Hyperbaric bioreactors use with Yarrowia lipolytica cultures : cellular adaptation to hyperbaric conditions

Abstract

Increase air pressure for aeration of microbial cell cultures can prevent oxygen limitation but cause oxidative stress and consequently affect cell physiology. A pressurized bioreactor was used for Y. lipolytica batch cultivation under increased air pressure up to 6 bar and no inhibition of cell growth was observed. Moreover, an increase of 6-fold led to a 3.4-fold increase in specific growth rate under atmospheric pressure. The antioxidant enzyme superoxide dismutase was induced by the air pressure raise, which indicates that the defensive mechanisms of the cells were effective and cells could cope with increased pressure. The extracellular lipase activity increased from 22.3 to 43.7 U/l using a 5-bar air pressure instead of air at 1 bar pressure.