Clostridium nitrophenolicum sp. nov., a novel anaerobic p-nitrophenol-degrading bacterium, isolated from a subsurface soil sample

• DOI: 10.1099/ijs.0.64604-0
• Publication Date: 2007-08-07T21:01:02Z
• Authors: K. Suresh; D. Prakash; N. Rastogi; R. K. Jain
• Keywords: Clostridium; DNA, Bacterial; Nitrophenols; Base Composition; 0303 health sciences; 03 medical and health sciences; RNA, Ribosomal, 16S; Fatty Acids; Molecular Sequence Data; DNA, Ribosomal; Phylogeny; Soil Microbiology

An obligate anaerobic, mesophilic, motile and endospore-forming bacterium, designated 1DT, was isolated from a subsurface soil sample. The young culture of strain 1DTwas Gram-positive and formed oval spores that were central in position. Based on the biochemical, chemotaxonomic and physiological data, strain 1DTappears to be a member of the genusClostridium. Strain 1DTwas found to be capable of degradingp-nitrophenol (pNP) at a concentration of 0.5 mM under anaerobic conditions as revealed by HPLC analysis. The major fatty acids were C16 : 0(28.02 %), iso-C17 : 1I/anteiso B (23.05 %) and C14 : 0(10.02 %). The major polar lipid content was diphosphatidylglycerol. Strain 1DTshowed highest 16S rRNA gene sequence similarity toClostridium aciditoleransJW/YJL-B3T(98.2 %) and similarity was less forClostridium scatologenesATCC 25775T(95.1 %),Clostridium drakeiSL1T(95.0 %) andClostridium carboxidivoransP7T(95.0 %). Phylogenetic analysis showed that it formed a coherent cluster with the species belonging to cluster I of the genusClostridium. The DNA G+C content was 35.5 mol%. DNA–DNA hybridization analysis indicated a mean value of 36.4 % between strain 1DTand its closest relativeC. aciditolerans. Several phenotypic differences from the closely related species were also revealed. On the basis of the polyphasic characteristics, strain 1DTrepresents a novel species of the genusClostridium, for which the nameClostridium nitrophenolicumsp. nov. is proposed. The type strain is 1DT(=MTCC 7832T=JCM 14030T).