STRAIN DIFFERENTIATION AND TAXONOMIC CHARACTERIZATION OF A THERMOPHILIC GROUP OF PHENOL-DEGRADING BACILLI

Thirteen new thermophilic phenol degrading strains were isolated from a number of geographically distinct thermal sources. The strains demon strated similar growth characteristics with pH optima between 6.0-7.2, temperature optima between 60 degrees C-70 degrees C and similar subs trate utilisation spectra. The comparison of chromosomal restriction e ndonuclease, ribotyping and total cellular protein patterns in additio n to bacteriocin typing was used for strain differentiation and result ed in the formation of five different groups to which the isolates cou ld be assigned. Eight of the isolates were assigned to group 2 based o n identical patterns generated for each method applied. Additional met hods such as the comparison of antibiotic MIC values, phenol tolerance , co-metabolic transformation of chlorophenols, fatty acid methyl este r (FAME) patterns and RFLP patterns revealed minor differences between the isolates of group 2. Isolate A2, of this group and A7, which disp layed differences using every technique applied, were selected for tax onomic identification and were identified as B. thermoleovorans and B. thermoglucosidasius respectively. This is the first report of phenol degrading isolates belonging to these species.