Changes of biofilm properties in response to sorbed substances - an FTIR-ATR study

1995 ◽  
Vol 32 (8) ◽  
pp. 149-155 ◽  
Author(s):  
Jürgen Schmitt ◽  
David Nivens ◽  
David C. White ◽  
Hans-Curt Flemming

Biofilms play an important role as sorbents in the process of distribution of pollutants in surface water systems. The sorption properties of biofilms will influence the kind and the amount of sorbed substances. The heterogeneity of biofilms provides different sorption sites which exhibit a different sorption preference and capacity. As dynamic systems, biofilms will respond physiologically to their environment. Thus, the sorption of one substance may lead to a change in the composition of the EPS or other biofilm components and further alter the original sorption properties. In this paper, the influence of toluene on a biofilm was investigated. As a suitable method, FTIR-ATR spectroscopy was applied. The method is non destructive and allows the observation of biofilm formation and behaviour on line and in situ. A biofilm was allowed to form in ATR flow-through cells. The test strain was genetically engineered and contained a bioluminescent reporter gene which was switched on when toluene was metabolized. Thus, the degree of toluene degradation activity could be observed with great sensitivity. The FTIR spectrometer contained three flow-through cells which could be operated in parallel: one was run with sterile medium only, one with medium and bacteria, and one with medium, bacteria and toluene. This arrangement allowed the discrimination of the biofilm response from other effects. The IR spectrum showed specific bands of proteins, polysaccharides, phosphoryl compounds and other groups of molecules. A significant increase of EPS-polysaccharide formation was observed at a toluene level of 5 mg L−1. At 15 mg L−1, significantly more carboxyl groups were formed. Thus, the effect of the lipophilic organic pollutant toluene increased the amount of negatively charged groups and, consequently, the sorption capacity for metal cations. This result indicates that biofilms respond in a complex manner to different sorbates and alter their environmental properties.

2021 ◽  
Author(s):  
Sarah Klingler ◽  
Julian Hniopek ◽  
Robert Stach ◽  
Michael Schmitt ◽  
Jürgen Popp ◽  
...  

Scientific questions in fields such as catalysis, monitoring of biological processes or environmental chemistry demand for analytical technologies combining orthogonal spectroscopies. Combined spectroscopic concepts facilitate in-situ on-line monitoring of dynamic processes providing for a better understanding of the involved reaction pathways. In the present study, a low-liquid-volume multi-spectroscopic platform was developed based on infrared attenuated total reflection (IR-ATR) spectroscopy combined with Raman spectroscopy and lumines-cence sensing. For demonstrating the measurement capabilities, exemplary analyte systems including water / heavy water and aqueous solutions of ammonium sulfate were analyzed as proof-of-principle studies. It was successfully demonstrated that three optical techniques may be integrated into a single analytical platform with-out interference providing synchronized and complementary datasets by probing the same minute sample vol-ume. In addition, the developed assembly provides a gas-tight lid sealing the headspace above the probed liq-uid for monitoring the concentration of molecular oxygen also in the gas phase via luminescence quenching. Hence, the entire assembly may be operated at inert conditions, as required for example during the analysis of photocatalytic processes.


1979 ◽  
Vol 25 (1) ◽  
pp. 39-43 ◽  
Author(s):  
H F Osswald ◽  
R Asper ◽  
W Dimai ◽  
W Simon

Abstract We describe a flow-through system with an ion-selective electrode for measurement of blood potassium ion concentration, continuously and on-line off the extracorporeal blood circulation in an operating theater during human open-heart surgery. Comparison measurements were made with the SMA flame photometer (blood plasma) and an Orion SS 30 sodium/potassium analyzer (whole blood). The potassium concentration values obtained with the flow-through system agree well with the ones determined with the flame photometer. The time delay of the measurement with the flow-through system was relatively long (2 min) but delays of only 10--20 s seem feasible. Short time delays can deepen insight and simplify rational treatment under surgery conditions.


The Analyst ◽  
2012 ◽  
Vol 137 (8) ◽  
pp. 1824 ◽  
Author(s):  
Jingya Qu ◽  
Hui Chen ◽  
Chao Lu ◽  
Zhihua Wang ◽  
Jin-Ming Lin

2016 ◽  
Author(s):  
V. Urboniene ◽  
M. Velicka ◽  
J. Ceponkus ◽  
M. Pucetaite ◽  
F. Jankevicius ◽  
...  

1989 ◽  
Vol 38 (4) ◽  
pp. T54-T58 ◽  
Author(s):  
Keiichi SATOH ◽  
Yoichi KIKUCHI ◽  
Toshio SUZUKI ◽  
Kiyoshi SAWADA

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