High throughput assay for identifying microbial redox enzymes

A method to identify a microbial redox enzyme (MRE) specific to a target analyte, the method comprising:

• a. preparing a genomic DNA (gDNA) library from a sample containing microbes, wherein the microbes contained in the sample comprise gDNA encoding at least one MRE;
• b. constructing an expression vector library comprising in an expression vector the gDNA library and a nucleic acid sequence encoding a readout enzyme (ReadE);
• c. contacting the expression vector library with a target analyte and at least one readout substrate (ReadS),
• wherein the target analyte is catalyzed by at least one MRE to produce H2O2, and
• wherein the ReadS can be converted to a readout product (ReadP) in the presence of hydrogen peroxide, wherein the ReadP produces a detectable signal;
• d. measuring the presence of the detectable signal produced by the ReadP;
• and
• e. identifying the MRE by sequencing the gDNA fragment identified by the detectable signal.