RECLASSIFICATION OF PAENIBACILLUS-DURUM (FORMERLY CLOSTRIDIUM-DURUM SMITH AND CATO 1974) COLLINS ET-AL 1994 AS A MEMBER OF THE SPECIES PAENIBACILLUS-AZOTOFIXANS (FORMERLY BACILLUS-AZOTOFIXANS SELDIN ET-AL 1984) ASH ET-AL 1994

Phenotypic studies, as well as the reaction of Paenibacillus durum gen omic DNA with a 16S ribosomal DNA (sequence of variable regions V1 to V4)-based Paenibacillus azotofixans-specific PCR system and oligonucle otide probe, the presence of sequences homologous to Klebsiella pneumo niae nifKDH in both P. durum and P. azotofixans, and the results of DN A-DNA hybridization experiments performed with the P. durum and P. azo tofixans type strains and one additional P. durum strain, showed that these two species form a homogeneous group. In addition, evidence was found for the presence of nif genes in P. durum, and P. durum was show n to fix atmospheric nitrogen. Therefore, the names P. durum and P. az otofixans should be considered synonyms. As P. durum was capable of fi xing nitrogen and fixation without inhibition by nitrate is a major ch aracteristic of the group, we propose that P. durum be included in the species P. azotofixans.