IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
capítulos de libros
Título:
How different culture conditions affect cellular stresses in the biofilms.
Autor/es:
ANGEL VILLEGAS N; ARCE MIRANDA J; BECERRA MC; BARONETTI J; RAVETTI S; SOTOMAYOR C; ALBESA I; PARAJE MG.
Libro:
Microbes in Applied Research: Current Advances and Challenges.
Editorial:
Formatex Research
Referencias:
Año: 2012; p. 629 - 635
Resumen:
The aim of this work was to characterize the cellular stress, the production of reactive oxygen species (ROS), the liberation of nitric oxide (NO) and the enzymatic activity of superoxide dismutase (SOD), in the two bacterial species Staphylococcus aureus and Escherichia coli, which have both been associated with the formation of biofilms. We studied the influence of a different range of culture conditions (sugar, osmotic stress and reduction conditions). The extracellular production of ROS was evaluated by the reduction of nitro blue tetrazolium (NBT), the NO production was detected as nitrite using the Griess reagent and SOD activity being assayed using the inhibition of NBT. We observed that ROS, RNI and their downstream derivatives played important roles in biofilm development. This suggests that cellular stress affected the biofilms grown under different conditions. Our results suggest that biofilm formation was influenced by the different conditions, with a close relation seen between cellular stress (ROS and NO) and biofilm formation. Under favourable culture conditions for biofilm formation, the polysaccharide matrix was increased because the sessile cells were present at lower cellular stresses. The decrease in the extracellular matrix observed under unfavorable conditions for increasing the cellular stress, caused radical oxidizers to accummulate in an extracellular medium and thereby affects the matrix. In conclusion, we suggest that biofilm formations in a variety of environmental conditions are influenced by cellular stress. An improved knowledge of ROS, RNI and enzymatic pathway regulation may help to clarify the relevance of biofilm formation, and new advances in this aspect could also be of great value in the development of better preventive and therapeutic measures.