Advanced Water Management Centre

AWMC Seminar Program: Microbial Electrosynthesis for Bioproduction of Chemicals

Microbial Electrosynthesis for Bioproduction of Chemicals - Bin Lai

Abstract: Pseudomonas putida is a promising host for the bioproduction of chemicals, but its industrial applications are significantly limited by its obligate aerobic character. In CEMES, we integrate the advantages of bioelectrochemical system with synthetic biology, to empower the anoxic metabolism of wide Pseudomonas putida to enable bioproduction anaerobically in high yield and good productivity. With the redox power from a bioelectrochemical system (BES), P. putida was able to survive and produce almost exclusively 2‑keto-gluconate from glucose under anoxic conditions, with the yield of over 90%. Effects of mediator compounds on the interaction with the cells, productivity and the intracellular status (energy level and redox equivalents) were tested for fundamental understandings. 

Combined with metabolic engineering tools, we were able to accelerate sugar conversion rate by co-expressing the membrane-bound gluconate dehydrogenase (EC 1.1.5.2) and gluconate 2-dehydrogenase (EC 1.1.99.3) gene clusters in a duet expression vector. The resulting strain exhibited an enhanced performance in the BES by more than halving the fermentation time.

For the first time, our work proved the principle that a BES driven bioconversion of glucose can be achieved for an obligate aerobe. This non-growth bioconversion achieved high yield, high purity and also could deliver the necessary metabolic energy for cell maintenance. While metabolic engineering allowed to significantly increase the conversion rates. The presented approach is a powerful new way to produce bio-chemicals and fuels.

Event Details
Date & Time: 
Friday, 13 May 2016
9am
Venue: AIBN Building 75, Level 1 Seminar Room

Event Contact: awmcseminars@awmc.uq.edu.au