Enhancement of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) accumulation in Arxula adeninivorans by stabilization of production

Microbial Cell Factories

Research

Reinhard Pätz¹  Rüdiger Bode²  Thomas Roick³  Mateusz Biernacki⁴  Gotthard Kunze⁴  Marek Marzec⁵  Kim Baronian⁶ 

[1] Division Bioprocess Technology, University of Applied Sciences, Bernburger Str. 55, 06366, Köthen, Germany;Institute of Microbiology, University of Greifswald, Jahnstr. 15, 17487, Greifswald, Germany;Jäckering Mühlen-und Nährmittelwerke GmbH, Vorsterhauser Weg 46, 59007, Hamm, Germany;Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466, Gatersleben, Saxony-Anhalt, Germany;Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466, Gatersleben, Saxony-Anhalt, Germany;Faculty of Biology and Environmental Protection, University of Silesia, Jagiellonska, 28, 40-032, Katowice, Poland;School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand;

关键词: Polyhydroxyalkanoates;    PHB-V;    Arxula adeninivorans;    Phasin;   

DOI  :  10.1186/s12934-017-0751-4

 received in 2017-06-20, accepted in 2017-07-26,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundIn recent years the production of biobased biodegradable plastics has been of interest of researchers partly due to the accumulation of non-biodegradable plastics in the environment and to the opportunity for new applications. Commonly investigated are the polyhydroxyalkanoates (PHAs) poly(hydroxybutyrate) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHB-V). The latter has the advantage of being tougher and less brittle. The production of these polymers in bacteria is well established but production in yeast may have some advantages, e.g. the ability to use a broad spectrum of industrial by-products as a carbon sources.ResultsIn this study we increased the synthesis of PHB-V in the non-conventional yeast Arxula adeninivorans by stabilization of polymer accumulation via genetic modification and optimization of culture conditions. An A. adeninivorans strain with overexpressed PHA pathway genes for β-ketothiolase, acetoacetyl-CoA reductase, PHAs synthase and the phasin gene was able to accumulate an unexpectedly high level of polymer. It was found that an optimized strain cultivated in a shaking incubator is able to produce up to 52.1% of the DCW of PHB-V (10.8 g L−1) with 12.3%mol of PHV fraction. Although further optimization of cultivation conditions in a fed-batch bioreactor led to lower polymer content (15.3% of the DCW of PHB-V), the PHV fraction and total polymer level increased to 23.1%mol and 11.6 g L−1 respectively. Additionally, analysis of the product revealed that the polymer has a very low average molecular mass and unexpected melting and glass transition temperatures.ConclusionsThis study indicates a potential of use for the non-conventional yeast, A. adeninivorans, as an efficient producer of polyhydroxyalkanoates.

【 授权许可】

CC BY   
© The Author(s) 2017