Abstract:

Biofuels are important supplements and alternatives to fossil fuels, which can alleviate the current global energy crisis and environmental pollution. Using microbes mined from nature or engineered in the lab to produce biofuels from renewable biomass of both economic and social benefits has become a major direction of sustainable biomanufacturing. It is necessary to develop robust microbial cell factories through synthetic biology for efficient and economic biofuel production, combining the strategy of systems biology to understand and design the synthetic pathways for biofuels and regulatory networks in microbes. This review discussed the major types of biofuels, the corresponding metabolic pathways, and current progress for producing these biofuels, including bioethanol, higher alcohols, biodiesel, fatty acid derivatives and isoprenoid derivatives. The strategies to understand, construct, and engineer synthetic microbial chassis as cell factories for diverse biofuel production were summarized, especially from substance metabolism, energy balance, physiological modification, and information regulation. In addition, current status and challenges for microbial biofuel production were analyzed. The insufficient understanding of natural biosynthetic pathways and the functions of biological components, lack of genetic manipulation tools for non-model biofuel chassis cells, low efficiency of gene editing, incompatibility between different heterologous pathways and chassis cells, toxicity of heterologous products and metabolic intermediates to cell factories, inhibition of many stress factors when using cheap renewable resources as raw materials, and engineering obstacles in industrial scale-up are the barriers and challenges to the industrial biofuel production. However, the rapid development of artificial intelligence and bioinformatics provides new solutions to these challenges. Finally, this review proposed future directions and key tasks based on the need for biofuel commercialization, emphasizing the combination of information technology and biotechnology as the trend in developing biofuel cell factories, which can provide tools and resources for strain engineering and accelerate the industrialization process of biofuels.

Key words: synthetic biology, biofuels, microbial cell factories, metabolic engineering, information technology, biotechnology

摘要：

生物燃料替代化石燃料可解决当前全球正面临的能源危机和环境危机。通过筛选、改造微生物，利用可再生资源高效生产具有经济效益和社会效益的生物燃料已成为可持续生物制造的重大发展方向。基于系统生物学理解并设计细胞工厂生物燃料的合成途径与调控网络，利用合成生物学手段开发高产稳产微生物细胞工厂是实现生物燃料经济生产的重要手段。本文概述了当前生物燃料的主要种类及对应的代谢途径，并总结了当前主要生物燃料的生产情况。重点介绍从微生物物质代谢、能量代谢、生理代谢和信息代谢四个方面去认识、改造、开发微生物底盘细胞使其成为高产稳产的生物能源细胞工厂。此外，本文也对当前生物能源的生产瓶颈和挑战进行了总结，并从酶元件库的挖掘、合成途径的创建与优化、底盘细胞的理解和性能改善、发酵工艺的智能控制等方面提出了未来的发展方向和目标任务，强调了在未来的研究中，信息技术（IT）和生物技术（BT）交叉融合是能源细胞工厂构建的发展趋势，可为高效生物燃料细胞工厂的构建提供工具和资源，加速生物能源的产业化进程。

关键词: 合成生物学, 生物燃料, 微生物细胞工厂, 代谢工程, 信息技术, 生物技术