1 st Mae Fah Luang University International Conference 2012 1 EFFECT OF GLUCOSE ON PHB PRODUCTION USING Alcaligenes eutrophus DSM 545 AND TISTR 1095 Jaruwan Marudkla 1 , Chiravoot Pechyen 2,3 and Sarote Sirisansaneeyakul 1,3* 1 Department of Biotechnology, Kasetsart University, Bangkok, 10900, Thailand 2 Department of Packaging and Materials Technology, Kasetsart University,Bangkok 10900, Thailand 3 Center for Advanced Studies in Tropical Natural Resources, National Research University Kasetsart University, Kasetsart University, Bangkok, 10900, Thailand *e-mail sarote.s@ku.ac.th Abstract Poly-β-hydroxybutyrate (PHB) is biodegradable plastics have received increased attention due to its properties that resemble those of petroleum-based plastics such as polyethylene. PHB could be accumulated within bacterial cells varying glucose concentration in the present study. The concentrations of 5, 10, 15 and 20 g L -1 glucose were employed as a single carbon source for the PHB production which compared between Alcaligenes eutrophus DSM 545 and A. eutrophus TISTR 1095. In shake flask culture, the maximum PHB concentrations were 9.437 g L -1 with 10 g L -1 glucose, and 1.679 g L -1 with 15 g L -1 glucose for A. eutrophus DSM 545 and A. eutrophus TISTR 1095, respectively. The highest PHB yield of 0.321 g PHB g -1 glucose was obtained from using 5 g L -1 glucose by A. eutrophus TISTR 1095. For A. eutrophus DSM 545, its highest PHB yield of 0.998 g PHB per g glucose was attainable from 10 g L -1 glucose. In addition, the production yield of PHB from A. eutrophus DSM 545 decreased against the glucose concentration increased from 15 to 20 g L -1 . As a result, the initial concentration of glucose beyond bacterial growth inhibition was appropriately found at 10 g L -1 . Further work would go for scale up of PHB production using A. eutrophus DSM 545. Keywords: Poly-β-hydroxybutyrate (PHB), glucose concentration, A. eutrophus DSM 545, A. eutrophus TISTR 1095 Introduction Plastic wastes are the global proportions which construct the environmental pollutions. Due to these conventional plastics derived from petroleum processes, they cannot be readily biodegradable. There are several families of biodegradable plastics such as poly-hydroxy alkanoates (PHAs), and their co-polymeric derivatives have been attracted due to their complete biodegradability (Kumar et al., 2004). Many microbial strains accumulate PHAs within their cells for using as carbon and energy sources. Alcaligenes eutrophus produced PHAs under the imbalance of nutrients and oxygen conditions (Yinguang et al., 2003). Furthermore, the limited nutrient and oxygen conditions were studied to increase the productivity of PHAs (Giannis et al., 2011). In addition to the ability of biodegradation,