Structural Biology and Biochemistry Research Theme Seminar

Investigating Metabolic Diversity in non-Saccharomyces Yeasts for Better Beer

presented by Dan Ellis

Abstract

Cultures around the world have been producing and consuming fermented beverages for millennia. Today, fermented beverages support a vast global industry of diverse products, which are typically produced by fermentation with Saccharomyces yeasts. However, growing interest can be see in the use of non-Saccharomyces yeast for the production of fermented beverages with a variety of sensory characteristics and actual or perceived health benefits. In large part, the diversity of flavours, aromas, and other sensory qualities, that can be obtained from fermentation with non-Saccharomyces yeasts is due to their production of diverse metabolites compared to conventional Saccharomyces yeasts. Here we have worked to establish and optimize a pipeline for the metabolomic analysis of yeast metabolites using untargeted DIA-LC-MS/MS and HS-GCMS approaches. We have collected native non-Saccharomyces yeasts from various plant materials, and using the pipeline we established begun characterising and quantifying the different metabolites produced by the yeast from this library of native non-Saccharomyces yeasts.

Biography

Dan is a PhD candidate in the Schulz lab where he predominantly works with wild non-Saccharomyces yeasts to see how they can be used to make beer and other fermented beverages. His research involves mass spectrometry-based metabolomics approaches to investigate the metabolites produce by non-Saccharomyces and how they can be used to make interesting flavours and aromas in beer and other fermented beverages. 

Optimisation of light-driven P450 biocatalysis in Chlamydomonas reinhardtii

presented by Bernad Agustinus

Abstract

Cytochrome P450 monooxygenases (P450s) are attractive for industrial biocatalyst due to their ability to transform broad range of substrate in regio- and stereospecific manner. However, P450s are dependent on NADPH and the co-expression of membrane bound auxiliary redox partner protein is often required. These bottlenecks can be overcome by coupling P450 to photosynthetic machinery in the chloroplast for light-driven biotransformation. The idea is to use the reducing potential produced in excess during photosynthesis that can be re-routed to drive P450 catalysis in the chloroplast circumventing cofactor dependency. Among photosynthetic organisms, microalgae such as Chlamydomonas reinhardtii offer excellent potential as a synthetic biology host due to its rapid growth rate compared to higher plants. Here using C. reinhardtii thylakoid membrane, we employed our extremely thermostable P450 ancestors for the light-driven conversion of drug compound into higher-value drug metabolites. We demonstrate in vitro that C. reinhardtii thylakoid membrane can support P450 ancestors’ activity upon light illumination using ferredoxin as electron carrier. This system exhibited almost 70% substrate turnover with the rate exceeding other systems. Furthermore, fusing redox partner to P450 allows direct shuttling of electron from PSI to P450 which is independent from the presence of ferredoxin in the system. In short, this study shows the potential of coupling P450 ancestors to photosynthetic machinery of C. reinhardtii for light-driven conversion of substrate into high value product.

Biography

Bernad graduated from the University of Indonesia with Bachelor of Pharmacy. After working at a pharmaceutical company for 2 years, he pursued a master’s degree in biotechnology at Martin Luther University in Germany. During which, he took a 6-months internship at Leibniz Institute for Plant Biochemistry working at metabolomics. His master thesis was conducted at Leibniz Institute for Plant Genetics, characterising transcription factor in barley. In 2020, he started his Ph.D with Prof. Elizabeth Gillam, looking at light-driven P450 biocatalysis in Chlamydomonas reinhardtii.