Optimization of cultivation conditions for the production of 1,3-dihydroxyacetone by Pichia membranifaciens using response surface methodology

By isolating soil samples, we obtained a novel Pichia strain (sp. ZJB-0009) capable of producing 1,3-dihydroxyacetone from glycerol. Based on the physiological, biochemical characteristics, and ITS rDNA gene sequence analysis, the strain was identified as Pichia membranifaciens and subsequently named P. membranifaciens ZJB-0009. A mathematical model was developed to investigate the influences of various fermentation parameters and to predict the optimum fermentation conditions for 1,3-dihydroxyacetone production. The maximal concentration of 1,3-dihydroxyacetone (12.91 g/L) was predicted to occur when the pH was 6.74, the incubation temperature was 29.6 °C, and the growth time was 48.8 h. A repeat fermentation of 1,3-dihydroxyacetone by P. membranifaciens ZJB-0009 was carried out in a 15-L fermenter under the optimized conditions for the verification of optimization. The maximum concentration of 1,3-dihydroxyacetone was 13.57 g/L, which was significantly higher than that obtained under unoptimized conditions.