Mg 2+ is one of the essential elements for bacterial cell growth. The presence of the magnesium cation (Mg 2+ ) in various concentrations often affects cell growth restoration in plant-associating bacteria. This study attempted to... more
Mg 2+ is one of the essential elements for bacterial cell growth. The presence of the magnesium cation (Mg 2+ ) in various concentrations often affects cell growth restoration in plant-associating bacteria. This study attempted to determine whether Mg 2+ levels in Sphingomonas yanoikuyae EC-S001 affected cell growth restoration in the host plant and what the threshold level is. S. yanoikuyae EC-S001, isolated from the rhizoplane of spinach seedlings grown from surface-sterilized seeds under aseptic conditions, displayed uniform dispersion and attachment throughout the rhizoplane and phylloplane of the host seedlings. S. yanoikuyae EC-S001 did not grow in potato-dextrose broth medium but grew well in an aqueous extract of spinach leaves. Chemical investigation of the growth factor in the spinach leaf extract led to identification of the active principle as the magnesium cation. A concentration of ca. 0.10 mM Mg 2+ or more allowed S. yanoikuyae EC-S001 to grow in potato-dextrose broth...
