Protein analysis of earthworm coelomic fluid. III. Isolation and characterization of several bacteriostatic molecules from Eisenia fetida andrei.

A bacteriostatic activity in Eisenia fetida andrei cell free coelomic fluid is described. This activity is detected by growth inhibition of a bacteria Bacillus megaterium. Gel filtration analysis revealed eleven coelomic fluid protein fractions designated A, B,..J. Antibacterial activity was mainly found within fractions B and C. Chromatofocusing resolved fractions B-C into five different peaks named alpha BC, beta BC,... epsilon BC. Antibacterial activity appeared mediated by three different proteins characterized by their molecular weights (20,000, 40,000 and 45,000) and their isoelectric points (4.9, 5.75 and 6.0). These bacteriostatic proteins possess either hemolysis or hemagglutination activities. The polymorphic aspect of this humoral antibacterial defense is discussed.