ml of lb broth amended with 100 u03bcg ml ampicillin an aliquot of 1 ml overnight culture was sub cultured to 100 ml of fresh lb broth also amended with 100 u03bcg ml of ampicillin the culture was incubated at 37 u00b0 c until the optical density reached 0 8 at 600 nm a final concentration of 1 mm iptg was then added to the culture and the flask was incubated at 30 u00b0 c for another 4 hours cells were harvested by centrifugation at 10 000 rcf for 10 minutes pelleted cells were resuspended in 20 mm sodium phosphate ph 7 4 and 500 mm nacl cell walls were disrupted by sonication on ice at intervals of 0 7 seconds for 1 minute followed by a 1 minute cool down this was repeated three times the sonicated cells were centrifuged at 10 000 rcf for 10 minutes the supernatant which contained the soluble adh1 was concentrated and desalted by spin dialysis using amicon ultra 15 devices millipore mass and stored in a new tube at 4 u00b0 c this method of recombination and expression was also used for a control plasmid pdest17 gus enzyme assay was prepared to determine the specific activity of adh1 the assay contained a final concentration of 1 mm nicotinamide adenine dinucleotide nad 0 1 u03bcg u03bcl artemisinic alcohol or dihydroartemisinic alcohol aaoh or dhaaoh and approximately 90 u03bcg of crude protein the assays were incubated at 30 u00b0 c for 30 minutes at 500 rpm followed by an ethyl.