A moderately thermophilic and alkaliphilic bacillus, which had been reported and designated BLx (Haruta et al., 2002), was isolated from a semi-continuous decomposing system of kitchen refuse. Cells of strain BLxT were strictly aerobic, rod-shaped, motile and spore forming. The optimum temperature and pH for growth were approximately 50 degrees C and pH 8-9. Strain BLxT was able to grow at NaCl concentrations from 0.5 to 7.5%, with optimum growth at 0.5% NaCl. The predominant menaquinone was MK-7, and the major fatty acid was iso-C(15 : 0). Phylogenetic analysis showed that strain BLxT was positioned in an independent lineage within the cluster that includes the genera Virgibacillus and Lentibacillus in Bacillus rRNA group 1. Strain BLxT exhibited 16S rDNA similarity of 92.8-94.8% to Virgibacillus species and 92.3% to Lentibacillus salicampi. Phenotypic, chemotaxonomic and phylogenetic analyses supported the classification of strain BLxT in a novel genus and species. Cerasibacillus quisquiliarum gen. nov., sp. nov. is proposed on the basis of phenotypic, chemotaxonomic and phylogenetic data. The type strain is BLxT (DSM 15825T=IAM15044T=KCTC 3815T).