Reclassification of Bacillus invictae as a later heterotypic synonym of Bacillus altitudinis.

The aim of this study was to reclarify the taxonomic status of strain Bacillus invictae Bi.FFUP1T by performing comparative analyses with the other four type strains within the Bacillus pumilus group. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains B. invictae Bi.FFUP1T ( = DSMZ 26896T = MCCC 1A07089T), B. altitudinis 41KF2bT ( = DSMZ 21631T = MCCC 1A06452T), B. safensis FO-36bT ( = DSMZ 19292T = MCCC 1A6451T), B. pumilus ATCC 7061T ( = DSMZ 27T = MCCC 1A06453T) and B. xiamenensis HYC-10T ( = MCCC 1A00008T) were, respectively, 82.90  % and 98.10  %, which are greater than the thresholds for bacterial species delineation, suggesting that they should belong to the same species, while the dDDH and ANI values between strain B. invictae DSMZ 26896T and the other three type strains within the B. pumilus group were below the respective thresholds of 70  % and 95  %. Meanwhile, B. invictae DSMZ 26896T and B. altitudinis 41KF2bT shared 98.7  % gyrB gene sequence similarity based on resequencing, whereas strain B. invictae DSMZ 26896T shared low similarities ( < 95  %) with the other three type strains. In addition, in comparison with those from the other three type strains, phenotypic data of B. invictae DSMZ 26896T and B. altitudinis 41KF2bT, including API 20NE, API ZYM, Biolog GN2 and API 50CHB tests, showed slight differences. The data from these combined genotypic and phenotypic analyses suggest that Bacillus invictae Branquinho et al. 2014 should be regarded as a later heterotypic synonym of Bacillus altitudinisShivaji et al. 2006.