Enhancing cobalamin (vitamin B12) production in E. coli to address demand and global security

贫血是一种流行程度的公共卫生状况，影响着世界30%的人口(20亿人)。患病率最高的是学龄前儿童和孕妇。这种情况导致健康不佳(虚弱、认知发育)、过早死亡和整个人口的工作能力下降，给各国和大陆带来严重的经济后果。尽管贫血多年来一直被认为是一个公共卫生问题，但进展甚微，全球贫血症的流行率仍然高得令人无法接受。世卫组织和儿童基金会强调迫切需要与贫血症作斗争，并强调必须认识到其多因素病因，以便制定有效的控制方案。铁缺乏约占贫血病例的三分之一，但显著的是，维生素B12缺乏已被确定为恶性(或非缺铁)贫血的主要组成部分之一，它还与脊柱裂、老年人较高水平的脑萎缩有关，并与心血管疾病和糖尿病的发展有关。全球范围的维生素B12补充计划将产生重大效果，但迄今尚未有人尝试这样做，因为目前维生素B12(又称钴胺)的价格高得令人望而却步，特别是对最需要维生素B12的发展中国家。此外，大约90%的B12是由中国制造的，这会在发生冲突或自然灾害时引发营养安全问题。维生素B12不仅对人类健康很重要，而且作为动物饲料和某些工业过程的补充剂也很重要，例如生物生产蛋氨酸和1，3-丙二醇。维生素B12是少数几种通过发酵产生的维生素和营养素之一。这也是产量最低的过程之一，营养物质的产量仅为400毫克/L左右。这种低产量加上一种生长非常缓慢的菌株，使得整个生产效率非常低。在这个项目中，我们将应用有理和随机筛选的组合，在沃伦集团的途径知识和杜邦/泰特&莱尔在菌种开发和优化方面的世界领先专业知识的基础上，在大肠杆菌中开发出B12的高产生产商。该项目将产生一种将产生g/L规模的B12的菌株，确保商业和人道主义需求的营养供应。该项目将为B12途径的控制和调控提供基本和基本的见解。我们的工作将有助于确定生物合成中的一些关键瓶颈，并开发克服这些问题的方法。生物合成是生物系统中发现的最复杂的问题之一。该项目旨在通过使用缺乏抑制限制的生物合成酶来降低该途径的复杂性。该途径将利用基因编辑技术在大肠杆菌中进行工程改造，以实现相关基因的最佳表达。该菌株将被进一步改造，以允许细胞获得构建分子所需的各种构建块。因此，该项目希望将合成生物学方法应用于当前的现实世界问题，这样做将为行业和营养市场带来巨大的好处。对于这个链接项目，杜邦/泰特和莱尔将提供总计470K GB的资金，其中包括10万GB的现金投资，这将用于资助一名全职技术人员。

Anemia is a public health condition of epidemic proportions, affecting 30% of the worlds' population (2 billion people). The highest prevalence is in preschool-age children and pregnant women. The condition results in ill-health (weakness, cognitive-development), premature death and reduction in work capacity of entire populations, bringing serious economic consequences to countries and continents. Although anaemia has been recognized as a public health problem for many years, little progress has been reported and the global prevalence of anaemia remains unacceptably high. WHO and UNICEF emphasize the urgent need to combat anaemia and stress the importance of recognizing its multifactorial etiology for developing effective control programmes. Iron deficiency accounts for around a third of anaemia cases, but significantly vitamin B12 deficiency has been identified as one of the major components of pernicious (or non-iron deficient) anaemia, which is further associated with spina bifida, higher levels of brain atrophy in the elderly and is linked with the development of cardiovascular disease and diabetes. A world-wide B12-supplementation programme would have a significant effect but this has so far not been attempted because the current price of vitamin B12, which is also referred to as cobalamin, is prohibitively expensive, especially for developing countries where it is needed most. Moreover, around 90% of B12 is made in China which raises nutrition security issues in the event of conflict or natural disasters. Not only is the nutrient important for human health it is also important as a supplement for animal feeds and for certain industrial processes such as the biological production of methionine and 1,3-propanediol.Vitamin B12 is one of the few vitamins and nutrients that is produced through fermentation. It is also one of the lowest yielding processes with the nutrient being produced only at around 400 mg/L of culture. This low yield is coupled with a strain that grows very slowly making the overall production very inefficient. In this project we will apply a combination of rational and random screens to develop a high-yielding producer of B12 in E. coli, building on the pathway knowledge of the Warren group and the world-leading expertise of DuPont/Tate & Lyle in strain development and optimisation. The project will result in the generation of a strain that will produce B12 on the g/L scale, ensuring a ready supply of the nutrient for commercial and humanitarian requirements.This project will provide basic and fundamental insights into the control and regulation of the B12 pathway. Our work will help identify some of the key bottlenecks in the biosynthesis, which is one of the most complex found in biological systems, and develop methods to overcome these issues. The project aims to reduce of the complexity in the pathway by using biosynthetic enzymes that lack inhibitory constraints. The pathway will be engineered into E. coli using gene editing technology to allow for optimal expression of the relevant genes. The strain will be further engineered to allow for the cellular procurement of the various building blocks that are required in the construction of the molecule. This project therefore looks to apply synthetic biology approaches to a current real-world problem and in so-doing will deliver a strain that will have enormous benefit to both industry and the nutrition markets.For this LINK project, DuPont/Tate & Lyle will provide a total of £470k, including a £100k cash investment, which will go towards funding a full-time technician.