Production of l-ornithine by arginine auxotrophic mutants of Brevibacterium ketoglutamicum in dual substrate-limited continuous culture

Genetic manipulation of a primary metabolic pathway for l-ornithine production in Escherichia coli

“…L-Ornithine is produced commercially from a citrulline-requiring mutant of a coryneform bacterium (Choi et al 1996). Although this auxotrophic mutant can produce a high level of L-ornithine, its growth often becomes unstable during the fermentation process due to reversion of the auxotrophic mutant and, consequently, the production of L-ornithine is markedly decreased.…”

Optimization of Fermentation Conditions of the Engineered Corynebacterium Glutamicum to Enhance L-Ornithine Production by Response Surface Methodology

“…Lee et al [15] reported that yeast extract as an arginine source and ammonium sulfate as an inorganic nitrogen source had significant effects on L-ornithine production and cell growth in Brevibacterium ketoglutamicum. Model of fed-batch culture, dilute rate and dual limitation of arginine and phosphate in continuum culture were also optimized for L-ornithine production and cell growth in Brevibacterium ketoglutamicum BK533 [7,14,16]. After these optimization, Brevibacterium ketoglutamicum BK533 production L-ornithine up to 74 g/L in a fed-batch culture by shorten the mixing time of the limiting nutrient in the fermenter [16] from 2 g/L in a batch culture [14].…”

“…Many studies have reported that L-ornithine was produced from a citrulline-or arginine-required mutant of a coryneform bacterium obtained by classical mutagenesis [7][8][9]. Although this mutant can produce a high yield of L-ornithine, its growth culture is always unstable because of reversion of the auxotrophic mutant, and then the production of Lornithine drops markedly.…”

Direct production of l-ornithine from casein by commercial digestive enzymes and in situ activated arginase

“…The concentration of L-ornithine at 48 h was found to be 26.07 ± 0.06 mM on the basis of the integrated peak area ratio of L-ornithine to its standard (Table 1). This yield is lower than that produced by a highly optimized fermentation process, but almost comparable to that by a conventional one [13,14]. From the increase in the concentration of L-ornithine, the production rate of L-ornithine between 12 and 24 h was estimated to be 4.17 lmol min -1 .…”

“…Analysis of the regulatory mechanisms of L-ornithine biosynthetic pathways has led to the improvement of the fermentation process, which has in turn resulted in a high yield of L-ornithine [6][7][8][9][10][11][12][13]. Production of L-ornithine by fed-batch culture using improved impellers and feeding methods increased the L-ornithine yield up to *70 g/l [14].…”