Life in the fast lane: selection of bespoke high-growth rate yeast strains in different conditions of industrial relevance
Prof D Delneri
Dr J Winterburn
Dr J-M Schwartz
Applications accepted all year round
Self-Funded PhD Students Only
For thousands of years yeast has been a pivotal microorganism in many industrial processes in the food and beverages businesses. One trait of value to all fermentation industries is growth rate, since the faster growth means savings of time, which can be costly. Hybrids between Saccharomyces species with different thermo profiles are found in many industrial situations, in particular in brewing (S. cerevisiae thermo-tolerant x S. eubayanus cold-tolerant) and wine making (S. cerevisiae thermo-tolerant x S. kudriavzevii cold-tolerant). As the optimal growth at a specific temperature may be different for different strains (brewing tends to be cold, 12 °C, while wine fermentation is a bit warmer, 16 °C) there might be several genetic/metabolic routes by which yeast can reach a fast growth. There is a clear potential benefit for improved growth rate: even a modest increase of say 10% could have profound effects on industry where the length of the process from substrate to product is the bottleneck in productivity and therefore income. Yeast growth rate can be improved by lowering the gene dosage of specific genes (haplo-proficiency phenotypes, Delneri et al. 2008) and such improvement can depend on nutrients and temperature conditions (Paget et al. 2014).
This project aims to exploit existent genetic diversity to find the faster growing yeast and develop bespoke strains that grow best under different conditions (industrial or environmental). The student will generate a large number of hybrid strains S. cerevisaie/S. kudriavzevii, with different combinations of alleles, and then select the fastest via a competition experiments in a turbidostat, a continuous culture methods where the continuous feeding of rich media allows each strain to grow at its maximum rate resulting in the fastest being selected (different selection temperatures will be applied). The student will carry out genomic, phenotypic and metabolomics analysis of the best performer and will shed light on how cell growth rate is regulated and how fast a eukaryotic cell can grow. Understanding how to improve of growth rate and biomass will be of interest to fermentation and biotech industries producing flavours and platform chemicals for new bespoke compounds development, biofuels, and new enzymes.
The successful candidate will be trained in a range of research and technical techniques, including:
• microbiology techniques
• genetic crossing and creation of hybrids
• continuous cultures and turbidostat, phenotypic essays
• molecular techniques
• genome profile studies
• Next Generation Sequencing
• data analysis
Candidates are expected to hold (or be about to obtain) a minimum upper second class honours degree (or equivalent) in a related area / subject.
This project has a Band 3 fee. Details of our different fee bands can be found on our website (https://www.bmh.manchester.ac.uk/study/research/fees/). For information on how to apply for this project, please visit the Faculty of Biology, Medicine and Health Doctoral Academy website (https://www.bmh.manchester.ac.uk/study/research/apply/).
Informal enquiries may be made directly to the primary supervisor.
1. Delneri D. et al., (2008) Nature Genetics 40: 113-117
2. Paget CM, et. al. (2014) Molecular Ecology 23: 5241-5257