A substrate feeding strategy--using an oxystat for L-phenylalanine fermentation by Corynebacterium glutamicum

Wang, Pei Ming; Yeh, Chuen Yang; Shu, Chin Hang; Liao, Chii Cherng

doi:10.1007/bf00152895

Cited by 3 publications

(3 citation statements)

References 3 publications

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“…Therefore, numerous studies have already been performed focusing, for instance, on L-phe production with isolated enzymes [5,6,7,8], immobilized cells [9] or resting cells [10]. Fermentation processes have also been investigated using Corynebacterium glutamicum [11,12,13] or, most importantly, Escherichia coli [14,15,16,17,18,19].…”

Section: Introductionmentioning

confidence: 99%

Fully integrated L-phenylalanine separation and concentration using reactive-extraction with liquid-liquid centrifuges in a fed-batch process with E. coli

Rüffer

Heidersdorf

Kretzers

et al. 2004

Bioprocess Biosyst Eng

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A novel in situ product recovery (ISPR) approach for the (fully) integrated separation of L-phenylalanine (L-phe) from a 20 l fed-batch process with the recombinant L-tyrosine auxotrophic strain E. coli F-4/pF81 is presented. The strain was rationally constructed for the production of the aromatic amino acid. Glucose and tyrosine control is used. A reactive extraction system consisting of kerosene, the cation-selective carrier D(2)EHPA and sulphuric acid, all circulating in liquid-liquid centrifuges, is applied for the on-line L-phe separation from cell- and protein-free permeate. Permeate is drained off from the bioreactor bypass. Using the novel ISPR approach, a significantly extended product formation period at 0.25 mmol/(g*h) together with a reduced by-product formation and a 28% relative glucose/L-phe yield increase is observed. Thus, the ISPR approach is superior to the reference non-ISPR process and even offers extraction rates approximately three times higher than the published membrane-based process.

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Section: Introductionmentioning

confidence: 99%

Fully integrated L-phenylalanine separation and concentration using reactive-extraction with liquid-liquid centrifuges in a fed-batch process with E. coli

Rüffer

Heidersdorf

Kretzers

et al. 2004

Bioprocess Biosyst Eng

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“…A DO-stat was adopted to control the timing of adding feed. Details of the DO-stat operation have been described elsewhere (Konstantinov et al, 1990;Wang et al, 1994).…”

Section: Cultivation Equipment and Conditionsmentioning

confidence: 99%

Optimization of L‐phenylalanine production of Corynebacterium glutamicum under product feedback inhibition by elevated oxygen transfer rate

Shu

Liao

2001

Biotech & Bioengineering

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Production feedback inhibition both on cell growth and on product formation of phenylalanine fermentation might be alleviated by elevated oxygen supply. Batch fermentations by a high phenylalanine producing strain Corynebacterium glutamicum CCRC 18335 at various initial phenylalanine concentrations (P(0)) ranging from 0 to 20 g/L and different oxygen transfer rate coefficients (K(L)a) ranging from 23 to 76 h(-1) were studied. The fermentation parameters with respect to P(0) were strongly dependent on K(L)a. Cell yield favored higher K(L)a and lower P(0). Product yield with respect to varying phenylalanine concentration was evaluated by the relative oxygen availability (ROA). The optimal ROA for phenylalanine formation was strongly dependent on the product concentration. While P(0) was low, the product inhibition was less significant and the maximum product yield occurred while ROA was at 0.5-0.6. While P(0) was high, the product inhibition was significant and the maximum product yield occurred while ROA was at 0.8-0.9. These results suggest that the product feedback inhibition of phenylalanine fermentation processes can be alleviated by a gradual increase in oxygen supply rate while the increasing product concentration is taken into account. The strategy is demonstrated in a fed-batch culture with elevated oxygen supply. The final phenylalanine concentration was 23.2 g/L, which was 45% better than that of the fed-batch fermentation without elevated oxygen supply. Likewise, the maximum productivity was improved by 42% at 0.37 g/(L x h).

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“…Co-expression of enzymes was carried out with Escherichia coli or Candida boidinii [6] and homologue bioconversion from phenylpyruvate to L-Phe by resting [7], immobilised [8], or growing E. coli [9,10] or Corynebacterium glutamicum cells [11,12]. Fermentation processes have been developed and optimised for mutants or genetically engineered from strains of C. glutamicum [35,36,37], Brevibacterium lactofermentum [38], Bacillus sublitis [39] or B. flavum [40] and especially of E. coli [13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34].…”

Section: Introductionmentioning

confidence: 99%

Enhanced pilot-scale fed-batch L-phenylalanine production with recombinant Escherichia coli by fully integrated reactive extraction

Maass

et al. 2002

Bioprocess and Biosystems Engineering

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A fully integrated process for the microbial production and recovery of the aromatic amino acid L-phenylalanine is presented. Using a recombinant L-tyrosine (L-Tyr) auxotrophic Escherichia coli production strain, a fed-batch fermentation process was developed in a 20-l-scale bioreactor. Concentrations of glucose and L-Tyr were closed-loop-controlled in a fed-batch process. After achieving final L-phenylalanine (L-Phe) titres >30 g/l the process strategy was scaled up to 300-l pilot scale. In technical scale fermentation L-phenylalanine was continuously recovered via a fully integrated reactive extraction system achieving a maximum extraction rate of 110 g/h (final purity >99%). It was thus possible to increase L-Phe/glucose selectivity from 15 mol% without to 20.3 mol% with integrated product separation.

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A substrate feeding strategy--using an oxystat for L-phenylalanine fermentation by Corynebacterium glutamicum

Cited by 3 publications

References 3 publications

Fully integrated L-phenylalanine separation and concentration using reactive-extraction with liquid-liquid centrifuges in a fed-batch process with E. coli

Fully integrated L-phenylalanine separation and concentration using reactive-extraction with liquid-liquid centrifuges in a fed-batch process with E. coli

Optimization of L‐phenylalanine production of Corynebacterium glutamicum under product feedback inhibition by elevated oxygen transfer rate

Enhanced pilot-scale fed-batch L-phenylalanine production with recombinant Escherichia coli by fully integrated reactive extraction

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