L-xylulose reductase involved in the catabolism of D-galactose through an oxidoreductive pathway. Catalyzes the NADPH-dependent reduction of L-xylo-3-hexulose. Is also active with D-ribulose and L-xylulose, and to a lesser extent with D-xylulose, D-fructose and L- and D-sorbose. In the reverse reaction, shows activity with D-sorbitol and D-mannitol, low activity with xylitol, but no activity with galactitol, ribitol, and L- and D-arabitol. D-sorbitol + NADP(+) = H(+) + L-xylo-3-hexulose + NADPH Carbohydrate degradation. Decreases growth on D-galactose and impairs growth on galactitol. Belongs to the short-chain dehydrogenases/reductases (SDR) family.