The expression of Ruminococcus flavefaciens 007S cellulases in different incubation time points (growth stages) and their substrate inducibility were analyzed by comparing the zymogram expression profiles of cultures grown on insoluble cellulose (Avicel) with cellobiose-grown cultures. The molecular weights of the enzymes were compared to (putative) cellulases encoded in the R. flavefaciens FD-1 genome.

• MeSH
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• celobiosa metabolismus   MeSH
• celulasy chemie   genetika   metabolismus   MeSH
• celulosa metabolismus   MeSH
• enzymatické testy MeSH
• exprese genu MeSH
• molekulární sekvence - údaje MeSH
• molekulová hmotnost MeSH
• Ruminococcus chemie   enzymologie   genetika   růst a vývoj   MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH

One of the main mechanisms of nanoparticle toxicity is known to be the generation of reactive oxygen species (ROS) which primarily damage cell membranes. However, very limited data on membrane effects in anaerobic environments (where ROS could not be the cause of membrane damage) are available. In the following study, rumen anaerobe Ruminococcus flavefaciens 007C was used as a bacterial model to assess the potential effects of Al(2)O(3) and TiO(2) nanoparticles on membranes in an anaerobic environment. Fatty acid profiles of cultures after exposure to Al(2)O(3) or TiO(2) nanoparticles were analyzed and compared with the profiles of non-exposed cultures or cultures exposed to bulk materials. Analysis revealed dose-effect changes in membrane composition exclusively when cells were exposed to Al(2)O(3) nanoparticles in a concentration range of 3-5 g/L, but were not present in cultures exposed to bulk material. On the other hand, the tested concentrations of nano-TiO(2) did not significantly affect the membrane profile of the exposed bacterium. The results suggest the possibility that Al(2)O(3) induces changes in bacterial membranes by direct physical interaction, which was supported by TEM image analysis.

• MeSH
• anaerobióza MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• metabolom účinky léků   MeSH
• nanočástice toxicita   ultrastruktura   MeSH
• oxid hlinitý toxicita   MeSH
• Ruminococcus účinky léků   metabolismus   MeSH
• titan toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH