[Excretion of organic compounds bei microorganisms in presence of diphenylamine]

Diphenylamine (DPA) causes an increased leakage of organic compounds with resting cells of Candida guilliermondii, Bacillus subtilis, Escherichia coli, and Staphylococcus aureus already after a treatment of 1 h. The leakage depends both on the concentration of DPA and the duration of the treatment. Moreover, DPA influences the composition of the leaked ninhydrine-positive compounds. After 20 h of treatment an increased release of mannan and ribose is observed in addition to the stronger leakage of ninhydrine positive compounds. With regard to the relation between structure and activity of DPA, the activity of 21 compounds was investigated. The two apolar phenyl groups as well as the secondary amino group being able to form ionic bounds are essential for maximal activity. A disturbance of the function of the cell membrane caused by DPA is discussed.