Effect of increasing oxygen partial pressure on Saccharomyces cerevisiae growth and antioxidant and enzyme productions
- PDF / 1,152,013 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 102 Downloads / 218 Views
BIOTECHNOLOGICAL PRODUCTS AND PROCESS ENGINEERING
Effect of increasing oxygen partial pressure on Saccharomyces cerevisiae growth and antioxidant and enzyme productions Na Cui 1 & Victor Pozzobon 1 & Cédric Guerin 1 & Patrick Perré 1 Received: 7 July 2020 / Revised: 17 July 2020 / Accepted: 10 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract This study investigated the impact of oxygen partial pressure on yeast growth. Saccharomyces cerevisiae cells were exposed to various hyperbaric air conditions from 1 bar to 9 bar absolute pressure (A). Batch cultures were grown under continuous airflow in a 750 mL (500 mL culture) bioreactor and monitored through growth rate and specific yields of ethanol and glycerol. In addition, the concentrations of antioxidant metabolites glutathione (reduced state, GSH and oxidized state, GSSG) and the activity of antioxidative enzymes superoxide dismutases (SOD) and catalases (CAT) were monitored. The results demonstrated that the different oxygen partial pressures significantly impacted the key growth parameters monitored. Compared with atmospheric pressure, under 2 to 5 bar (A), yeast cells showed higher growth rates (μ = 0.32 ± 0.01 h−1) and higher catalase (CAT) concentrations (214 ± 5 mU/g). GSH/GSSG ratio (6.36 ± 0.37) maintained until 6 bar (A) and total SOD (240 ± 5 mU/g) level significantly increased compared with 2 bar (A) until 7 bar (A). Under 6 to 9 bar (A), cell growth was inhibited, and a pressure of 9 bar (A) led to excessive GSSG accumulation (GSH/GSSG = 0.31 ± 0.06). The inhibition of t-SOD (160 ± 3 mU/g) and CAT (62.73 ± 0.2 mU/g) was observed under 9 bar (A). A reference experiment (8 bar (A) N2 + 1 bar (A) air) confirmed that the observed behaviors were entirely due to O2. In addition to their utility in biotechnological process design, these results showed that growth impairment was solely due to oxidative stress induced by excessive oxygen pressure. Key Points • Yeast cells were grown in batch mode under 1 to 9 bar (A) air pressures and up to 5 bar (A) promoted then hindered growth. • The GSH/GSSG ratio was stable up to 5 bar (A) then GSSG accumulated to excess. • Complementary investigations of the activity of SOD and CAT validated growth limitations due to oxidative stress. Keywords Saccharomyces cerevisiae . Oxygen pressure . Growth rate . Glutathione . Carbon balance
Introduction Yeast utilization by humans can be traced back to the first breadmaking approximately 4500 years ago in ancient Egypt
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00253-020-10824-4) contains supplementary material, which is available to authorized users. * Na Cui [email protected] 1
Chair of Biotechnology, LGPM, CentraleSupélec, Université Paris-Saclay, SFR Condorcet FR CNRS 3417, Centre Européen de Biotechnologie et de Bioéconomie (CEBB), 3 rue des Rouges Terres, 51110 Pomacle, France
(Abdel-Azeem 2010). Today, yeast is used in many applications, ranging from food and brewing to green ene
Data Loading...
