Three phenol- and alkanes-degrading bacterial strains were isolated from a freshwater sample. Upon the 16S rRNA gene analysis, phenotype and physiological features, the three strains were designated as Acinetobacter sp. with both phenol hydroxylase gene (phe) and alkane monooxygenase gene (alkM) detected. They could simultaneously degrade phenol and n-hexadecane for growth, but prefer phenol than n-hexadecane. Between phenol (400 mg l(-1)) and n-hexadecane (400 mg l(-1)), n-hexadecane enhanced phenol degradation in mineral salt medium (MSM), while phenol affects negatively the n-hexadecane degradation. However, combination of phenol (400 mg l(-1)) and n-hexadecane (400 mg l(-1)) in MSM led to higher growth of the strains than the phenol and n-hexadecane separately. The transcription levels of phe and alkM genes supported the physiological properties of the strains. (C) 2012 Elsevier Ltd. All rights reserved.