Effect of carbon sources on lipid accumulation in Rhodococcus cells

•Production of lipids by Rhodococcus erythropolis and Rhodococcus opacus cells was assessed.•The cells accumulated triacylglycerols which are relevant for biodiesel production.•The phospholipids:glycolipids:apolar lipids ratio depended on growth conditions.•The FAMEs blends presented cetane numbers compatible with international standards.

New regenerative and ecologically friendly processes to produce energy are required to replace petroleum-based derived combustibles. The objective of this work was to assess the usefulness of Rhodococcus erythropolis DCL14 and Rhodococcusopacus PWD4 cells to produce lipids for biodiesel blends. These cells accumulated triacylglycerols (TAGs), the most relevant lipids for biodiesel production, in addition to other lipids, including apolar lipids and phospholipids, which contained fatty acids that could be esterified. The proportion between phospholipids and storage lipids was dependent on carbon source and culture age. The estimated cetane number of the fatty acid blends produced ranged between 60.5 and 61.7 for R. erythropolis and 50.5 and 69.8 for R. opacus.