Paenibacillus xanthanilyticus sp. nov., a xanthan-degrading bacterium isolated from soil

Abstract

A xanthan-degrading bacterium, strain AS7^T, was isolated from soil and its taxonomic position was determined using a polyphasic approach. Strain AS7^T was a Gram-stain-variable, spore-forming, motile, aerobic, rod-shaped bacterium. Phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that strain AS7^T belongs to the genus Paenibacillus, sharing the highest level of sequence similarity with Paenibacillus phyllosphaerae PALXIL04^T (98.0 %). The cell-wall peptidoglycan contained meso-diaminopimelic acid. MK-7 was the dominant isoprenoid quinone and the major fatty acid was anteiso-C15 : 0. Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. These chemotaxonomic characteristics were consistent with the isolate belonging to the genus Paenibacillus. The G+C content of the genomic DNA was 51.0 mol% and the DNA-DNA hybridization value between strain AS7^T and P. phyllosphaerae PALXIL04^T was only 14.4±2.5 %. On the basis of phylogenetic analyses, phenotypic and chemotaxonomic characteristics, and DNA-DNA relatedness value, strain AS7^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus xanthanilyticus sp. nov. is proposed. The type strain is AS7^T (=IBRC M 10987^T=LMG 29451^T).

Keywords: Paenibacillus; polyphasic taxonomy; xanthanolytic bacterium.