Monitoring and Control of Bioprocesses

The research in Monitoring and Control of Bioprocesses includes:

  • Development of image analysis procedures and chemometrics tools
  • Design of software sensors for state and parameter estimation
  • Process Analytical Technology solutions for bioprocess characterization

Ongoing research includes

  • Image analysis techniques to characterize the biomass morphology and physiology, and to characterize the main groups of bacteria present in biological wastewater treatment;
  • Chemometric techniques, combined with spectroscopy techniques and image analysis tools, for supervision, prediction and control of biological wastewater treatment and biotechnological processes;
  • Electronic tongues for goat milk adulterations, gliadins detection in foodstuffs and for monitoring cork contaminants.

Main achievements

  • Quantitative Image Analysis (QIA) was developed and applied to activated sludge systems monitoring of bulking events. QIA was also developed for determining the contents of intracellular storage compounds in activated sludge.
  • Activated sludge reactors were surveyed using online UV-visible and NIR spectroscopy and chemometrics to predict several parameters from the process.
  • Soft-sensors for estimation of biomass concentration using interval observers in an E. coli fed-batch fermentation.
  • Electronic tongues were built and applied for identification of goat milk adulterations with bovine milk, gliadins semi-quantitative detection in foodstuffs.
  • Cyclic voltammetry is being used for monitoring cork contaminants like TCA.

Monitoring of activated sludge processes

Monitoring of activated sludge using quantitative image analysis (correlation with settleability, SVI, detection of bulking events): data from morphological sludge characterization (microbial aggregates and protruding filaments) is treated using chemometrics techniques (PLS).

Also, an activated sludge reactor has been surveyed using online UV-visible and NIR spectroscopy and chemometrics.

Protozoa in Wastewater Treatment Processes

QIA is being used in automatic recognition of protozoa and metazoa populations most frequently found in wastewater treatment plants. Image analysis procedures were developed for determining the geometrical, morphological and signature data and subsequent processing by discriminant analysis and neural network techniques.

Image analysis is also used in the determination of the movement changes of ciliates exposed to toxics.

Anaerobic Digestion

QIA of granular sludge and multivariate statistical analysis have been used for monitoring high-rate anaerobic reactors.

Image Analysis is being used to characterize granular anaerobic sludge from EGSB Reactors fed with oleic acid. QIA allows for automatic detection of granules disintegration constituting a tool to recognize anaerobic granulation time.

Other Applications of QIA in Biotechnology

  • Assessment of physiological conditions in E. coli fermentations
  • Measurement of CBDs adsorbed onto cellulose fibers
  • Classification of Saccharomyces cerevisiae morphology
  • Morphological analysis of Yarrowia lipolytica under stress conditions

The research carried out in Modelling, Monitoring, and Control of Bioprocesses by the BIOSYSTEMS group has been focused in the development of mathematical and computational tools aiming the optimization of the operational conditions of relevant bioprocesses like recombinant proteins production with E. coli, baker's yeast fermentation, production of prebiotics with yeast and fungi, production of phages and animal cell culture. The main areas of activities are the following:

Bioprocess Modelling

  • Construction of state-space dynamical models of bioprocesses in view of process optimization and control
  • Optimal experimental design for the estimation of yield coefficients dynamic models of fed-batch fermentation processes
  • Applications: recombinant proteins production in high cell density culture of E. coli; baker's yeast, oligosaccharides production; phage production

Software Sensors

Design and implementation of algorithms for estimating on-line state variables like biomass concentration from common bioreactor measurements like dissolved and exhausted oxygen concentrations.

Observer based estimators for on-line measurement of specific growth rates.

Applications: estimation of biomass concentration and specific growth rates in high cell density fed-batch culture of E. coli.

Control of Fermentation Processes

Model-based adaptive linearizing control for the regulation of substrates/products during the fed-batch fermentations.

Development and implementation of control laws for the specific growth rate in fed-batch fermentation (PI like feedforward/feedback controllers).

Applications: recombinant proteins production in high cell density culture of E. coli; baker's yeast production.