| 1. |
- Nivens, David E., et al.
(författare)
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Monitoring microbiol adhesion and biofilm formation by attenuated total reflection/Fourier transform infrared spectroscopy
- 1993
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Ingår i: Journal of Microbiological Methods. - 0167-7012. ; 17:3, s. 199-213
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Tidskriftsartikel (refereegranskat)abstract
- A major problem in accurately defining bacterial adhesion mechanisms and processes occurring in biofilms on surfaces is the lack of techniques that nondestructively provide on-line information about the microorganisms, their extracellular polymers, and metabolites. The attenuated total reflectance (ATR) technique of Fourier transform infrared spectroscopy (FT-IR) is ideally suited to monitor molecular interactions at the solution/internal reflection element (IRE) interface, and we report its application to biofilm research. Two methodologies were utilized to obtain the ATF/FT-IR spectra of living Caulobacter crescentus cells attached to germanium crystals. Initially, spectra of attached bacteria in high purity water produced molecular details of the attachment process without spectral interferences from components of the medium. A growth medium, utilized in the second method, allowed direct examination of the infrared absorption bands associated with the actively growing microorganisms on the surface of the IRE in the spectral region of 2000 to 1200 cm-1. Using the amide II band as a marker for biofilm biomass, the detection limit was determined to be approximately 5 × 105 cells·cm-2. These results proved that the ATR-FT/IR methodologies can be utilized to provide chemical information from bacteria and bacterial products located within approximately 1 μm of the surface without spectral interferences due to components of the medium.
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| 2. |
- Tunlid, Anders, et al.
(författare)
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Infrared monitoring of the adhesion of Catenaria anguillulae zoospores to solid surfaces
- 1991
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Ingår i: Experimental Mycology. - : Elsevier BV. - 0147-5975. ; 15:3, s. 206-214
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Tidskriftsartikel (refereegranskat)abstract
- Electron microscopic studies of nematodes infected with the chytridiomycetous fungusCatenaria anguillulae indicated that zoospores of the fungus adhered to the cuticle of nematodes by a layer of extracellular polymers. The chemical composition of the adhesive polymers and their interaction with a solid surface were examined with Fourier transform infrared spectroscopy, using an attenuated total reflectance cell. On-line monitoring of the adhesion of zoospores to a germanium crystal with this technique showed that the adhesive polymers consisted of a protein(s) containing amide I and II bands. The adsorption of these proteins, measured as the increase in the amide II band, had a rapid initial phase of ca. 20 minutes, followed by a slower increase during the course of incubation. Fluorescein isothiocyanate staining of the attached cells at the end of the experiment showed that the adhesion of the zoospores occurred before the formation of the cyst wall.
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