Repeated biotransformation of glycerol to 1,3-dihydroxyacetone by immobilized cells of Gluconobacter oxydans with glycerol- and urea-feeding strategy in a bubble column bioreactor

• Published in: Bioresource technology Vol. 233; pp. 144 - 149
• Main Authors: Hu, Zhong-Ce, Tian, Sheng-Ying, Ruan, Li-Juan, Zheng, Yu-Guo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2017
• Subjects: 1,3-Dihydroxyacetone; Bioreactors; Biotransformation; Bubble column bioreactor; Cells, Immobilized - metabolism; Dihydroxyacetone - biosynthesis; Gluconobacter oxydans; Gluconobacter oxydans - metabolism; Glycerol - metabolism; Glycerol- and urea-feeding strategy; Immobilization; Urea - metabolism; Immobilization; Gluconobacter oxydans; 1,3-Dihydroxyacetone; Glycerol- and urea-feeding strategy; Bubble column bioreactor
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.02.096

•Achievement of near colorless DHA solution with few impurities.•Repeated production by continuous-feeding of glycerol and urea.•High DHA productivity and conversion rate of glycerol to DHA.•Immobilized cells on porous ceramics in a home-made bubble column bioreactor. Some inorganic nitrogen sources and amino acids instead of yeast extract, which resulted in trouble of product purification, were introduced for 1,3-dihydroxyacetone (DHA) production by biotransformation with Gluconobacter oxydans. The results showed that urea is an optimal nitrogen source. Furthermore, the effects of glycerol- and urea-feeding strategies for DHA production by immobilized cells in a home-made bubble column bioreactor were optimized. Cells immobilization was prepared by cultivation in the bioreactor packed with porous ceramics, and then the broth was removed. Then, repeated biotransformation by continuous-feeding of glycerol and urea was developed. Up to 96.4±4.1g/L of average DHA concentration with 94.8±2.2% of average conversion rate of glycerol to DHA was achieved after 12 cycles of run. Near colorless DHA solution with few impurities was obtained and the production cost could be decreased.