title: Studies on the removal of Cd ions by gastrointestinal lactobacilli.
abstract: Accumulation of toxic metal ions in food and water is nowadays a growing health-related problem. One detoxification method involves the use of microorganisms naturally inhabiting the gastrointestinal tract (GIT). The purpose of this study was to prove that lactic acid bacteria derived from the GIT are able to effectively remove Cd2+from water solution. Seven strains of lactobacilli, out of 11 examined, showed tolerance to high concentrations of cadmium ions. The metal-removal efficiencies of these seven lactobacilli ranged from 6 to 138.4 μg/h mg. Among these bacteria, Lactobacillus gallinarum and Lactobacillus crispatus belonged to the highest (85%) Cd-removal efficiency class. An analysis of the zeta potential (ζ) indicated that the bacterial cell surface had a negative charge at the pH ranging from 3 to 10. The presence of carboxyl, amide, and phosphate groups was favorable for Cd2+binding to the cell surface, which found confirmation in FTIR-ATR spectra. Elemental SEM/EDS analysis and TEM imaging not only confirmed the adsorption of Cd2+on the cell envelope but also gave us a reason to suppose that Lb. crispatus accumulates metal ions inside the cell. Our findings open perspectives for further research on the new biological function of GIT lactobacilli as natural biosorbents.
authors.affiliation: Department of Biotechnology, Human Nutrition and Science of Food Commodities, University of Life Sciences in Lublin, Lublin, Poland. 3mj@wp.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Polak-Berecka
authors.affiliation: Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Boguta
authors.affiliation: Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Cieśla
authors.affiliation: Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Bieganowski
authors.affiliation: Laboratory of Confocal and Electron Microscopy, Interdisciplinary Research Center, John Paul II Catholic University of Lublin, Lublin, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Skrzypek
authors.affiliation: Department of Biotechnology, Human Nutrition and Science of Food Commodities, University of Life Sciences in Lublin, Lublin, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Czernecki
authors.affiliation: Department of Biotechnology, Human Nutrition and Science of Food Commodities, University of Life Sciences in Lublin, Lublin, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Waśko
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000378:metabolism* / Q000494:pharmacology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007778:Lactobacillus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D007477:Ions; D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Bioaccumulation; Biosorption; Cadmium; Lactobacillus sp.; Metal ions