Monitoring of sterigmatocystin biosynthesis using RT-qPCR in airborne Aspergillus species of the series Versicolores.

Aspergilli series Versicolores have been shown to be explanatory variables for different symptoms like coughing and dizziness experienced by residents of mold-damaged homes. Among these species, eight are particularly recurrent in bioaerosols: Aspergillus amoenus, A. creber, A. fructus, A. jensenii, A. protuberus, A. puulaauensis, A. sydowii and A. tabacinus. In order to monitor the biosynthesis of sterigmatocystin (a mycotoxin associated with a risk of cancer development) and the development of these molds, we developed an RT-qPCR tool by targeting the aflR and rho1 genes. A total of 30 fungal isolates representing these eight species were included. For each of them, sterigmatocystin was quantified by UPLC-HRMS and (1 â†’ 3)-ß-D-glucan by visible spectrophotometry using Endosafe®-PTS™-Glucan Cartridges. After validation of our method by RT-qPCR, the direct assay was compared to the amount of aflR and rho1 cDNA. The sterigmatocystin and aflR assays showed a significant correlation between these two approaches (p < 0.0001), demonstrated for the first time the production of sterigmatocystin by A. tabacinus and suggested the ability of A. sydowii to synthesize sterigmatocystin. Assays conducted on (1 â†’ 3)-ß-D-glucan and rho1 did not show a correlation, supporting the multiplicity of functions performed in fungal cells by the RHO1 GTPase. The proposed tool could allow monitoring of sterigmatocystin biosynthesis by Aspergillus of the series Versicolores under different culture and climatic conditions.

Characterization of harbor sediments from the English Channel: assessment of heavy metal enrichment, biological effect and mobility.

For a full assessment of the environmental risk posed by dredged sediments not only the anthropogenic enrichment of contaminants, but also their mobility and biological impact should be considered. This study reports on the enrichment factor (EF), mobility, and Adverse Effect Index (AEI) of metals and metalloids in nine dredged sediments. Significant enrichment of As, Cd, Pb and Zn with respect to background values is detected, and calculated AEI values for these elements suggest that it is possible that a corresponding biological effect may be observed. Correlation coefficients also reveal a link between mobility in HCl and enrichment for Cd, Cr, Ni, Pb and Zn, however As and Cu do not display such a link, possibly suggesting that the source of contamination for these elements is less recent. Mobility and enrichment are two parameters which are often studied separately; however this paper shows that in some cases strong correlations occur.