title: Isolation of Squarebop I bacteriorhodopsin from biomass of coastal salterns.
abstract: Squarebop I bacteriorhodopsin is a light-activated proton pump present in the membranes of the archeon Haloquadratum walsbyi, a square-shaped organism representing 50-60% of microbial population in the crystallizer ponds of the coastal salterns. Here we describe: (1) the operating mode of a bioreactor designed to concentrate the saltern biomass through a microfiltration process based on polyethersulfone hollow fibers; (2) the isolation of Squarebop I bacteriorhodopsin from solubilized biomass by means of a single chromatographic step; (3) tightly bound lipids to the isolated and purified protein as revealed by MALDI-TOF/MS analysis; (4) the photoactivity of Squarebop I bacteriorhodopsin isolated from environmental samples by flash spectroscopy. Yield of the isolation process is 150 μg of Squarebop I bacteriorhodopsin from 1l of 25-fold concentrated biomass. The possibility of using the concentrated biomass of salterns, as renewable resource for the isolation of functional bacteriorhodopsin and possibly other valuable bioproducts, is briefly discussed.
authors.affiliation: Department of Basic Medical Sciences, University of Bari Aldo Moro, Bari, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Lobasso
authors.forename: Patrizia
authors.initials: P
authors.lastname: Lopalco
authors.forename: Roberto
authors.initials: R
authors.lastname: Angelini
authors.forename: Alfieri
authors.initials: A
authors.lastname: Pollice
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Laera
authors.forename: Francesco
authors.initials: F
authors.lastname: Milano
authors.forename: Angela
authors.initials: A
authors.lastname: Agostiano
authors.forename: Angela
authors.initials: A
authors.lastname: Corcelli
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000302:isolation & purification*; D018533:Biomass; D004777:Environment; D005374:Filtration; D006216:Halobacteriaceae / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D012623:Seawater
chemical_list: D008055:Lipids; D001436:Bacteriorhodopsins