Bacillus invictae sp. nov., isolated from a health product

Abstract

A Gram-positive, rod-shaped, endospore-forming Bacillus isolate, Bi.FFUP1 T, recovered in Portugal from a health product was subjected to a polyphasic study and compared with the type strains of Bacillus pumilus , Bacillus safensis , Bacillus altitudinis and Bacillus xiamenensis , the phenotypically and genotypically most closely related species. Acid production from cellobiose, d-glucose and d-mannose and absence of acid production from d-arabinose, erythritol, inositol, maltose, mannitol, raffinose, rhamnose, sorbitol, starch and l-tryptophan discriminated this new isolate from the type strains of the most closely related species. Additionally, a significant different protein and carbohydrate signature was evidenced by spectroscopic techniques, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and Fourier transform IR spectroscopy with attenuated total reflectance. Using a chemometric approach, the score plot generated by principal component analysis clearly delineated the isolate as a separate cluster. The quinone system for strain Bi.FFUP1 T comprised predominantly menaquinone MK-7 and major polar lipids were diphosphatidylglycerol, an unidentified phospholipid and an unidentified glycolipid. Strain Bi.FFUP1 T showed ≥99 % 16S rRNA gene sequence similarity to B. safensis FO-036bT, B. pumilus (7061T and SAFR-032), B. altitudinis 41KF2bT and B. xiamenensis HYC-10T. Differences in strain Bi.FFUP1 T gyrB and rpoB sequences in comparison with the most closely related species and DNA–DNA hybridization experiments with Bi.FFUP1 T and B. pumilus ATCC 7061T, B. safensis FO-036bT, B. altitudinis 41KF2bT and B. xiamenensis HYC-10T gave relatedness values of 39.6 % (reciprocal 38.0 %), 49.9 % (reciprocal 42.9 %), 61.9 % (reciprocal 52.2 %) and 61.7 % (reciprocal 49.2 %), respectively, supported the delineation of strain Bi.FFUP1 T as a representative of a novel species of the genus Bacillus , for which the name Bacillus invictae sp. nov. is proposed, with strain Bi.FFUP1 T ( = DSM 26896T = CCUG 64113T) as the type strain.