EVALUATION OF BIOLOG SYSTEM FOR IDENTIFICATION OF STRAINS OF PAENIBACILLUS-AZOTOFIXANS

Biolog system was evaluated for the identification of strains of Paeni bacillus azotofixans as no data concerning this species were in the li st of Bacillus currently identified using Biolog data base. The P. azo tofixans type strain P3L5 was first tested with the results recorded m anually or using the automatic plate reader. In both cases, P3L5 utili zed 22 carbon sources and when the results obtained were compared to d ata of Biolog software (Release 3.50), P3L5 was identified as B. azoto formans with a similarity coefficient of 0.913 (data recorded manually ) and of 0.791 (data recorded automatically). Metabolic profiles of P3 L5 were also compared after readings of 4 and 24 h using the computer- driven automatic plate reader. No significant difference was observed in both cases and P3L5 was identified again as B. azotoformans with in dices of similarity considered only for 'excellent identification'. Be sides P3L5, other 15 P. azotofixans strains were tested with the Biolo g system and all were identified as B. azotoformans with similarity co efficients varying from 0.511 to 0.927. Phenotypic and genetic charact eristics of B. azotoformans were compared to those described for P. az otofixans to explain the misidentification of the latter species. We c ould conclude that these two species are quite different and that data of Biolog software are from P. azotofixans and not from B. azotoforma ns.