In this interview, AZoMaterials speaks with Andrew Saarni, Director of Fermentation at Geltor, and Dan Merriman, Senior Advisor, Marketing Process Monitoring at Thermo Fisher Scientific, about how precision fermentation and online mass spectrometry are transforming collagen production for sustainable biofoods.
Can you please introduce yourself and your role at your company?
Andrew Saarni (Geltor): I’m Andrew Saarni, Director of Fermentation at Geltor. With a bioengineering degree from UC Berkeley and a master’s in chemical engineering from UC Davis, I lead strain evaluation, process development, and scale-up workflows focused on bio-designed collagen.
Dan Merriman (Thermo Fisher): I’m Dan Merriman, a senior advisor at Thermo Fisher specializing in process analytical technology (PAT) and mass spectrometry in biotechnology. I joined in 1988 and have over 35 years of experience in the field.
Image Credit: Anusorn Nakdee/Shutterstock.com
What is collagen, and why is it important to Geltor’s mission?
Saarni: Collagen accounts for roughly 30 % of the body's protein and plays a key role in supporting skin, joints, gut, and nail health. Naturally, our collagen production begins to decline by about 1 % each year starting around age 20, and certain lifestyle factors can speed up that decline.
At Geltor, we produce collagen through fermentation, which is completely free of animal sources. This approach also allows us to precisely design the amino acid sequence to optimize functionality.
Why choose sustainable, bio-manufactured collagen over traditional animal-derived sources?
Saarni: Traditionally, collagen comes from cattle, pig, or fish by-products, which brings up concerns around animal welfare, deforestation, immunogenic risks, batch-to-batch variability, odor, color, and even religious restrictions. With precision fermentation, we can create collagen that’s cleaner, ethically produced, highly consistent, and fully customizable—without relying on animals.
How does mass spectrometry support your fermentation workflows?
Merriman: We use Thermo Scientific Prima BT and Prima PRO mass spectrometers paired with a Rapid Multistream Sampler (RMS) to monitor inlet and outlet gas compositions in real time. By tracking oxygen consumption and CO2 production, we calculate metrics like the respiratory quotient (RQ), which help us understand and control the fermentation process. The system integrates directly with our control platforms to maintain consistent process quality.
Saarni: That data is fundamental across the entire workflow—from strain screening to process development. It's as essential as monitoring pH or temperature.
How is Geltor’s mass-spec infrastructure configured in the lab?
Saarni: Geltor’s lab is centered around a single Prima PRO mass spectrometer, supporting 36 fermenters—both BioFlow 5 L and Sartorius systems—installed in July 2022.
All fermenters are plumbed into the central mass spec, with equal-length exhaust lines to prevent sampling bias. Each line includes a slipstream that feeds real-time gas data into the analyzer. This setup continuously tracks metabolic parameters like OUR, CER, and RQ, which are essential for strain evaluation and scale-up design.
How do you ensure your scale-up is robust and consistent?
Saarni: We focus on two key constraints: oxygen transfer rate (OTR) and heat removal—both of which directly correlate with oxygen uptake rate (OUR), a metric we track precisely using mass spectrometry.
Our engineering models take into account factors like K_La, broth viscosity, gas velocity, and available cooling area to guide process design. To build in flexibility, we develop multiple fermentation protocols—standard, attenuated, and conservative—to anticipate possible deviations and ensure the process is truly scale-ready.
Could you give an example of accessing the 'inaccessible' via biotech?
Saarni: A great example is HumaColl™21, our human-type collagen produced using engineered microbes. Taking it a step further, we’ve even bio-manufactured mastodon collagen using reconstructed protein sequences from extinct species.
Merriman: These examples show how protein design allows us to access materials far beyond the limits of traditional biological sourcing.
What maintenance does the RMS require?
Merriman: The rotating stream selector has a seal that contacts the body face. We recommend replacing it about every three years. It’s a straightforward task that typically takes 20–30 minutes, so the downtime is minimal.
How frequently do you calibrate the mass spec?
Merriman: Calibration is usually done monthly or even less frequently. We periodically sample a standard gas cylinder, and the system’s software automatically updates the sensitivity factors. The full calibration process is automated and takes about 30 minutes.
What trends do you foresee for precision fermentation and collagen production?
Saarni: I see a strong shift ahead—where many traditional petrochemical and animal-derived products will be replaced by precision-fermented ingredients. Mass spectrometry will continue to be a cornerstone, but I expect more innovation in non-invasive, real-time analytics, and a move toward continuous rather than fed-batch bioprocessing.
Merriman: I agree. We’re also seeing sustained growth in fermentation for bio-based ethanol and alternative fuels, which ties into global clean-energy goals. Collagen is just one example of how biotech is expanding into sustainable, high-performance materials.
About the Speakers
Andrew Saarni
Andrew Saarni is Director of Fermentation at Geltor, a California-based biotech company founded in 2015 by Princeton-trained scientists. He holds a bachelor's degree in bioengineering from UC Berkeley and a master's in chemical engineering from UC Davis, bringing over a decade of expertise in microbial fermentation and protein design.
At Geltor, Saarni leads the fermentation team across the full development pipeline—from strain evaluation to scale-up—focused on producing high-quality, animal-free collagen and other bio-designed ingredients for applications in beauty, wellness, and food.
Dan Merriman
Dan Merriman is Senior Advisor, Marketing Process Monitoring at Thermo Fisher Scientific, based in the UK. Since joining the company—then VG Instruments—in 1988, he has built over 35 years of expertise in mass spectrometry and process analytical technology across the biotechnology, pharmaceutical, and chemical industries.
Dan has played a key role in advancing online gas analysis for fermentation and biomanufacturing, helping implement systems like the Thermo Scientific Prima BT and Prima PRO platforms, which are now widely used in sustainable production technologies.
This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific - Chromatography and Mass Spectrometry.
For more information on this source, please visit Thermo Fisher Scientific - Chromatography and Mass Spectrometry.
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