Paenibacillus thailandensis sp nov and Paenibacillus nanensis sp nov., xylanase-producing bacteria isolated from soil

Two strains of xylanase-producing bacteria, S3-4A(T) and MX2-3(T), isolated from soils in Thailand, were characterized on the basis of their phenotypic and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene sequences. The novel strains were Gram-positive, facultatively anaerobic, spore-forming, rod-shaped bacteria. They contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The DNA G+C contents of strains S3-4A(T) and MX2-3(T) were 52.7 and 52.9 mol%, respectively. The major isoprenoid quinone was MK-7. The dominant cellular fatty acids were anteiso-C-15:0 and iso-C-16:0 .Phylogenetic analyses using 16S rRNA gene sequences showed that both novel strains were affiliated to the genus Paenibacillus. Strains S3-4A(T) and MX2-3(T) were closely related to Paenibacillus agaridevorans DSM 1355(T) with 97% and 97.3% gene sequence similarities, respectively. The DNA-DNA relatedness between strains S3-4A(T), MX2-3(T) and P. agaridevorans DSM 1355 T was low (6.0-30.3%). The novel strains could be clearly distinguished from P. agaridevorans DSM 1355 T by physiological and biochemical characteristics. Therefore, these two strains represent novel species of the genus Paenibacillus, for which the names Paenibacillus thailandensis sp. nov. (type strain S3-4A(T) =KCTC 13043(T)= PCU 275(T) TISTR 1827(T)) and Paenibacillus nanensis sp. nov. (type strain MX2-3(T) =KCTC 13044(T)= PCU 276(T) =TISTR 1828(T)) are proposed.