S. Lechner et al., BACILLUS-WEIHENSTEPHANENSIS SP. NOV. IS A NEW PSYCHROTOLERANT SPECIESOF THE BACILLUS-CEREUS GROUP, International journal of systematic bacteriology, 48, 1998, pp. 1373-1382
The Bacillus cereus group comprises the four valid species Bacillus ce
reus, Bacillus mycoides, Bacillus thuringiensis and Bacillus anthracis
. Some isolates of B. cereus are known to be psychrotolerant (growth a
t 7 degrees C or below). Here, specific sequence differences are descr
ibed between the 16S rDNA, the 23S rDNA, the 16S-23S rDNA spacer regio
n and the genes of the major cold-shock protein homologue cspA in a va
riety of psychrotolerant and mesophilic B. cereus and B. mycoides stra
ins. Randomly amplified polymorphic DNA analysis using three different
primers clearly separated psychrotolerant strains of both species fro
m the rest of the B, cereus group, as did inverse PCR patterns of the
rDNA operons. These data strongly support a hitherto unrecognized fift
h sub-group within the B. cereus species group comprising psychrotoler
ant, but not mesophilic, B. cereus strains. Despite the latter finding
, the DNA sequences investigated exhibited a high degree of sequence s
imilarity indicating a close relationship between the species of the B
. cereus group. Considering the unusual importance of B. cereus in bot
h food poisoning and food spoilage and to avoid merging all species of
the group, a new species, Bacillus weihenstephanensis sp. nov., compr
ising psychrotolerant 'cereus' strains, is proposed. Isolates of the n
ew species grow at 4-7 degrees C but not at 43 degrees C and can be id
entified rapidly using rDNA or cspA targeted PCR. The type strain is B
. weihenstephanensis WSBC 10204(T) (= DSM 11821(T)).