Low-cost noninvasive optical CO2 sensing system for fermentation and cell culture

Abstract

High-throughput bioprocessing is a very promising technique for bioprocess development and optimization because of its high efficiency. The key to its development has been the availability of simple and inexpensive sensors to monitor the bioprocesses conducted in its small-scale bioreactors. Here we report on a low-cost noninvasive CO2 sensing system suitable for any transparent vessel. The system was composed of a CO2 sensing patch, a coaster, an interface, and a computer. The sensing film was prepared using the ion-pair technique. The coaster was a small self-made device with necessary optics and electronics for ratiometric measurements with a component cost of less than dollar 100. Results show that the system was stable and reliable despite its simplicity and low cost. The sensitivity of the CO2 sensing system was not affected by pH, media type, or temperature. It was shown to be stable for at least 10 days, long enough for most bioprocesses.

Real‐time dissolved carbon dioxide monitoring II: Surface aeration intensification for efficient CO2 removal in shake flasks and mini‐bioreactors leads to superior growth and recombinant protein yields

“…However, due to the lack of reliable portable sensors for shake flask and mini‐bioreactor cultures, the parameters such as DO and dCO 2 are rarely measured and their impact at this small scale is not clearly understood (Chopda, Gomes, & Rathore, ; Chopda, Pathak, Batra, Gomes, & Rathore, ; Gomes, Chopda, & Rathore, ). Due to the process analytical technology drive, the last decade has witnessed advances in shake flask monitoring sensors which led to improved understanding of the effect of various parameters on the culture growth and overall metabolism (Ge, Kostov, & Rao, &, ; Hanson et al, ; Kermis, Kostov, Harms, & Rao, ; Tolosa, Kostov, Harms, & Rao, ; Vallejos, Brorson, Moreira, & Rao, ). Various researchers proved that as the success of large‐scale operations is determined significantly by DO and dCO 2 concentrations, similarly, these parameters have a significant role at small scale bioprocessing system too (Blombach & Takors, ).…”

Mini‐review: soft sensors as means for PAT in the manufacture of bio‐therapeutics

“…Partly, this can be ascribed to reliability, durability, stability, and the low price of these sensors. Other common low‐cost alternatives are gas analysers and dip‐stick methods for metabolites and nutrient components . The latter are not commercially available so far for on‐line use but may technically be realized.…”

Recent advances in bioreactor engineering

“…When used for Escherichia coli fermentation, the microbioreactor showed similar pH, dissolved oxygen, and optical density profiles as those in a standard 1-L bioreactor. This work provided a basis for developing a multiple-bioreactor system for high-throughput bioprocess optimization, such as a low-cost noninvasive optical CO 2 sensing system for fermentation and cell culture [58], 24-well plate miniature bioreactor for microbial cultivations assessment [59], and as a scaledown model for cell culture process development [60].…”