Online OD Measurement
Monitor biomass, non-invasively, in fermentors having a glass wall or glass viewing port. The instrument consists of an optical sensor that is mounted onto the exterior of the fermentation vessel, and a monitor that processes the sensor signals. By combining reflectance signals measured at multiple source-detector distances, linear response to biomass change is achieved over a wide range of biomass.
Development and Evaluation of Methods to Infer Biosynthesis and Substrate Consumption in Cultures of Cellulolytic Microorganisms Four different on-line Optical
Density systems were tested for measuring optical density and compared to off-line analysis data (elemental analysis/quantitative saccharification). The optical density signal was much better correlated with off-line data for the ex situ system reported herein than probes we tested that were immersed in the fermentation broth.
Extremum Seeking Control of Batch Cultures of Microalgae Nannochloropsis O culata in Pre-Industrial Scale Photobioreactors
Jean-Sebastien Deschenes, Pierre N. St-Onge, Jean-Charles Collin, Rejean Tremblay
Extremum seeking control is applied to batch cultures of microalgae Nannochloropsis Oculata with the objective of maximizing the growth rate through manipulation of the pH. A commercial biomass monitor (BugEye from Buglab) using on-line optical density (OD) measurements at 725 nm is used to provide signals relative to both biomass density and growth.
Measuring Filamentous Processes
Abstract:….all current non-invasive technology, such as Near Infra-Red, is limited on biomass measurement of animal and insect cells. Biomass monitoring of industrial bioprocesses of filamentous microorganisms still requires sample removal from the vessel, which could potentially compromise sterility. This study has focused on the application of a non-invasive optical sensor in the on-line monitoring of the biomass of the filamentous microorganism Streptomyces coelicolor A3…
Optimizing Sensor Linear Response Range Under Challenging Process Conditions
The recent trend in bioprocess development toward small bioreactors and high cell densities presents challenges for accurate on-line monitoring of liquid cell cultures. To accommodate the trend toward smaller vessels, a more recent approach (BE3000 probe), uses a small diameter (e.g. 3 mm) fiber optic probe measuring back-reflectance at 1310 nm.