Design of a bacterial consortium for consolidated bioprocessing

PI: Schmidt-Dannert， claudia提案号：1235714机构：明尼苏达大学双子城分校标题：设计一个细菌联合体，用于综合生物处理生物技术生物过程通常使用纯培养的代谢工程微生物菌株。相比之下，环境过程通常利用天然微生物群体中存在的代谢多样性来完成单个生物体无法单独完成的任务。寻求发展用于生物燃料生产的综合生物工艺，将难降解的木质纤维素生物质的水解与随后的糖转化为生物燃料相结合，重新激发了对混合培养使用的研究。目前，人们正在采用不同的策略来获得既能分解木质纤维素又能生产先进生物燃料的菌株，但到目前为止，没有一种工程菌株能同时有效地完成这两项任务。在合成生物学领域中应用的具有新涌现特性的生物网络工程为设计和研究合成微生物群落提供了工具和策略。通过将代谢功能划分为单独的微生物种群，每个菌株的代谢网络可以针对不同的任务进行优化，这些任务共同导致所需化合物的产生。因此，在生物过程中共同培养的不同工程微生物菌株可以被视为单独的代谢模块，可以与其他模块交换或增强。然而，这种混合微生物群落工程的先决条件是种群控制系统的建立。该项目将设计一个原型合成微生物群落，作为综合生物处理的概念验证。所提出的研究结果可以指导使用工程微生物联合体的其他生物工艺的发展。具体来说，该项目将设计一种由枯草芽孢杆菌、不透明红球菌和大肠杆菌组成的混合培养物，用于新生物柴油的生产。工业蛋白表达宿主枯草芽孢杆菌将被设计为分泌纤维素水解酶以从生物质中释放糖，而产油的不透明芽孢杆菌和产乙醇的大肠杆菌菌株将共同将糖转化为脂肪酸乙酯（生物柴油）。开发这样一个联合体的关键是设计和配置足够的系统，以根据过程的要求控制每个联合体成员的增长。该项目将使用细菌群体感应系统的组件设计这种人口控制系统。本文将建立系统仿真模型，指导我们设计这些控制系统。该项目将为生物加工工程微生物群落的开发和应用提供概念验证。因此，混合培养物在生物技术方面的应用可能会得到振兴，并从前dna技术转移到合成生物学领域。该应用程序的结果将为人口控制系统的设计提供见解和模型，以根据特定过程的要求调整人口规模。这项研究将对生物技术和合成生物学领域产生影响。这项研究的发现可能会为生物燃料生产和其他生物生产过程带来新的和更有效的方法。本项目将为1名博士后和4名本科生提供遗传与代谢工程方面的培训。

PI: Schmidt-Dannert, ClaudiaProposal Number: 1235714Institution: University of Minnesota-Twin CitiesTitle: Design of a bacterial consortium for consolidated bioprocessingBiotechnological bioprocesses typically use pure cultures of metabolically engineered microbial strains. In contrast, environmental processes generally utilize the metabolic diversity present in native microbial consortia to accomplish tasks that not one single organism can do alone. The quest for the development of consolidated bioprocesses for biofuel production, where hydrolysis of recalcitrant lignocellulosic biomass and subsequent sugar conversion into biofuels are combined, has reinvigorated investigations into the use of mixed cultures. Currently different strategies are being pursued to obtain strains that are both lignocellulolytic and advanced biofuel producers, but so far none of the engineered strains is efficient at both tasks.The engineering of biological networks with new emergent properties employed in the field of synthetic biology has provided tools and strategies with which it becomes possible to design and investigate synthetic microbial consortia. By compartmentalizing metabolic functions into separate microbial populations, the metabolic network of each strain can be optimized for distinct tasks that together result in the production of a desired compound. The different engineered microbial strains co-cultured in a bioprocess can therefore be considered as individual metabolic modules that may be exchanged or augmented with additional modules. Prerequisite for the engineering of such mixed microbial communities, however, is the establishment of population control systems.This project will design a prototype synthetic microbial community as a proof-of-concept for consolidated bioprocessing. Results from the proposed research can guide the development of other bioprocesses using engineered microbial consortia. Specifically, this project will engineer a mixed culture consisting of B. subtilis, Rhodococcus opacus and E. coli for de novo biodiesel production. The industrial protein expression host B. subtilis will be engineered to secrete cellulolytic enzymes for sugar release from biomass, while the oleaginous R. opacus and the ethanologenic E. coli strain together will convert sugars into fatty acid ethyl esters (biodiesel). Key to the development of such a consortium is the engineering and configuration of adequate systems to control growth of each consortium member in accordance to the requirements of the process. The project will design such population control systems using components of bacterial quorum sensing systems. A system simulation model will be built to guide us in the design these control systems.The project will provide a proof-of-concept for the development and application of engineered microbial consortia for bioprocessing. The use of mixed cultures for biotechnology may thus be revitalized and moved from the pre-DNA technology into the synthetic biology area. Results from this application will provide insights and a model for the design of population control systems needed to adjust population sizes to the requirements of a specific process. The proposed research will impact the field of biotechnology and synthetic biology. Findings of this research may lead to new and more efficient approaches for biofuel production and other bioproduction processes. The proposed research will provide training in genetic and metabolic engineering for one postdoctoral researcher and four undergraduate students.