L-Sorbose 1-dehydrogenase (EC 1.1.99.32, SDH) is an enzyme with systematic name L-sorbose:acceptor 1-oxidoreductase.^[1] This enzyme catalyses the following chemical reaction

L-sorbose + acceptor ${\displaystyle \rightleftharpoons }$ 1-dehydro-L-sorbose + reduced acceptor

The product, L-sorbosone, is an intermediate in bacterial 2-keto-L-gulonic-acid formation. Co²⁺ stimulate activity of this membrane-bound enzyme, while Cu²⁺ act as an inhibitor.