Microbial Conversion of Greenhouse Gases into Fermentation-Ready Sugars

与人类相关的活动，如化石燃料生产、农业、垃圾填埋场的使用和城市污水是全球甲烷排放的主要来源。这些人为排放的广泛而稳定的增长使甲烷不仅成为气候变化的主要因素，而且也是近期气候调节的主要目标。本项目将开发一种新的沼气生物利用干法发酵工艺。这一过程是基于嗜盐、消耗甲烷的细菌的独特能力，它们不仅在没有水补充的情况下保持固定状态的活性，而且在水可用性低的情况下积累糖。干发酵将生物系统的全部潜力与技术发展相结合，以解决负担得起的甲烷减排问题。建议开发一种具有活性甲烷消耗细胞的微纤维阵列，用于将甲烷转化为可提取的蔗糖。该提案的具体目标包括：(i)合理修饰微生物催化剂，通过减少外托因、糖原和（外）多糖的合成来提高蔗糖生产能力；（ii）合理修饰微生物催化剂以降低耗氧量，包括过表达细菌甲氰菊酯以提高耗氧量，以及开发菌株特异性载体以快速整合大片段DNA；（iii）通过研究水分胁迫对甲烷消耗和甲烷营养“活”微纤维中蔗糖积累速率的影响，对开发的干发酵模块进行实验室规模的设计和验证。提议的模块可以代表甲烷转化为有用产品的变革性解决方案。该模块可以进一步开发成空气净化盒，可以在任何甲烷排放热点实施，作为气体火炬的可持续替代品。本项目构建的宏基因组文库代表了一种利用非传统宿主发现天然产物的新方法。该项目将积极吸引研究生、本科生和高中生参与，并鼓励跨学科合作，并与工业界建立伙伴关系。该奖项由CBET部门的生物技术和生化工程项目颁发，由分子和细胞生物科学部的系统和合成生物学项目共同资助。

1605031Kalyuzhnaya, Marina Human-related activities, such as fossil fuel production, agriculture, landfill use, and municipal wastewater are major contributors to global methane emission. Widespread and steady growth of these man-made emissions make methane not only a major contributor to climate change but also the primary target for near-term climate regulation. In this project a new dry fermentation process for biological methane utilization will be developed. This process is based on the unique ability of salt-loving, methane-consuming bacteria to not only stay active in an immobilized state without water supplementation but also to accumulate sugar in response to low water availability. Dry fermentation merges the full potential of biological systems with technology development to address affordable methane mitigation. Proposed is the development of an array of micro-fibers with active methane-consuming cells engineered to convert methane into extractable sucrose. The specific aims of the proposal include (i) the rational modification of microbial catalysts to enhance sucrose production capabilities by reducing ectoine, glycogen and (exo)polysaccharides synthesis; (ii) the rational modification of the microbial catalyst to reduce oxygen consumption, including overexpression of bacteriohemerythrin to improve oxygen consumption, and development of strain-specific vectors for rapid integration of large DNA fragments; (iii) the lab-scale design and validation of the developed Dry Fermentation Module by investigating water-stress impacts on methane consumption and sucrose accumulation rates in methanotrophic 'living' micro-fibers. The proposed modules could represent a transformative solution for methane conversion into useful products. The module could be developed further into air-purifying cartridges that could be implemented at any hot-spot of methane emission, as a sustainable alternative to gas flare. The metagenomic libraries constructed in this project represent a novel approach for natural products discovery with a non-traditional host. The project will actively involve graduate, undergraduate, and high school students and encourage cross-disciplinary collaboration and establish partnerships with industry.This award by the Biotechnology and Biochemical Engineering Program of the CBET Division is co-funded by the Systems and Synthetic Biology Program of the Division of Molecular and Cellular Biosciences.