Abstract: The biological production of beta-hydroxyisovalerate (?HIV) using at least one non-natural enzyme. The non-natural enzyme for the biologically-derived ?HIV provides more beta-hydroxyisovalerate synthase activity than the wild-type parent. The non-natural enzyme having one or more modifications of substrate-specificity positions. The non-natural enzyme can be expressed in a microorganism, such as a yeast or bacteria, wherein the microorganism comprises an active ?HIV metabolic pathway for the production of ?HIV. Alternatively, the non-natural enzyme can be a ?HIV synthase used to produce ?HIV in a cell-free environment. The biological derivation of ?HIV eliminates toxic by-products and impurities that result from the chemical production of ?HIV, such that ?HIV produced by a non-natural enzyme prior to any isolation or purification process has not been in substantial contact with any halogen-containing component.

Abstract: The biological production of beta-hydroxyisovalerate (?HIV) using a non-natural microorganism. The non-natural microorganism for the biologically-derived ?HIV provides more beta-hydroxyisovalerate synthase activity than the wild-type parent. The non-natural microorganism can host a non-natural enzyme, such as the non-natural enzyme expressed in a yeast or bacteria, wherein the non-natural microorganism comprises an active ?HIV metabolic pathway for the production of ?HIV. The biological derivation of ?HIV eliminates toxic by-products and impurities that result from the chemical production of ?HIV, such that ?HIV produced by a non-natural microorganism prior to any isolation or purification process has not been in substantial contact with any halogen-containing component.