LAUSR

In the early twenty-first century, with the integration of engineering strategies withmodern biology, systems science and synthetic science, “Synthetic Biology” has been proposed (Chen et al., 2019). Further, a new bio-manufacturing industry, which can provide industrial commodities based on large-scale material processing and transformation with biological function, was generated. At present, the production and manufacture of fuels and bulk chemical products mainly rely on petrochemical refining (Speight, 2021), which is facing the challenges of high risk of production safety, great pressure of environmental protection, and contradiction between supply and demand of oil and gas resources. Bio-manufacturing is a new manufacturing mode that breaks away from the route of petrochemical industry, and has the typical characteristics of low carbon, recyclable, green, and clean. Microalgae can use solar energy to fix CO2 and convert C1 compound into organic matter, which can further generate a variety of metabolites through a variety of metabolic pathways and then produce a variety of biofuels and fine chemicals through genetic engineering modification (Qin et al., 2012; Maheswari et al., 2018; Chen and Wang, 2021). Therefore, microalgae have attracted much attention in recent years as “green cell factories” (Machado and Atsumi, 2012). Compared with heterotrophic chassis cells, microalgae-based synthetic biology and bio-manufacturing also play a role in carbon sequestration and emission reduction (Chen and Wang, 2020). Developing microalgae-based green bio-manufacturing industry is expected to solve the problems of current energy crisis and the unsustainable production of chemical products, and alleviate the greenhouse effect at the same time. However, in general, microalgae have the disadvantages of low product content and high cost in cell culture and collection when producing target products. It is necessary to sort out the key problems one by one from the upstream cell factory construction to the downstream microalgal culture engineering (Figure 1).