, 2006). In this study, we observed that oxidative and nitrosative stress could be produced inside biofilms, thereby affecting their growth under different conditions and resulting in ROS and RNI production, with a decrease of the extracellular matrix. Our data and those from other authors (Beenken et al., 2004; Resch et al., 2005; Zhu et al., 2007) suggest Antiinfection Compound Library manufacturer a strong relation between the incubation atmosphere and biofilm formation. Consistent with previous observations, our data demonstrated S. aureus

in a biofilm to be growing microaerobically, and after 24 h the residual nitrite concentrations rose in the culture supernatants with respect to the initial levels of nitrate and nitrite. When we compared the effect of microaerobiosis, it was evident that the strains exhibited maximum extracellular stress, with the reduced culture possibly increasing the shelf life of these species and their derivatives in these conditions. As no other report was found

in the literature about this effect, the oxidative stress stimuli should now be incorporated into the list of factors involved in the formation of biofilm. In conclusion, we observed Selleckchem HDAC inhibitor that ROS, RNI and its downstream derivatives could play an important role in biofilm development. This suggests that cellular stress is produced inside biofilms, thereby affecting their growth under different conditions and resulting in ROS and

RNI production, with a decrease of the extracellular matrix occurring under unfavorable conditions. These radical oxidizers could then accumulate in an extracellular medium and thus affect the matrix. These results contribute to a better understanding of the processes that enable adherent biofilms to grow on inert surfaces and lead to an improved knowledge of ROS and RNI regulation, which may help to clarify the relevance of biofilm formation in medical devices. J. Arce Miranda is a research fellow of FONCyT. M.G.P. and C.E.S. are members of the Research Career of CONICET. The authors wish to thank C. Mas, M.C. Sampedro and P. Icely for their excellent technical assistance. This work was supported by the following grants: SECyT, FONCyT, MinCyT and CONICET. “
“Aflatoxin B1 (AFB1) is FER a potent mycotoxin with mutagenic, carcinogenic, teratogenic, hepatotoxic, and immunosuppressive properties. In order to develop a bioremediation system for AFB1-contaminated foods by white-rot fungi or ligninolytic enzymes, AFB1 was treated with manganese peroxidase (MnP) from the white-rot fungus Phanerochaete sordida YK-624. AFB1 was eliminated by MnP. The maximum elimination (86.0%) of AFB1 was observed after 48 h in a reaction mixture containing 5 nkat of MnP. The addition of Tween 80 enhanced AFB1 elimination.