Methods for purifying and/or producing anti-freeze proteins

Abstract

A method of purifying an antifreeze protein (AFP) and methods of producing AFPs are disclosed. The method of purifying an AFP includes heating a crude AFP in an aqueous medium to a temperature and for a length of time sufficient to precipitate at least some thermally unstable proteins in the crude AFP and form a precipitate and a supernatant; and removing the precipitate from the supernatant. One method of producing an AFP includes collecting a crude source of the AFP; and purifying the AFP by the purification method. Another method of producing an AFP includes growing or culturing a host configured to express a recombinant AFP in a growth medium, and collecting a crude AFP from the host and/or the growth medium. The growth medium comprises water, a protein hydrolysate or other source of amino acids, a yeast extract, a biologically metabolizable C-Cpolyol, and one or more phosphate salts.