Open AccessA simple method for screening porphyrin secretion by colonies of Escherichia coli
Author(s) -
Javor George T.,
Kim Henry
Publication year - 1988
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1988.tb03176.x
Subject(s) - escherichia coli , porphyrin , mutant , chemistry , sephadex , secretion , fluorescence , biochemistry , microbiology and biotechnology , biology , chromatography , enzyme , gene , physics , quantum mechanics
Abstract Escherichia coli secretes porphyrins when exposed to 20 mM 1‐thioglycerol. A method was devised to isolate mutants, which do not excrete porphyrins in the presence of thiols. DEAE‐Sephadex beads were incorporated into plates growing colonies of E. coli . The secreted porphyrins on these plates formed a fluorescent halo around each colony, when the plates were viewed under long‐wave ultraviolet light. Mutants were found, that formed either halo‐less colonies or a colony with excess halo. This method of incorporating immobilized ion exchangers into plates may be useful in isolating non‐secretor or super‐secretor mutants of a variety of organisms.