Publications by Urs von Stockar

Related publications (30)

Biothermodynamics of live cells: a tool for biotechnology and biochemical engineering

The aim of this contribution is to review the application of thermodynamics to live cultures of microbial and other cells and to explore to what extent this may be put to practical use. A major focus is on energy dissipation effects in industrially relevan ...

De Gruyter2010

Influence of Uncertainties in pH, pMg, Activity Coefficients, Metabolite Concentrations, and Other Factors on the Analysis of the Thermodynamic Feasibility of Metabolic Pathways

Urs von Stockar

Thermodynamic feasibility analysis (TFA) has been used as a toot capable of providing additional constraints to the mass balance-based methods of analysis of Metabolic networks (e.g., flux balance analysis). Several publications have recently appeared in w ...

2009

Removal of pharmaceuticals from water: Using liquid-core microcapsules as a novel approach

Urs von Stockar, Ian William Marison

In recent years ever-increasing amounts of pharmaceuticals are being detected in the aquatic environment and in some cases, they have even been discovered in drinking water. Their presence is attributed mainly to the inability of sewage treatment plants to ...

2010

Formation of Microcapsules from Polyelectrolyte and Covalent Interactions

Urs von Stockar, Ian William Marison, Véronique Breguet

A new approach combining electrostatic and covalent bonds was established for the formation of resistant capsules with long-term stability under physiol. conditions. Three kinds of interactions were generated in the same membrane: (1) electrostatic bonds b ...

2005

On-Line Recalibration of Spectral Measurements Using Metabolite Injections and Dynamic Orthogonal Projection

Urs von Stockar, Michael Amrhein, Pamandeep Singh Gujral, Michal Dabros

Spectrometers are enjoying increasing popularity in bioprocess monitoring due to their non-invasiveness and in-situ sterilizability. Their on-line applicability and high measurement frequency create an interesting opportunity for process control and optimi ...

2007

Optimal energy dissipation in growing microorganisms and rectification columns

Urs von Stockar

This paper proposes a new point of view in analyzing the optimal Gibbs energy dissipation in growing microorganisms. Small Gibbs energy dissipation in growth would be of biological advantage because less resource is consumed and the biomass yield on these ...

De Gruyter2014

How reliable are thermodynamic feasibility statements of biochemical pathways?

Urs von Stockar

The driving force for organo- or lithotrophic growth as well as for each step in the metabolic network is the Gibbs reaction energy. For each enzymic step it must be neg. Thermodn. contributes therefore to the in-silico description of living systems. It ma ...

2005

Thermodynamics of microbial growth and metabolism: An analysis of the current situation

Urs von Stockar, Ian William Marison

This paper attempts to review in how far thermodn. anal. can be used to understand and predict the performance of microorganisms with respect to growth and bioproduct synthesis. In the first part, a simple thermodn. model of microbial growth is developed w ...

2006

The role of thermodynamics in biochemical engineering

Urs von Stockar

This article is an adapted version of the introductory chapter of a book whose publication is imminent. It bears the title "Biothermodynamics - The role of thermodynamics in biochemical engineering." The aim of the paper is to give a very short overview of ...

De Gruyter2013

Influence of specific growth rate on specific productivity and glycosylation of a recombinant avidin produced by a Pichia pastoris Mut(+) strain

Urs von Stockar, Ian William Marison, Jonas Schenk, Carmen Jungo

A recombinant avidin-producing Mut(+) Pichia pastoris strain was used as a model organism to study the influence of the methanol feeding strategy on the specific product productivity (q(p)) and protein glycosylation. Fed-batch cultivations performed at var ...

2008

Immobilization of rapeseed press-cake in an alginate matrix for the sorption of atrazine

Urs von Stockar, Ian William Marison, Julien Boucher, Véronique Breguet

Due to residual oil retained within it, rapeseed press-cake has been shown to be effective for the removal of atrazine from water through an absorption mechanism. However, it is difficult to put this into practice due to the hygroscopic nature of the press ...

2008

Cole-Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Urs von Stockar, Ian William Marison, Michal Dabros

This work evaluates three techniques of calibrating capacitance (dielectric) spectrometers used for on-line monitoring of biomass: modeling of cell properties using the theoretical Cole-Cole equation, linear regression of dual-frequency capacitance measure ...

Springer-Verlag2009

Can microbial growth yield be estimated using simple thermodynamic analogies to technical processes?

Urs von Stockar

In view of the prime importance of the biomass yield in microbial growth for research, for environmental and for industrial applications some thermodynamic concepts are reviewed that were developed over the years in order to understand the large variations ...

2008

Enzymatic hydrolysis of organic-core microcapsules to produce aqueous-core microcapsules

Urs von Stockar, Ian William Marison, Véronique Breguet

This paper describes the development of a new method to obtain aqueous-core microcapsules from organic-core capsules. The direct production of microcapsules, using tripropionin as organic material, followed by the hydrolysis of the core by a lipase was inv ...

2008

On-line monitoring of nine different batch cultures of E-coli by mid-infrared spectroscopy, using a single spectra library for calibration

Urs von Stockar, Ian William Marison, Jonas Schenk

A single spectra library was used to monitor on-line, by mid-infrared spectroscopy, nine different batch cultures of Escherichia coli performed with various medium compositions, including chemically complex formulations. Whereas the classic chemometrics ap ...

2008

Data Reconciliation of Concentration Estimates from Mid-Infrared and Dielectric Spectral Measurements for Improved On-Line Monitoring of Bioprocesses

Dominique Bonvin, Urs von Stockar, Ian William Marison, Michael Amrhein, Michal Dabros

Real-time data reconciliation of concentration estimates of process analytes and biomass in microbial fermentations is investigated. A Fourier-transform mid-infrared spectrometer predicting the concentrations of process metabolites is used in parallel with ...

2009

Novel reactive perstraction system applied to the hydrolysis of penicillin G

Urs von Stockar, Ian William Marison, Anne Wyss

The activity of penicillin acylase has been studied in aq. and org. solvents, as free enzyme as well as immobilized within the membrane of liq.-core capsules. The activity of the enzyme is inhibited by the accumulation of the products of the hydrolysis rea ...

2005

Application of bench-scale biocalorimetry to photoautotrophic cultures

Urs von Stockar

Bench-scale biocalorimetry (>=1 L) allows for the detn. of the metabolic heat flow during bioprocesses under complete control of all process conditions for extended periods of time. It can be combined with a no. of online and off-line measurement technique ...

2005

Mixed feeds of glycerol and methanol can improve the performance of Pichia pastoris cultures: A quantitative study based on concentration gradients in transient continuous cultures

Ian William Marison, Urs von Stockar, Carmen Jungo

2007

Calorimetry and thermodynamic aspects of heterotrophic, mixotrophic, and phototrophic growth

Ian William Marison, Urs von Stockar

A simple stoichiometric model is proposed linking the biomass yield to the enthalpy and Gibbs energy changes in chemo-heterotrophic, mixotrophic, and photo-autotrophic microbial growth. A comparison with calorimetric experiments on the algae Chlorella vulg ...

2011