{"title":"Effects of Mg2+ and Ca2+ on Fe2+ uptake by Bifidobacterium thermophilum.","authors":"E Kot, A Bezkorovainy","doi":"10.1016/0020-711x(93)90117-w","DOIUrl":null,"url":null,"abstract":"<p><p>Ferrous iron uptake was investigated in Bifidobacterium thermophilum (B. thermophilum) in the presence of Mg2+ and Ca2+ with the following findings: 1. Mg2+ inhibited Fe2+ accumulation in the cells in a dose-dependent manner at 37 degrees, but not at 0 degrees. Removal of Mg2+ from the medium resulted in a resumption of rapid iron uptake. 2. Mg2+ had no effect on the binding of Fe2+ by B. thermophilum protoplasts, its cellular particulate fraction, or distribution between the particulate and soluble fractions. 3. Ca2+ exerted a stimulatory effect on iron uptake by B. thermophilum, but was not able to reverse the inhibitory effects of Mg2+. 4. It was concluded that Mg2+ has no effect on the binding of iron on the surface or interior of B. thermophilum and that it affected the Fe2+ transport mechanism (permease) in a reversible manner. It is possible that iron and magnesium share the same permease in this microorganism.</p>","PeriodicalId":22539,"journal":{"name":"The International journal of biochemistry","volume":"25 7","pages":"1029-33"},"PeriodicalIF":0.0000,"publicationDate":"1993-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-711x(93)90117-w","citationCount":"15","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The International journal of biochemistry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1016/0020-711x(93)90117-w","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 15
Abstract
Ferrous iron uptake was investigated in Bifidobacterium thermophilum (B. thermophilum) in the presence of Mg2+ and Ca2+ with the following findings: 1. Mg2+ inhibited Fe2+ accumulation in the cells in a dose-dependent manner at 37 degrees, but not at 0 degrees. Removal of Mg2+ from the medium resulted in a resumption of rapid iron uptake. 2. Mg2+ had no effect on the binding of Fe2+ by B. thermophilum protoplasts, its cellular particulate fraction, or distribution between the particulate and soluble fractions. 3. Ca2+ exerted a stimulatory effect on iron uptake by B. thermophilum, but was not able to reverse the inhibitory effects of Mg2+. 4. It was concluded that Mg2+ has no effect on the binding of iron on the surface or interior of B. thermophilum and that it affected the Fe2+ transport mechanism (permease) in a reversible manner. It is possible that iron and magnesium share the same permease in this microorganism.