Abstract

A novel cellulolytic bacterium, strain S23T, was isolated from the rhizosphere of the pine trees in Daejeon, Republic of Korea. This isolate was Gram-positive, strictly aerobic, rod-shaped, catalase-negative, oxidase- positive, motile by means of peritrichous flagella, and tested positive for alkaline phosphatase, esterase lipase, leucine arylamidase, α-galactosidase, and β-galactosidase activities. The DNA G+C content was 49.5mol%. The main cellular fatty acids were anteiso-C15:0 (51.9%), iso-C16:0 (14.7%), and iso-C15:0 (13.2%). The major isoprenoid quinone was menaquinone 7 (MK-7). Diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. Comparative 16S rRNA gene sequence analysis showed that this strain clustered with Paenibacillus species. The 16S rRNA gene sequence similarity values between S23T and other Paenibacillus species were between 89.9% and 95.9%, and S23T was most closely related to Paenibacillus tarimensis SA-7-6T. On the basis of phylogenetic and phenotypic properties of strain S23T, the isolate is considered as a novel species belonging to the genus Paenibacillus. Therefore, the name, Paenibacillus pinihumi sp. nov., is proposed for the rhizosphere isolate; the type strain is S23T (=KCTC 13695T =KACC 14199T =JCM 16419T)

• Keywords: cellulose; novel bacterium; pine tree; rhizosphere; Paenibacillus pinihumi