title: Influence of temperature on ionic sparing effect and cell-associated cations in the moderate halophile, Micrococcus varians var. halophilus.
abstract: Cells of the moderately halophilic Micrococcus varians var. halophilus grew well in a chemically defined medium containing 1 to 3 M NaCl and 0.0103 M K+. The requirement for NaCl could be partially replaced by K+,:Li+ and Cs+. The efficiency of the sparing effect of these cations for NaCl was in order of K+ GReater than Li+ greater than Cs+. Increase in growth temperature was found to enchance the sparing effect of Li+ and Cs+ but not that of K+. Over the range of NaCl concentrations in which the cells grew well, cell-Na+ concentrations were similar to the medium NaCl concentrations while cellK+ concentrations were several-fold that in the medium. Cell-bound Na+ and K+ concentrations increased proportionally with medium NaCl concentration and growth temperature. The temperature-dependent cation accumulation was more obvious with K+ than Na+. The cell-associated Na+ + K+ concentrations were almost as high as or slightly higher than the external media which contained appropriate levels of NaCl regardless of the growth temperature.
mesh_terms: D002586:Cesium / Q000378:metabolism; D003470:Culture Media; D005516:Food Microbiology; D008094:Lithium / Q000378:metabolism; D008837:Micrococcus / Q000254:growth & development / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism; D013696:Temperature
chemical_list: D003470:Culture Media; D002586:Cesium; D012965:Sodium Chloride; D008094:Lithium; D012964:Sodium; D011188:Potassium