Automated measurement of pH-dependent solid-liquid equilibria of itaconic acid and protocatechuic acid

Holtz, Arne; Görtz, Jonas; Kocks, Christian; Junker, M.; Jupke, Andreas

doi:10.1016/j.fluid.2020.112893

Cited by 9 publications

(25 citation statements)

References 37 publications

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“…The used solid-liquid equilibria of PCA in the fermentation medium for different pH values is shown in Figure 4B. The course of the solubility over the pH of recent experimental data for 30°C fits well with the results from the fitted Henderson-Hasselbalch equation [48,49]. Based on the measured solubility of 5.0 g L −1 at 5°C and a pH of 2.99, the equation was then used to estimate the solubility of PCA over the pH at a temperature of 5°C.…”

Section: Separation and Purification Of Pcasupporting

confidence: 67%

“…Dashed line represents a possible recycle of the mother liquid to the fermentation. B) Solubility of PCA in fermentation medium from [48] (diamond) for 30 °C and experimental result for 5 °C (circle). The Henderson-Hasselbalch [49] equation was used to correlate pH-dependent solubility for 30 °C (black line) and 5 °C (gray line).…”

Section: Resultsmentioning

confidence: 99%

“…The pH-dependent solid-liquid equilibrium for PCA at 30 °C was taken from a previous study [48] and the solubility at 5 °C was determined using the shake-flask method [63]. The solubility of PCA was calculated for different pH values using solubility data, the pK a,COOH value of PCA, and the Henderson-Hasselbalch equation [49, 64].…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Metabolic and Process Engineering for Microbial Production of Protocatechuate from Xylose withCorynebacterium glutamicum

Labib

Goertz

Bruesseler

et al. 2021

Preprint

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3,4-Dihydroxybenzoate (protocatechuate, PCA) is a phenolic compound naturally found in edible vegetables and medicinal herbs. PCA is of interest in the chemical industry as a building block for novel polymers and has wide potential for pharmaceutical applications due to its antioxidant, anti-inflammatory, and antiviral properties. In the present study, we designed and constructed a novel Corynebacterium glutamicum strain to enable the efficient utilization of D-xylose for microbial production of PCA. The engineered strain showed a maximum PCA titer of 62.1 ± 12.1 mM (9.6 ± 1.9 g L-1) from D-xylose as the primary carbon and energy source. The corresponding yield was 0.33 C-molPCA C-molXYL-1, which corresponds to 38 % of the maximum theoretical yield and is 14-fold higher compared to the parental producer strain on D-glucose. By establishing a one-pot bioreactor cultivation process followed by subsequent process optimization, the same maximum titer and a total amount of 16.5 ± 1.1 g was reached. Downstream processing of PCA from this fermentation broth was realized via electrochemically induced crystallization by taking advantage of the pH-dependent properties of PCA. Since PCA turned out to be electrochemically unstable in combination with several anode materials, a three-chamber electrolysis setup was established to crystallize PCA and to avoid direct anode contact. This resulted in a maximum final purity of 95.4 %. In summary, the established PCA production process represents a highly sustainable approach, which will serve as a blueprint for the bio-based production of other hydroxybenzoic acids from alternative sugar feedstocks.

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Section: Separation and Purification Of Pcasupporting

confidence: 67%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Metabolic and Process Engineering for Microbial Production of Protocatechuate from Xylose withCorynebacterium glutamicum

Labib

Goertz

Bruesseler

et al. 2021

Preprint

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“…The rising solubility can be explained by the dissociation of succinic acid, which leads to an increased amount of the dissociated species at higher pH values. The dissociated succinic acid species, in this case sodium salts of succinic acid, are more soluble than the protonated form of succinic acid, which is why the total solubility concentration of succinic acid increases towards higher pH values [19,20,25]. Furthermore, the solubility concentration decreases with increasing sodium sulfate concentration due to a higher ionic strength of the solution [20].…”

Section: Resultsmentioning

confidence: 99%

“…The supersaturated species can crystallize [19]. However, usually the solubility concentration is reported as a summation of all species concentrations over the pH, often referred to as pH-dependent solubility [20], allowing incorporation of the dissociation (Equations ( 5) and ( 6)) and the solubility of all species into one value c * for a given pH, temperature and composition of the solution.…”

Section: Electrochemically Induced Ph-shift Crystallizationmentioning

confidence: 99%

Determination of the Metastable Zone Width and Nucleation Parameters of Succinic Acid for Electrochemically Induced Crystallization

et al. 2021

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Electrified downstream processes for biotechnologically produced carboxylic acids reduce waste salt generation significantly and make biotechnological production ecologically and economically more attractive. In order to design, optimize, scale-up and control electrochemically induced crystallization processes, knowledge of the metastable zone width (MSZW) is essential. An optical observation approach of nucleation processes close to the electrode and determination of the MSZW is presented. This work presents a method for MSZW measurements for electrochemically induced pH-shift crystallization processes by monitoring the nucleation, the saturation pH value and saturation concentration for different current densities. The measured MSZWs for electrochemically induced pH-shift crystallization are narrow due to the foreign surface, gas bubbles and electrode surface, and rising current densities lead to even smaller MSZW. Nucleation parameters are estimated from MSWZ data, adapting the classical approach of Nývlt to electrochemically induced crystallization.

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Metabolic and process engineering for microbial production of protocatechuate with Corynebacterium glutamicum

Labib

Görtz

Brüsseler

et al. 2021

Biotech & Bioengineering

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3,4-Dihydroxybenzoate (protocatechuate, PCA) is a phenolic compound naturally found in edible vegetables and medicinal herbs. PCA is of high interest in the chemical industry and has wide potential for pharmaceutical applications. We designed and constructed a novel Corynebacterium glutamicum strain to enable the efficient utilization of D-xylose for microbial production of PCA. Shake flask cultivation of the engineered strain showed a maximum PCA titer of 62.1 ± 12.1 mM (9.6 ± 1.9 g L −1 ) from D-xylose as the primary carbon and energy source. The corresponding yield was 0.33 C-mol PCA per C-mol D-xylose, which corresponds to 38% of the maximum theoretical yield. Under growthdecoupled bioreactor conditions, a comparable PCA titer and a total amount of 16.5 ± 1.1 g PCA could be achieved when D-glucose and D-xylose were combined as orthogonal carbon substrates for biocatalyst provision and product synthesis, respectively. Downstream processing of PCA was realized via electrochemically induced crystallization by taking advantage of the pH-dependent properties of PCA. This resulted in a maximum final purity of 95.4%. The established PCA production process represents a highly sustainable approach, which will serve as a blueprint for the bio-based production of other hydroxybenzoic acids from alternative sugar feedstocks.

show abstract

Automated measurement of pH-dependent solid-liquid equilibria of itaconic acid and protocatechuic acid

Cited by 9 publications

References 37 publications

Metabolic and Process Engineering for Microbial Production of Protocatechuate from Xylose withCorynebacterium glutamicum

Metabolic and Process Engineering for Microbial Production of Protocatechuate from Xylose withCorynebacterium glutamicum

Determination of the Metastable Zone Width and Nucleation Parameters of Succinic Acid for Electrochemically Induced Crystallization

Metabolic and process engineering for microbial production of protocatechuate with Corynebacterium glutamicum

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