Microbial and algal oils: Do they have a future for biodiesel or as commodity oils?

Abstract

We review the prospects of using yeasts and microalgae as sources of cheap oils that could be used for biodiesel. We conclude that yeast oils, the cheapest of the oils producible by heterotrophic microorganisms, are too expensive to be viable alternatives to the major commodity plant oils. Algal oils are similarly unlikely to be economic; the cheapest form of cultivation is in open ponds which then requires a robust, fast-growing alga that can withstand adventitious predatory protozoa or contaminating bacteria and, at the same time, attain an oil content of at least 40% of the biomass. No such alga has yet been identified. However, we note that if the prices of the major plant oils and crude oil continue to rise in the future, as they have done over the past 12 months, then algal lipids might just become a realistic alternative within the next 10 to 15 years. Better prospects would, however, be to focus on algae as sources of polyunsaturated fatty acids.

Evaluation of the Potential of Biodiesel 3g: Closed Photobioreactors

“…In general, productivity and lipid content were inversely related, Ratledge and Cohen (2008) have explained this fact by the high metabolic cost of lipid biosynthesis, in this present work lipid-rich specie showed lower biomass productivity, confirming that high biomass productivity and high lipid content are mutually exclusive. The best lipid producer is the strain showing the best combination of biomass productivity and lipid content.…”

Evaluation of lipid biosynthesis ability by Rhodotorula and Sporobolomyces strains in medium with glycerol

“…The cost-effectiveness of the process is significantly determined by the cost of substrate. It is estimated that one ton of microbial fat production requires about 5 t of carbon substrate [40]. Therefore, the aim is to apply cheap sources of assimilable carbon, often the side products of various industry branches, e.g., molasses, hydrolyzed starch, whey.…”

Use of Limited Proteolysis and Mutagenesis To Identify Folding Domains and Sequence Motifs Critical for Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase Activity

“…This fact has a great biotechnological potential, since there is a growing interest in the production of sustainable oils for their use as biodiesel or as commodity oils (2). These SCO have been found to be produced by different oleaginous microorganisms, such as microalgae, yeast, fungi, and bacteria (3).…”