RT Journal Article SR Electronic(1) A1 Rowbury, R. J.YR 1964 T1 The Accumulation of O-Succinylhomoserine by Escherichia coli and Salmonella typhimurium JF Microbiology, VO 37 IS 2 SP 171 OP 180 DO https://doi.org/10.1099/00221287-37-2-171 PB Microbiology Society, SN 1465-2080, AB SUMMARY: After growth of Escherichia coli strain 7/9, the culture fluid and organisms contained an amino acid which gave a yellow-brown colour with ninhydrin. This compound was shown by comparison with synthetic material to be O-succinylhomoserine believed from previous work with this E. coli strain to be a methionine precursor. Its accumulation gave proof that it was formed in large amounts by the growing organisms. The formation of O-succinylhomoserine occurred equally well in the presence or absence of added homoserine and succinate, but when the succinate was added to growth media, synthesis occurred preferentially from it and the utilization of endogenously-formed succinate was diminished. Without added homoserine the extent of accumulation was such (up to 440 mg. O-succinyl-homoserine/1.) that homoserine synthesis may have been increased above normal to provide the required quantities (up to 240 mg./1.) of homoserine. Methionine completely suppressed accumulation of O-succinylhomoserine, threonine and lysine had no effect. A cystathionine-requiring mutant of Salmonella typhimurium also accumulated O-succinylhomoserine; the amount (20-30 mg./1.) being only about 5 % of that given by E. coli, and methionine prevented its accumulation by this organism too. It appears that the methionine synthesis pathway in S. typhimurium is very similar to that in E. coli and is subject to end-product control., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-37-2-171