Analytical ChemistryUniversity of Lund
P. O. Box 124
Lund, SWEDEN
Analytical Chemistry
Research Interests
Characterisation, evaluation of microdialysis membranes, and application of different modes of microdialysis sampling to enzymatic bioprocess monitoring problems, especially in small-volume bioreactors. Initial work was focused on coupling microdialysis sampling on-line to high performance anion exchange chromatography with integrated pulsed electrochemical detection (HPAEC-IPED). This hyphenation of techniques was developed and used to characterise enzymes and study kinetics of hydrolysis of lignocellulosic polymer substrates. Investigations to enhance the in vitro performance of microdialysis sampling by modifying microdialysis membranes with PEG-PEI polymers and also to study protein adsorption on microdialysis membranes, are in progress. Microdialysis has also been coupled to ion spray mass spectrometry (MS) for the unequivocal characterisation of carbohydrate hydrolysates using their MS/MS properties. The application of a cation exchange membrane desalting device (CEMDD) has enabled the use of sodium ion concentrations up to 600 mM. The CEMDD is employed for the desalting of lignocellulosic broths during the monitoring of monosaccharides. A liquid chromatography/mass spectrometry set-up with electrospray (ESI) and atmospheric pressure chemical ionisation (APCI) is also being used for the qualitative determination of inhibitors in lignocellulosic hydrolysates. Present work also involves investigative studies on the oxidation of carbohydrates at gold and copper rotating disk electrodes, using hydrodynamic electroanalytical methods, a search for an ideal electrode material that understands characteristics and the detection of carbohydrates.
PUBLICATIONS
P1 N. Torto, T. Buttler, L. Gorton, G. Marko-Varga, H. Stålbrand and F. Tjerneld
On-line monitoring of enzymatic modification of 0.25 % ivory nut mannan using microdialysis sampling and anion exchange chromatography with integrated pulsed electrochemical detection. Anal Chim Acta. 313: 15-24, 1995
P2 N. Torto, G. Marko-Varga, L. Gorton, H. Stålbrand and
P3 N. Torto, T. Laurell, L. Gorton, G. Marko-Varga.
A study of a polysulfone membrane for use in an in-situ tunable microdialysis probe during monitoring of starch enzymatic hydrolysates. J. Memb. Sci. 130 239-248, 1997
P4 N. Torto, L. Gorton, G. Marko-Varga, J. Emnéus, C. Åkerberg, G. Zacchi,
P5 J. D. Breccia, N. Torto, L. Gorton, F. Sinneriz,
P6 N. Torto, A. Hofte, R. van der Hoeven, U. Tjaden, L. Gorton, G. Marko-Varga, J. van der Greef, C. Bruggink
P7 R. A. M. van der Hoeven, A. J. P. Hofte, U. Tjaden, J. van der Greef,
N. Torto, L. Gorton, G. Marko Varga,
P8 N. Torto, J. Bång, S. Richardson, G. Nilsson, L. Gorton, T. Laurell,
P9 E. NordbergKarlsson, L. Dahlberg, N. Torto, E. Bartonek-Roxå and
P10 L. Dahlberg, N. Torto and O. Holst
P11 N. Torto, L. Gorton, G. Marko-Varga,
PR12 N. Torto, T. Laurell, L. Gorton, G. Marko-Varga
P13 N. Torto, A. Cohen, L. Gorton, T.Laurell, R. A. M. van der Hoeven
Manuscripts M1 N. Torto, T. Ruzgas, L. Gorton
M2 C. Åkerberg, G. Zacchi. N. Torto and L. Gorton
M3 G. S. Nilsson, S. Richardson, Anton Huber,N. Torto, T. Laurell and L. Gorton.
M4 P. Ademark, J. Lundqvist, M. Tenkanen, N. Torto, L. Gorton, and F. Tjerneld.
M5 S. Richardson, G. S. Nilsson, N. Torto, T. Laurell, L. Gorton
M6 N. Torto, T. Laurell, G. Marko-Varga, L. Gorton
M7 N. Torto, C. Åkerberg, J. D. Breccia, R.A.M van der Hoeven, L. Gorton
CHECK OUT SOME OF MY LINKS
Last updated feb 12, 1999.
On-line quantification of enzymatic mannan hydrolysis in small-volume bioreactors by means of microdialysis sampling with integrated pulsed electrochemical detection in column liquid chromatography, J. Chrom A. 725:165-176, 1996
Post column switching during monitoring of starch enzymatic degradation by microdialysis, anion exchange chromatography, and integrated pulsed electrochemical detection. Biotec and Bioeng. 56 (5) 546-554, 1997
Specificity and mode of action of thermostable xylanase from Bacillus amyloliquefaciens. On-line monitoring of hydrolysis products. Applied Biochem. and Biotec. 68 167-175, 1997
Microdialysis introduction HPAEC/Ionspray MS for monitoring of on-line desalted carbohydrate hydrolysates. J. Mass Spectrometry. 33 334-341, 1998
Sensitivity Improvements in the Analysis of Oligosaccharides by On-line High-performance Anion-exchange Chromatography/Ion Spray Mass Spectrometry. Rapid Comm. Mass Spectrom, 12 69-74 1998
Enhancement of microdialysis performance in enzymatic bioprocess monitoring by optimal membrane choice. J. Chrom A. 806/2, 265-278, 1998
Sequence of a truncated xylanase from Rhodothermus marinus encoding the catalytic domain, and characterisation of the gene product expressed in Escherichia coli
J. of Biotechnology 60 23-35 1998
Purification and characterisation of a thermostable Endo-xylanase from Rhodothermus marinus. J. Fermentation. and Bioeng. in press.
in Cereals: Novel uses and Processes; Ed, G. M. Campbell, C. Webb, T. Mackee, Plenum Pub. Corp, New York, 63-67, 1997. On-line monitoring of enzymatic bioprocesses by microdialysis, anion exchange chromatography and integrated pulsed electrochemical detection.
Recent Trends in the Application of Microdialysis in Bioprocesses Anal Chim. Acta, in press
An Automated System for Carbohydrate Analysis Based on Microdialysis, HPAEC, Electrochemical Detection and Mass Spectrometry Lab. Robotics and Automation, in press.
Electrochemical oxidation of carbohydrates at a copper electrode. (subm. to J. Electroanal. Chemistry).
A kinetic model of the enzymatic saccharification of wheat starch (subm. Enzyme and Microbial Technol)
On-line Microdialysis with HPAEC-IPED for the Determination of b-Limit and Chain Length Distribution of Starch (manu. in prep).
Substrate specificity of a b-mannosidase purified from Aspergillus niger (manu. in prep).
Microdialysis sampling for monitoring of the performance of starch hydrolysing enzymes (manu in prep).
Potential and Future of New Trends of in vitro Microdialysis Sampling in Bioprocesses (Trends in Anal Chem. manu in prep)
On-line Analysis, Enzymatic hydrolysis and Process Optimisation:- The Essential Ingredients for Biotechnology Research. (for Recent Research Developments in Biotechnology and Bioengineering).