INHIBITION OF BACTERIAL-CELL SURFACE EXTENSION BY VARIOUS MEANS CAUSES BLOCKING OF MACROMOLECULAR-SYNTHESIS

It has been suggested that, in rod-shaped bacteria, two sites for pept idoglycan assembly exist: one which is responsible for septum formatio n and the other, for lateral wall extension. The balance between the a ctivities of these two sites enables bacteria to conserve their own mo rphology during cell growth, The effect of specifically inhibiting sep tum formation by different means (antibiotics and/or mutations), upon cell surface extension and macromolecular synthesis in rod-shaped and coccoid bacteria of various species, was studied. inhibition of either cell wall expansion or macromolecular synthesis did not occur when se ptum formation was impaired in both rod-shaped bacteria and cocci poss essing the two sites for peptidoglycan assembly, whereas a rapid and c omplete block of such synthesis was caused by inhibiting both sites in rod-shaped bacteria, or septum formation in cocci which possess only this site. These data indicate that bacteria possess a control mechani sm that prevents macromolecular synthesis when envelope extension is i nhibited.