Adaptation of Salmonella typhimurium mutants containing uncoupled enzyme IIGlc to glucose-limited conditions

Salmonella typhimurium proline mutants.

Proline Mutants of Salmonella Typhimurium.

CCORDING to previous analyses of 16 proline-requiring mutants of SalmonA d l a typhimurium, made genetically by NIELSEN (DEMEREC et al. 1954) and biochemically by JSANAZIR (1956; DEMEREC et al. 1955), the mutants fell into at least three groups. Recently, the number of proline-requiring mutants in our collection was increased to more than 200, and useful new techniques were devised or adapted f...

Experimental adaptation of Salmonella typhimurium to mice.

Experimental evolution is a powerful approach to study the dynamics and mechanisms of bacterial niche specialization. By serial passage in mice, we evolved 18 independent lineages of Salmonella typhimurium LT2 and examined the rate and extent of adaptation to a mainly reticuloendothelial host environment. Bacterial mutation rates and population sizes were varied by using wild-type and DNA repai...

6-Aminonicotinamide-resistant mutants of Salmonella typhimurium.

Resistance to the nicotinamide analog 6-aminonicotinamide has been used to identify the following three new classes of mutants in pyridine nucleotide metabolism. (i) pncX mutants have Tn10 insertion mutations near the pncA locus which reduce but do not eliminate the pncA product, nicotinamide deamidase. (ii) nadB (6-aminonicotinamide-resistant) mutants have dominant alleles of the nadB gene, wh...

Isoleucine - Valine Requiring Mutants of Salmonella Typhimurium

E have isolated a number of mutant strains of Salmonella typhimurium that display a marked inhibition of growth when valine is added to minimal medium. Attempts to elucidate the nature of the mutation(s) in these valinesensitive strains have included enzymatic and transductional analyses, as well as growth studies, on four of these strains. The results of these studies are presented and discuss...