Microbial cell factories for bio-based isoprenoid production to replace fossil resources

Concerns about environmental issues and limited fossil resources have increased interest and efforts in developing sustainable production of bio-based chemicals and fuels using microorganisms. Advanced metabolic engineering has developed microbial cell factories (MCFs) with the support of synthetic biology and systems biology. Isoprenoids are one of the largest classes of natural products and possess many practical industrial applications. However, it is challenging to meet the market demand for isoprenoids because of the current inefficient and unsustainable strategies for isoprenoid production such as chemical synthesis and plant extraction. Therefore, many efforts have been made to build isoprenoid-producing MCFs by applying metabolic engineering strategies, biological devices, and machinery from synthetic biology and systems biology. This review introduces recent studies of strain engineering and applications of biological tools and systems for developing isoprenoid MCFs. In addition, we also reviewed the isoprenoid fermentation strategies that lead to the best performance of isoprenoid-producing MCFs.