Cell engineering to enhance biohydrogen production from agricultural waste

细胞工程提高农业废弃物的生物氢产量

• 批准号: 2878511
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2878511
• 关键词: Cell; engineering; enhance; biohydrogen; production

Hydrogen is considered one of the most promising substitutes for fossil fuels, being a source of green energy that could potentially lead to decarbonization. Its combustion only delivers water and heat energy as reaction products, making it a pollution free alternative. Dark fermentation (DF) is a biological hydrogen production method in which under anaerobic conditions and absence of light, microorganisms break down complex organic matter into simpler compounds producing biohydrogen and volatile fatty acids (VFAs). Given the high cost of using pure carbohydrates as a substrate on a commercial scale, there has been a lot of interest in biohydrogen production using renewable and less expensive feedstocks. Over 220 billion tonnes of agricultural waste are generated yearly, making it an accessible renewable resource to use as feedstock for dark fermentation. Therefore, using agricultural waste for biohydrogen production is a circular economy approach in which organic waste is treated to produce renewable energy, making the dark fermentation of these substrates both environmentally and economically compelling.Theoretically, a maximum of 12 mol of H2 can be obtained from the complete oxidation of one mole of glucose. However, only 4 mol of H2 can be obtained per mole of glucose through dark fermentation, with acetate and CO2 as the other fermentation end products, and this yield is obtained when the particle pressure of H2 is kept adequately low. Theoretically, during the acidogenesis for fermentative hydrogen generation, one-third of carbon from glucose is broken down into hydrogen (H2) and carbon dioxide (CO2), while the remaining two-thirds remain soluble as VFAs in the and less than 20% of the chemical oxygen demand (COD) is removed. Nowadays, the yield of biohydrogen production by dark fermentation is between 1.2 and 2.3 mol H2/mol hexose, which is only 30-50% of the maximum theoretical production of 4 mol H2/mol glucose.The low yield of H2 by biohydrogen production methods is one of the major challenges that needs to be addressed before it can be used for industrial purpose. In this project, we will look into which strains, feedstocks and conditions are the most promising for hydrogen production. However, due to the great potential of dark fermentation but low efficiency, the conventional approach is not enough. The accessibility of huge sequenced genomes, functional genomic studies, the development of in silico models at the genome scale, metabolic pathway reconstruction, and synthetic biology approaches, has risen during the last years. This bioinformatic and biotechnological approaches hold the key for augmentation of biohydrogen production.The aim of this project is to enhance biohydrogen production from agricultural waste through metabolic engineering of the metabolic pathways involved in dark fermentation. The following questions will be investigated during this project:(1) Which strain and biomass feedstocks are more promising for biohydrogen production? For this, we will test bacterial strains reported in the literature (Shewanella oneidensis MR-1) and novel strains isolated from extreme environments. Different lignocellulosic materials from agricultural waste (willow, hay, wheat and barley) will be tested as feedstock.(2) Which are the key points in the metabolic pathways that lead to biohydrogen production during dark fermentation? A multi-omics approach, considering genomics, transcriptomics, proteomics and metabolomics, will be taken to unravel these key points. Bioinformatics and experimental data will be used. (3) How can this process be optimized? To redirect the carbons from the agricultural waste into biohydrogen production, synthetic biology techniques will be used to perform metabolic engineering in the selected strain to favour the metabolic pathway leading to increased hydrogen production. Bioprocessing studies will be done using Design of Experiments (DoE) to explore the most optimal conditio

氢被认为是化石燃料最有前途的替代品之一，是可能导致脱碳化的绿能来源。它的燃烧只能将水和热能作为反应产物，使其成为无污染的替代品。深色发酵（DF）是一种生物氢生产方法，在这种方法中，在厌氧条件下，没有光，微生物将复杂的有机物分解成产生生物氢和挥发性脂肪酸（VFAS）的更简单化合物。考虑到在商业规模上使用纯碳水化合物作为基材的高成本，使用可再生和便宜的原料对生物氢的产生引起了很多兴趣。每年产生超过2200亿吨的农业废物，使其成为可访问的可再生资源，可用作黑暗发酵的原料。因此，将农业废物用于生物氢生产是一种循环经济学方法，在这种方法中，有机废物被治疗以产生可再生能源，从而使这些底物的深色发酵在环境和经济上引人注目。从理论上讲，最多可以从一摩尔一摩尔的葡萄糖氧化中获得12摩尔的H2。但是，每摩尔的葡萄糖只能通过黑暗发酵获得4摩尔的H2，乙酸和CO2作为其他发酵端产物，当H2的颗粒压力保持充分低时，可以获得此产率。从理论上讲，在发酵氢产生的酸中，来自葡萄糖的碳的三分之一被分解为氢（H2）和二氧化碳（CO2），而其余的三分之二则在溶解中作为VFA，而较小的化学氧需求（COD）中的VFA被溶解。如今，黑暗发酵产生生物氢的产量在1.2至2.3 mol H2/mol己糖中，仅是4 mol H2/mol葡萄糖的最大理论生产的30-50％。生物氢生产方法的低收益率低是在用于工业目的之前需要解决的主要挑战之一。在这个项目中，我们将研究哪些菌株，原料和条件是生产氢的最有希望的。但是，由于黑暗发酵的潜力但效率低，传统方法还不够。在过去的几年中，巨大测序基因组，功能基因组研究，在基因组量表上的发展，代谢途径重建和合成生物学方法的可及性在过去几年中有所增加。这种生物信息学和生物技术方法是增强生物氢生产的关键。该项目的目的是通过对黑暗发酵涉及的代谢途径的代谢工程来增强农业废物的生物氢化产量。在此项目期间将研究以下问题：（1）哪些菌株和生物量原料对生物氢的产生更有希望？为此，我们将测试文献中报道的细菌菌株（Shewanella Oneidensis MR-1）和从极端环境中分离出来的新型菌株。农业废物（柳树，干草，小麦和大麦）的不同木质纤维素材料将被测试为原料。（2）哪些是代谢途径中导致黑暗发酵过程中生物氢化的关键点？考虑基因组学，转录组学，蛋白质组学和代谢组学的一种多态方法将采用这些关键点。将使用生物信息学和实验数据。 （3）如何优化此过程？为了将农业废物从生物氢化产生重新定向，合成生物学技术将用于在选定菌株中进行代谢工程，以有利于代谢途径，从而导致氢产生增加。生物处理研究将使用实验设计（DOE）进行，以探索最佳的Conditio