Bacteriorhodopsin (BR) is the only photoconductive protein present in the purple membrane of Halobacterium halobium.The biological function of the BR is acted as a light-driven proton pump.

• 细菌视紫红质（英文名称为Bacteriorhodopsin，以下简称BR）是嗜盐菌紫膜中的唯一光敏蛋白质，具有光驱动质子泵功能。