%0 Journal Article %A Schmidt, G. %T Genetical Studies on the Lipopolysaccharide Structure of Escherichia colik12 %D 1973 %J Microbiology, %V 77 %N 1 %P 151-160 %@ 1465-2080 %R https://doi.org/10.1099/00221287-77-1-151 %I Microbiology Society, %X SUMMARY: Escherichia coli K12 strain 2578 was crossed with an E. coli O8 donor. Most of the recombinants selected for the donor his allele were agglutinable by anti-O8 serum. This indicated that the recombinants can synthesize O8-specific units and attach them to the K12 lipopolysaccharide (LPS) core in consequence of the transfer of the his-linked donor rfb cluster determining O8-chain synthesis. In serological tests and phage sensitivity tests most O8-reactive recombinants behaved like typical smooth E. coli O8 strains. This implies that E. coli K12 strain 2578 synthesizes a complete core structure, which is a prerequisite for the formation of smooth recombinants. Some O8-reactive recombinants displayed a partly rough phenotype. In addition, the typical smooth recombinants segregated partly rough forms. Thus the smooth recombinants appear to be partial diploids for some donor gene(s) involved in LPS synthesis. Serological tests and phage typing showed that the Escherichia coli K12 core is different from other known core types of Salmonella (Ra) and E. coli (R1–-R3). The genes (rfa) for the K12 core type were mapped by conjugation at approximately 72 min on the Escherichia coli linkage map. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-77-1-151