Relation of lipids to the action of streptomycin on Bacillus subtilis and Escherichia coli and griseofulvin and fungizone on Aspergillus niger.

An attempt was made to reveal the relation between the lipid content and components of B. subtilis and E. coli and the action of streptomycin, and those of A. niger and the action of griseofulvin and fungizone (Amphotericin B). Total lipids were extracted in CO2 atmosphere, dried, and weighed. Lipid components were analyzed by thin-layer chromatography. Complements to the growth medium of A. niger with extracted total lipids and phospholipids were made to verify the obtained results. It has been found that the action of streptomycin and griseofulvin was not correlated with lipids. On the other hand, fungizone action was manifested by the decrease in total lipids, free sterols, sterol esters, and triglycerides. Supplementation studies gave evidence of the role of total lipids and phospholipids in protecting A. niger cells against fungizone. Supplementation of 1 g of phospholipid per litre medium raised the M.I.D. of fungizone from 2.5 up to 25 microgram/ml. It was suggested to keep the fat level controlled at a minimum if it is required to increase fungizone activity.