Protease‐Induced Multicell Formation in Staphylococcus haemolyticus

A New Two-Component Regulatory System Involved in Adhesion, Autolysis, and Extracellular Proteolytic Activity of Staphylococcus aureus

“…It has been shown that secreted autolysins are susceptible to inactivation by serine proteases (1,22,58). In Staphylococcus haemolyticus, addition of subtilisin (a serine protease of Bacillus subtilis) to exponentially growing cells causes a loss of cell wall lytic activity (58). As the mutant strain BF16 does not produce detectable serine protease activity, we can postulate that this deficiency of protease increases the levels of secreted autolysins and is responsible for the increased autolysis of the mutant cells.…”

“…It might be paradoxical that a strain, such as our mutant, presenting decreased cell aggregation also forms a biofilm on polystyrene surfaces. Since autolysin production is enhanced in this mutant, decreased cell aggregation in this case might reflect the role of peptidoglycan hydrolases in cell division rather than in intercellular adhesion (58). The increased autolysis rate could be due to increased autolysin activity associated with the cells (by overproduction of autolysins, increase of the translocation enzyme, or decrease of proteases inactivating autolysins) or to an increased susceptibility of the cell wall to autolysin.…”

“…As proteases are known to modify autolysis and cell wall turnover (1,22,34,58), supernatants from overnight cultures were assayed for proteolytic activity using the substrate azocoll. Total extracellular proteolytic activity of the mutant strain BF16 was undetectable by this method, whereas those of wild-type strain ISP794 and complemented mutant BF17 were at least 30-fold higher (Table 2).…”

“…In mutant strain BF16 all proteases, including serine, metalloproteases, and thiol proteases, were strikingly decreased in comparison to the wild-type strain and the complemented mutant (Table 2). It has been shown that secreted autolysins are susceptible to inactivation by serine proteases (1,22,58). In Staphylococcus haemolyticus, addition of subtilisin (a serine protease of Bacillus subtilis) to exponentially growing cells causes a loss of cell wall lytic activity (58).…”

Sll0254 (CrtL diox ) Is a Bifunctional Lycopene Cyclase/Dioxygenase in Cyanobacteria Producing Myxoxanthophyll

“…6), already have been reported for strains impaired in biosynthesis of carotenoids and specifically of myxoxanthophyll (19), although the virtual formation of tetrads upon cell division was not observed before in myxoxanthophyll biosynthesis mutants. In Staphylococcus haemolyticus, formation of tetrads has been reported after protease treatment, which presumably leads to a lack of a protein with cell wall lytic activity and, thereby, a lack of separation of cells after division (30). In the case of Synechocystis cells that are depleted in cyclic carotenoids and carry hydroxylated linear carotenoids, changes in the cell wall and permeability may have led to a similar decrease in the separation of the cell wall between daughter cells, in line with our finding that myxoxanthophyll is very important for cell wall properties (19).…”