Antibacterial activity of the seminal plasma of Paracentrotus lividus

Abstract

Seminal plasma from Paracentrotus lividus exerted an inhibitory action on the growth of bacterial colonies. The antibacterial reaction took 30 min to reach full expression and depended on both the dose of seminal plasma and the bacterial cell number. Heating at 56 °C for 60 min did not lower the antibacterial power of the seminal plasma. Morphological examination of bacteria treated with seminal plasma revealed a conspicuous alteration of their surface and suggested a lytic mode of action for the antibacterial factor(s). Lysozyme could be involved in this process. In fact, inhibition of bacterial growth strongly decreased when this hydrolase was inactivated by heating at a basic pH.