Patent ID: 7575910

Claim:
An isolated polynucleotide selected from the group consisting of: (A) a polynucleotide comprising the nucleotide sequence of SEQ ID NO: 15, (B) a polynucleotide which hybridizes with a polynucleotide comprising a nucleotide sequence which is complementary to the full-length of the nucleotide sequence of SEQ ID NO:15 under stringent conditions comprising 1×SSC and 0.1% SDS at 60° C. and encodes a protein having a dehydrogenase activity which results in the synthesis L-fuculose from L-fucitol, (C) a polynucleotide which encodes a protein comprising the amino acid sequence of SEQ ID NO:16, and (D) a polynucleotide which encodes a protein comprising the amino acid sequence of SEQ ID No. 16, wherein said sequence includes one or several amino acid mutations selected from the group consisting of substitution, deletion, insertion, and addition, and wherein said sequence is at least 90% homologous to SEQ ID NO: 16, and said protein has a dehydrogenase activity which results in the synthesis of L-fuculose from L-fucitol.