Phenetic diversity of alkaliphilic Bacillus strains: Proposal for nine new species

One hundred and nineteen strains of alkaliphilic and alkalitolerant, aerobic endospore-forming bacteria were examined for 47 physiological and biochemical characters, and DNA base composition. Numerical analysis (S₁, and S(SM)/UPGMA clustering) revealed 11 clusters that comprised three or more strains. Most of the phena were further characterized by analysis of carbohydrate utilization profiles using the API 50CH system, but strains of two taxa could not be cultured by this method. DNA reassociation studies showed that nine of the phena were homogeneous, but strains of phenon 4 and phenon 8 were each subdivided into two DNA hydridization groups. The strains could therefore be classified into 13 taxa plus a number of unassigned single-membered clusters. Two taxa were equated with Bacillus cohnii and B. alcalophilus and nine of the remainder are proposed as new species with the following names: B. agaradhaerens sp. nov., B. clarkii sp. nov., B. clausii sp. nov., B. gibsonii sp. nov., B. halmapalus sp. nov, B. halodurans comb. nov., B. horikoshii sp., nov., B. pseudalcalophilus sp. nov. and B. pseudofirmus sp. nov. Two taxa were insufficiently distinct to allow confident identification and these have therefore not been proposed as new species.