Recent advances in synthetic biology offer tremendous opportunities to design biological systems at the molecular level for novel functions. While synthetic biology has been mostly applied in biomedical and biomanufacturing fields, its potential for developing innovative strategies to address environmental challenges is gaining increasing attention. Particularly, there is an ongoing shift to view waste as resources rather than as environmental and economical burdens. This talk will discuss our recent research work in engineering microbial cells to address waste-to-value challenges, including i) plastic degradation and upcycling, and ii) phosphorus conversion and recovery.