Isolation and characterization of Keratinibaculum paraultunense gen. nov., sp. nov., a novel thermophilic, anaerobic bacterium with keratinolytic activity

Authors

  • Yan Huang,

    1. Biogas Institute of Ministry of Agriculture, Chengdu, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    Search for more papers by this author
  • Yingjie Sun,

    1. Biogas Institute of Ministry of Agriculture, Chengdu, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    Search for more papers by this author
  • Shichun Ma,

    1. Biogas Institute of Ministry of Agriculture, Chengdu, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    Search for more papers by this author
  • Lu Chen,

    1. Biogas Institute of Ministry of Agriculture, Chengdu, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    Search for more papers by this author
  • Hui Zhang,

    1. Biogas Institute of Ministry of Agriculture, Chengdu, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    Search for more papers by this author
  • Yu Deng

    Corresponding author
    1. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu, China
    • Biogas Institute of Ministry of Agriculture, Chengdu, China
    Search for more papers by this author

Correspondence: Yu Deng, Section 4-13, Renmin Nanlu, Chengdu 610041, China. Tel.: +86-28-85215106; fax: +86-28-85215106; e-mail: dengkaiyu@yahoo.com.cn

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 BST (DSM 10521T) and Tepidimicrobium xylanilyticum PML14T (= JCM 15035T), respectively. We propose the name Keratinibaculum paraultunense gen. nov., sp. nov., with KD-1 (=JCM 18769T =DSM 26752T) as the type strain.

Ancillary