Assimilation of hexadecane by Yarrowia lipolytica for co-production of microbial lipids and enzymes

Abstract

The improper disposal of petroleum-derived effluents has negative impacts on the environment and human health owing to the hydrophobic pollutant compounds, especially hydrocarbons. This work aimed to assess the potential of Y. lipolytica CBS 2075 to use hexadecane as the sole carbon source and produce added-value compounds (enzymes and microbial lipids) under different oxygenation conditions and medium composition. In bioreactor experiments, the increase of kLa to 132 h-1 improved hexadecane assimilation and lipids-rich biomass production. Simultaneous synthesis of protease was observed, which is a new feature that was not previously reported. In cultures supplemented with corn steep liquor, the increase in C/N ratio enhanced biomass production, faster hexadecane assimilation and lipids synthesis (27 % w/w). At the highest C/N ratio conditions, lipase (several applications, including the biodiesel industry) and protease (used in the pharmaceutical, detergent and food industries) were also produced. Lipids from Y. lipolytica CBS 2075, composed of palmitic, palmitoleic, oleic, and linoleic acids, are a potential source of feed and food supplements or feedstock for biodiesel. The results obtained are quite promising since demonstrated the potential of Y. lipolytica to convert hydrophobic compounds (hexadecane) from wastewaters into valuable compounds, under the scope of the circular economy concept.