Polyhydroxyalkanoate (PHA) is a plastic-like material synthesized by many bacteria. PHA serves as an energy and carbon storage compound for the bacteria. PHA can be extracted and purified from the bacterial cells and the resulting product resembles some commodity plastics such as polypropylene. Because PHA is a microbial product, there are natural enzymes that can degrade and decompose PHA. Therefore, PHA is an attractive material that can be developed as a bio-based and biodegradable plastic. In addition, PHA is also known to be biocompatible and can be used in medical devices and also as bioresorbable tissue engineering scaffolds. In this chapter, a brief introduction about PHA and the fermentation feedstock for its production are given.