Cocoa-Butter-Equivalent Production from &lt;i&gt;Yarrowia lipolytica&lt;/i&gt; by Optimization of Fermentation Technology

Lina Zhao,Dan Xiong,Huaiyuan Zhang,Hongyin Zhang,Shengru Yang,Bo Li,Xin Tang,Yuanda Song

doi:10.3844/ajbbsp.2016.196.205

Abstract

In order to obtain the optimal control point for single-cell lipid production with fatty acid profile similar to cocoa butter, this study explored the effects of carbon source, nitrogen source, temperature, sterculic acid methyl ester, cobalt on cell growth and lipid accumulation of Yarrowia lipolytica. Glycerol and ammonium tartrate-yeast extract were chosen as carbon source and nitrogen source for production of cocoa butter equivalent. Gradual increase in temperature (20-35°C) resulted in growth reduction, while increased in lipid content per Cell Dry Weight (CDW) (10.13 to 19.7%, w/w) and Saturated Fatty Acids (SFA). Our results suggests that the optimum conditions for Y. lipolytica to synthesize cocoa butter equivalent was 30°C with 0.6 mg L-1 of CoCl2.6H2O or 0.03 mL L-1 sterculic acid methyl ester in the medium with glycerol and ammonium tartrate-yeast extract as carbon source and nitrogen source.

Highlights

Cocoa butter mainly consists of Triacylglycerol (TAG) of POP, POS and SOS (P: Palmitic acid, O: Oleic acid, S: Stearic acid), commonly used in the food industries and in chocolate manufactures due to its specific characteristics (Papanikolaou and Aggelis, 2011)
We studied the effects of carbon source, nitrogen source, temperature, sterculic acid methyl ester, cobalt on cell growth and lipid accumulation of Yarrowia lipolytica, in order to obtain the optimal control point for single-cell lipid production with fatty acid profile similar to cocoa butter and this study could provide theoretical basis for using the yeast as raw material to commercialized production of cocoa butter
The contents of oleic acid (C18:1) and total unsaturated fatty acids (UFA) at Sn-2 position were the highest (83.39% and 93.63%, respectively) when glucose was utilized as substrate

Summary

Introduction

Cocoa butter mainly consists of Triacylglycerol (TAG) of POP, POS and SOS (P: Palmitic acid, O: Oleic acid, S: Stearic acid), commonly used in the food industries and in chocolate manufactures due to its specific characteristics (Papanikolaou and Aggelis, 2011). One common industrial applications of yeast lipid is to synthesize microbial substitutes of cocoa butter (Papanikolaou and Aggelis, 2010; Ratledge and Wynn, 2002). These microorganisms reserve their lipids mostly in the form of Triglycerides (TAGs) esterified in the Sn-2 position by unsaturated fatty acids (Ratledge, 1994). Since oleaginous yeasts can accumulate unsaturated fatty acids more than 65% (w/w) of the total lipids but cocoa butter contains saturated lipid (palmitic and stearic acid) more than 60% (w/w) (Ratledge, 1994). Numerous strategies have been explored to the increase of Saturated Fatty Acids (SFA), such as the genetic manipulation of oleaginous yeast (Ykema, 1989), inhibition of ∆9 and ∆12 dehydrogenase (Moreton, 1985), cultivation of yeasts on low-oxygenated media (Davies et al, 1990) and addition

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Conclusion