Fermentation

Expression of Recombinant Antibody Fragments: High-Density Fermentation in Multiuse and Single-Use Systems

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Single-use fermentors (SUFs) offer dramatic advantages over traditional stainless-steel clean-in-place (CIP)/sterilization-in-place (SIP) fermentors. Single-use technology eliminates the need for steam, chemicals, and water to clean and sterilize stainless vessels, which provides a direct reduction in capital cost and environmental-impact mitigation. Single-use platforms also increase equipment and process flexibility significantly, making it possible to switch campaigns from one product to another in minimal time, while eliminating cleaning and associated validation steps (1). Both Cytiva and Thermo Fisher Scientific offer SUFs that…

February 9, 2022

Ask the Expert: A Novel Escherichia coli System for Controlled Release of Difficult-to-Secrete Proteins

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Although Escherichia coli often enables dependable, highly productive expression of nonglycosylated recombinant proteins, the efficiency with which it secretes a target protein into culture supernatant can depend greatly on that molecule’s physicochemical properties. Some proteins remain trapped in periplasm, thus diminishing process yield and productivity. In June 2021, Marcel Thoen (head of Wacker Biotech’s Global Competence Center for Cell Line Development) described how his company’s improved ESETEC (E. coli secretion technology) solutions can address productivity challenges raised by difficult-to-secrete recombinant…

September 29, 2021

Model-Based Process Monitoring of Algae Cultures Using eve Software

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In bioreactor processes, the on-line monitoring of key parameters relies on the use of adequate sensors. In this article, we implement model-based software sensors to monitor nitrate concentrations in an algae batch process. Nitrate concentration is a crucial component in algae growth, and its assessment is used to achieve optimal growth conditions or to determine optimal harvest times. Batch cultivation of the algae Chlamydomonas reinhardtii is carried out in a Labfors 5 airlift photobioreactor provided by INFORS-HT. By means of…

August 27, 2021

Engineering Alternatives: Modern Technology Enables Expression System Developers to Think Beyond CHO Cells

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Major biopharmaceutical companies are teaming up with academics and the Bill & Melinda Gates Foundation to develop new biomanufacturing cell lines and methods. The project — known as the AltHost Consortium — is exploring innovative ways to produce biologics and vaccines for clinical usage in diseases from diabetes to cancer. Lead researcher J. Christopher Love at the Massachusetts Institute of Technology (MIT) likens this precompetitive, open-access collaboration to the early days of the biopharmaceutical industry. “When biomanufacturing first emerged as…

May 24, 2021

Oxygen Control Strategy and Yield of Recombinant Antibody Fragments Produced in Fermentation

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Immunoglobulin molecules are used extensively in therapeutic treatments, diagnostic applications, and fundamental academic research. Traditionally, full-length antibodies and smaller fragments such as the recombinant antigen-binding fragment (rFab) are produced through mammalian cell culture. rFabs also are small enough to be produced in Escherichia coli through fermentation (1, 2). Because disulfide bonds cannot be formed efficiently in the reducing cytoplasm of E. coli, rFabs are supplemented most commonly with a signal sequence that directs them to the more oxidizing bacterial periplasm…

February 4, 2021

eBook: Microbial Expression — The Right Choice for Large Peptides and Small Proteins

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Although animal cell culture has dominated the biopharmaceutical industry for some years now, microbial expression remains important for producing proteins that don’t require posttranslational modifications — or only those that prokaryotic microbes can perform. It also offers an affordable option for antibody fragments and gene therapies. Microbes may be less fragile than animal cells, and they do require simpler media, but they present other challenges related to temperature management and oxygen transfer in culture. Wherever practical, bacterial expression is preferred…

March 31, 2020

Comparative Study of Single-Use and Reusable Fermentors: Production of Recombinant Proteins Through Bacterial Fermentation

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Single-use bioreactors have become widely accepted and well established for cell culture applications in the biopharmaceutical industry for over a decade (1). Abbott Diagnostics has moved into this technology already for commercial production of some biologic molecules. However, single-use systems (SUSs) are rarely available for microbial applications, mostly because of the technical challenge in designing cost-effective SUSs that can meet high oxygen transfer needs and remove excessive heat generated during fermentation. Thus, an important part of our biologics manufacturing —…

October 28, 2019

eBook: Of Microbrews and Medicines — Understanding Their Similarities and Differences in Bioprocessing Can Help Improve Yields and Quality While Reducing Cost

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Meeting a biopharmaceutical scientist or engineer who proclaims a love for brewing is not surprising. Perhaps it’s because of the challenge of mixing raw ingredients together and waiting patiently for the final product, maybe it’s the hands-on nature of the equipment or the data analytics entertainment, or it just might be the simple joy of creating something. Whatever attracts a scientist or engineer to making medicines and/or craft brews, a surprising number of principles hold true for both bioprocesses despite…

February 8, 2018

CO2, O2, and Biomass Monitoring in Escherichia coli Shake Flask Culture: Following Glucose–Glycerin Diauxie Online

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Carbon dioxide (CO2) is an important parameter in microbial cultures because it can inhibit or stimulate growth under certain conditions. In our experiment, we monitored Escherichia coli diauxie growth phases online and focused on dissolved CO2 (dCO2) and oxygen readings. We assessed diauxic growth in medium containing glycerin and glucose online with the SFR vario system (from PreSens), which optically measures oxygen, pH, and biomass in an Erlenmeyer flask. The shake flask contained an oxygen sensor spot and an optical…

November 17, 2017

Orbital Shaking and Acoustic-Resonance Mixing: Comparing Culture Characteristics

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Production of recombinant proteins usually happens in suspension cultures, with oxygen limitation playing a major role. Oxygen and nutrition feeds are of great significance to aerobic suspension cultures. Oxygen is often the controlling factor in orbital shaken systems because oxygen transfer occurs only through diffusion, which is limited by gas-exchange surface and mixing characteristics. Here, we compare growth characteristics of microbial cultures in a standard shaken incubator with those of cultures in a RAMbio fermentation system, paying particular attention to…

May 11, 2016