Project description:To investigate the molecular mechanisms of how Cupriavidus basilensis SRS may aid bioextraction of metals from ores, we exposed C. basilensis SRS to different metals, as well as natural ores
Project description:A bacterial strain identified as Cupriavidus basilensis uses aromatic compounds as carbon and energy sources and has a high capability to transform the structurally related and hormonally active substance bisphenol A (BPA). Biphenyl-grown and phenol-grown cells converted BPA to five products within 24 h of incubation representing four different transformation pathways: (a) ring hydroxylation, (b) ring fission, (c) transamination and acetylation, and (d) dimerization. Products of the ring fission pathway were non-toxic and all five products exhibited a significantly reduced estrogenic activity compared to BPA. Cell cultivation in nutrient broth resulted in lower product quantities and dimerization was not proved. Thus the question arose whether enzymes of the biphenyl or phenol degradation pathway are involved in the transformation of BPA. Proteomic analyses revealed the constitutive expression of biphenyl degrading enzymes and indicated that the 2,3 dihydroxybiphenyl-1,2-dioxygenase might catalyse the meta-cleavage of the aromatic ring of BPA while enzymes of other pathways seemed to be involved in ring hydroxylation.
Project description:Ochratoxin-A (OTA) is a mycotoxin with possibly carcinogenic and nephrotoxic effects in humans and animals. OTA is often found as a contaminant in agricultural commodities. The aim of the present work was to evaluate OTA-degrading and detoxifying potential of Cupriavidus basilensis ŐR16 strain. In vivo administration of OTA in CD1 male mice (1 or 10 mg/kg body weight for 72 hours or 0.5 mg/kg body weight for 21 days) resulted in significant elevation of OTA levels in the blood, histopathological alterations- and transcriptional changes in OTA-dependent genes (annexinA2, clusterin, sulphotransferase and gadd45 and gadd153) in the renal cortex. These OTA-induced changes were not seen in animals that have been treated with culture supernatants in which OTA was incubated with Cupriavidus basilensis ŐR16 strain for 5 days. HPLC and ELISA methods identified ochratoxin α as the major metabolite of OTA in Cupriavidus basilensis ŐR16 cultures, which is not toxic in vivo. This study has demonstrated that Cupriavidus basilensis ŐR16 efficiently degrade OTA without producing toxic adventitious metabolites.
