Species-specific oligonucleotides for enumeration of Pseudomonas putida F1, Burkholderia sp. strain JS150, and Bacillus subtilis ATCC 7003 in biodegradation experiments

Species-specific sequences were identified within the V4 variable region of 16S rRNA of two bacterial species capable of aromatic hydrocarbon metaboli sm, Pseudomonas putida PP and Burkholderia sp, strain JS150, and a third, B acillus subtilis ATCC 7003, that can Function as a secondary degrader. Fluo rescent in site hybridization (FISH) with species-specific oligonucleotides was used for direct counting of these species throughout a phenol biodegra dation experiment in batch culture, Traditional differential plate counting methods could not be used due to the similar metabolism and interactions o f the primary degraders and difficulties in selecting secondary degraders I n mixed culture, In contrast, the FISH method provided reliable quantitativ e results without interference from those factors.