Genomics innovation initiative
Synthetic biology and metabolic engineering are frontier areas of biological research. These cutting-edge technologies represent exciting new opportunities in areas such as the creation of plant-derived pharmaceuticals, production of economically feasible sources of biofuels and major improvements in current food and beverage production.
The yeast Saccharomyces cerevisiae represents an obvious target for synthetic engineering. It is an established and prominent industrial microorganism, used to produce a diversity of high-value food, beverage and biotechnology products such as biofuels, pharmaceuticals, wine and beer. In addition, yeast is a key model organism for the development of new technologies in fundamental research, including genomics, transcriptomics, metabolomics and systems biology. The existing fundamental knowledge provides an extensive base on which to build a synthetic biology strategy that can be applied in an industrial setting to address key opportunities. Specific objectives of this project are to engineer Saccharomyces cerevisiae with new metabolic pathways to enable biosynthesis of compounds such as monoterpenes, raspberry ketone, anthocyanins and lactic acid during fermentation.
In partnership with Macquarie University, the AWRI is also a member of the international Sc2.0 collaboration that is building the world’s first synthetic yeast. Macquarie and the AWRI are responsible for chromosome XIV. Other collaborating institutions on the project are located in the USA, China, the UK and Singapore.
Biosynthesis of raspberry ketone
The production of raspberry ketone by S. cerevisiae has been successfully achieved through the introduction of four heterologous enzyme activities into the yeast genome. Laboratory-scale fermentations in Chardonnay juice showed that this recombinant yeast strain is capable of producing raspberry ketone at levels far above the sensory threshold, while retaining the ability to efficiently complete fermentation. Further work is underway to maximise raspberry ketone yield through further modifications to yeast metabolism.
Sc2.0 international collaboration
Work is in progress on the synthesis of the chromosome allocated to the Macquarie/AWRI partnership. The AWRI’s focus is on additional work needed to ensure that the new knowledge gained about yeast through the project has relevance to yeasts used in industries such as wine, beer, sake, baking or biofuels.