Effect of proteorhodopsin production in marine bacterium grown under different culture conditions

Abstract

The proteorhodopsins (PRs) are retinal-containing membrane proteins belonging to the rhodopsin family and catalyze a light-activated proton efflux across cell membrane. PRs are estimated to be present in 13% of all marine bacteria in the photic zone. A Gram-negative and orange pigmented marine bacterium was which produced proteorhodopsin isolated from seawater collected in Gwangalli, Korea, and designated as PR-J. The optimum culture conditions for growth of PR-J were at 25℃, pH 7 and PPES-Ⅱ medium containing 3% NaCl. The proteorhodopsin gene from PR-J was cloned and characterized. The expressional studies of proteorhodopsin gene of PR-J were performed.