Paenibacillus marinum sp. nov., a thermophilic xylanolytic bacterium isolated from a marine hot spring in Tunisia

Abstract

Among a large collection of Tunisian hot springs bacterial isolates a bacterial strain, THE22T, with xylanolytic properties was identified. The bacterium was isolated from a natural hot spring "Ain Echefa" at Mediteranean sea (Korbous, North-Eastern Tunisia). The novel strain was Gram positive, spore-forming, rod-shaped, facultatively anaerobic and grew optimally under conditions of 55°C, 1% (w/v) NaCl and pH 7-8. The 16S rRNA gene sequence analysis showed that strain THE22T fell within the radiation of the cluster comprising Paenibacillus species with Paenibacillus phyllosphaerae PALXIL04T as the closest phylogenetic neighbour (95.8%). The predominant components in the fatty methyl ester profile were iso-C16:0 (34.46%), C16:0 (19.64%), anteiso-C15:0 (19.18%) and anteiso-C17:0 (18.11%). The major respiratory quinone was menaquinone-7 (MK-7). The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The base composition of DNA was 56 mol%. Based on the polyphasic taxonomic data, strain THE-22T (=DSM 18499T=LMG 23758T) was recognized as a novel species within the genus Paenibacillus. The name Paenibacillus marinum sp. nov. is proposed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.