title: Effect of various metals and calcium metabolism inhibitors on the growth of Bifidobacterium bifidum var. pennsylvanicus.
abstract: In view of the facts that the normal intestinal flora exerts beneficial effects and that bifidobacteria are a more important component in the breast-fed than in the bottle-fed infant, factors affecting the growth of the latter microorganisms are of interest. A series of transition and other metals were shown to be growth inhibitors of Bifidobacterium bifidum var. pennsylvanicus. Such inhibition could be reversed fully or partially by 0.5-1.0 mM Fe2+ in the case of Zn2+, Cu2+, Au3+, Pt4+, La3+, Cr3+, Mn2+, Ni2+, and Cd2+, but not with Ag+, Hg2+, and VO2+. In addition, 2-4 mM Ca2+ substantially relieved the inhibitory effects of Zn2+, Mn2+, and La3+, and partially relieved the effects of Cd2+. Mg2+ was ineffective in relieving Zn2+ inhibition, but Ba2+ and Sr2+ could replace Ca2+ to some extent. The calcium metabolism antagonists verapamil, ruthenium red, 2-chloroadenosine, lasalocid, Ca-ionophore A-23187, and calmodulin inhibitors W-5 and W-7 inhibited microbial growth. Inhibition could be relieved fully or partially with 0.5-1 mM Fe2+. Mg2+ relieved the inhibition by lasalocid, Ca-ionophore A-23187, and verapamil, whereas Ca2+ was effective only in the case of Ca-ionophore A-23187. We conclude that calcium and magnesium fluxes play an important role in the physiology of the bifidobacteria and that several metal growth inhibitors interfere with iron metabolism.
mesh_terms: D001644:Bifidobacterium / Q000254:growth & development* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000378:metabolism*; D006131:Growth Inhibitors; D007501:Iron / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008670:Metals / Q000378:metabolism*
chemical_list: D002121:Calcium Channel Blockers; D006131:Growth Inhibitors; D008670:Metals; D007501:Iron; D008274:Magnesium; D002118:Calcium