[WORLD SCIENTIFIC Proceedings of the II International Conference on Environmental, Industrial and Applied Microbiology (BioMicroWorld2007) - University of Seville, Spain (28 November – 1 December 2007)] Current Research Topics in Applied Microbiology and Microbial Biotechnology - The role of Beta-Proteobacteria in aromatic hydrocarbon degradation: fingerprinting of 16S rRNA gene and catechol 2,3-dioxygenase gene by T-RFLP in BTEX degradative bacterial communities