Production and characterization of two medium-chain-length polydroxyalkanoates by engineered strains of Yarrowia lipolytica

Florence Bordes,Connie Ocando,Luc Avérous,Sophie Lajus,Coraline Rigouin,Jean Marc Nicaud,Vinciane Borsenberger,Alain Marty

doi:10.1186/s12934-019-1140-y

Abstract

BackgroundThe oleaginous yeast Yarrowia lipolytica is an organism of choice for the tailored production of various compounds such as biofuels or biopolymers. When properly engineered, it is capable of producing medium-chain-length polyhydroxyalkanoate (mcl-PHA), a biobased and biodegradable polymer that can be used as bioplastics or biopolymers for environmental and biomedical applications.ResultsThis study describes the bioproduction and the main properties of two different mcl-PHA polymers. We generated by metabolic engineering, strains of Y. lipolytica capable of accumulating more than 25% (g/g) of mcl-PHA polymers. Depending of the strain genetic background and the culture conditions, we produced (i) a mcl-PHA homopolymer of 3-hydroxydodecanoic acids, with a mass-average molar mass (Mw) of 316,000 g/mol, showing soft thermoplastic properties with potential applications in packaging and (ii) a mcl-PHA copolymer made of 3-hydroxyoctanoic (3HO), decanoic (3HD), dodecanoic (3HDD) and tetradecanoic (3TD) acids with a Mw of 128,000 g/mol, behaving like a thermoplastic elastomer with potential applications in biomedical material.ConclusionThe ability to engineer Y. lipolytica to produce tailored PHAs together with the range of possible applications regarding their biophysical and mechanical properties opens new perspectives in the field of PHA bioproduction.

Highlights

The oleaginous yeast Yarrowia lipolytica is an organism of choice for the tailored production of various compounds such as biofuels or biopolymers
Polymer accumulation depending on PhaC synthase variant expressed by the yeast Recent studies have demonstrated that some specific mutations in PhaC can enhance, alone or in combination, PHA polymer production and composition when expressed in bacteria [36, 37]
PhaC was targeted to the peroxisome as this compartment is the site of fatty acid degradation by the β-oxidation pathway and the site where 3-hydroxy fatty acids (3-OH FA), the substrates of PhaC, are synthesized as intermediates of the β-oxidation pathway

Summary

Introduction

The oleaginous yeast Yarrowia lipolytica is an organism of choice for the tailored production of various compounds such as biofuels or biopolymers When properly engineered, it is capable of producing medium-chainlength polyhydroxyalkanoate (mcl-PHA), a biobased and biodegradable polymer that can be used as bioplastics or biopolymers for environmental and biomedical applications. Polyhydroxyalkanoates (PHAs) are a family of microbial, biobased and biodegradable polyesters representing an attractive ecofriendly alternative to some fossil-based polymers. They are biosynthesized by various types of microorganisms in conditions of excess of available carbon and of a limited supply of one of the nutrients essential to bacterial cell growth [1]. The well-studied scl-PHA, P3HB (poly3-hydroxybutyrate), has poor mechanical properties

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Conclusion