A novel microorganism identified as Pseudomonas putida strain MAO12 was isolated from waste water in Saudi Arabia. The microorganism is capable of producing high levels of the biodegradable polymer poly--hydroxybutrate (PHB). Biodegradable PHB is an environmentally-friendly alternative to petrochemical-based plastics and has broad applicability in numerous fields including medicine and agriculture. The present methods provide an inexpensive means of producing high levels of PHB on renewable carbon sources.