This invention provides improved monoxygenases, dehydrogenases, and transferases that are useful for the biocatalytic synthesis of compounds such as &agr;-hydroxycarboxylic acids, and aryl- and alkyl-hydroxy compounds. The polypeptides provided herein are improved in properties such as regioselectivity, enzymatic activity, stereospecificity, and the like. Methods for obtaining recombinant polynucleotides that encode these improved polypeptides are also provided, as are organisms that express the polypeptides and are thus useful for carrying out said biocatalytic syntheses. Also provided by the invention are methods for increasing said solvent resistance of organisms that are used in the synthetic methods.