Patent ID: 7435556

Claim:
A method for increasing the ratio of p-hydroxybenzoic acid (pHBA) ester glucoside to total pHBA glucose conjugates in pHBA-producing microorganisms or green plant cells, the method comprising: (a) transforming a pHBA-producing microorganism or green plant cell with a nucleic acid fragment encoding a polypeptide having UDP-glucosyltransferase activity operably linked to suitable regulatory sequences, the polypeptide having 1) an amino acid sequence that is at least 95% identical to SEQ ID NO: 18; 2) at least a 4.88-fold substrate preference for pHBA over sinapic acid at a 10 mM substrate concentration; and 3) a turnover number of at least 1.77 sec −1 for conversion of pHBA to pHBA ester glucoside, (b) growing the transformed microorganism or green plant cell of step (a) under suitable conditions for expressing UDP-glucosyltransferase activity and producing pHBA ester glucoside; and (c) recovering pHBA ester glucoside, the ratio of pHBA ester glucoside to total pHBA glucose conjugates at least 10% greater than the ratio of pHBA ester glucoside to total pHBA glucose conjugates produced by the corresponding untransformed microorganisms or green plant cells.