Noppadon Chamchoi, J. Rajagukguk, K. Teanchai, W. Siriprom
Recently, the isolates of Acetobacter orientalis, Gluconobacter frateurii, and Gluconobacter thailandicus have been identified for their ability to biotransform glycerol to dihydroxyacetone (DHA). In order to increase the production of DHA, this study aimed to investigate the effect of different concentrations of intial glycerol on bacterial growth and DHA productivity by Acetobacter orientalis, Gluconobacter frateurii, and Gluconobacter thailandicus isolates. The bacteria isolates were evaluated for their growths in various initial glycerol concentrations of 40, 50, 55, and 60 g/L; and their DHA production. The quantitative screening was performed by shake-flask fermentation at diffiernt initial concententrations of glycerol at 40, 50, 55, and 60 g/L. The cultured media were analyzed for DHA concentration and yields. In bioreactor, the feasibility of a large-scale biosynthesis of DHA in low-cost media was studied by using only glycerol as a carbon source and inorganic salts as supplemented nutrients for industrial production of DHA. Gluconobacter thailandicus BCC14436 could biotransform glycerol to DHA and generate a high DHA concentration and yield, when compared to other acetic acid bacteria. G. thailandicus BCC14436 produced the highest DHA concentration (p) at 56.08±2.82 g/L with a DHA product yield (ysp) of 95.57±4.80% of DHA moles/glycerol moles at the highest glycerol concentration of 60 g/L in a shake-flask screening. In bioreactor batch fermentation (BBF), the DHA concentration (p) of 61.69±0.81 g/L with a DHA production yields (ysp) of 99.61±0.37% were achieved at the 90th h. This study reveals the possible use of G. thailandicus BCC14436 for an industrial application of DHA production for the first time. © Suranaree University of Technology.
Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok, 10300, Thailand; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia; Material Science and Applied Physics Research Unit, Faculty of Science at Si Racha, Kasetsart University, Si Racha campus, Chonburi, 20230, Thailand; Faculty of Science at Si Racha, Kasetsart University, Si Racha campus, Chonburi, 20230, Thailand
