The filamentous fungus Aspergillus tubingensis that belongs to the black Aspergillus section has the capacity to produce high-value metabolites, for instance, Naphtho-Gamma-Pyrones (NGPs). For these fungal secondary metabolites, numerous biological properties of industrial interest have been demonstrated, such as antimicrobial, antioxidant and anti-cancer capacities. It has been observed that these secondary metabolites production is linked with the fungal sporulation. The aim of this research was to apply environmental stresses to trigger the production of NGPs in liquid cultures with CYB (Czapek Dox Broth): osmotic and oxidative stresses. In addition, numerous parameters were tested during the experiments, such as pH value, incubation time, container geometry, and static and agitation conditions. Results demonstrate that the produced amount of NGPs can be enhanced by decreasing the water activity (aw) or by adding an oxidative stress factor. In conclusion, this study can contribute to our knowledge regarding A. tubingensis to present an effective method to increase NGPs's production, which may support the development of current industrial processes.

Actinobacteria are well known for their production of metabolites of interest. They have been previously studied to identify new antibiotics in medical research and for their ability to stimulate plant growth in agronomic research. Actinobacteria represents a real source of potential biocontrol agents (BCAs) today. With the aim of reducing the use of phytosanitary products by 50% with the different Ecophyto plans, a possible application is the fight against mycotoxin-producing fungi in food matrices and crops using BCAs. To deal with this problem, the use of actinobacteria, notably belonging to the Streptomyces genus, or their specialized metabolites seems to be a solution. In this review, we focused on the impact of actinobacteria or their metabolites on the development of mycotoxigenic fungi and mycotoxin production on the one hand, and on the other hand on their ability to detoxify food matrices contaminated by mycotoxins.

Crop contamination by aflatoxin B1 (AFB1), an Aspergillus-flavus-produced toxin, is frequently observed in tropical and subtropical regions. This phenomenon is emerging in Europe, most likely as a result of climate change. Alternative methods, such as biocontrol agents (BCAs), are currently being developed to reduce the use of chemicals in the prevention of mycotoxin contamination. Actinobacteria are known to produce many bioactive compounds, and some of them can reduce in vitro AFB1 concentration. In this context, the present study aims to analyze the effect of a cell-free supernatant (CFS) from Streptomyces roseolus culture on the development of A. flavus, as well as on its transcriptome profile using microarray assay and its impact on AFB1 concentration. Results demonstrated that in vitro, the S. roseolus CFS reduced the dry weight and conidiation of A. flavus from 77% and 43%, respectively, and was therefore associated with a reduction in AFB1 concentration reduction to levels under the limit of quantification. The transcriptomic data analysis revealed that 5198 genes were differentially expressed in response to the CFS exposure and among them 5169 were downregulated including most of the genes involved in biosynthetic gene clusters. The aflatoxins’ gene cluster was the most downregulated. Other gene clusters, such as the aspergillic acid, aspirochlorine, and ustiloxin B gene clusters, were also downregulated and associated with a variation in their concentration, confirmed by LC-HRMS.

The wine industry is facing a global crisis with a significant decline in wine consumption. This decline is particularly marked for red wine and the industry is seeking innovations to increase the attractiveness of such wine. The addition of sugars is known to improve the palatability of red wine, but the risk of in‐bottle fermentation necessitates the use of stabilizers. Xylitol is a non‐fermentable sugar alcohol with a sweetening power similar to sucrose. To evaluate young adult perception of xylitol‐sweetened products, we applied an innovative penalty analysis approach combining liking scores with CATA (Check‐All‐That‐Apply) questions. The results obtained in this study show that its addition to red wine significantly increased liking among a panel of 119 young adults, with an average age of 22 years. The combination of CATA, liking, and penalty analyses revealed that attributes such as sweet, soft, and fruity were enhanced by xylitol addition and positively impacted liking, whereas attributes such as acidic, bland, and bitter characterized the control red wines and negatively impacted liking.