Effect of Specific Ions in Agar on Antibiotic Production by Burkholderia glumae

Burkholderia glumae produced antibiotic substance(s) on agar plate media, but none in various liquid media. Some minor elements in agar were considered to be involved in the antibiotic production. K⁺, Ca²⁺, Mg²⁺ and NH⁺₄ were shown to play significant roles in the production by culturing the bacterium in liquid media supplemented with various inorganic chemicals. Highest production was observed when B. glumae was cultured in the liquid medium containing a mixture of MgCl₂, KCl and CaCl₂. No antibiotic production was observed in PGC broth containing MgSO₄which was substituted for MgCl₂ or Mg(NO₃)₂. These results suggest that specific cations and anions are involved in antibiotic(s) production by B. glumae.