Paraburkholderia caseinilytica sp. nov., isolated from the pine and broad-leaf mixed forest soil.

A novel Gram-stain-negative, aerobic, non-spore-forming, motile and rod-shaped bacterial strain, designated HM451, was isolated from forest soil sampled at the Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). It grew optimally at 28 °C, pH 5.0-6.0 and in the presence of 0-2.5 % (w/v) NaCl on R2A medium. Strain HM451 was closely related to Paraburkholderia mimosarum NBRC 106338 (98.6 % 16S rRNA gene sequence similarity), Paraburkholderia heleia NBRC 101817 (98.4 %) and Paraburkholderia silvatlantica SRMrh-20 (98.0 %). The 16S rRNA gene sequence analysis showed that strain HM451 and the three closely related strains formed a clade within the genus Paraburkholderia, but was clearly separated from the established species. The DNA-DNA relatedness value between strain HM451 and its phylogenetically closest relative, P. mimosarum NBRC 106338, was much lower than 70 %. Strain HM451 contained ubiquinone 8 as the major respiratory quinone. Major fatty acids were C16 : 0, C17 : 0cyclo and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content of strain HM451 was 65.4 mol%. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminophospholipids, one unidentified aminolipid and a polar lipid. The phenotypic, chemotaxonomic and phylogenetic data showed that strain HM451 represents a novel species of the genus Paraburkholderia, for which the name Paraburkholderia caseinilytica sp. nov. is proposed. The type strain is HM451 (=GDMCC 1.1190=LMG 30092).