Conception and characterization of a continuous plug flow bioreactor

Tisseyre, B.; Coquille, Jean Claude; Gervais, Patrick

doi:10.1007/bf00369693

Cited by 6 publications

(2 citation statements)

References 7 publications

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“…The metabolic zonation of the liver (1), resulting from the organ's lobular architecture that functions as a plug-flow reactor (29), poses particular challenges to the measurement of fractional synthesis of biopolymers by MID analysis using this assumption. This is because each cell along the liver lobule is in contact with blood of continuously changing composition in terms of substrate concentrations and isotopic enrichment of tracers.…”

Section: Resultsmentioning

confidence: 99%

In Vitro Modeling of Fatty Acid Synthesis under Conditions Simulating the Zonation of Lipogenic [13C]Acetyl-CoA Enrichment in the Liver

Bederman¹,

Kasumov²,

Reszko

et al. 2004

Journal of Biological Chemistry

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In the companion report (Bederman, I. R., Reszko, A. E., Kasumov, T., David values of (i) lower and upper limits for the precursor enrichment, (ii) the shape of the gradient, and (iii) the fractional synthesis. At each step, the mass isotopomer distributions of the samples were analyzed by ISA and the two-isotopomer method to determine whether each method could correctly (i) detect gradients of precursor enrichment, (ii) estimate the gradient limits, and (iii) estimate the fractional synthesis. The two-isotopomer method did not identify gradients of precursor enrichment and underestimated fractional synthesis by up to 2-fold in the presence of gradients. ISA uses all mass isotopomers, correctly identified imposed gradients of precursor enrichment, and estimated the expected values of fractional synthesis within the constraints of the data.In the companion report (1) (2) of the activities of glycolytic (2-5) and lipogenic enzymes (7-9) (perivenous Ͼ periportal) versus the activity of cytosolic acetyl-CoA synthetase (periportal Ͼ perivenous) (10). Gradients of precursor enrichment were detected using isotopomer spectral analysis (ISA) (11). In addition, we found that fractional lipogenesis calculated by the two-isotopomer method (an algebraic method similar to that described by Chinkes et al. (12)) produces lower estimates of fractional synthesis than those produced by the best fit estimates of ISA. Although the "linear gradient" ISA model (see companion report (1) for model definitions) yielded a better fit than the "Single pool" ISA model, it was not possible to evaluate the effect of gradients on estimates of fractional synthesis. Thus, we could not quantitatively evaluate the performance of the ISA in comparison to the two-isotopomer method, because the true rates of fractional synthesis in the liver dog and rat liver perfusion study were unknown.The goal of the present study was to evaluate the differences in estimates of precursor enrichment and fractional synthesis calculated by the two-isotopomer method and ISA. We used an experimental model where both the gradient in precursor enrichment and the fractional synthesis are known. This was accomplished by in vitro preparations that simulated the zonation of acetyl-CoA enrichment. Lipogenesis from sub-populations of hepatocytes across the liver lobule was simulated, in parallel incubations, by synthesizing a fatty acid using purified fatty acid synthase (13,14) and [U-13 C 3 ]malonyl-CoA of varying enrichment. We used gradients of malonyl-CoA enrichment, because fatty acid synthesis involves the conversion to malonyl-CoA of all acetyl units added to the primer. We used [U-13 C 3 ]propionyl-CoA as a primer to avoid the possibility of contamination of our newly synthesized pentadecanoate with unlabeled pentadecanoate. In the presence of unlabeled malonyl-CoA, the process yields M3 2 [13,14, C 3 ]pentadecanoate. By monitoring the distribution of M3 to M15 isotopomers of pentadecanoate, we simulated in vitro the polymerization of six [13 C]acetyl units

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Section: Resultsmentioning

confidence: 99%

In Vitro Modeling of Fatty Acid Synthesis under Conditions Simulating the Zonation of Lipogenic [13C]Acetyl-CoA Enrichment in the Liver

Bederman¹,

Kasumov²,

Reszko

et al. 2004

Journal of Biological Chemistry

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“…While tubular reactors (TRs) have not been extensively explored for the BM process, they are well-studied and industrialized for continuous bioprocesses, such as algae production [19,20]. Extensive discussions in the literature, including their simplicity compared to CSTRs, highlight the advantages of TRs in bioprocesses, offering benefits such as thorough mixing, reduced dead zones and a significantly improved area-to-volume ratio for enhanced mass and heat transfer efficiencies [21][22][23]. In addition, employing helically shaped tubes and generating secondary radial flow can further enhance mixing intensity [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Improved biological methanation using tubular foam-bed reactor

Khesali Aghtaei,

Heyer,

Reichl

et al. 2024

Biotechnol Biofuels

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Background Power-to-gas is the pivotal link between electricity and gas infrastructure, enabling the broader integration of renewable energy. Yet, enhancements are necessary for its full potential. In the biomethanation process, transferring H2 into the liquid phase is a rate-limiting step. To address this, we developed a novel tubular foam-bed reactor (TFBR) and investigated its performance at laboratory scale. Results A non-ionic polymeric surfactant (Pluronic® F-68) at 1.5% w/v was added to the TFBR’s culture medium to generate a stabilized liquid foam structure. This increased both the gas–liquid surface area and the bubble retention time. Within the tubing, cells predominantly traveled evenly suspended in the liquid phase or were entrapped in the thin liquid film of bubbles flowing inside the tube. Phase (I) of the experiment focused primarily on mesophilic (40 °C) operation of the tubular reactor, followed by phase (II), when Pluronic® F-68 was added. In phase (II), the TFBR exhibited 6.5-fold increase in biomethane production rate (MPR) to 15.1 $$({\text{L}}_{{\text{CH}}_{4}}\text{/}{\text{L}}_{\text{R}}\text{/d)}$$ ( L CH 4 /L R /d) , with a CH4 concentration exceeding 90% (grid quality), suggesting improved H2 transfer. Transitioning to phase (III) with continuous operation at 55 °C, the MPR reached 29.7 $${\text{L}}_{{\text{CH}}_{4}}\text{/}{\text{L}}_{\text{R}}\text{/d}$$ L CH 4 /L R /d while maintaining the grid quality CH4. Despite, reduced gas–liquid solubility and gas–liquid mass transfer at higher temperatures, the twofold increase in MPR compared to phase (II) might be attributed to other factors, i.e., higher metabolic activity of the methanogenic archaea. To assess process robustness for phase (II) conditions, a partial H2 feeding regime (12 h 100% and 12 h 10% of the nominal feeding rate) was implemented. Results demonstrated a resilient MPR of approximately 14.8 $${\text{L}}_{{\text{CH}}_{4}}\text{/}{\text{L}}_{\text{R}}\text{/d}$$ L CH 4 /L R /d even with intermittent, low H2 concentration. Conclusions Overall, the TFBR’s performance plant sets the course for an accelerated introduction of biomethanation technology for the storage of volatile renewable energy. Robust process performance, even under H2 starvation, underscores its reliability. Further steps towards an optimum operation regime and scale-up should be initiated. Additionally, the use of TFBR systems should be considered for biotechnological processes in which gas–liquid mass transfer is a limiting factor for achieving higher reaction rates.

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Fermentation processes for second-generation biofuels

Patinvoh

Taherzadeh

2019

Second and Third Generation of Feedstocks

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Conception and characterization of a continuous plug flow bioreactor

Cited by 6 publications

References 7 publications

In Vitro Modeling of Fatty Acid Synthesis under Conditions Simulating the Zonation of Lipogenic [13C]Acetyl-CoA Enrichment in the Liver

In Vitro Modeling of Fatty Acid Synthesis under Conditions Simulating the Zonation of Lipogenic [13C]Acetyl-CoA Enrichment in the Liver

Improved biological methanation using tubular foam-bed reactor

Fermentation processes for second-generation biofuels

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