Microbial conversion of lignin to monomers for bio-based plastics using synthetic biology (MILIMO)

在欧盟国家，社会需要开发新型生物塑料，可用于替代目前的石油基塑料，用于一系列包装应用。该项目的工业合作伙伴Biome生物塑料有限公司（英国）一直在开发新的聚酯塑料，其中含有用于PET或PBAT等石油基塑料的对苯二甲酸的替代品。Bugg教授和Biome Bioplastics开发了一种生物催化途径，从植物细胞壁中发现的生物聚合物木质素到2,4-和2,5-吡啶二羧酸，可以用作对苯二甲酸的生物基替代品。该项目将寻求从木质素中提高2,4- pdca和2,5- pdca的产量，直至可以开发出商业上可行的生产方法。该项目将利用合成生物学方法提高两种降解木质素的细菌：乔氏红球菌（Rhodococcus jostii） RHA1和恶臭假单胞菌（Pseudomonas putida） KT2440的木质素氧化率。我们还将致力于将羟基肉桂酸或木质纤维素的纤维素部分转化为PDCA单体。合成生物学还将用于重新设计恶臭假单胞菌KT2440的代谢途径，以优化不同植物原料中PDCA单体的生产。我们还将研究利用不同的木质纤维素降解菌群将木质素转化为PDCA单体，模拟土壤中木质素降解菌群和纤维素降解菌群合作分解木质纤维素生物质的情况。在实验室条件下开发了一种小规模生产PDCA的高产工艺后，生物催化工艺将扩大规模，以产生一种有效的基于发酵的方法，将木质素或木质纤维素原料转化为PDCA单体，这可能由Biome Bioplastics商业化。

There is a societal need in EU countries to develop new types of bio-plastics that could be used to replace current petroleum-based plastics for a range of packaging applications. The industrial partner in this Project, Biome Bioplastics Ltd (UK), has been developing new polyester plastics containing replacements for terephthalic acid used in petroleum-based plastics such as PET or PBAT. Professor Bugg and Biome Bioplastics have developed a biocatalytic route from the biopolymer lignin, found in plant cell walls, to 2,4- and 2,5-pyridinedicarboxylic acid, which can be used as biobased replacements for terephthalic acid. This project will seek to enhance the yields of 2,4-PDCA and 2,5-PDCA from lignin, to the point where a commercially feasible method of production could be developed. The project will use synthetic biology methods to enhance the rate of lignin oxidation in two lignin-degrading bacteria: Rhodococcus jostii RHA1 and Pseudomonas putida KT2440. We will also aim to convert hydroxycinnamic acids or the cellulose fraction of lignocellulose into PDCA monomers. Synthetic biology will also be used to redesign the metabolic pathways of Pseudomonas putida KT2440 in order to optimise the production of PDCA monomers from different plant feedstocks. We will also investigate the use of consortia of different lignocelluose-degrading bacteria for the conversion of lignin into PDCA monomers, mimicking the situation in soil where consortia of lignin-degrading specialists and cellulose-degrading specialists co-operate in order to break down lignocellulosic biomass. Having developed a high-yield process for production of PDCAs on a small scale under laboratory conditions, the biocatalytic process will be scaled up to yield an efficient fermentation-based method for conversion of lignin or lignocellulose feedstocks to PDCA monomers, that could be commercialised by Biome Bioplastics.