Bacillus dicomae sp. nov., a new member of the Bacillus cereus group isolated from medicinal plant Dicoma anomala

A Gram-stain-positive, endospore-forming endophytic bacterial strain designated MHSD28^T was isolated from surface-sterilized leaves of Dicoma anomala collected from Eisleben, Botlokwa, Limpopo Province, South Africa. The phenotypic and phylogenetic characteristics of strain MHSD28^T were consistent with those of members within the Bacillus cereus group. Comparative analysis between this strain and its relatives confirmed that it belongs to this group and forms a monophyletic branch. The digital DNA–DNA hybridization values between strain MHSD28^T and its relatives were lower than the 70 % threshold for species delineation. To further determine its phylogenetic position, multi-locus sequence analysis (MLSA) based on five con-catenated housekeeping gene (gyrB, atpD, DnaK, rpoB and rpoD) sequences, phenotypic analysis, matrix-assisted laser desorp-tion/ionization time-of-flight (MALDI-TOF) biotyper identification, fatty acid and polar lipid profile analyses were carried out. Phenotypic characterization, MLSA, whole genome sequence based analyses and MALDI-TOF results placed strain MHSD28^T within the B. cereus group. The major fatty acids were iso-C_{15: 0} and summed feature 3 and the main polar lipids were diphos-phatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The respiratory quinone was menaquinone-7. The cell-wall peptidoglycan structure included meso-diaminopimelic acid. Considering the above results, strain MHSD28^T represents a novel species of the B. cereus group, for which the name Bacillus dicomae sp. nov. is proposed. The type strain is MHSD28^T (=BD 2262^T=LMG 32287^T=CECT 30671^T).