Polyhydroxyalkanoate Production by Cupriavidus necator with Inedible Rice

Abstract

Because of their lower environmental impact, biodegradable polymers such as polyhydroxyalkanoates (PHAs) produced within cultured bacteria represent promising alternatives to petroleum-based plastics. PHA production in flasks yielded optimal results with a carbon-to-nitrogen ratio of 22. The 5-L scale experimental results revealed that when glucose was used as the carbon source, Cupriavidus necator could produce 4.74 g/L PHA with 77.6% of PHA content in the microorganism 72 h after the initiation of the experiment. When the hydrolysis liquid from inedible rice was used as the carbon source, the highest concentration of PHA and ratio of PHA content in the microorganism were 4.82 g/L and 68.6%, respectively, after 72 h. Using the hydrolysis liquid from inedible rice as the carbon source reduced the culture cost and shortened the culture time, without affecting the structure of the PHA during production. Using the hydrolysis liquid from rice as the carbon source in PHA production (by C. necator) yielded optimal results, and the results may serve as a reference for applications involving other PHA-producing bacteria. Employing alternative carbon sources to culture bacteria might become a means of increasing the productivity and ensuring the quality of PHA products in the future.