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

A xanthan-degrading bacterium, strain AS7, was isolated from soil and its taxonomic position was determined using a polyphasic approach. Strain AS7 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 belongs to the genus Paenibacillus, sharing the highest level of sequence similarity with Paenibacillus phyllosphaerae PALXIL04 (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 and P. phyllosphaerae PALXIL04 was only 14.4±2.5 %. On the basis of phylogenetic analyses, phenotypic and chemotaxonomic characteristics, and DNA-DNA relatedness value, strain AS7 represents a novel species of the genus Paenibacillus, for which the name Paenibacillus xanthanilyticus sp. nov. is proposed. The type strain is AS7 (=IBRC M 10987=LMG 29451).