Biofermentation requires continuous monitoring of processing conditions and periodical checks on reaction processes. In-line pH, oxygen and conductivity measurements and Raman-spectroscopy help labs to control and optimize bioreactor processes. “We offer labs the equipment to scale up from lab to pilot, or pilot to production, and to meet the most stringent regulations in controlled environments,” says Tomaso Della Vedova, Food & Beverage and Life Sciences Industry Manager at Endress+Hauser.

Text and photography: FOODnote

“We are known for our process analysis sensors, which measure parameters like temperature, pressure, pH, oxygen content and conductivity. These sensors are used in pharmaceutical bio processes. They are validated for that environment and can support head-to-tail processes. However, they’re also suitable for research purposes and can be used at lab or pilot scale. We’re talking 3 to 100 liter bioreactors then. Our industrial probes work just as well in a lab. Obviously, this makes scaling up all the easier: you’re working with FDA-compliant equipment right from the start and the same sensor can be used at any scale, even in a one thousand-liter tank. And all the data are collected in a LIMS. Thanks to our takeover of Kaiser Optical Systems about five years ago, we also sell Raman spectroscopes. Raman is a multi-parameter technology that allows you to do multiple checks simultaneously. The results are available in a matter of minutes. It’s a non-invasive technology that is also suitable for single use. It measures directly in the biofermentor. There’s no need for sampling, which cuts out one possible source of contamination. You can assess how well the fermentation organisms are doing, how many yeasts and bacteria are involved, what the vital cell density is, what their reaction products are and at what rate they’re producing. You can see whether the desired proteins are being produced, and monitor the formation of various sugars, acids or esters, like lactose, phosphate and glycerides. You can measures dozens of those.”


“Biofermentation depends on the health and activity of the bacteria. You have to strike a balance between the various fermentation processes. So it’s helpful to be able to monitor the pH, oxygen and conductivity levels. But if you really want to know what’s going in pharmaceutical and chemical fermentors, you need Raman spectroscopy. Raman allows you to see if and when A and B are going to produce product C and when you need to stop. This enables you to finetune the process to ensure you get the desired result in the shortest possible time. We know companies that went from producing two batches per day to three per day, thanks to Raman and the insights this technology provided. That’s real process optimization!”

“Raman is a bit of a black box. That’s why we offer training sessions and are happy to help our customers to quickly find the correlation between various Raman measurement results and to validate the Raman measurements in our customers’ processes. Every process is unique, because it involves different bio-organisms and chemicals and the conditions vary. In terms of investment, the hardware needed for the Raman technology starts at € 150,000, but the payback period can be surprisingly short. We have customers who broke even on their investment in just six months, simply through process optimization. Another contributing factor is that you need fewer lab analyses. It’s enough to take a few samples somewhere in the middle and at the end of the process. You just need to meet the criteria you have laid down in your quality assurance system. That makes a big difference in logistics and analytics, while you’re still monitoring almost continuously. Raman typically takes measurements at 10 minute intervals. So after 150 hours of operation, you get a comprehensive analysis of the fermentation of your active pharmaceutical ingredients, for example. You can use all the data you’ve collected to run optimization models: that’s easy money. But your wins may also be in downstream processing, when reprocessing the product after ultra-filtration or chromatography. And last but not least, Raman is very flexible in use. You can connect four probes to one spectrometer, three of which can be used to monitor your process and one for lab measurements. Wired, you can go to 100 meters, with a 300 meter maximum.”

The payback period can be surprisingly short
Tomaso Della Vedova, Food & Beverage and Life Sciences Industry Manager at Endress+Hauser

“It’s no accident that Raman spectroscopy has gained so much popularity in the past few years in green, grey and red biotechnology. It’s about products with a lot of added value, such as proteins, sugars or biopolymers, whose processes are very critical. Monitoring your process off-line, in a lab, is too slow, too labor-intensive and provides too few measurements. Just imagine, you urgently need your samples checked, but the analyst is on a coffee break, or the analyzer is in use, so your samples are put on hold. That’s why Raman is such a sea change: it tells you immediately what’s going on, for various parameters at the same time, during the whole process.”