Brazilian Journal of Microbiology Brazilian Journal of Microbiology
Braz J Microbiol 2018;49:856-64 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.03.008
Biotechnology and Industrial Microbiology
Free fatty acids reduce metabolic stress and favor a stable production of heterologous proteins in Pichia pastoris
Andrea B. Zepedaa,b, Carolina A. Figueroaa,b, Adalberto Pessoab, Jorge G. Faríasa,,
a Universidad de La Frontera, Facultad de Ingeniería, Ciencias y Administración, Departamento de Ingeniería Química, Temuco, Chile
b Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Tecnologia Bioquímico-Farmacêutica, São Paulo, SP, Brazil
Received 19 July 2017, Accepted 21 March 2018
Abstract

The growth of yeasts in culture media can be affected by many factors. For example, methanol can be metabolized by other pathways to produce ethanol, which acts as an inhibitor of the heterologous protein production pathway; oxygen concentration can generate aerobic or anaerobic environments and affects the fermentation rate; and temperature affects the central carbon metabolism and stress response protein folding. The main goal of this study was determine the implication of free fatty acids on the production of heterologous proteins in different culture conditions in cultures of Pichia pastoris. We evaluated cell viability using propidium iodide by flow cytometry and thiobarbituric acid reactive substances to measure cell membrane damage. The results indicate that the use of low temperatures and low methanol concentrations favors the decrease in lipid peroxidation in the transition phase from glycerol to methanol. In addition, a temperature of 14°C+1%M provided the most stable viability. By contrast, the temperature of 18°C+1.5%M favored the production of a higher antibody fragment concentration. In summary, these results demonstrate that the decrease in lipid peroxidation is related to an increased production of free fatty acids.

Keywords
Lipid peroxidation, Pyruvate pathway, Yeast
Braz J Microbiol 2018;49:856-64 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.03.008