IESc Seminar Series: Microbial Transition State (MTS) Model Applications in Activated Sludge Modeling and Insights from Metatranscriptomics by Tuğçe Katipoğlu Yazan

Institute of Environmental Sciences Seminar Series

“Microbial Transition State (MTS) Model Applications in Activated Sludge Modeling and Insights from Metatranscriptomics”

by Tuğçe Katipoğlu Yazan

Istanbul Technical University

We cordially invite you to our seminar “Microbial Transition State (MTS) Model Applications in Activated Sludge Modeling and Insights from Metatranscriptomics” to be held by Tuğçe Katipoğlu Yazan, Istanbul Technical University

When: 26 October, 2026, Monday, 13:30-15:00

Where: Institute of Environmental Sciences Seminar Room (Hisar Campus E-Block)

Contact: pinar.ertor@bogazici.edu.tr for any questions.

Abstract:

Traditional engineering models known as Activated Sludge Model (ASM) are commonly used for operation, design, and optimization of wastewater treatment systems. These models basically use empirical Monod equation for determining growth kinetics of involved processes through simulation and calibration of many model parameters. Recently, a framework has been established for providing insight to functioning of environmental systems which relies on thermodynamic laws and deriving stoichiometry of related catabolic and anabolic reactions. Moreover, a new approach, Microbial Transition State (MTS), was proposed linking thermodynamic balances from biochemical reactions with growth rates. Adoption of MTS for modelling environmental systems requires prediction of a small number of parameters where outputs and yields of microbial metabolisms such as nitrification is described in terms of chemical species, and energy. Application of MTS on activated sludge modelling may result in accurate estimation of involved process kinetics under both inhibitory and non-inhibitory conditions, and better understanding of toxicity/inhibition mechanisms. The current study demonstrates this capability by evaluating the impacts of heavy metals on nitrifying cultures. In the case of nickel as an inhibitor, the results highlighted the predictive ability of MTS approach for estimating growth kinetics of both AOB and NOB, which is crucial for both traditional and new nitrogen removal systems. Metatranscriptomic analyses further revealed that fundamental cell functions for substrate uptake, energy generation, and replication were impacted by nickel exposure. These molecular-level effects were highly consistent with the model predictions, demonstrating the robustness of the MTS framework

Short bio:

Assoc. Prof. Tuğçe Katipoğlu Yazan, who has degrees in environmental engineering, molecular biology, and genetics, is working at the intersection of these disciplines. She recently completed her Marie Skłodowska-Curie Actions ERA Fellowship at Istanbul Technical University, where her work specifically focused on the modelling of nitrification kinetics in activated sludge systems with a new thermodynamics-based approach in the presence of inhibitory compounds using MTS theory. She is currently involved as a researcher in the TÜRK-ArT project. Her research interests are directed towards environmental biotechnology, modelling of activated sludge systems, microbial thermodynamics, biodegradation and growth inhibition kinetics of micropollutants, metagenomics, metatranscriptomics, and sludge stabilization.