A strain of Acinetobacter baumannii cultured in butyric acid media was found to take up phosphate following a period of phosphate release. PCR was used to clone the polyphosphate kinase (ppk) gene from the strain. The promoter for the ppk gene was functional in the heterologous Escherichia coli host. Using RT-PCR, transcription of the ppk gene was found to be regulated by phosphate concentration.