In-situ transesterification of single-cell oil for biodiesel production: a review

Abstract

In recent years, biodiesel synthesis and production demands have increased because of its high degradability, cleaner emissions, non-toxicity, and an alternative to petroleum diesel. In this context, Single Cell Oil (SCO) has been identified as an alternative feedstock, having the advantage of accumulating high intracellular lipid. SCO/microbial lipids are potential alternatives for sustainable biodiesel production. The traditional technique for biodiesel production from the oils obtained from microbes generally requires two steps: lipid extraction and transesterification. In-situ transesterification is an innovative and renewable process for biodiesel production. It rules out the need to isolate and refine the feedstock lipid, as it directly uses biomass in a single step, i.e., the pretreated biomass will be subjected to in-situ transesterification in the presence of catalysts. Hence, the production cost can be reduced by eliminating the lipid extraction procedure. The current review focuses on the basic features and advantages of in-situ transesterification of SCO for biodiesel production with the aid of short-chain alcohols along with different acid, base, and enzyme catalysts. In addition, a comparative study was carried out to highlight the merits of in-situ transesterification over conventional transesterification.

Graphical Abstract

Keywords:

• Biodiesel
• In-situ transesterification
• Oleaginous microbe
• single-cell oil

Acknowledgments

The authors wish to express their sincere thanks to the Department of Biotechnology, SRM Institute of Science and Technology, for providing research and analytical facilities.

Authors’ contributions

Tasneem Gufrana, Hasibul Islam, Shivani Khare, and Ankita Pandey performed the paper writing and final editing of the manuscript. P. Radha took care of the conceptualization, supervision, and final manuscript review. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.