Reaction catalyzed by 2-oxo-acid reductase (1.1.99.30)

		+			=			+
	lactobionate	+		oxidized anthraquinone-2,6-disulfonate	=		4-O-(beta-D-galactopyranosido)-D-arabino-hex-2-ulosonate	+		reduced anthraquinone-2,6-disulfonate