Abstract
Vibrio natriegens is a promising industrial chassis with a super-fast growth rate and high substrate uptake rates. V. natriegens was previously engineered to produce 1,3-propanediol (1,3-PDO) from glycerol by overexpressing the corresponding genes in a plasmid. However, antibiotic selection pressure for plasmid stability was not satisfactory and plasmid loss resulted in reduced productivity of the bioprocess. In this study, we developed an antibiotic-free plasmid stabilization system for V. natriegens. The system was achieved by shifting the glpD gene, one of the essential genes for glycerol degradation, from the chromosome to plasmid. With this system, engineered V. natriegens can stably maintain a large expression plasmid during the whole fed-batch fermentation and accumulated 69.5 g/L 1,3-PDO in 24 h, which was 23% higher than that based on antibiotic selection system. This system was also applied to engineering V. natriegens for the production of 3-hydroxypropionate (3-HP), enabling the engineered strain to accumulate 64.5 g/L 3-HP in 24 h, which was 30% higher than that based on antibiotic system. Overall, the developed strategy could be useful for engineering V. natriegens as a platform for the production of value-added chemicals from glycerol.Graphic
Highlights
The development of economically competitive bioprocesses to produce fuels and chemicals from renewable bioresources is important to achieve the goal of carbon neutrality (Becker and Wittmann 2015; Clomburg et al 2017)
Plasmid stability assay of a recombinant V. natriegens during 1,3‐PDO production In our previous work, a recombinant V. natriegens VN10 was constructed to produce 1,3-PDO from glycerol (Zhang et al 2021)
An optimized 1,3-PDO synthesis module was overexpressed in plasmid pTrc99a by placing dhaBCE and gdrAB genes encoding glycerol dehydratase and its activator under promoter J23106 and yqhD gene encoding NADPH-dependent alcohol dehydrogenase under promoter J23100 (Fig. 1)
Summary
The development of economically competitive bioprocesses to produce fuels and chemicals from renewable bioresources is important to achieve the goal of carbon neutrality (Becker and Wittmann 2015; Clomburg et al 2017). Vibrio natriegens is a promising next-generation chassis for industrial biotechnology which has a remarkably short doubling time of less than 10 min in complex media (Weinstock et al 2016). It can utilize diverse substrates and has an exceptionally high glucose uptake rate under both aerobic and anaerobic conditions (Hoffart et al 2017), making it an attractive candidate for industrial application. The engineered strain can produce 56.2 g/L 1,3PDO with a high productivity of 2.36 g/L/h
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
