RT Journal Article SR Electronic(1) A1 Tamura, Tomohiko A1 Ishida, Yuumi A1 Otoguro, Misa A1 Hatano, Kazunori A1 Labeda, David A1 Price, Neil P. A1 Suzuki, Ken-ichiroYR 2008 T1 Reclassification of Streptomyces caeruleus as a synonym of Actinoalloteichus cyanogriseus and reclassification of Streptomyces spheroides and Streptomyces laceyi as later synonyms of Streptomyces niveus JF International Journal of Systematic and Evolutionary Microbiology, VO 58 IS 12 SP 2812 OP 2814 DO https://doi.org/10.1099/ijs.0.65560-0 PB Microbiology Society, SN 1466-5034, AB Previous studies have proposed that Streptomyces caeruleus is an earlier heterotypic synonym for Streptomyces niveus and Streptomyces spheroides. In this study, phylogenetic analysis of the almost complete 16S rRNA gene sequences of the Streptomyces caeruleus type strains NBRC 13344T, JCM 4014T and NRRL B-2194T revealed that S. caeruleus was closely related to Actinoalloteichus cyanogriseus and not to S. niveus, S. spheroides or any other species of the genus Streptomyces. Moreover, the diagnostic cell-wall diamino acid was found to be meso-diaminopimelic acid in S. caeruleus and DNA–DNA hybridization studies revealed that S. caeruleus NBRC 13344T was a member of the same species as A. cyanogriseus NBRC 14455T. Based on these chemotaxonomic and phylogenetic data, it is proposed that Streptomyces caeruleus ( Baldacci 1944 ) Pridham et al. 1958 be reclassified as a heterotypic synonym of Actinalloteichus cyanogriseus Tamura et al. 2000 . Furthermore, based on phylogenetic, morphological and MALDI-TOF MS analyses, it is proposed that the species Streptomyces laceyi Manfio et al. 2004 and Streptomyces spheroides Wallick et al. 1956 are reclassified as later heterotypic synonyms of Streptomyces niveus Smith et al. 1956 ., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.65560-0