Effect of temperature and water activity on the production of fumonisins by Aspergillus niger and different Fusarium species

<p>Abstract</p> <p>Background</p> <p>Fumonisins are economically important mycotoxins which until recently were considered to originate from only a few <it>Fusarium </it>species. However recently a putative fumonisin gene cluster was discovered in two different <it>Aspergillus niger </it>strains followed by detection of an actual fumonisin B₂(FB₂) production in four strains of this biotechnologically important workhorse.</p> <p>Results</p> <p>In the present study, a screening of 5 <it>A. niger </it>strains and 25 assumed fumonisin producing <it>Fusarium </it>strains from 6 species, showed that all 5 <it>A. niger </it>strains produced FB₂and 23 of 25 <it>Fusarium </it>produced fumonisin B₁and other isoforms (fumonisin B₂and B₃). Five <it>A. niger </it>and five <it>Fusarium </it>spp. were incubated at six different temperatures from 15-42°C on Czapek Yeast Agar +5% salt or Potato Dextrose Agar. <it>A. niger </it>had the highest production of FB₂at 25-30°C whereas <it>Fusarium </it>spp. had the maximal production of FB₁and FB₂at 20-25°C. Addition of 2.5-5% NaCl, or 10-20% sucrose increased the FB₂production of <it>A. niger</it>, whereas addition of glycerol reduced FB₂production. All three water activity lowering solutes reduced the fumonisin production of the <it>Fusarium </it>species.</p> <p>Conclusion</p> <p>The present study shows that the regulation of fumonisin production is very different in <it>A. niger </it>and <it>Fusarium</it>, and that food and feeds preserved by addition of sugar or salts may be good substrates for fumonisin B₂production by <it>A. niger</it>.</p

Genome Sequence of Talaromyces atroroseus, Which Produces Red Colorants for the Food Industry

Talaromyces atroroseus is a known producer of Monascus colorants suitable for the food industry. Furthermore, genetic tools have been established that facilitate elucidation and engineering of its biosynthetic pathways. Here, we report the draft genome of a potential fungal cell factory, T. atroroseus IBT 11181 (CBS 123796)

Genes Linked to Production of Secondary Metabolites in Talaromyces atroroseus Revealed Using CRISPR-Cas9

The full potential of fungal secondary metabolism has until recently been impeded by the lack of universal genetic tools for most species. However, the emergence of several CRISPR-Cas9-based genome editing systems adapted for several genera of filamentous fungi have now opened the doors for future efforts in discovery of novel natural products and elucidation and engineering of their biosynthetic pathways in fungi where no genetic tools are in place. So far, most studies have focused on demonstrating the performance of CRISPR-Cas9 in various fungal model species, and recently we presented a versatile CRISPR-Cas9 system that can be successfully applied in several diverse Aspergillus species. Here we take it one step further and show that our system can be used also in a phylogenetically distinct and largely unexplored species from the genus of Talaromyces. Specifically, we exploit CRISPR-Cas9-based genome editing to identify a new gene in T. atroroseus responsible for production of polyketide-nonribosomal peptide hybrid products, hence, linking fungal secondary metabolites to their genetic origin in a species where no genetic engineering has previously been performed