This document describes a screening method developed to isolate polyhydroxyalkanoate (PHA)-producing purple non-sulfur photosynthetic bacteria from natural seawater. Natural seawater samples were cultured in nutrient-rich medium designed for purple non-sulfur photosynthetic bacteria. Twelve pigmented bacterial colonies were isolated and four were found to produce PHA ranging from 0.5-24.4% of dry cell weight based on gas chromatography mass spectrometry analysis. 16S rRNA gene sequencing identified one isolate as a marine purple non-sulfur photosynthetic bacteria. This demonstrates that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions