378:metabolism; D020459:Genes, rRNA; D005971:Glutamates / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D013696:Temperature
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005971:Glutamates; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D006859:Hydrogen