Over the past two decades, light sheet fluorescence microscopy has developed to a powerful tool for studies of dynamics in biological systems. In a new development, we apply light sheet fluorescence microscopy as a novel experimental measurement technology within the field of multiphase process engineering and fluid dynamics. The technology enables a number of novel studies of single- and multiphase transport phenomena on a microscopic scale. In the current publication, we introduce the first implementation of light sheet fluorescence microscopy in the field and demonstrate its applicability on one exemplary measurement of diffusive oxygen mass transfer from an oxygen bubble to degassed water. The results prove that such measurements can be conducted with a high spatial resolution with a submicron pixel pitch and enable precise studies on microscopic transport phenomena. Besides measurements of mass transfer, on which we lay the focus here, light sheet fluorescence microscopy further enables studies of fluid dynamics on a microscopic scale.

The development and validation of a mathematical model for a highly integrated biocatalytic process are presented. A multienzymatic cascade comprising three parallel and sequential reaction steps was implemented in a miniplant setup, integrating an enzyme membrane reactor (EMR) and a reactive extraction centrifuge (REC) to enable intensified biotransformations. Laboratory-scale experiments were conducted to obtain the kinetic and thermodynamic data necessary for model development. The resulting process model captures both the enzymatic reaction kinetics and the dynamic behavior of the integrated unit operations. Model validation was performed under representative process conditions in the miniplant system. The results demonstrate good agreement between the model and experimental data, confirming the predictive power of the model and supporting its use in future process design, scale-up, and optimization. This work underscores the importance of model-based development for advancing sustainable and efficient biocatalytic processes.

The “11th International Congress on Biocatalysis (biocat2024)” was part of a biennial series that unites the fields of biology and chemistry, attracting researchers from the life sciences, engineering, and computer science. This international forum provides an opportunity for scientists worldwide to connect, seek collaboration for future projects, and gain insights into contemporary topics and innovative techniques. Biocat covers a range of compelling subjects and recent advancements in biocatalysis, including enzyme discovery, evolution, and applications. This congress focused on six key topics: AI and computational methods, structure–function analysis and enzyme engineering, enzymatic and whole-cell biotransformations, reaction cascades (electro-, chemo-, and photoenzymatic synergies), bioprocess engineering and the design of smart reactors, and facing climate change through sustainability and a circular bioeconomy. In 2024, we welcomed 344 expert delegates alongside 21 internal attendees, including 154 women and 1 non-binary participant, bringing the total number of participants to an impressive 365. Established researchers and emerging scientists from academia and industry delivered a total of 119 presentations, comprising 59 standard lectures, 60 lightning talks, and 195 posters. Six industry exhibitors showcased their latest products and services, providing an excellent opportunity to strengthen the connection between science and industry. Furthermore, the biocat award, recognized as one of the most prestigious honors in biotechnology, was presented for the eleventh time in the categories of “Science in Academia”, “Lifetime Achievement,” and “Industry”.

Biotechnological processes have a high potential to make industrial processes more sustainable. However, biotechnological processes often have low product concentrations and production rates. This is where process intensification can help to make these processes competitive. Using the example of the multi-enzymatic synthesis of natural cinnamyl cinnamate, it is shown how an existing multi-enzymatic process can be intensified by using an enzyme membrane reactor. The individual enzymatic reactions are first characterised in laboratory scale and then combined in a mini plant. In addition, a process model of the mini plant is developed. It is shown that the use of an enzyme membrane reactor can increase the production rate of the multi-enzymatic process by a factor of 10 compared to a previously investigated set-up.

Utilizing pressure as a process parameter can make biotechnological processes more efficient and attractive compared to established ones. This paper presents a high-pressure reactor setup for enzymatically catalyzed gas-liquid reactions, which can be operated up to 15.0 MPa. The reactor is equipped with optical measurement technology for inline and in situ monitoring of the oxygen concentration under high-pressure conditions. The setup is characterized by assessing the influence of the process parameter pressure on the conversion of the glucose oxidation to d-glucono-delta-lactone by immobilized glucose oxidase. The study demonstrates that the increased oxygen availability due to higher solubility reduces the reaction time in a batch reactor from 270 to 90 min.

Continuous flow technologies have become increasingly important for biocatalytic processes. In this study, we present the application and modelling of covalently immobilised N-acetylglucosamine 2-epimerase and N-acetylneuraminic acid lyase in packed bed reactors for the synthesis of N-acetylneuraminic acid. The immobilised enzymes were stable under continuous flow process conditions with half-life times of >28 d (epimerase immobilised on hexamethylamino methacrylate HA403/M) or 58 d (lyase immobilised on dimenthylamino methacrylate ECR8309M), suitable for continuous flow applications. Kinetic studies revealed Michaelis–Menten kinetic behaviour for both enzymes. The kinetic parameters and the inhibitions were analysed under continuous flow conditions and were integrated into a process model using Python. The model was validated by varying flow rates, the mass of immobilised enzymes and the reactor dimensions and shows a low error compared to the measured data. An error accuracy of 6% (epimerase) or 9% (lyase) was achieved. The product concentrations of the enzyme cascade at the end of the packed bed reactor can be predicted with an accuracy of 9% for the calculation of a large column (84.5 mL) or of 24% if several small columns (2.5 mL, 0.8 mL) are connected in series. The developed model has proved to be valid and will be used to optimise the process with respect to substrate concentrations, reactor dimensions and flow rate.

AbstractSide streams from the milling industry offer excellent nutritional properties for animal feed; yet their use is constrained by the elevated phosphorus (P) content, mainly in the form of phytate. Biotechnological P recovery fosters sustainable P management, transforming these streams into P-depleted animal feed through enzymatic hydrolysis. The enzymatic P mobilization not only enables P recovery from milling by-products but also supports the valorization of these streams into P-depleted animal feeds. Our study presents the scalability and applicability of the process and characterizes the resulting P-depleted rye bran as animal feed component. Batch mode investigations were conducted to mobilize P from 100 g to 37.1 kg of rye bran using bioreactors up to 400 L. P reductions of 89% to 92% (reducing from 12.7 gP/kg to 1.41–1.28 gP/kg) were achieved. In addition, High Performance Ion Chromatography (HPIC) analysis showed complete depletion of phytate. The successful recovery of the enzymatically mobilized P from the process wastewater by precipitation as struvite and calcium hydrogen phosphate is presented as well, achieving up to 99% removal efficiency. Our study demonstrates a versatile process that is easily adaptable, allowing for a seamless implementation on a larger scale. Graphical Abstract

Chiral amines are key building blocks for the synthesis of many active pharmaceutical ingredients (APIs). Biocatalytic routes offer significant advantages to provide sustainable access to such motifs on commercial scale, with sacubitril valsartan sodium hydrate as a recent example. In this study a deeper mechanistic and kinetic understanding of the central biocatalytic step in the synthesis of sacubitril valsartan sodium hydrate, applying the evolved transaminase CDX-043, was gained. The equilibrium of the transamination reaction was investigated in detail, and two kinetic models (ping-pong two-substrate kinetics and Michaelis-Menten double substrate kinetics) were established, considering substrate and product inhibition. The determined equilibrium constant indicates that the equilibrium lies strongly on the product side. The results of the kinetic studies demonstrate that the transaminase reaction is in conformity with the Michaelis-Menten double substrate kinetic model. Product inhibition was found to be more severe than substrate inhibition. The application of a plug flow reactor (PFR) was shown to be the preferred reactor setup to reduce the occurring inhibition.

The fixation of CO2 by enzymatic carboxylation for production of valuable carboxylic acids is one way to recycle carbon. Unfortunately, this type of reaction is limited by an unfavourable thermodynamic equilibrium. An excess of the C1 substrate is required to increase conversions. Solvents with a high CO2 solubility, such as amines, can provide the C1 substrate in excess. Here, we report on the effect of CO2 pressures up to 1100 kPa on the enzymatic carboxylation of resorcinol in aqueous triethanolamine. Equilibrium yields correlate to the bicarbonate concentration. However, inhibition is observed at elevated pressure, severely reducing the enzyme activity. The reaction yields were reduced at higher pressures, whereas at ambient pressure, higher yields were achieved. Overall, CO2 pressures above 100 kPa have been demonstrated to be counterproductive for improving the biotransformation, as productivity decreases rapidly for only a modest improvement in conversion. It is expected that CO2 carbamylation intensifies at elevated CO2 pressures, causing the inhibition of the enzyme. To further increase the reaction yield, the in situ product precipitation is tested by the addition of the quaternary ammonium salt tetrabutylammonium bromide.

The utilization of oxidases suffers from insufficient oxygen availability due to its low solubility in gas-liquid multiphase systems. To overcome this limitation, oxygen is continuously supplied to the reaction medium during the course of the reaction, however, it causes significant gas consumption. In this study, a novel experimental set-up was established by installing a sintered frit porous sparger in the SpinChem® rotating bed reactor. Covalently immobilized glucose oxidase on epoxy-functionalized carriers was used in the rotating bed reactor with an activity yield of the immobilization of over 98%. For fine bubble aeration, the volumetric mass transfer coefficient kLa (67.3h-1) tripled compared to macrobubble aeration (22.5h-1), while the volume-specific aeration rate remained constant. A maximum reaction yield of 96.5% was reached. The reaction rate was improved by a factor of 12.9 for the fine bubble aeration compared to macrobubble aeration under identical conditions. With fine bubble aeration, the oxygen consumption was reduced by 87.5% over macrobubble aeration, establishing the same enzyme-specific reaction rates at a comparable kLa. Validation was carried out in repetitive batches, achieving the same glucose oxidase specific activity. This study demonstrates the advantages of fine bubble aeration and presents promising results for addressing the sustainable biotransformation processes.

The occurrence of organically bound phosphorus (P) as phytate in plant-based feeding material is a challenge for livestock farming due to limited utilization during the digestion by the animal. Its excretion into the environment through the manure pathway, poses a challenge, due to increased eutrophication and restrictions for P. Hence, while the routine supplementation of phytase enzymes in monogastric diets is common practice, metabolically triggering endogenous plant enzymes by wet-treatment prior to feeding can also lead to a better utilization of phytate bound P and increased digestibility by the animal. Nonetheless, traditional quantification of residual phytate content in plant material is both labor- and chemical-intense. The aim of this study is, therefore, to predict the remaining phytate content during wet-treatment through a straightforward and flexible methodological approach based on real-time analysis. For this, rye bran is used as a model substrate. A partial least squares regression algorithm relates the infrared spectra to the concentrations and predict the amount of P species that are transferred from the bran matrix to the liquid phase. By applying a mass balance for P and considering the effect of water compression, the amount of residual phytate content in rye bran at different time points of wet-treatment is determined. Results are compared to wet chemical methods, resulting in a RMSEP of 0.28 gphytate∙100 gbran−1. In addition, the study demonstrates the feasibility of this approach and provides insights into phytate degradation in plant residuals. The method holds the potential for further applications for the screening and investigation of feed material conditioning and also offers the possibility to employ various real-time analytical techniques for assessing phytate remnants in biological samples during wet-treatment.

For the enzymatic carboxylation of resorcinol to 2,6-dihydroxybenzoic acid (2,6-DHBA) using gaseous CO2 in an aqueous triethanolamine phase, an adsorption-based in situ product removal was demonstrated. The aim is to improve the reaction yield, which is limited by an unfavourable thermodynamic equilibrium. First, a screening for a high-affinity adsorber was carried out. Then, the application of a suitable adsorber was successfully demonstrated. This enabled achieving reaction yields above 80% using the adsorber for in situ product removal. The applied biotransformation was scaled up to 1.5 L at lab-scale. Furthermore, a downstream process based on the elution and purification of the product bound to the adsorber was developed to obtain 2,6-DHBA in high purity. Recycling is one of the key factors in this system, making it possible to recycle the reaction medium, the adsorber and the solvents in additional batches.

Immobilisation plays an important role in the industrial application of enzymes. The stabilisation and reusability of immobilised enzymes reduce the cost of the catalyst and facilitate their use in continuously operated reactors. For this purpose, an applicable type of immobilisation needs to be identified. In this study, we investigate the conversion of CDP and PolyP to CTP by NDP polyphosphate phosphotransferase 3 from Ruegeria pomeroyi (RpPPK2-3) and describe the covalent immobilisation of RpPPK2-3. In order to select a suitable carrier for the immobilisation of RpPPK2-3, a screening with different amino methacrylate (glutaraldehyde-pre-activated) and epoxy methacrylate carriers was carried out. The epoxy methacrylate carrier ECR8209M (Purolite®) was found to be the most suitable. With a half-life of 462 d when stored at 6 °C and a 50-fold reusability with a 93% residual activity, the immobilised enzyme showed a higher stability compared to the soluble enzyme with a half-life of 0.04 d. Although the half-life of the soluble enzyme could be increased to 32 d by adding PPi, it could not reach the stability of the immobilisate. Due to the resilience of the immobilisate, it is suitable for application in continuous reactor set-ups, e.g., packed-bed reactors.

When facing today’s scarcity of mineral phosphorus (P) resources and the environmental issues following enhanced P losses especially from agriculture, new solutions need to be implemented. In this framework, the potential for a mechanical separation of a P rich grain fraction from wheat, rye, barley and oats is investigated in order to provide animal feed with reduced organic P content. Thus, P accumulation in manure and soils should be prevented. Also, the subsequent utilization of the separated organic P, which occurs in the form of inositol P, for a sustainable P management via activation of intrinsic enzymes is evaluated. It was shown that in grain layers at 7.0, 5.5, 6.4 and 2.5% cross section of wheat, rye, barley and oats, respectively, maximum inositol P occurs with 1.6, 0.8, 1.4 and 1.2 g/100 g. Phytase activity is also highest in the outer layers of the grains with maxima of 9300, 12,000, 8400 and 2400 U/kg, respectively. A removal of the specific layers where inositol P is accumulated could possibly achieve a 24, 31, 60 and 27% organic P reduction for wheat, rye, barley and oats with 7, 14, 25 or 7% grain elimination. A debranning, eliminating all the outer grain layers to a certain extent, in contrast, leads to significantly higher mass losses. Within the P enriched layer determined from inositol P distribution, phytase activity is calculated to be around 285, 831, 777 and 42 U/kg for wheat, rye, barley and oats, respectively.

Abstract The availability of organically bound phosphorus (P) as phytate in plant-based feeding material is a challenge for livestock farming due to limited utilization during the digestion by the animal. Another issue is the following output into the environment as manure, due to increasing restrictions for nitrogen and phosphorus. As a solution, enzymes such as phytases are added in livestock farming to increase digestibility. However, the activation of intrinsic enzymes by wet-treatment of feeding material can also effectively reduce phytate content and can be applied prior to feeding. In this study, we report on a non-invasive method based on Attenuated Total Reflection Fourier Mid-Infrared Spectroscopy (ATR-FT-MIR) and chemometrics for rapid quantification of residual phytate content during rye bran treatment; rye bran is used as an example for a plant-based feeding material. For model calibration, KH2PO4 was used as the internal standard, as phytate and its hydrolytic product ortho-phosphate experienced similar mid-infrared absorbance pattern. The residual phytate content after different treatment times was determined by applying a mass balance for P. The developed inline analysis is compared to standard offline analytical methods resulting in a RMSE of 6.2 mgphytate·100gbran-1. Thus, the developed method shows high accuracy and holds the potential for further applications for the screening and investigation of feed material conditioning prior to feeding.

Natural deep eutectic solvents (NADESs) were investigated for the activity and stability of the laccase enzyme. Laccase was found to be active only in a low amount of choline chloride containing NADESs while it maintained its activity both in high and low amounts of betaine containing NADESs. Rutin, as a flavonoid monomer shows high antioxidant, antibacterial, antiviral and anti-inflammatory properties and these properties are enhanced in the polymerised form. In this study, the organic co-solvent that is conventionally used in the oligomerization of rutin was replaced with two different green solvents, choline chloride-ethylene glycol (1:2 molar ratio) and betaine-mannose (5:2 molar ratio). LC-MS results revealed spontaneous derivatization of rutin as well as the oligomerization of the derivatives besides rutin. The final products were found to have enhanced superoxide radical activity. In this study, enzymatic oligomerization of rutin was investigated for the first time in the presence of eco-friendly green solvents presenting an alternative pathway without any toxic components.

One of the key elements in stirred tank reactor set-ups is the submersed aeration system. Aeration with microbubbles provides high gas utility coupled with prolonged enzyme stability by lowering the interfacial area renewing rate depending on the aeration mode.

Chemie Ingenieur TechnikVolume 94, Issue 9 p. 1301-1302 Poster FTIR Quantification of Phytic Acid for Feed Conditioning N. Widderich, Corresponding Author N. Widderich niklas.widderich@tuhh.de Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanyCorrespondence: N. Widderich (niklas.widderich@tuhh.de), Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this authorA. Liese, A. Liese Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this authorP. Bubenheim, P. Bubenheim Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this author N. Widderich, Corresponding Author N. Widderich niklas.widderich@tuhh.de Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanyCorrespondence: N. Widderich (niklas.widderich@tuhh.de), Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this authorA. Liese, A. Liese Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this authorP. Bubenheim, P. Bubenheim Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, GermanySearch for more papers by this author First published: 25 August 2022 https://doi.org/10.1002/cite.202255084AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume94, Issue9Special Issue: (Bio)Process Engineering – a Key to Sustainable Development: ProcessNet and DECHEMA-BioTechNet Jahrestagungen 2022 together with 13th ESBES SymposiumSeptember 2022Pages 1301-1302 RelatedInformation

A circular phosphorus (P) bioeconomy is not only worthwhile for conserving limited mineral P reservoirs, but also for minimizing negative environmental impacts caused by human-made alterations. Although P is an essential nutrient, most of the P in concentrates based on cereals, legumes and oilseed byproducts is organically bound to phytate. The latter cannot be efficiently utilized by monogastric animals and is therefore diluted into the environment through the manure pathway. This review examines various strategies for improved P utilization in animals and reflects the respective limitations. The strategies considered include feeding of debranned feedstuffs, pre-germinated feed, co-feeding of phytase and feeding material with high native phytase activity. All these approaches contribute to an improved P bioavailability. However, about half of the organic P content continues to be excreted and therefore remains unused by the animals. Nevertheless, technologies for an efficient utilization of P from cereal-based feed already exist; however, these are not industrially established. Conditioning feed material prior to feeding fosters P-reduced feed; meanwhile, P bound to phytate can be recovered. Based on known techniques for P separation and solubilisation from cereal products and phytate conversion, potential designs for feed material conditioning processes are proposed and evaluated.

Biorefineries are a model for greener production processes, based on the concept of bioeconomy. Instead of targeting first-generation biofuels-that compete with food supply-the focus relies on lignocellulosic material, considering many aspects, such as sustainable fuel production, as well as valorization of waste, as an alternative to the traditional petrochemical approach of goods production. Especially, in tropical countries agricultural activities lead to tremendous amounts of biomass, resulting in waste that has to be dealt with. In the case of Costa Rica, the five major crops cultivated for export are coffee, oil palm, pineapple, sugarcane, and banana. Traditional ways of waste treatment cannot cope with the increasing amount of biomass produced and therefore, bear various challenges often related to increased pollution. This review aims to bring up the recent state of waste treatment but even more, stress potential opportunities of adding value to not used residues; thus, improve sustainability in the agro industrial sector. Part I of the review already highlighted the potential of producing promising bioactive chemical compounds by novel biorefinery concepts from agricultural waste originating from coffee and oil palm cultivation. This second part focuses on the lignocellulose-rich biowaste from pineapple, sugarcane, and banana, showing biorefinery concepts, where fuel and energy production, as well as establishment of novel products and new applications, play an important role.