Journal
BIOTECHNOLOGY FOR BIOFUELS
Volume 12, Issue -, Pages -Publisher
BMC
DOI: 10.1186/s13068-019-1427-6
Keywords
Adaptive laboratory evolution; Organic acid tolerance; Propionic acid; TRK1; Potassium uptake; Yeast
Funding
- Synthetic Biology initiative at Macquarie University
- Bioplatforms Australia
- New South Wales (NSW)
- NSW Government's Department of Primary Industries
- Co-funded China Scholarship Council-Macquarie University Research Excellence Scholarship (iCFCSCMQ)
- CSIRO Synthetic Biology Future Science Platform
- Australian Research Council Laureate Fellowship
Ask authors/readers for more resources
BackgroundPropionic acid (PA), a key platform chemical produced as a by-product during petroleum refining, has been widely used as a food preservative and animportant chemical intermediate in many industries. Microbial PA production through engineering yeast as a cell factory is a potentially sustainable alternative to replace petroleum refining. However, PA inhibits yeast growth at concentrations well below the titers typically required for a commercial bioprocess.ResultsAdaptive laboratory evolution (ALE) with PA concentrations ranging from 15 to 45mM enabled the isolation of yeast strains with more than threefold improved tolerance to PA. Through whole genome sequencing and CRISPR-Cas9-mediated reverse engineering, unique mutations in TRK1, which encodes a high-affinity potassium transporter, were revealed as the cause of increased propionic acid tolerance. Potassium supplementation growth assays showed that mutated TRK1 alleles and extracellular potassium supplementation not only conferred tolerance to PA stress but also to multiple organic acids.ConclusionOur study has demonstrated the use of ALE as a powerful tool to improve yeast tolerance to PA. Potassium transport and maintenance is not only critical in yeast tolerance to PA but also boosts tolerance to multiple organic acids. These results demonstrate high-affinity potassium transport as a new principle for improving organic acid tolerance in strain engineering.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available