Involvement of meso-α,∊-Diamino-pimelateD-Dehydrogenase in Lysine Biosynthesis inCorynebacterium glutamicum

Analysis and Engineering of Metabolic Pathway Fluxes in Corynebacterium glutamicum

“…The first pioneering studies of C. glutamicum using stable isotopes to elucidate metabolic properties were initiated soon after its isolation [103]. Focusing each on selected reaction, these labeling studies identified the dual lysine pathway in C. glutamicum [104] or provided first estimates on central pathways, i.e., citric acid cycle, anaplerosis, and glyoxylate shunt [105]. The major findings on metabolic fluxes and their regulation in C. glutamicum result from the fully integrated approaches comprising stoichiometric and isotopomer balancing with 13 C labeling and thus are quite recent ( Table 2).…”

13C NMR Studies of Lysine Fermentation with aCorynebacterium glutamicumMutant

“…Other details have appeared in our preceding paper. 9 ) Calculation of 13c population. As the 13C NMR measurements of natural lysine revealed that the peak area of each carbon (except for C-l) was proportional to the lysine Abbreviations: NMR, nuclear magnetic resonance; Hom., homoserine; AEC, S-(2-aminoethyl)-L-cysteine; PEP, phosphoenolpyruvate; DAP, c<,e-diaminopimelate; TCA, tricarboxylate; EMP, Embden-Meyerhoff pathway; HMP, hexosemonophosphate pathway.…”

“…Methods for the 13C NMR analysis and other details of the experiment were according to our preceding paper. 9 ) RESULTS AND DISCUSSION 13C NMR spectra of the culture filtrate Figure 2 shows a 13C NMR spectrum of the filtrate from a 24 hr-culture of a lysine producer, C. glutamicum ATCC 21543, with [6-13C]glucose as the substrate. As can be seen in the figure, five peaks were observed at 55.4, 40.1, 30.7, 27.2 and 22.2ppm which were assigned to C-2, C-6, C-3, C-5 and C-4, respectively, of L-Iysine thus formed.…”

13C NMR Studies of Histidine Fermentation with aCorynebacterium glutamicumMutant

“…We have applied 13C NMR spectroscopy to studies on the metabolism to L-histidine in these producers, as reported for glutamic acid 2 ) and lysine fermentation. 3 ) Figure l(A) shows a typical 13 C NMR spectrum of the culture filtrate of C. glutamicum N-730, a histidine producing mutant, grown in a medium containing D-[1-13 C]glucose as the sole carbon source. The yield of L-histidine from glucose was 5% (2.5 g per liter).…”

“…l3C NMR spectra were obtained as previously described 3 ) except that the sample solution was prepared by freeze-drying of the culture filtrate and suspending the powder in approximately 0.3 ml of water and 0.03 ml of D 2 0. The spectrum represents the sum of 20,000 free induction decays obtained using 45°pulses and a repetition time of 2.6 sec.…”