ANTIMICROBIAL PROPERTIES OF MESOHYLAR GRANULAR CELLS OF HALISARCA DUJARDINI JOHNSTON, 1842 (DEMOSPONGIAE, HALISARCIDA)

It was shown that granular mesohylar cells of Halisarca dujardini Johnston, 1842 contain cationic peptides and proteins. As it is known that such agents are the molecular factors of resistance to bacteria and lowest fungi, the proposed toxic activity of these peptides and proteins was studied. We have shown that some isolated protein and peptide fractions have antimicrobial activity against Escherichia coli and Listeria monocytogenes. Molecular weights of antimicrobial substances were about 6.2 kDa for peptide fractions and about 14 - 25 kDa for protein fractions. These results suggest an important biological role of the cationic peptides and proteins in defense processes of adults and larvae of H. dujardini.