title: Isolation and characterization of Keratinibaculum paraultunense gen. nov., sp. nov., a novel thermophilic, anaerobic bacterium with keratinolytic activity.
abstract: A novel thermophilic, anaerobic, keratinolytic bacterium designated KD-1 was isolated from grassy marshland. Strain KD-1 was a spore-forming rod with a Gram-positive type cell wall, but stained Gram-negative. The temperature, pH, and NaCl concentration range necessary for growth was 30-65 °C (optimum 55 °C), 6.0-10.5 (optimum 8.0-8.5), and 0-6% (optimum 0.2%) (w/v), respectively. Strain KD-1 possessed extracellular keratinase, and the optimum activity of the crude enzyme was pH 8.5 and 70 °C. The enzyme was identified as a thermostable serine-type protease. The strain was sensitive to rifampin, chloramphenicol, kanamycin, and tetracycline and was resistant to erythromycin, neomycin, penicillin, and streptomycin. The main cellular fatty acid was predominantly C15:0 iso (64%), and the G+C content was 28 mol%. Morphological and physiological characterization, together with phylogenetic analysis based on 16S rRNA gene sequencing identified KD-1 as a new species of a novel genus of Clostridiaceae with 95.3%, 93.8% 16S rRNA gene sequence similarity to Clostridium ultunense BS(T) (DSM 10521(T)) and Tepidimicrobium xylanilyticum PML14(T) (= JCM 15035(T)), respectively. We propose the name Keratinibaculum paraultunense gen. nov., sp. nov., with KD-1 (=JCM 18769(T) =DSM 26752(T)) as the type strain.
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Sun
authors.forename: Shichun
authors.initials: S
authors.lastname: Ma
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Deng
mesh_terms: D000818:Animals; D001421:Bacteria, Anaerobic / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D004795:Enzyme Stability; D005241:Feathers / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006358:Hot Temperature; D007633:Keratins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D007633:Keratins; D010447:Peptide Hydrolases; C035855:keratinase
keywords: KD-1; anaerobe; feather degradation; keratinase