An enzyme-displaying yeast as a whole-cell biocatalyst is an alternative to immobilized enzyme, due to its low-cost preparation and simple recycle course. Here, lipase-displaying Pichia pastoris whole-cell was used as a biocatalyst to synthesize diisooctyl adipate in the non-aqueous system. The maximum productivity of diisooctyl adipate was obtained as 85.0% in a 10 mL reaction system. The yield could be reached as high as 97.8% when the reaction system was scaled up to 200 mL. The purity obtained is 98.2% after vacuum distillation. Thus, the lipase-displaying P. pastoris whole-cell biocatalyst was promising in commercial application for diisooctyl adipate synthesis in non-aqueous phase.
Adipates ; metabolism ; Industrial Microbiology ; Lipase ; metabolism ; Pichia ; metabolism

Adipic acid is a high-value-added dicarboxylic acid which is primarily used in the production of nylon-66 for manufacturing polyurethane foam and polyester resins. At present, the biosynthesis of adipic acid is hampered by its low production efficiency. By introducing the key enzymes of adipic acid reverse degradation pathway into a succinic acid overproducing strain Escherichia coli FMME N-2, an engineered E. coli JL00 capable of producing 0.34 g/L adipic acid was constructed. Subsequently, the expression level of the rate-limiting enzyme was optimized and the adipic acid titer in shake-flask fermentation increased to 0.87 g/L. Moreover, the supply of precursors was balanced by a combinatorial strategy consisting of deletion of sucD, over-expression of acs, and mutation of lpd, and the adipic acid titer of the resulting E. coli JL12 increased to 1.51 g/L. Finally, the fermentation process was optimized in a 5 L fermenter. After 72 h fed-batch fermentation, adipic acid titer reached 22.3 g/L with a yield of 0.25 g/g and a productivity of 0.31 g/(L·h). This work may serve as a technical reference for the biosynthesis of various dicarboxylic acids.
Escherichia coli/metabolism* ; Metabolic Engineering ; Bioreactors ; Fermentation ; Adipates/metabolism*

Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.
Adipates ; metabolism ; Bacteria ; genetics ; metabolism ; Fungi ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; methods ; Metabolic Networks and Pathways ; genetics

Biobased chemicals are one of the main missions of bioeconomy. In this special issue, we reviewed the recent progress in the metabolic engineering and fermentation control study on biobased succinic acid, adipic acid, lactic acid, 3-hydroxypropanoic acid, glucaric acid, glycerol, xylitol, higher alcohols and ethylene, recombinant construction for the direct utilization of lignocelluloses, biotransformation of bio-based lactic acid, and salting-out extraction of bio-based chemicals. Some research articles on biobased succinic acid, D-mannitol, malic acid, 5-aminolevulinic acid, 1,3-propanediol, and butanol are also included.
Adipates ; metabolism ; Biotechnology ; methods ; Biotransformation ; Escherichia coli ; genetics ; metabolism ; Industrial Microbiology ; methods ; Lactic Acid ; metabolism ; Lignin ; metabolism ; Metabolic Engineering ; methods ; Organic Chemicals ; metabolism ; Saccharomyces cerevisiae ; genetics ; metabolism ; Succinic Acid ; metabolism