Harnessing cellular perception apparatus for smart metabolic reprogramming

Abstract

Metabolic reprogramming (MRP) is a fundamental approach in synthetic biology that involves redirecting metabolic flux and remodeling metabolic networks. However, only few approaches have been made in effective metabolic operations, especially at global level of metabolic networks. Naturally existing cellular perception apparatuses (CPAs), such as histidine kinases (HKs), are considered to sit on sensitive nodes of the metabolic network, which can trigger natural MRP upon perceiving environmental fluctuations. We develop a plateform for global MRP by natural environmental stimulation based on the combinational interference of CPAs. The plateform consists of a CRISPRi-mediated dual-gene combinational knockdown (CDCK) strategy and survivorship-based metabolic interaction analysis (SMIA). A total of 35 histidine kinase (HK) genes and 24 glycine metabolism genes were selected as targets to determine effectiveness of our approach for fast-growing chassis Vibrio FA2. Combined knockdown of several genes of HKs and glycine metabolism increased the glycine production. Other other hand, effects of CDCK on bacterial antibiotic resistance were assessed by targeting HKs. Many HKs were identified to be associated with antibiotic resistance in Vibrio FA2, of which combinational knockdown of two HK genes sasA_8 and 04288 reduced the ampicillin resistance. This MRP strategy is powerful and cost-effective, and can be considered as a smart strategy capable of operating a broad range of metabolic networks in microorganisms.