D-cellobiose + A <=> D-cellobiono-1,5-lactone + AH2
d-cellobiose + a <=> d-cellobiono-1,5-lactone + ah2
D-cellobiose + A <=> D-cellobiono-1,5-lactone + AH2
d-cellobiose + a <=> d-cellobiono-1,5-lactone + ah2