Oxidases remove hydrogen from substrates, transferring it to molecular oxygen to generate hydrogen peroxide or water. Since oxidases catalyze fundamental synthetic transformations, including alcohol-aldehyde and aldehyde-carboxylic acid conversions, they have attracted attention as targets of directed evolution for further improvement (1 ,2 ). The co-product hydrogen peroxide can be detected by various methods (3 ) and provides a basis for screening oxidases in a high throughput fashion.
