Substrate concentration, system arrangement and dissolved oxygen availability have been identified as key factors in the development of a natural phenol-degrading consortium used to biodegrade aqueous phenol. Significant shifts in microbial community occurred throughout the acclimation phase in a stirred tank bioreactor, and during the cell attachment on cyclodextrin hydrogel particles and operation within a draft-tube spouted bed bioreactor (DTSB). Episodes of lack of oxygen in the DTSB also affected the distribution of bacterial populations. The results demonstrate the feasibility of successfully treating phenol loading rates as high as 2.79 kg/m3 d in the DTSB. C. acidovorans was the dominant strain during periods of maximum phenol biodegradation, although A. baumannii was the most resistant to phenol in batch experiments and, growing up to at least 1000 mg-phenol/l. Future work will be addressed to improve the oxygen transfer efficiency in the DTSB in order to increase its maximum phenol removal capacity.