Selection and subsequent physiological characterization of industrial Saccharomyces cerevisiae strains during continuous growth at sub- and- supra optimal temperatures

• Published in: Biotechnology reports (Amsterdam, Netherlands) Vol. 26; p. e00462
• Main Authors: Lip, Ka Ying Florence, García-Ríos, Estéfani, Costa, Carlos E., Guillamón, José Manuel, Domingues, Lucília, Teixeira, José, van Gulik, Walter M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2020; Elsevier
• Subjects: Chemostat; Energetic efficiency; Saccharomyces; SBR; Temperature tolerance; SBR; Saccharomyces; Energetic efficiency; Chemostat; Temperature tolerance
• ISSN: 2215-017X; 2215-017X
• DOI: 10.1016/j.btre.2020.e00462

[Display omitted] •A growth phenotypic screening of one laboratory and 12 industrial yeast strains revealed large differences in optimum growth temperature.•Two industrial strains, one with low and one with high temperature tolerance and the laboratory strain were selected for further physiological characterization in anaerobic chemostat and sequential batch (SBR) cultures. The SBR results confirmed their temperature dependency of the growth rate observed from the phenotypic screening. During chemostat cultivation, the three strains responded very differently to different growth temperatures, in terms of net conversion rates, substrate yields, and energetic efficiency of biomass formation.•At a fixed growth rate all three strains accumulated mainly glycogen at sub optimal and trehalose at supra optimal temperatures.•Increased temperature tolerance coincided with a higher energetic efficiency of cell growth. A phenotypic screening of 12 industrial yeast strains and the well-studied laboratory strain CEN.PK113-7D at cultivation temperatures between 12 °C and 40 °C revealed significant differences in maximum growth rates and temperature tolerance. From those 12, two strains, one performing best at 12 °C and the other at 40 °C, plus the laboratory strain, were selected for further physiological characterization in well-controlled bioreactors. The strains were grown in anaerobic chemostats, at a fixed specific growth rate of 0.03 h−1 and sequential batch cultures at 12 °C, 30 °C, and 39 °C. We observed significant differences in biomass and ethanol yields on glucose, biomass protein and storage carbohydrate contents, and biomass yields on ATP between strains and cultivation temperatures. Increased temperature tolerance coincided with higher energetic efficiency of cell growth, indicating that temperature intolerance is a result of energy wasting processes, such as increased turnover of cellular components (e.g. proteins) due to temperature induced damage.