Abstract
Eleven psychrotolerant Bacillus strains with ornithine as diamino acid in position 3 of the peptide side chain of the cell wall and a G+C range of 35.7--38.4 mol% were characterized taxonomically. DNA--DNA hybridization studies confirmed previously physiologically established groups. High DNA-binding values (>70%) were found within groups I A (consisting of the type strain of Bacillus insolitus DSM 5(T) and Bacillus insolitus DSM 2272), I B (consisting of isolates 3H1(T), 71H1, 84E1, 87H2 and 4H2) and I C (consisting of isolates 68E3(T), 61E1, 4E3 and 67E1). Low DNA-binding values (<60%) were revealed between the three groups. Consequently, strains of groups I B and I C were considered as being representatives of new psychrotolerant species. For group I B strains the name Bacillus psychrotolerans sp. nov. is proposed with the type strain 3H1(T) (=DSM 11706(T)=NCIMB 13838(T)) and for group I C strains the name Bacillus psychrodurans sp. nov. is proposed with the type strain 68E3(T) (=DSM 11713(T)=NCIMB 13837(T)).