FIG. 2.

SDS-PAGE of affinity-purified LPS extracted from S. meliloti 2011 and from mutant strains. Each well contained the total LPS extracted from about 10 mg (wet weight) of cells of the indicated bacterial strain, using EDTA and polymyxin B as described in Materials and Methods. (A) SDS-PAGE (18% polyacrylamide); (B) R-LPS components from a gel where increased resolution was achieved by extending the running time. The positions of LPS components that are present only in the mutants are indicated to the left. Genotypes of S. meliloti (Sme) strains 20-B, 20-E, 20-D, and 20-C are described in Table 1; Sme 2011 corresponds to the parental wild-type strain.