Production of glycerate from glucose using engineered Escherichiacoli.

In this study, glycerate was produced from glucose using engineered Escherichia coli BW25113. Plasmid pSR3 carrying gpd1 and gpp2 encoding two isoforms of glycerol-3-phosphate dehydrogenase from Saccharomyces cerevisiae and plasmid pLB2 carrying aldO encoding alditol oxidase from Streptomyces violaceoruber were introduced into E. coli to enable the production of glycerate from glucose via glycerol. Disruptions of garK and glxK genes in the E. coli genome were performed to minimize the consumption of glycerate produced. As a result, E. coli carrying these plasmids could produce nearly three times higher concentration of glycerate (0.50 ± 0.01 g/L) from 10 g/L glucose compared to E. coli EG_2 (0.14 ± 0.02 g/L). In M9 medium, disruption of garK and glxK resulted in an impaired growth rate with low production of glycerate, while supplementation of 0.5 g/L casamino acids and 0.5 g/L manganese sulfate to the medium replenished the growth rate and elevated the glycerate titer. Further disruption of glpF, encoding a glycerol transporter, increased the glycerate production to 0.80 ± 0.00 g/L. MR2 medium improved the glycerate production titers and specific productivities of E. coli EG_4, EG_5, and EG_6. Upscale production of glycerate was carried out in a jar fermentor with MR2 medium using E. coli EG_6, resulting in an improvement in glycerate production up to 2.37 ± 0.46 g/L with specific productivity at 0.34 ± 0.11 g-glycerate/g-cells. These results indicate that E. coli is an appropriate host for glycerate production from glucose.

Design and Synthesis of Cyclopropane Congeners of Resolvin E2, an Endogenous Proresolving Lipid Mediator, as Its Stable Equivalents.

Lipid chemical mediator resolvins with highly potent anti-inflammatory activity can be leads to develop novel anti-inflammatory drugs; however, they are unstable in oxygen due to their characteristic polyunsaturated structures. To solve the problem, CP-RvE2 has been designed and synthesized in which the cis-olefin of RvE2 was replaced with a cyclopropane. CP-RvE2s were much more stable than RvE2 against autoxidation and equipotent or more potent than RvE2. CP-RvE2s were successfully identified as stable equivalents of RvE2.