Fig. 1

Micrograph of the cell wall of E. coli compared to that of a cyanobacterium, Phormidium uncinatum. The cyanobacterium has a much thicker peptidoglycan layer and a unique external layer containing an S-layer and exopolysaccharide. We tested a series of enzymes and chemicals meant to degrade each of these layers as shown at right. EL = external layer (S-layer and exopolysaccharide); OM = outer membrane; P = peptidoglycan; CM = cytoplasmic membrane. The detergents used were 3-(4-Heptyl)phenyl-3-hydroxypropyl)dimethylammoniopropanesulfonate (upper structure) and 3-(N,N-Dimethylmyristylammonio)propanesulfonate (lower structure). Scale bars are 100 nm. PDB IDs: 3LZM (lysozyme), 1OLQ (cellulase). The cell wall images were adapted from [20]