A New Application of Data-Driven Soft Sensor: Estimating Individual Biomass in Mixed Cultures

Due to many advantages associated with mixed cultures, the application of mixed cultures in biotechnology has expanded rapidly in recent years. At the same time, many challenges remain for effective mixed culture applications. One of them is how to efficiently and accurately monitor the individual cell populations in a mixed culture. The current approaches on individual cell mass quantification are suitable for off-line, infrequent characterization of mixed cultures. In this work, we propose a fast and accurate soft sensor approach for estimating individual cell concentrations in mixed cultures. The proposed approach is the first to utilize absorption spectrum of a mixed culture sample measured by a spectrophotometer over a range of wavelengths. A multivariate linear regression model is developed to correlate individual cell concentrations to the spectrum. Two experimental case studies are used to demonstrate the performance of the proposed approach.