Metabolic engineering of threonine catabolism enables Saccharomyces cerevisiae to produce propionate under aerobic conditions

Abstract

Background: Propionate is widely used as a preservative in the food and animal feed industries. Propionate is currently produced by petrochemical processes, and fermentative production of propionate remains challenging. Methods and Results:In this study, a synthetic propionate pathway was constructed in the budding yeast Saccharomyces cerevisiae, for propionate production under aerobic conditions. Through expression of tdcB and aldH from Escherichia coli and kivD from Lactococcus lactis, L-threonine was converted to propionate via 2-ketobutyrate and propionaldehyde. The resulting yeast aerobically produced 0.21 g L -1 propionate from glucose in a shake flask. Subsequent overexpression of pathway genes and elimination of competing pathways increased propionate production to 0.37 g L -1 . To further increase propionate production, carbon flux was pulled into the propionate pathway by weakened expression of pyruvate kinase (PYK1), together with overexpression of phosphoenolpyruvate carboxylase (ppc). The final propionate production reached 1.05 g L -1 during fed-batch fermentation in a fermenter. Conclusions and Implications:In this work, a yeast cell factory was constructed using synthetic biology and metabolic engineering strategies to enable propionate production under aerobic conditions. Our study demonstrates engineered S. cerevisiae as a promising alternative for the production of propionate and its derivatives.

In Vitro Activity of Vernonia cumingiana Benth.

“…Refer to the potassium ferricyanide reduction method [22][23][24][25][26]. Add 1.00 mL of sample solution, 2.50 mL of 1% potassium ferricyanide solution, and 2.50 mL PBS to the test tube, shake well, put it in a water bath at 50 °C for 30 minutes, quickly cool with cold water, and then add 2.50 mL of 10% trichloroacetic acid, and put in a centrifuge and set 4000 r•min −1 ; 10 minutes later, take 2.50 mL of the supernatant and place it in a test tube, add 2.50 mL of 0.1% ferric chloride solution and 2.50 mL distilled water, mix the three evenly, and measure the absorbance with 700 nm as the wavelength after standing for 10 min, measured in parallel three times.…”

Microbial production of odd‐chain fatty acids

“…For example, due to the less competitive price, the production of PHBV which also needed the exogenous supplementation of propionate to form propionyl‐CoA, was withdrawn from the PHBV market (Aldor & Keasling, 2003; Chanprateep, 2010). Considering that propionate was widely used as a preservative in the food and animal feed industries (Ding et al, 2022; R Axayacatl Gonzalez‐Garcia et al, 2017), the economic competitiveness of the exogenous supplementation of propionate could be limited.…”

In vitro anticancer and antibacterial performance of biosynthesized Ag and Ce co-doped ZnO NPs

“…The primary prevention of infection [ 72 – 74 ] and cancers’ diseases [ 75 – 77 ], new development in research [ 78 – 80 ] and innovation [ 81 – 84 ], such as nanotechnology [ 85 , 86 ], materials [ 87 – 89 ] and digital technologies [ 90 ], have the need to improve our understanding of diseases [ 91 – 93 ] such as cancer [ 94 – 97 ]. In fact, recent developments [ 98 ] in all field of science [ 99 – 101 ] and technology [ 102 – 104 ] have impact on human health [ 105 – 108 ] and life [ 109 – 112 ].…”