Online citations, reference lists, and bibliographies.
← Back to Search

Heavy Metal Resistance Patterns Of Frankia Strains

Joel W. Richards, Glenn D. Krumholz, Matthew S. Chval, Louis S. Tisa

Cite This
Download PDF
Analyze on Scholarcy
ABSTRACT The sensitivity of 12 Frankia strains to heavy metals was determined by a growth inhibition assay. In general, all of the strains were sensitive to low concentrations (<0.5 mM) of Ag1+, AsO2 1−, Cd2+, SbO2 1−, and Ni2+, but most of the strains were less sensitive to Pb2+ (6 to 8 mM), CrO4 2− (1.0 to 1.75 mM), AsO4 3− (>50 mM), and SeO2 2− (1.5 to 3.5 mM). While most strains were sensitive to 0.1 mM Cu2+, four strains were resistant to elevated levels of Cu2+ (2 to 5 mM and concentrations as high as 20 mM). The mechanism of SeO2 2− resistance seems to involve reduction of the selenite oxyanion to insoluble elemental selenium, whereas Pb2+ resistance and Cu2+ resistance may involve sequestration or binding mechanisms. Indications of the resistance mechanisms for the other heavy metals were not as clear.