100 for 100: Bioproduction Powerhouses

Item 68/100: Pond Scum or Superhero?
Baisali Ray, PhD, Senior Technical Writer - Authentication
ATCC® 12716™ – Euglena gracilis Klebs

The global population is projected to reach 9 billion by 2050, requiring a dramatic increase in food and energy consumption. According to the International Energy Agency (IEA), the bioenergy sector will experience significant growth over the coming decades, rising from the current 10 percent to 30 percent of the world's primary energy mix by 2050.¹ Herein comes our humble pond scum (microalgae), serving as a resource for the "5Fs"—food, fiber, feed, fertilizer, and fuel. ATCC has a large collection of fully authenticated algal cultures, which can be used for research and biomanufacturing purposes. One interesting strain in the collection is Euglena gracilis strain Z (ATCC® 12716™), which was deposited by the renowned plant physiologist E. G. Pringsheim whose collection of single-celled algae in Prague dates back to 1950.

Researchers are interested in finding the role of E. gracilis, a unicellular eukaryotic alga, in combating global food shortages. Like other microalgae, E. gracilis produces highly digestible proteins containing all 20 amino acids. This makes it a promising alternative to conventional dietary protein sources like meat and fish. Additionally, it is a rich source of beta carotenoid, ascorbate, and alpha tocopherol, making it an excellent supplement for vitamins A, C, and E.²

E. gracilis also produces significant amounts of fatty acids and wax esters that can be utilized in biofuel production. Another valuable product from this alga is paramylon, a water-insoluble storage polysaccharide. Paramylon is a promising candidate for biofuel generation and an alternative to petroleum-based plastics. It also offers numerous health benefits, including immunostimulatory and antioxidant properties, dietary fiber, and the ability to lower blood cholesterol levels. It has been reported to reduce the risk of cancer and has potential therapeutic applications for conditions such as atopic dermatitis, rheumatoid arthritis, and wound healing. Apart from nutraceuticals, paramylon serves as an organic fertilizer and enhances the nutritional value of livestock feed.²

Despite being a strong contender in the nutraceutical industry as well as an alternative to fossil fuel, the large-scale cultivation of Euglena is still not economically viable. Current research is focusing on the genetic modification of the organism to manipulate its unique metabolic pathways, which could potentially lead to product enhancement.²

Item 69/100: A Moldy Melon and a Bioproduction Breakthrough
Shahin Ali, PhD, Senior Scientist
ATCC® 9480™ – Penicillium rubens Biourge

The battle against infectious disease reached a turning point with the discovery of penicillin. While Alexander Fleming’s 1928 identification of the antibiotic from Penicillium rubens (then P. notatum) was groundbreaking, the real challenge lay in scaling up production for widespread therapeutic use. During World War II, a critical need arose for large-scale penicillin production to treat wounded Allied soldiers. The search led researchers at the USDA Northern Regional Research Laboratory (NRRL) in Peoria, Illinois, to investigate new approaches like deep-tank fermentation. In a stroke of luck, a moldy cantaloupe purchased at a local Peoria market yielded a remarkable Penicillium rubens strain, NRRL 1951 (ATCC® 9480™). This strain was highly adaptable to deep-tank fermentation and produced significantly more penicillin than previous strains.³ This crucial discovery, paired with the corn steep liquor method, revolutionized penicillin production.

To further enhance productivity, scientists launched intensive classical strain improvement (CSI) programs. Using mutagenesis techniques such as x-ray and UV radiation, they developed even more potent descendants of NRRL 1951 (ATCC® 9480™). One such strain, WIS 54-1255 (ATCC® 28089™), became a cornerstone of industrial penicillin production.⁴ These efforts laid the foundation for modern microbial strain engineering and biomanufacturing. The ability to mass produce penicillin had a profound impact on World War II, saving countless lives and marking a new era in pharmaceutical production. P. rubens’ (ATCC® 9480™) legacy was recognized in 2021 when it was designated the official State Microbe of Illinois. This commemorates the crucial role of this humble mold and the scientific efforts in Illinois that brought a lifesaving drug to the world.

Item 70/100: Raising the Barr at ATCC
Eric Mazur, MS, Senior Biologist
ATCC® VR-1492™ – Human gammaherpesvirus 4 (Epstein-Barr Virus)

In 1971, Neil Blacklow and colleagues collected samples from a patient who had developed mononucleosis syndrome 5 weeks after receiving multiple blood transfusions. The group was then able to culture Epstein-Barr virus (EBV) in patient-derived lymphoblastoid cells (833L).⁵ After receiving this infected cell line, George Miller and collaborators isolated this EBV strain from the 833L cell line and established persistently infected simian leukocytes thereby creating the B95-8 cell line.⁶ Over the course of multiple publications, Miller’s group showed that this cell line produced higher EBV titers than previously established cell lines, and the virus maintained the ability to transform both human and primate B-cells.^7-9 The B95-8 cell line was eventually deposited into the ATCC collection in 1981 by George Miller.

The EBV (ATCC® VR-1492™) derived from this cell line continues to be an invaluable resource in research and industry to this day and is one of the most popular items in the ATCC virology catalog. This virus is commonly used in the generation of lymphoblastoid cell lines but has also been used in studying the role of Epstein-Barr virus in the development of multiple sclerosis.^10-11 We are looking forward to seeing how this isolate’s impact on research will continue to evolve over the next 100 years at ATCC.

Item 71/100: MicroQuant™ - A Reference Material for Microbial QC Testing
Kyle Young, MBA, Product Manager
ATCC® 6538-HQ-PACK™ – MicroQuant™ Staphylococcus aureus, high CFU

Microbial quality control (QC) testing has long been an important aspect of pharmaceutical production but was only formalized in the past 100 years. The Sulfanilamide Incident of 1937 led to the finalization of the Food, Drug, and Cosmetic Act, under which pharmaceutical products are still regulated.¹² Twenty-seven years later in 1965, the United States Pharmacopoeia (USP) would publish the first microbiological QC monograph.¹³ It would take until 2009—another 44 years—to publish the monograph USP <61> “Microbiological Examination of Nonsterile Drug Products: Microbial Enumeration Tests” in harmonization with the European Pharmacopoeia (EP 2.6.12) and the Japanese Pharmacopoeia (JP 4.05).¹⁴

These monographs and others, which describe assays for bioburden & sterility testing, antimicrobial effectiveness testing, growth promotion testing, and environmental monitoring, all cite the use of specific ATCC strains as controls. To simplify and accelerate these high-volume assays, the ATCC Cryobiology team developed a proprietary new preservation process and created MicroQuant™—a pellet format that is refrigerator stable, rehydrates immediately, is passage zero (direct from ATCC), and is pre-quantified to the CFU range specified in pharmacopeial assays. Six strains were launched in 2024 to support antimicrobial effectiveness testing and bioburden testing, another 3 in the first half of 2025 to support assays for the Burkholderia cepacia complex, and full support for all USP-harmonized monographs on bioburden and sterility testing is anticipated in Q3 of 2025.

Item 72/100: HEK293 – An Essential Tool in Bioprocessing
Fang Tian, PhD, Director Cell Biology Content and Product Development
ATCC® CRL-1573™ – 293 [HEK-293]

The HEK-293 cell line (ATCC® CRL-1573™) is one of the most commonly used human cell lines in research. This cell line and its derivatives have become the most cited cell lines in recent years, especially in the bioprocessing space. HEK-293 cells are easy to grow, have high transfectability, and can be adapted to suspension culture, which enables scalable production in bioreactors. Using mammalian cells as an expression platform enables the production of complex biomolecules. When compared to the widely used CHO cell line, HEK-293—being of human origin—offers biosynthetic capabilities that enable the production of biotherapeutics with more desirable, human-like post-translational modifications, enhancing product stability and potency.¹⁵

The HEK-293 cell line was established in 1973 by expressing adenoviral 5 (Ad5) genome fragments, including the E1A and E1B genes. In addition to enabling the continuous culture of HEK-293 cells through modulating apoptosis and cell cycle, E1A and E1B are essential helper factors for adeno-associated virus (AAV) production.¹⁶ These features make HEK-293 cells attractive production hosts for both therapeutic protein and viral vectors.

Of the many HEK-293 cell line derivatives, HEK-293T (ATCC® CRL-3216™) contains the SV40 large T-antigen and has become particularly popular for producing recombinant proteins. Researchers have been continuously making additional improvements to the original HEK-293 cell line and HEK-293T cell line. For example, the HEK293T/17 (ATCC® CRL-11268™) cell line is considered better than the parental cells due to this cell clone 17 being selected specifically for its high transfection efficiency.¹⁷

In recent years, ATCC created the enhanced host cell model 293.STAT1 BAX KO (ATCC® CRL-1573-VHG™) by CRISPR gene editing. Both the STAT1 and BAX genes were knocked out from the parental HEK-293 cell line. STAT1 is a transcription factor required for the interferon-based cellular anti-viral response. BAX is a member of Bcl-2 family, which regulates cell apoptosis. Therefore, this HEK-293 STAT1 BAX double KO cell line exhibits significantly increased viral titer and enhanced virus production capability when compared to its parental cell line.

Overall, HEK-293 and its derivatives have emerged to be the valuable tool and critical platform in bioproduction space. Continuous advancements in cell line developments, growth adaptation, and media formation of HEK-293 cells will further unleash the power of this group of cell lines.

Item 73/100: A Bioproduction Pioneer in Citric Acid Manufacturing
Shahin Ali, PhD, Senior Scientist
ATCC® 1015™ – Aspergillus niger van Tieghem

In the world of industrial biotechnology, few microbes have had as lasting an impact as Aspergillus niger (ATCC® 1015™). This filamentous fungus is the original workhorse behind the bioproduction of citric acid, a compound used globally in food, beverages, pharmaceuticals, and cleaning products. The story began in the early 20^th century, when A. niger was used in the first patented microbial process for citric acid fermentation.¹⁸ Its ability to convert sugar into citric acid made it ideal for industrial-scale production. This innovation marked a turning point, replacing inefficient fruit extraction methods with a microbial fermentation process that was scalable, sustainable, and cost-effective.

A. niger strain NRRL 328 (ATCC® 1015™), which was isolated in 1914, laid the foundation for a new generation of engineered progeny strains optimized for even greater productivity. Notable examples include strain A-1-233 (ATCC® 11414™), which is known for its enhanced citric acid yield and is widely used in fermentation optimization studies,¹⁹ and strain MZKI A60 (ATCC® 201122™), which can utilize agricultural byproducts like corn distillers, supporting circular bioeconomy goals.

These strains are cultivated in controlled bioreactors, where parameters such as pH, aeration, and nutrient availability are finely tuned to maximize citric acid output. Substrates like glucose, sucrose, and molasses serve as carbon sources, while the fermentation process is optimized to suppress byproduct formation and improve yield. Today, A. niger strain NRRL 328 (ATCC® 1015™) and its descendants remain central to the global bioproduction of citric acid, producing millions of tons annually. Their continued use underscores the power of microbial biotechnology to deliver sustainable, high-efficiency manufacturing solutions for essential chemicals. From its patented origins to its modern role in green chemistry, A. niger exemplifies how microbial platforms can drive innovation in industrial bioproduction.

Item 74/100: Bread Yeast or Biofuel Superstar? Why Not Both?
Ana Eckert, BS, Lead Innovation Specialist
ATCC® 200062™ – Saccharomyces cerevisiae Meyen ex E.C. Hansen

Bioethanol is one of the best alternatives to fossil fuels because of its low carbon emission, ease of production, and high-octane content. For bioethanol production, Saccharomyces cerevisiae, more commonly known as “Baker’s Yeast,” is a renewable energy star. This microorganism is the most common one used for bioethanol production due to its fast growth, efficiency in ethanol yield, and high tolerance to a variety of environmental stressors.²⁰ Right now, bioethanol is mostly produced using sugar- and starch-containing materials like corn or sugar beets. However, other sources are being introduced that don’t compete with food and livestock feed production. Using starch sources that are not used for human or animal consumption will make bioethanol production even more sustainable.²¹ S. cerevisiae also has a well-known genetic toolbox that makes it easy for researchers to modify in order to achieve different fuel sustainability goals. For example, modifying S. cerevisiae to increase production of fatty acid-derived biofuels fuel for heavy trucks and jets.²² By using Baker’s yeast to produce an easily accessible, energy-efficient biofuel, we are one step closer to a clean energy future.

Item 75/100: Supporting Safety in Biopharmaceutical Manufacturing with Quantitative MRC-5 Genomic DNA
Leka Papazisi, PhD, Principal Scientist, Product Lifecycle Management, ATCC Research & Industrial Solutions
ATCC® 1592112 - Quantitative MRC-5 Genomic DNA

Producing biopharmaceuticals—such as vaccines, antibodies, therapeutic proteins, or viral vectors for cell and gene therapy—often involves many cell types modified for biotechnological use. No matter how thoroughly the product is purified, tiny fragments of the host’s genetic material, called residual host cell DNA (rcDNA), can linger in the final medicine.²³ While the chance of rcDNA causing harm like cancer or infection is extremely low (about one in ten billion), global health agencies set strict limits to keep patients safe.²⁴

To meet safety standards, manufacturers test for residual DNA at multiple stages of production and verify their results using analytical reference materials like quantitative MRC-5 genomic DNA from trusted organizations, such as the USP and ATCC. Regulatory agencies recommend a “case-by-case” risk assessment, taking into account the cell type, intended use, and manufacturing process of each medicine.²⁵ Thanks to advances in DNA detection—especially powerful PCR-based tools—and the availability of high-quality cell lines, biopharmaceutical companies can deliver safer products to patients worldwide, thereby reinforcing trust in the remarkable achievements of modern medicine.

Did you know?

In September 2022, the White House issued an executive order focused on advancing biomanufacturing and biotechnology to create a sustainable bioeconomy. This directive highlights bioprocesses as a driver for innovative solutions in human health, energy, agriculture, the environment, and food security.

References

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