Paenibacillus taihuensis sp. nov., isolated from an eutrophic lake

Two Gram-stain-negative, facultatively anaerobic and endospore-forming rod-shaped bacterial strains, THMBG22^T and R24, were isolated from decomposing algal scum. Phylogenetic analysis of 16S rRNA gene sequences showed that the two strains were closely related to each other (99.7 % similarity) and that they were also closely related to Paenibacillus sacheonensis DSM 23054^T (97–97.1 %) and DSM 17399^T (96.1–96.4 %). This affiliation was also supported by rpoB-based phylogenetic analyses. Growth was observed at 20–40 °C (optimum, 30–37 °C) and at pH 5.0–9.0 (optimum, pH 6.0–7.0). The cells contained MK-7 as the sole respiratory quinone and anteiso-C_15 : 0 as the major cellular fatty acid. Their cellular polar lipids were composed of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and 12 unidentified polar lipids. The diamino acid of their cell-wall peptidoglycan was meso-diaminopimelic acid. The DNA–DNA hybridization value between THMBG22^T and R24 was 84 %, and DNA–DNA relatedness to the most closely related species with a validly published name (P. sacheonensis) was 35–37 %. These results supported the assignment of the new isolates to the genus Paenibacillus and also distinguished them from the previously described species of the genus Paenibacillus. Hence, it is proposed that strains THMBG22^T and R24 represent a novel species of the genus Paenibacillus, with the name Paenibacillus taihuensis sp. nov. The type strain is THMBG22^T ( = CGMCC 1.10966^T = NBRC 108766^T).