However, many strains of B. subtilis are capable of anaerobic growth in the presence of glucose (Rooney et al., 2005) and a number of strains are capable of growth at or above 56 uC (Supplementary Table S2, available in IJSEM Online), which reinforces the observation that species within the B. subtilis complex cannot be reliably differentiated on the basis of morphological, physiological, biochemical or other phenotypic properties.