General Information: Formerly Halobacterium lacusprofundi, this organism is an extremely halophilic archaeon isolated from Deep Lake, Antarctica. Extremely halophilic archaeon isolated from the Antarctic. Halorubrum lacusprofundi is a red pigmented halophilic archaeon which has been found in hypersaline marine enviornments. Originally thought to be a psychrophile, further research determined that the optimum temperature for growth for Halorubrum lacusprofundi was from 31 - 37 degrees C.