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Vorträge und Posterpräsentationen (mit Tagungsband-Eintrag):

C. Koch, M. R. Plata Torres, S. Radel, B. Lendl:
"Ultrasound enhanced ATR mid-IR fibre optic probe for spectroscopy of particles in suspensions";
Vortrag: SciX 2012, Kansas City, MO, USA (eingeladen); 30.09.2012 - 05.10.2012; in: "SciX 2012 - Final Book of Abstracts", (2012), S. 211 - 212.



Kurzfassung englisch:
Attenuated Total Reflection mid-infrared (ATR mid-IR) spectroscopy
in combination with a fibre optic probe or an optical conduit probe,
respectively, has successfully been used for in-line bioprocess
monitoring. It currently allows for quantification of dissolved
analytes like substrates or extracellular metabolites. Spectroscopic
measurements of the cells themselves which give information on the
physiological state of the cells, however, are not possible. We have
successfully combined an ATR mid-IR spectroscopy with ultrasonic
particle manipulation, which is a recognised technique for filtering
and sorting of small particles or cells in suspension by acoustic
standing waves. Placing an ultrasonic transducer directly opposite the
ATR element of a mid-IR fibre optic probe, we are able to build up
an acoustic resonator between them. By tuning the ultrasound
frequency, we are able to actively keep yeast cells (S.cerevisiae)
away from, or push them into, the evanescent field of the ATR
element. Thus, we acquired spectra of the particles only, and of the
medium only, respectively. Yeast cell undergoing nitrogen limitation
during the fed-batch phase of fermentations change their chemical
constitution by building and agglomerating storage carbohydrates
(trehalose and glycogen). This is reflected by changes in the
carbohydrate region of FTIR spectra. Results obtained during fed-batch fermentations of S. cerevisiae (strain: CBS 8340) with the
prototype in-line probe will be compared to reference spectra of
samples drawn from the fermentation. Furthermore, HPLC-RI
measurements were performed for identification and quantification of
sugar content (trehalose, glucose, mannose) and correlated with
spectral changes. Total protein and total carbohydrate content were
determined as well.

Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.