Coenzyme-linked glucose dehydrogenase and polynucleotide encoding the same

A method for producing a biosensor for measuring glucose in a sample liquid comprising:

• (i) contacting a transformed host cell with a liquid culture medium, wherein the transformed host cell comprises a recombinant expression vector comprising a polynucleotide encoding an Aspergillus species flavin adenine dinucleotide-linked glucose dehydrogenase (FAD-GLD) which comprises a sequence set forth in SEQ ID NO:8, a sequence set forth in SEQ ID NO:9, a sequence set forth in SEQ ID NO:10, a sequence set forth in SEQ ID NO:11, and a sequence set forth in SEQ ID NO:12, so as to recombinantly express the FAD-GLD and obtaining recombinant FAD-GLD from the transformed host cell;
• (ii) purifying the recombinant FAD-GLD;
• and
• (iii) forming a biosensor comprising an electrode system and an enzyme reaction layer on an electrode of the electrode system, the enzyme reaction layer comprising the recombinant FAD-GLD and an electron acceptor, wherein the recombinant FAD-GLD has an activity toward glucose of catalyzing dehydrogenation of glucose in the presence of the electron acceptor and has an activity toward maltose of 5% or less with respect to the activity toward glucose.