Effect of secreted Rpf protein on intracellular contacts in Micrococcus luteus and Mycobacterium smegmatis cultures

The effect of Resuscitation promoting factor (Rpf) on intercellular contacts in the cultures of Micrococcus luteus and Mycobacterium smegmatis was investigated using dynamic light scattering (DLS, photon correlation spectroscopy). During the stationary growth phase, the cells of the tested cultures formed extensive aggregates 100 and 300 μ in size for M. smegmatis and M. luteus, respectively. The number of solitary cells was insignificant. Addition of the recombinant Rpf protein (15 μg/ml) resulted dispersion of cell aggregates and emergence of solitary cells. This effect of Rpf decreased in the presence of nitrophenylthiocyanates (NPTs), specific Rpf inhibitors. Presumably, Rpf is involved in the regulation of intracellular interactions and in biofilm formation.