Catalyzes the oxidation of sulfoquinovose to 6-deoxy-6-sulfo-D-glucono-1,5-lactone, with a strong preference for NAD(+) as the electron acceptor. Is involved in a degradation pathway of sulfoquinovose (SQ) that allows P.putida SQ1 to use SQ as the sole carbon and energy source for growth. 6-sulfo-D-quinovose + NAD(+) = 6-deoxy-6-sulfo-D-glucono-1,5-lactone + H(+) + NADH kcat is 33.8 sec(-1) for sulfoquinovose oxidation with NAD(+). kcat is 1.4 sec(-1) for sulfoquinovose oxidation with NADP(+). Optimum pH is 8-9. Is highly up-regulated during growth on sulfoquinovose, compared to growth on glucose or succinate (at protein level). Belongs to the short-chain dehydrogenases/reductases (SDR) family.