Effect of culture conditions on growth and adhesion of Bacillus licheniformis

Adhesion to glass of actively growing cells of the thermophilic Bacillus licheniformis, isolated from the Medyaginskaya test borehole (Yaroslavl' oblast), was studied. The reversible adhesion (RA) manifests itself in a decline of cell density (short of cell lysis) in the liquid culture over the first 20-40 min of growth followed by normal exponential growth. The RA is minimal under favorable growth conditions but increases when cells are transferred to a new medium, especially one with a pH, temperature, salinity, or concentration of Ca2+ ions nonoptimal for the given species. Under unfavorable growth conditions, the adhesion becomes irreversible. The obtained data suggest that RA represents an adaptation mechanism important for population survival.