Metabolic engineering of Yarrowia lipolytica for the simultaneous production of succinic acid(SA)and polyhydroxyalkanoates(PHAs)

项目来源

香港研究资助局基金(RGC)

项目主持人

Dr Lin, Carol Sze Ki

项目受资助机构

City University of Hong Kong

立项年度

2013

立项时间

未公开

项目编号

189713

项目级别

省级

研究期限

未知 / 未知

受资助金额

567353.00港币

学科

Biological Sciences

学科代码

未公开

基金类别

Early Career Scheme

关键词

未公开

参与者AI

高翠娟;连思琪;祁庆生

参与机构AI

临沂大学;香港城市大学;山东大学

项目标书摘要:Increasing demand for fuels and chemicals,driven by factors including over-population,the threat of global warming and the scarcity of fossil resources,strain our resource system and make necessary the development of sustainable and innovative strategies for the chemical industry.The strain that our resource system is under drives industry to increase its overall efficiency by improving existing processes or finding new uses for waste.Succinic acid(SA)is an important platform chemical for the production of surfactants,petro-fuel,antibiotics,protein building blocks,and vitamins.Because of its industrial importance,it was identified as one of the top twelve potential chemical building blocks for the future by the US Department of Energy in the past decade.One way of producing SA is by fermentation using the bacterium Actinobacillus succinogenes,which can also fix atmospheric CO2 in the process,making this a green chemical process.The use of this micro-organism,however,has not reached industrial scale due to limitations of yield and high production cost.The major drawback associated with bacterial SA fermentation is the formation of dicarboxylic acid salt due to the addition of alkali to maintain a neutral pH of fermentation broth.As a consequence,most acids will be produced in their salt form and the salts will have to be converted into acid.This is neither practical nor efficient in large-scale production processes and increases the production cost.The most promising alternative to petroleum-derived plastics is the production of biodegradable and durable polymers that can be produced from renewable sources.Polyhydroxyalkanoates(PHAs)are one of the most promising groups of biodegradable plastics that can be produced as intracellular energy-reserve granules via microbial fermentation of renewable resources.They are biocompatible,biodegradable,and withstand relatively high temperatures.However,these biopolymers are usually made from cost-intensive non-sustainable starting materials.This limits their industrial applications and full potential.This proposal aims to bioengineer a yeast Yarrowia lipolytica using established methods of genetic engineering,so it can simultaneously produce SA and PHAs.Metabolic engineering can alter the metabolic pathways of Y.lipolytica in such a way that more enzymes can be produced to degrade the food waste,at the same time,to produce SA and PHAs at higher productivity and yield.Fermentations using acidic medium consisting glycerol and fatty acids as carbon sources will be studied for SA and PHAs production.Integrated procedure with the fermentation process will be developed to recover succinic acid directly from fermentation broth.The proposed research will provide an innovative food valorisation solution,which could contribute to a future bio-based economy.It will also enhance Hong Kong’s competitiveness and wealth by promoting research and development of novel processes for chemical production based on renewable and no-cost feedstocks.;

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  • 1.代谢工程构建重组耶氏解脂酵母生产中长链聚羟基脂肪酸酯

    • 关键词:
    • mcl-PHA;PHA合成酶;代谢工程;重组耶氏解脂酵母
    • 高翠娟,,;连思琪;祁庆生
    • 《中国生物工程学会第六次全国会员代表大会暨第九届学术年会》
    • 中国上海
    • 会议

    中长链聚羟基脂肪酸酯(mcl-PHA)是一大类由微生物合成的天然生物聚酯,因具有可再生性和生物降解性愈来愈受到人们的关注。Mcl-PHA可由一些假单胞菌利用自身的脂肪酸合成途径或β-氧化途径来合成。耶氏解脂酵母具有很好的脂/脂肪酸分解代谢能力,但是它体内缺乏PHA合成酶(intrinsic)不能合成mcl-PHA。本文采用代谢工程策略构建重组解脂酵母,外源表达来自铜绿假单胞菌PAO1(P.aeruginosa PAO1)的PHA合成酶基因PhaC1。在PhaC1基因的末端添加PTS1过氧化物酶体定位信号序列,使其在过氧化物酶体内发挥功能。利用pINA1312载体构建表达框,借助载体上的zeta序列元件将PhaC1基因表达框整合至酵母基因组,完成基因的稳定表达。重组菌PSOC在葡萄糖为唯一碳源的培养基中几乎不产PHA,添加0.5%的油酸时可合成占细胞干重0.67%的mcl-PHA。在含三油酸甘油酯的培养基中发酵72 h产生1.51%PHA。本实验表明解脂酵母成为有潜力的生产细胞工厂,在将来可以利用一些食品厨余垃圾等富含油脂的廉价资源生产mcl-PHA。

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