Xylose Metabolism and the Effect of Oxidative Stress on Lipid and Carotenoid Production inRhodotorula toruloides: Insights for Future Biorefinery

Autor(es)

Pinheiro, Marina Julio ^{[1, 2]} ; Bonturi, Nemailla ^[1] ; Belouah, Isma ^[1] ; Miranda, Everson Alves ^[2] ; Lahtvee, Petri-Jaan ^[1]

Afiliação do(s) autor(es)

^[1] Univ Tartu, Inst Technol, Tartu - Estonia

^[2] Univ Estadual Campinas, Sch Chem Engn, Dept Mat & Bioproc Engn, Campinas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY; v. 8, AUG 19 2020.
• Citações Web of Science: 0

Resumo

The use of cell factories to convert sugars from lignocellulosic biomass into chemicals in which oleochemicals and food additives, such as carotenoids, is essential for the shift toward sustainable processes.Rhodotorula toruloidesis a yeast that naturally metabolises a wide range of substrates, including lignocellulosic hydrolysates, and converts them into lipids and carotenoids. In this study, xylose, the main component of hemicellulose, was used as the sole substrate forR. toruloides, and a detailed physiology characterisation combined with absolute proteomics and genome-scale metabolic models was carried out to understand the regulation of lipid and carotenoid production. To improve these productions, oxidative stress was induced by hydrogen peroxide and light irradiation and further enhanced by adaptive laboratory evolution. Based on the online measurements of growth and CO(2)excretion, three distinct growth phases were identified during batch cultivations. Majority of the intracellular flux estimations showed similar trends with the measured protein levels and demonstrated improved NADPH regeneration, phosphoketolase activity and reduced beta-oxidation, correlating with increasing lipid yields. Light irradiation resulted in 70% higher carotenoid and 40% higher lipid content compared to the optimal growth conditions. The presence of hydrogen peroxide did not affect the carotenoid production but culminated in the highest lipid content of 0.65 g/g(DCW). The adapted strain showed improved fitness and 2.3-fold higher carotenoid content than the parental strain. This work presents a holistic view of xylose conversion into microbial oil and carotenoids byR. toruloides, in a process toward renewable and cost-effective production of these molecules. (AU)

• Processo FAPESP: 16/10636-8 - Da fábrica celular à biorrefinaria integrada Biodiesel-Bioetanol: uma abordagem sistêmica aplicada a problemas complexos em micro e macroescalas
• Beneficiário: Roberto de Campos Giordano
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático