In situ continuous countercurrent cloud point extraction of microalgae cultures

Racheva, Ralena; Tietgens, Nick; Kerner, Martin; Смирнова, Ирина

doi:10.1016/j.seppur.2017.08.066

Cited by 16 publications

(12 citation statements)

References 33 publications

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“…Different approaches have been tested to overcome these limitations. One strategy is 'milking' the cells by in situ extraction of the target substance (Hejazi and Wijffels, 2004;Racheva et al, 2018). Although this idea was published more than 10 years ago, the technological readiness of this approach is still on the level of research and milking by in situ extraction still separates algal growth and harvesting in two different production phases and a continuous bioproduction is not achieved and thus, the energy conversion efficiency is reduced.…”

Section: Introductionmentioning

confidence: 99%

Glycolate from microalgae: an efficient carbon source for biotechnological applications

Taubert

Jakob

Wilhelm

2019

Plant Biotechnology Journal

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Summary Glycolate is produced in autotrophic cells under high temperatures and C i ‐limitation via oxygenation of ribulose‐1,5‐bisphosphate. In unicellular algae, glycolate is lost via excretion or metabolized via the C 2 cycle by consuming reductants, ATP and CO 2 emission (photorespiration). Therefore, photorespiration is an inhibitory process for biomass production. However, cells can be manipulated in a way that they become glycolate‐producing ‘cell factories’, when the ratio carboxylation/oxygenation is 2. If under these conditions the C 2 cycle is blocked, glycolate excretion becomes the only pathway of photosynthetic carbon flow. The study aims to proof the biotechnological applicability of algal‐based glycolate excretion as a new biotechnological platform. It is shown that cells of Chlamydomonas can be cultivated under specific conditions to establish a constant and long‐term stable glycolate excretion during the light phase. The cultures achieved a high efficiency of 82% of assimilated carbon transferred into glycolate biosynthesis without losses of function in cell vitality. Moreover, the glycolate accumulation in the medium is high enough to be directly used for microbial fermentation but does not show toxic effects to the glycolate‐producing cells.

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Section: Introductionmentioning

confidence: 99%

Glycolate from microalgae: an efficient carbon source for biotechnological applications

Taubert

Jakob

Wilhelm

2019

Plant Biotechnology Journal

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“…For a continuous process this would mean that a low feed‐to‐solvent ratio is favourable, which, according to the litearture, results in high extraction efficiencies. [ 26,27 ] Thus, it could be beneficial for a continuous extractive biocatalysis in countercurrent mode to use low feed‐to‐solvent ratios.…”

Section: Resultsmentioning

confidence: 99%

“…The application of AMTPS for extraction purposes is often referred as cloud point extraction (CPE). [ 26–28 ] It is important to consider that all components added to the systems, like salts, organics, or reactants, influence the phase equilibria and change the CPT, shifting the operation window of the extraction significantly. [ 7,29,30 ] Considering all these aspects, in this work APTMS is chosen as a medium for the extraction.…”

Section: Introductionmentioning

confidence: 99%

Process design of a continuous biotransformation with in situ product removal by cloud point extraction

Fellechner

Смирнова

2021

Can J Chem Eng

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In this work, a continuous, heterogeneous extractive biocatalysis was realized with penicillin G hydrolysis as a model reaction. Therefore, commercially available structured packing CY from Sulzer were coated with enzyme‐containing gels and their catalytic activity was examined. Thereby, the potential of aqueous micellar two‐phase systems (ATPMS) as an extraction medium was evaluated. Triton X‐114 was used as model surfactant. It was found that the separation efficiency of the packing is not affected by the coating and ATPMS allows for a good separation yield. With these results, different process concepts for the continuous, heterogeneous extractive biocatalysis were compared. Overall, a countercurrent process with side inlet (YPAAside inlet = 78.1% ± 1.3%) has shown a great potential for a selective product separation and thus, higher yields in comparison to a monophasic batch operation (YPAAitalicbatch,italicmonophasic = 51.9% ± 0.6%) as well as a biphasic batch operation (YPAAitalicbatch,italicbiphasic = 67.6% ± 1.0%, wTriton X‐114 = 5%) were achieved.

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“…Among the downstream process techniques suitable for separation and purification of biomolecules, downstream processes applying aqueous two-phase systems (ATPSs) could be an alternative to conventional chromatographic approaches. ,,− As coacervation systems, they mostly provide an aqueous environment and mild operational conditions, allowing the molecule to retain its native conformation, which makes them attractive alternatives also for enzymatic synthesis in flow . Recently, aqueous micellar two-phase systems (AMTPSs) as a special version of ATPSs have been introduced. ,, They are composed of water and small amounts of a nonionic surfactant, creating a benign, more biocompatible, and cheap extraction system. , Their application in the separation of proteins from cell extracts containing high amounts of water, such as macroalgae with water contents over 85%, has high potential.…”

Section: Introductionmentioning

confidence: 99%

Development of a Microfluidic Platform for R-Phycoerythrin Purification Using an Aqueous Micellar Two-Phase System

Seručnik

Vicente

Brečko

et al. 2020

ACS Sustainable Chem. Eng.

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Temperature-dependent aqueous micellar two-phase systems (AMTPSs) have recently been gaining attention in the isolation of high-added-value biomolecules from their natural sources. Despite their sustainability, aqueous two-phase systems, and particularly AMTPSs, have not been extensively applied in the industry, which might be changed by applying process integration and continuous manufacturing. Here, we report for the first time on an integrated microfluidic platform for fast and low-material-consuming development of continuous protein purification using an AMTPS. A system comprised of a microchannel incubated at high temperature, enabling instantaneous triggering of a two-phase system formation, and a microsettler, allowing complete phase separation at the outlets, is reported here. The separation of phycobiliproteins and particularly the purification of R-phycoerythrin from the contaminant proteins present in the aqueous crude extract obtained from fresh cells of Gracilaria gracilis were thereby achieved. The results from the developed microfluidic system revealed that the fractionation performance was maintained while reducing the processing time more than 20-fold when compared with the conventional lab-scale batch process. Furthermore, the integration of a miniaturized ultrafiltration module resulted in the complete removal of the surfactant from the bottom phase containing R-phycoerythrin, as well as in nearly twofold target protein concentration. The process setup successfully exploits the benefits of process intensification along with the integration of various downstream processes. Further transfer to a meso-scale integrated system would make such a system appropriate for the separation and purification of biomolecules with high commercial interest.

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In situ continuous countercurrent cloud point extraction of microalgae cultures

Cited by 16 publications

References 33 publications

Glycolate from microalgae: an efficient carbon source for biotechnological applications

Glycolate from microalgae: an efficient carbon source for biotechnological applications

Process design of a continuous biotransformation with in situ product removal by cloud point extraction

Development of a Microfluidic Platform for R-Phycoerythrin Purification Using an Aqueous Micellar Two-Phase System

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