Characteristics of cell walls from morphological variants of Escherichia coli.

Two strains (E-26 and B) of Escherichia coli were examined for their growth response in a medium containing 0.75 yo (w/v) NaCl, 1 yo (w/v) L-lysine hydrochloride, 2 % (w/v) glucose, 2.4 % (w/v) nutrient broth, and 5 % (w/v) casein hydrolysate. Strain E-26 grew as a rod which was slightly larger than when it was grown in a defined medium. Strain B grew as a filamentous and branched form; while in defined medium it grew as a rod of normal dimensions. Cell walls were isolated from both strains. Chemical analysis showed that the filamentous and branched forms had one-third the amount of hexosamine and one-fifth the amount of reducing sugar as compared with the morphologically normal form. The abnormal cell walls were more susceptible to trypsin action, more resistant to lysozyme action and more completely disaggregated by sodium dodecyl sulphate than the walls from the morphologically normal organisms.