Calcium Transport by Frankia sp. Strain EAN1pec
When incubated at 25°C, N2-grown cells of Frankia strain EAN1pec actively accumulated calcium, while NH4Cl-grown cells did not accumulate calcium. When incubated at 0°C, both N2-grown and NH4Cl-grown cells did not actively accumulate calcium. Inhibitors of respiration inhibited calcium accumulation by N2-grown cells at 25°C. Isolated vesicles also accumulated calcium in an energy- and temperature-dependent manner. Two lines of evidence show that Frankia strain EAN1pec has an active calcium extrusion mechanism. First, NH4Cl-grown cells incubated under deenergizing conditions accumulated calcium. Second, calcium efflux from calcium-loaded cells required an energy source and was blocked by inhibitors. The results of this study indicate that Frankia strain EAN1pec has two systems for calcium transport: a calcium extrusion system and a developmentally regulated calcium uptake system.
Molecular, Cellular and Biomedical Sciences
Digital Object Identifier (DOI)
Tisa, L.S. 1998. Calcium transport in Frankia sp. EAN1pec. Current Microbiol. 37:12-16. (DOI: 10.1007/s002849900329)
© Springer-Verlag New York Inc. 1998