Two novel psychrotolerant species, Bacillus psychrotolerans sp. nov. and Bacillus psychrodurans sp. nov., which contain ornithine in their cell walls.

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(T0, 71H1, 84E1, 87H2 and 4H2) and I C (consisting of isolates 68E39T), 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)).