title: Effect of manganese and zinc ions on the growth of Rhizobium.
abstract: Five strains, representing four species of Rhizobium, were grown in specially purified synthetic culture solutions with manganese or zinc ion concentrations ranging from 0 to 10(-5)m. Omission of Mn(2+) restricted growth to 0.4 to 10% of that of controls, depending on the species. Growth was generally maximum with 10(-6)m Mn(2+) and nearly so with 10(-5)m. Omission of Zn(2+) restricted growth to 1 to 20% of that of controls. Growth was generally maximum with 10(-7)m Zn(2+). The 10(-5)m level of Zn(2+) was toxic to a variable degree to all species, suppressing the growth of one strain of R. meliloti to 49% of that of controls, and of R. phaseoli to only 0.4% of that of controls. A Mn(2+) x Zn(2+) interaction was also obtained as evidenced by a higher apparent Zn(2+) requirement with 10(-7)m Mn(2+) than with 10(-6)m Mn(2+).
mesh_terms: D001431:Bacteriological Techniques; D003470:Culture Media; D005374:Filtration; D007477:Ions; D008345:Manganese / Q000494:pharmacology*; D012231:Rhizobium / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D015032:Zinc / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D007477:Ions; D008345:Manganese; D015032:Zinc