Enhanced production of para-hydroxybenzoic acid by genetically engineered Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae is a popular organism for metabolic engineering; however, studies aiming at over-production of bio-replacement precursors for the chemical industry often fail to overcome proof-of-concept stage. When intending to show real industrial attractiveness, the challenge is twofold: formation of the target compound must be increased, while minimizing the formation of side and by-products to maximize titer, rate and yield. To tackle these, the metabolism of the organism, as well as the parameters of the process, need to be optimized. Addressing both we show that S. cerevisiae is well-suited for over-production of aromatic compounds, which are valuable in chemical industry and are particularly useful in space technology. Specifically, a strain engineered to accumulate chorismate was optimized for formation of para-hydroxybenzoic acid. Then a fed-batch bioreactor process was developed, which delivered a final titer of 2.9 g/L, a maximum rate of 18.625 mg/(g × h) and carbon-yields of up to 3.1 mg/g.

Metabolic Engineering of the Shikimate Pathway for Production of Aromatics and Derived Compounds—Present and Future Strain Construction Strategies

“…Further, ubiC was screened against the mutated version ubiC CCSS , which supposedly has enhanced solubility (Holden et al, 2002 ). Surprisingly ubiC still performed better (Averesch et al, 2017 ), also kinetic limitations appeared to be not as profound as reported (Holden et al, 2002 ). The strain was then used to stepwise develop a production process; in a fed-batch bioreactor a final titer of 2.9 g/L could be reached, at a productivity of almost 30 mg/(L × h) and a yield that reached 4% of the theoretical maximum.…”

Economic Process Evaluation and Environmental Life-Cycle Assessment of Bio-Aromatics Production

“…3 These prices indicate the dutiable value on the US border prior to applying tariffs and in our opinion reflect the bulk prices for chemicals robustly. We assume that a mineral medium is based on a previously published yeast-based process (Averesch et al, 2017). For the bacterial process, it is assumed that sucrose metabolism is as active as glucose metabolism, which was previously demonstrated for certain strains of Escherichia coli (Arifin et al, 2014), for instance.…”

“…For this simulation we assume a production either with a recombinant strain of baker's yeast as described previously (Averesch et al, 2017) or an optimized strain of Corynebacterium glutamicum (Kitade et al, 2018). The yeast-based process could be run in an acidic pH range and potentially under anaerobic conditions, while the bacterial process needs to be controlled around pH 7.0 with sufficient aeration.…”

Bioprocess Optimization for the Production of Aromatic Compounds With Metabolically Engineered Hosts: Recent Developments and Future Challenges

“…To increase the flux to chorismate, they expressed ARO4 K229L and aroL. This strain was then used and allowed a PHBA formation from CHO, with a titer of 2.9 g L −1 and yield of 3.1 mg g glucose −1 , in a fed-batch process (Averesch et al, 2017). To date, the highest PHBA titer was reported by Kitade et al (2018) in C. glutamicum (Table 1).…”