title: Selenite-stress selected mutant strains of probiotic bacteria for Se source production.
abstract: Selenium deficiency is a major health problem worldwide for about 1 billion people. Bacterial cells usually possess low tolerance to selenite stress and also low ability to reduce high concentrations of toxic selenite. Here, high tolerance to selenite and selenium bioaccumulation capability were developed in mutated clones of probiotic and starter bacteria including Enterococcus faecium, Bifidobacterium animalis ssp. lactis, Lactobacillus casei and Lactococcus lactis ssp. lactis by food-level strain development process and clone selection. All mutant clones possessed increased glutathione concentration and glutathione reductase activity. The selenite treatment increased further these values in L. casei mutant strain pointing at a different selenite reduction pathway and/or stress response in this organism. Considerable conversion of selenite to cell bound selenium forms with a concomitant high biomass production was detected in E. faecium and B. animalis ssp. lactis cultures. Possible application of these strains as food and feed supplements is under investigation.
authors.affiliation: Central Laboratory, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Böszörményi út 138, Debrecen H-4032, Hungary. Electronic address: pusztahelyi@agr.unideb.hu.
authors.forename: Tünde
authors.initials: T
authors.lastname: Pusztahelyi
authors.affiliation: Central Laboratory, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Böszörményi út 138, Debrecen H-4032, Hungary.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Kovács
authors.affiliation: Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Pócsi
authors.affiliation: Institute of Bio- and Environmental Energetics, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Prokisch
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001644:Bifidobacterium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007778:Lactobacillus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D019936:Probiotics / Q000494:pharmacology*; D020887:Selenious Acid / Q000494:pharmacology*; D012643:Selenium / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D005980:Glutathione Reductase; D020887:Selenious Acid; D005978:Glutathione; D012643:Selenium
keywords: Glutathione; Glutathione reductase; Lactic acid bacteria; Selenite; Selenium