The Gene and Linda Voiland School of Chemical Engineering and Bioengineering is hosting a seminar presented by Cristian Picioreanu, Associate Professor in the Department of Biotechnology from Delft University of Technology (TU Delft) in the Netherlands.

Cristian Picioreanu is an Associate Professor in the Department of Biotechnology from Delft University of Technology (TU Delft) in the Netherlands.  He graduated chemical engineering at University “Politehnica” Bucharest, Romania, and worked as lecturer in chemical and biochemical reaction engineering at the same university.  After his PhD at TU Delft, he followed an academic career in the group of Environmental Biotechnology from TU Delft.  Several fellowships and sabbatical stages were spent at the Isaac Newton Institute for Mathematics (Univ. of Cambridge, UK), Univ. of Notre Dame (Indiana, US), University of Queensland (Brisbane, Australia) and Newcastle University (UK). He is currently spending the Spring semester at the Univ. of Notre Dame.

His main research theme consists in applying chemical engineering and computational methods to biological systems, environmental and bioprocess engineering. He is internationally recognized for leading research in the mathematical modelling of biofilms and microbial communities. He has extended collaborations with several leading institutions around the world.  He published more than 110 scientific papers (h 51/Google); organized international conferences and courses; was associate editor for the journal Microbiology; and supervised many postdoctoral, doctoral and master projects over 27 years in the academic community.  He teaches regular MSc courses on Numerical Methods, Modelling and Simulation, Scale-up/Scale-down in (Bio)Chemical Engineering, and Algorithmics and Programming and annual international postgraduate courses on Biofilm Modelling and Environmental Biotechnology. In 2017 he received the “Teacher of the Year” award at TU Delft.

Numerical modelling of microbial communities: linking science and engineering

Most microorganisms in nature are associated with interfaces, forming microbial communities termed biofilms. Biofilms are of utmost significance in the medical field, but also in nearly all technical systems where they cause biofouling, clogging or corrosion.  On the other hand, biofilms can be beneficial in engineered systems for wastewater treatment.  Engineers and researchers face invariably the challenge of understanding complex relationships between physical, chemical and biological processes occurring at very different spatial and temporal scales.  I argue that the best available tool for integrating the overwhelming amount of dispersed experimental observations in a rational environment is mathematical modeling.

This presentation will introduce concepts and approaches to numerical modeling of microbial communities at multiple scales, from continuum to individual-based models. The need for a multidisciplinary approach will be discussed, as the microbial community models have to be coupled (function of application) with fluid dynamics, reactive solute transport, solid mechanics and electrochemistry, all in media with possibly complex geometries.  Critical challenges are linking the experiments with models and efficient computing at multiple scales in order to support not only scientific hypotheses but also to offer predictions of practical importance.

Examples in this presentation will illustrate how numerical models can be particularly useful to study pattern formation due to cell motility and spreading of microbial colonies made of mixed cell morphotypes (spheres, rods, filaments, branched hyphae and mixtures of them). Furthermore, several examples of models assessing the microbial ecology and the relation with microbially-induced mineral precipitation will be presented.  Another series of applications evaluates the biofouling of porous media, reverse osmosis membrane devices for water desalination and the impact of biofilms on proppant-packed fractures in shale gas reservoirs.  Model extensions show how biofilm lysis can create flow paths continuously changing position even after the medium permeability reached steady state.  Finally, the usefulness of numerical models in bioelectrochemical processes for energy or product formation may be shortly discussed.