Low-carbon biosynthesis, using renewable carbon resources such as CO2 or lignocellulose biomass as feedstock and engineered biological systems as biotools for material processing and manufacturing, is a sustainable route for replacing fossil feedstock, a new mode of low-carbon production of chemical and agricultural products, and a new path for industrial carbon sinks for the efficient conversion and utilization of CO2. At present, the route of low-carbon biosynthesis cannot compete with the traditional chemical synthesis route with respect to industrial influence and technical economy, etc. The industrial applicability and conversion efficiency of CO2 and other renewable carbon resources, and industrial capacity of low-carbon biosynthesis are still the significant challenges, which should be solved as soon as possible through the great efforts of many parties. The emerging engineering biology is a new and important research field in which the structure and function of the biological systems could be reprogrammed and needed. Engineering biology could be promoting a new paradigm of designing and building the biological systems, and will fundamentally improve the ability and efficiency of biological systems to convert CO2 and other renewable carbon resources into bio-based products, and trigger a disruptive breakthrough in the bioindustry. Firstly, we analyze the development opportunities of low-carbon biosynthesis and confirm that the development of low-carbon biosynthesis is an important route to achieve the goal of "carbon peak and carbon neutrality", will bring significant environmental, economical and social benefits, and is a strategic battleground for China's bio-economy. Then, we summarize the current scientific and technological advances and trends of low-carbon biosynthesis at home and abroad. Currently, main developed countries, including US, UK, Germany, Australia, Japan and Korea, etc., enact and issue many strategies and action plans to accelerate the development of global sci-tech innovation for low-carbon biosynthesis, and major scientific breakthroughs in the field of low-carbon biosynthesis has made continuously achieved. More and more biobased products could be efficiently manufactured by low-carbon biosynthesis. Further, we discuss the scientific and technological challenges and key directions of low-carbon biosynthesis. Low-carbon biosynthesis have developed rapidly in recent years, however, the performance and efficiency of natural biological systems cannot be fully compared with chemical catalysts and it is still difficult for low-carbon biosynthesis to fully compete with chemical synthesis. The key scientific and technological barriers that need to be solved urgently in the development of low-carbon biosynthesis are how to design and build the high-performance synthetic biological systems with predictable, reconstructed and adjustable functions, which significantly improve the efficiency of renewable carbon source conversion and utilization, and create a new mode of material bioprocessing and biomanufacturing. Hence, it is necessary to focus on the layout of CO2 bioconversion and C1 biochemical engineering, biomass metabolic conversion as well as manufacturing of biobased products, so as to provide scientific and technological basis for enhancing the core competitiveness of low-carbon manufacturing innovation and China's green bioeconomy. Finally, we put forward relevant opinions and suggestions for future development, and think it is necessary to strengthen the layout of cutting-edge basic research and fund major projects in the field low-carbon biosynthesis, and it is also indispensable to rebuild the institutional systems and promote scientific and technological innovation and the healthy development of bioindustry.
