Extracellular complex from the culture filtrate of Ferrobacillus ferrooxidans

Abstract

An extracellular complex was isolated from the culture filtrate of Ferrobacillus ferrooxidans grown on either iron or sulfur. The complex isolated from the culture filtrate of iron-grown cells was red with an absorption maxima at 500–510 mμ. This complex consisted of approximately 60% non-phosphorus lipid. Ferrous iron was exclusively associated with a lipopolysaccharide–phospholipid fraction of the complex. The sulfur complex unlike the iron complex contained approximately 70% phospholipid and was yellowish. On the basis of hexosamine and heptose values, less lipopolysaccharide appeared to be associated with the phospholipid fraction of the complex from sulfur-grown cells than from the iron-grown cells.