Production of Palmitoleic and Linoleic Acid in Oleaginous and Nonoleaginous Yeast Biomass

Irena Kolouchová,Jan Masák,Tomáš Řezanka,Karel Sigler,Olga Maťátková

doi:10.1155/2016/7583684

Abstract

We investigated the possibility of utilizing both oleaginous yeast species accumulating large amounts of lipids (Yarrowia lipolytica, Rhodotorula glutinis, Trichosporon cutaneum, and Candida sp.) and traditional biotechnological nonoleaginous ones (Kluyveromyces polysporus, Torulaspora delbrueckii, and Saccharomyces cerevisiae) as potential producers of dietetically important major fatty acids. The main objective was to examine the cultivation conditions that would induce a high ratio of dietary fatty acids and biomass. Though genus-dependent, the type of nitrogen source had a higher influence on biomass yield than the C/N ratio. The nitrogen source leading to the highest lipid accumulation was potassium nitrate, followed by ammonium sulfate, which is an ideal nitrogen source supporting, in both oleaginous and nonoleaginous species, sufficient biomass growth with concomitantly increased lipid accumulation. All yeast strains displayed high (70–90%) content of unsaturated fatty acids in total cell lipids. The content of dietary fatty acids of interest, namely, palmitoleic acid and linoleic acid, reached in Kluyveromyces and Trichosporon strains over 50% of total fatty acids and the highest yield, over 280 mg per g of dry cell weight of these fatty acids, was observed in Trichosporon with ammonium sulfate as nitrogen source at C/N ratio 70.

Highlights

Microorganisms produce lipids in standard quality; the waste biomass and byproducts are biodegradable and nontoxic [1,2,3,4,5]
DBM 2171; Rhodotorula glutinis CCY 20-2-20; Saccharomyces cerevisiae DBM 2115; Torulaspora delbrueckii DBM 39; Trichosporon cutaneum CCY 30-5-10; Yarrowia lipolytica CCY 29-26-36 supplied by Culture Collection of Yeast, Institute of Chemistry, Slovak Academy of Sciences, Bratislava, and by Collection of Yeasts and Industrial Microorganisms of University of Chemistry and Technology, Prague
Glucose was used as carbon source, because it is an expensive substrate as a pure compound, it is often used as a model substrate for the estimation of yeast production abilities

Summary

Introduction

Microorganisms produce lipids in standard quality; the waste biomass and byproducts are biodegradable and nontoxic [1,2,3,4,5]. All types of microorganisms produce lipids but they can be differentiated by the amount produced: nonoleaginous strains (the majority of microorganisms, many technologically employed strains, e.g., Saccharomyces sp.) do not accumulate lipids in high quantity while oleaginous strains accumulate more than 20% lipids in dry cell weight and can be exploited for production of fatty acid methyl esters, that is, biodiesel [6]. Yeasts appear to be the most exploitable microorganism due to their fast lipid accumulation, relatively high biomass yield, and unicellular character [9, 10]. These properties might be advantageous for subsequent lipid isolation and processing and following biodiesel production. The technoeconomical evaluation of the process has been published [12] and it has been demonstrated that the overall cost of the process is principally due to the cost of the fermentation (e.g., aeration and agitation) in large scale and the starting material does not play a material role

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Results

Discussion

Conclusion