Involved in the biosynthesis of the acyclic C50 carotenoid bacterioruberin (BR) (PubMed:21840984). Acts as a bifunctional elongase/hydratase that catalyzes the elongation of lycopene by attaching a C(5) isoprene unit at C-2, as well as the hydroxylation of the previous end of the molecule (By similarity). The enzyme acts at both ends of the substrate, and catalyzes the conversion of lycopene to the C(45) intermediate dihydroisopentenyldehydrorhodopin (DH-IDR) and the conversion of isopentenyldehydrorhodopin (IDR) to the C(50) carotenoid dihydrobisanhydrobacterioruberin (DH-BABR) (By similarity). Can also catalyze the conversion of lycopene to tetrahydrobisanhydrobacterioruberin (TH-BABR) (By similarity). all-trans-lycopene + dimethylallyl diphosphate + H2O = dihydroisopentenyldehydrorhodopin + diphosphate dimethylallyl diphosphate + H2O + isopentenyldehydrorhodopin = dihydrobisanhydrobacterioruberin + diphosphate Carotenoid biosynthesis. H.volcanii does not produce any known rhodopsins and unlike in H.salinarum, Lye is not regulated by bacterioopsin. Belongs to the UbiA prenyltransferase family.