In the realm of bioprocess optimization and monitoring, the ability to accurately track critical parameters such as biomass, product, and substrate concentrations in real-time is crucial. Traditional methods often rely on limited standard parameters, leaving significant aspects unmonitored. Advanced spectroscopy-based sensors, such as Fourier transform (FT) Raman spectroscopy, offer a promising solution for real-time monitoring and control in bioprocesses. This article explores the application of FT-Raman spectroscopy for online monitoring of biomass production, intracellular metabolites, and carbon substrates during submerged fermentation of oleaginous and carotenogenic microorganisms.
The study focuses on the use of FT-Raman spectroscopy with a flow cell in a recirculatory loop, coupled with predictive data modeling, to monitor two different microorganisms (Rhodotorula toruloides and Schizochytrium sp.) grown on glucose and glycerol substrates. The system enables real-time data on carbon substrate utilization, biomass production, carotenoid pigments, and lipids. Robust multivariate regression models demonstrated high correlations between online FT-Raman spectral data and reference measurements, showcasing the system’s accuracy and sensitivity in monitoring fermentation processes. Compared to at-line spectroscopic methods, the online FT-Raman approach provided more comprehensive, timely, and precise concentration profiles, proving its superiority in real-time monitoring applications.
Microbial biotechnology, particularly fermentation processes, plays a vital role in sustainable production practices. Heterotrophic bioreactor fermentations are utilized for various products, including biofuels, food, enzymes, and chemicals. Oleaginous and carotenogenic microorganisms have the potential to accumulate lipids and carotenoids intracellularly, making them valuable for bioprocesses. Effective monitoring and control are essential for achieving process stability and ensuring product quality. However, real-time monitoring of critical parameters like substrate and product concentrations remains a challenge, often relying on offline analyses which can be time-consuming and costly.
Raman spectroscopy has emerged as a powerful tool for real-time monitoring in fermentation processes. By utilizing vibrational spectroscopy techniques to analyze bioprocess substrates and products, Raman spectroscopy offers fast, cost-effective, and sensitive monitoring capabilities. The non-invasive monitoring approach, such as using a flow cell in a recirculatory loop, minimizes contamination risks and simplifies sensor usage. Raman spectra provide detailed information on microbial biomass constituents and growth media components, enabling comprehensive analysis through chemometric and machine learning methods.
Challenges in Raman spectroscopy, such as weak scattering intensities and fluorescence interference, are addressed by utilizing near-infrared excitation lasers and FT-Raman spectrometers for signal enhancement. The system’s ability to detect low-concentration analytes in biological samples, coupled with advanced data processing techniques, enhances its applicability in bioprocess monitoring. By establishing multivariate regression models and conducting PCA analyses, the study demonstrates the feasibility and effectiveness of FT-Raman spectroscopy for real-time monitoring of fermentation processes.
In conclusion, the application of FT-Raman spectroscopy for online monitoring in microbial fermentation processes presents a valuable approach to enhance process efficiency, product quality, and control. By enabling real-time data on critical parameters, this spectroscopic technique offers a comprehensive and precise monitoring solution for bioprocess optimization. The study’s findings support the potential of FT-Raman spectroscopy as a process analytical technology for monitoring biomass production, intracellular metabolites, and carbon substrates in submerged fermentation. This research contributes to advancing the field of bioprocess monitoring and highlights the significance of spectroscopic techniques in enhancing fermentation processes.
Tags: microbial fermentation, process analytical technology, yeast, chromatography, bioreactor, biofuels, bioprocess, quality control, filtration, high throughput screening
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