Catalyzes the NADPH-dependent reduction of a wide variety of carbonyl-containing compounds to their corresponding alcohols with a broad range of catalytic efficiencies (PubMed:14551196). Probably affects several metabolic pathways in addition to converting glucose to sorbitol (PubMed:14551196). Affects group size (PubMed:14551196). an alditol + NADP(+) = an aldose + H(+) + NADPH Present in vegetative cells; the levels decrease slightly upon starvation and remain constant until 10 hours of development and then decline. At 25 hours there is very little detectable protein. Cells show a decrease in the ability to reduce both glyceraldehyde and glucose in an NADPH-coupled reaction and a decrease in glucose levels. They grow normally but form long unbroken streams and huge groups. They show normal adhesion but a reduced motility. They secrete low levels of countin and CF50, two component of the counting factor (CF) but are responsive to CF and partially responsive to recombinant countin and CF50. Belongs to the aldo/keto reductase family.