Polyhydroxyalkanoates (PHAs) is a biodegradable alternative of plastic. Hydrogen is a clean and renewable alternative of fossil fuel. Phototrophs, including microalgae and purple non-sulfur bacteria, have competitive PHA and hydrogen yields by utilizing the organic matters from municipal wastewater. This project explores the mechanisms of PHA and hydrogen productions, related technologies of cultivation and harvesting, factors affecting the yields and the possibility of commercially utilizing the process.