menaquinone-9 + AH2 => beta-dihydromenaquinone-9 + A
menaquinone-9 + ah2 => beta-dihydromenaquinone-9 + a
menaquinone-9 + AH2 => beta-dihydromenaquinone-9 + A
menaquinone-9 + ah2 => beta-dihydromenaquinone-9 + a