Teaching an old pET new tricks: tuning of inclusion body formation and properties by a mixed feed system in E. coli

Against the outdated belief that inclusion bodies (IBs) in Escherichia coli are only inactive aggregates of misfolded protein, and thus should be avoided during recombinant protein production, numerous biopharmaceutically important proteins are currently produced as IBs. To obtain correctly folded, soluble product, IBs have to be processed, namely, harvested, solubilized, and refolded. Several years ago, it was discovered that, depending on cultivation conditions and protein properties, IBs contain partially correctly folded protein structures, which makes IB processing more efficient. Here, we present a method of tailored induction of recombinant protein production in E. coli by a mixed feed system using glucose and lactose and its impact on IB formation. Our method allows tuning of IB amount, IB size, size distribution, and purity, which does not only facilitate IB processing, but is also crucial for potential direct applications of IBs as nanomaterials and biomaterials in regenerative medicine.COMET6676761

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Study of an enzymatic packed bed reactor for production of butyl acetate under liquid and supercritical conditions

Zsfassung in dt. SpracheEster von kurzkettigen Säuren und Alkoholen, die als Aroma- und Geschmacksstoffe bekannt sind, werden in der Lebensmittel-, Kosmetik- und Pharmazeutischen Industrie eingesetzt. Herkömmlicherweise wird die Synthese dieser Substanzen in organischen Lösungsmitteln mit sauren Katalysatoren ausgeführt. Aktuelle Studien zeigen, dass nicht konventionelle Lösungsmittel wie überkritische Fluide viele Vorteile im Vergleich zu klassischen Lösungsmitteln bieten. Zusätzlich ist das Enzym Candida antarctica Lipase B (CALB) dafür bekannt, die Synthese von kurzkettigen Estern auch unter überkritischen Bedingungen zu katalysieren. Somit wird eine biologische Katalyse ermöglicht, wodurch Probleme, die durch chemische Synthese verursacht werden, verhindert werden können. Ein "grünes" Lösungsmittel wie überkritisches Kohlendioxid kombiniert mit Lipasen als Biokatalysatoren bereitet einen sehr attraktiven Ansatz zu einem umweltfreundlichen und nachhaltigen Prozess. Das Ziel dieser Diplomarbeit war die Entwicklung eines Prozesses zur Synthese eines Aromastoffes, der in der Lebensmittelindustrie eingesetzt werden kann, in einem Festbettreaktor und unter überkritischen Bedingungen. Eine Methode zur Immobilisierung der Lipase CALB auf einem keramischen Träger wurde entwickelt und die Modellreaktion der Synthese von Butylacetat wurde in einer Pilotanlage mit überkritischem Kohlendioxid als Lösungsmittel durchgeführt. Nach einer Literaturrecherche und Vorversuchen in wässrigem und organischem Medium konnten Reaktionsparameter wie Substratverhältnis, Konzentration, Temperatur und Druck optimiert werden. Es wurde auch festgestellt, dass die Wasseraktivität einen entscheidenden Einfluss auf die Enzymaktivität hat. Schließlich wurde die Aktivität der Enzyme bezüglich der Synthese von Butylacetat in organischem Lösungsmittel und unter überkritischen Bedingungen ermittelt. Verglichen mit organischen Lösungsmitteln wurden ähnliche Umsätze und sogar höhere Aktivitäten für die Reaktion in überkritischem Kohlendioxid beobachtet, was dieses neue Konzept sehr interessant für zukünftige Studien und industrielle Anwendungen macht.Esters of short chained acids and alcohols which are known for their aroma and flavour quality are widely used in food, cosmetic and pharmaceutical industries. The synthesis of those substances is conventionally carried out in organic solvents with acid catalysers. Recent studied showed that non-conventional solvents such as supercritical fluids offer many advantages compared to conventional solvents. In addition Candida antarctica Lipase B (CALB) is known to catalyse the synthesis of short chained esters also under supercritical conditions and then allow to carry out a biological catalysis thus avoiding problems induced by chemical ones. A green solvent such as supercritical Carbondioxide combined with lipases as biocatalysts is a very attractive approach towards an environmentally friendly and sustainable process. The goal of this master thesis was to develop a process to synthesise a flavour that can be used for food industry with an enzymatic packed bed reactor under supercritical conditions. A way of immobilising the lipase CALB on a ceramic support was found and the model reaction synthesis of butyl acetate was carried out in a pilot plant of industrial scale with sc-CO2 as solvent. After literature revue and preliminary experiments in aqueous and organic solvent optimised reaction parameters were found regarding substrate ratio, concentration, temperature and pressure. The effect of water activity was found to play an important role on the enzymes activity. Finally the activity of the immobilised enzymes regarding the synthesis of butyl acetate was measured in an organic solvent and in under supercritical conditions. The results showed equal yield and even higher activities when carrying out the reaction in supercritical CO2 compared to an organic solvent making this new concept very attractive for further studies and industrial applications.8

Novel Methods to facilitate Escherichia coli bioprocess development

Zusammenfassung in deutscher SpracheDas Bakterium Escherichia coli ist einer der meist genutzten Organismen für rekombinante Protein Produktion und ungefähr 30% aller im Handel erhältlichen Biopharmazeutika werden in diesem Wirt produziert. Die Entwicklung von effizienten Bioprozessen ist eine äußerst komplexe Herausforderung die sich von der Stammgenerierung, über die Entwicklung von Upstream- und Downstream-Prozess bis hin zur Formulierung des Endprodukts erstreckt. Regulierungsbehörden beharren auf der Wichtigkeit einer konstanten Produktqualität und eines Herstellungsprozesses, der immer die vorgesehene Leistung bringt. Um die gewünschte Produktqualität zu garantieren, müssen zuvor identifizierte kritische Prozessparameter überwacht und kontrolliert werden. Daher ist die Entwicklung neuer Methoden zur Überwachung und Kontrolle von relevanten Parametern in der Entwicklung eines Bioprozesses, als auch während biopharmazeutischer Produktionsprozesse, eine nicht enden wollende Herausforderung. Obwohl die Limitierung von Prozessen heutzutage hauptsächlich im Downstream liegt, ist der Fokus dieser Arbeit auf der Entwicklung von Methode, die die Überwachung und Steuerung von Qualitätsattributen des Produktes und des Prozesses bereits im Upstream-Prozess erlauben und dadurch den nachfolgenden Downstream-Prozess erleichtern können. Die mächtigen und vielseitigen Methoden, die in dieser Arbeit entwickelt wurden, benutzen zuvor generiertes mechanistisches Wissen und modellbasiertes Experimentaldesign, ermöglichen eine verbesserte-integrierte Bioprozess-Entwicklung und können in der Zukunft den Weg für kontinuierliche Bioprozesse ebnen.The bacterium Escherichia coli is one of the most widely used organisms for recombinant protein expression and currently about 30% of all marketed biopharmaceutical are produced in this host. Development of an efficient bioprocess is a very complex task that ranges from generation of a suitable strain, Upstream and Downstream development, to formulation of the final product. Regulatory authorities emphasize the need of delivering a constant product quality and a manufacturing process that consistently delivers the intended performance. To ensure that the product is of desired quality, identified critical process parameters need to be monitored and controlled. Therefore there is a never-ending challenge of developing methods to monitor and control certain parameters in bioprocess development and in biopharmaceutical production processes. Even though nowadays the major bottleneck lies in Downstream processes, the focus of this Thesis was to develop methods that allow monitoring and tuning of product and process quality attributes already in the Upstream process to potentially facilitate the subsequent Downstream process. The powerful and versatile methods developed within this Thesis use generated mechanistic knowledge and model based experimental design, can be used for enhanced integrated bioprocess development and may pave the way for continuous bioprocessing in the future.20

Physiological Characterization of Sulfolobus acidocaldarius in a Controlled Bioreactor Environment

The crenarchaeal model organism Sulfolobus acidocaldarius is typically cultivated in shake flasks. Although shake flasks represent the state-of-the-art for the cultivation of this microorganism, in these systems crucial process parameters, like pH or substrate availability, are only set initially, but cannot be controlled during the cultivation process. As a result, a thorough characterization of growth parameters under controlled conditions is still missing for S. acidocaldarius. In this study, we conducted chemostat cultivations at 75 °C using a growth medium containing L-glutamate and D-glucose as main carbon sources. Different pH values and dilution rates were applied with the goal to physiologically characterize the organism in a controlled bioreactor environment. Under these controlled conditions a pH optimum of 3.0 was determined. Washout of the cells occurred at a dilution rate of 0.097 h−1 and the optimal productivity of biomass was observed at a dilution rate of 0.062 h−1. While both carbon sources were taken up by S. acidocaldarius concomitantly, a 6.6-fold higher affinity for L-glutamate was shown. When exposed to suboptimal growth conditions, S. acidocaldarius reacted with a change in the respiratory behavior and an increased trehalose production rate in addition to a decreased growth rate

Production strategies for active heme-containing peroxidases from E. coli inclusion bodies – a review

Heme-containing peroxidases are frequently used in medical applications. However, these enzymes are still extracted from their native source, which leads to inadequate yields and a mixture of isoenzymes differing in glycosylation which limits subsequent enzyme applications. Thus, recombinant production of these enzymes in Escherichia coli is a reasonable alternative. Even though production yields are high, the product is frequently found as protein aggregates called inclusion bodies (IBs). These IBs have to be solubilized and laboriously refolded to obtain active enzyme. Unfortunately, refolding yields are still very low making the recombinant production of these enzymes in E. coli not competitive. Motivated by the high importance of that enzyme class, this review aims at providing a comprehensive summary of state-of-the-art strategies to obtain active peroxidases from IBs. Additionally, various refolding techniques, which have not yet been used for this enzyme class, are discussed to show alternative and potentially more efficient ways to obtain active peroxidases from E. coli

The production of a recombinant tandem single chain fragment variable capable of binding prolamins triggering celiac disease

Abstract Background Celiac disease (CD) is one of the most common food-related chronic disorders. It is mediated by the dietary consumption of prolamins, which are storage proteins of different grains. So far, no therapy exists and patients are bound to maintain a lifelong diet to avoid symptoms and long-term complications. To support those patients we developed a tandem single chain Fragment variable (tscFv) acting as a neutralizing agent against prolamins. We recombinantly produced this molecule in E. coli, but mainly obtained misfolded product aggregates, so-called inclusion bodies, independent of the cultivation strategy we applied. Results In this study, we introduce this novel tscFv against CD and present our strategy of obtaining active product from inclusion bodies. The refolded tscFv shows binding capabilities towards all tested CD-triggering grains. Compared to a standard polyclonal anti-PT-gliadin-IgY, the tscFv displays a slightly reduced affinity towards digested gliadin, but an additional affinity towards prolamins of barley. Conclusion The high binding specificity of tscFv towards prolamin-containing grains makes this novel molecule a valuable candidate to support patients suffering from CD in the future

A combination of HPLC and automated data analysis for monitoring the efficiency of high-pressure homogenization

Abstract Background Cell disruption is a key unit operation to make valuable, intracellular target products accessible for further downstream unit operations. Independent of the applied cell disruption method, each cell disruption process must be evaluated with respect to disruption efficiency and potential product loss. Current state-of-the-art methods, like measuring the total amount of released protein and plating-out assays, are usually time-delayed and involve manual intervention making them error-prone. An automated method to monitor cell disruption efficiency at-line is not available to date. Results In the current study we implemented a methodology, which we had originally developed to monitor E. coli cell integrity during bioreactor cultivations, to automatically monitor and evaluate cell disruption of a recombinant E. coli strain by high-pressure homogenization. We compared our tool with a library of state-of-the-art methods, analyzed the effect of freezing the biomass before high-pressure homogenization and finally investigated this unit operation in more detail by a multivariate approach. Conclusion A combination of HPLC and automated data analysis describes a valuable, novel tool to monitor and evaluate cell disruption processes. Our methodology, which can be used both in upstream (USP) and downstream processing (DSP), describes a valuable tool to evaluate cell disruption processes as it can be implemented at-line, gives results within minutes after sampling and does not need manual intervention