Yarrowia lipolytica Growth Under Increased Air Pressure: Influence on Enzyme Production

Abstract

Improvement of microbial cell cultures oxygenation can be achieved by the increase of total air pressure, which increases oxygen solubility in the medium. In this work, a pressurized bioreactor was used for Yarrowia lipolytica batch cultivation under increased air pressure from 1 to 6 bar. Cell growth was strongly enhanced by the pressure rise. Fivefold and 3.4-fold increases in the biomass production and in specific growth rate, respectively, were observed under 6 bar. The increase of oxygen availability caused the induction of the antioxidant enzyme superoxide dismutase, which indicates that the defensive mechanisms of the cells against oxidative stress were effective and cells could cope with increased pressure. The pregrowth of Y. lipolytica under increased pressure conditions did not affect the lipase production ability of the cells. Moreover, the extracellular lipase activity increased 96% using a 5-bar air pressure instead of air at 1-bar pressure during the enzyme production phase. Thus, air pressure increase in bioreactors is an effective mean of cell mass and enzyme productivity enhancement in bioprocess based in Y. lipolytica cultures.

Culture Conditions and Investigation of Bioreactor Configurations for Lipase Production by Rhizopus oryzae

“…On the other hand, a good agitation favors turbulence which leads to a decrease of the thickness of the liquid layer on the gas/liquid interface, reducing the resistance to oxygen mass transfer. This statement is in accordance with the conclusions reported by Lopes et al [9], who recorded an increase of 96 % in lipase activity values when using 5 bar air pressure instead of 1 bar pressure during the culture of Yarrowia lipolytica. In the same way, Deive et al [41] observed higher lipolytic enzyme levels in a stirred-tank bioreactor compared to an air-lift one.…”

“…However, a considerable amount of the research carried out to date has focused on small-scale procedures, while less information is available on the particular characteristics of lipolytic enzyme biosynthesis in bioreactors and the feasibility of diverse culture modes, such as batch, fed-batch, or continuous systems [6][7][8]. Over the last few months, research concerning lipase production by yeasts and fungi in bioreactors has been employed to obtain high levels of lipase production, thus demonstrating the interest that the scale-up of this kind of biological process is triggering nowadays and then encouraging further research in this field [9][10][11][12].…”

Industrial Production of Superoxide Dismutase (SOD): A Mini Review

“…Thus, the microbial sources were chosen which could be feasible for induction of SOD subjected to ROS stress and the large scale production of SOD. The proliferation of SOD was induced by increase in the air pressure from 1 to 6 bar in a batch cultivation of Yarrowia lipolytica [13].…”

Study on the Properties of Immobilized Biocatalysts with Lipase Activity Produced by Yarrowia lipolytica in Batch Culture

“…It is known that lipolytic activity of Y. lipolytica is influenced by many factors, including: the type and concentration of the carbon source in the medium, the pH value of the culture, the oxygen partial pressure, the temperature of the culture and the amount of inoculum 24,25 . Furthermore, cell activity is closely associated with the growth phase of microorganism.…”