Glucose sensing and light regulation: A mutation in the glucose sensor RCO-3 modifies photoadaptation in Neurospora crassa

Light irradiation can regulate the growth characteristics and metabolites compositions of Rhodotorula mucilaginosa

Light is an important factor that can induce the growth of varieties of organisms including fungi and their secondary metabolites. The evolutions of biomass, carotenoids, lipid production, compositions and contents of fatty acid and amino acid in Rhodotorula mucilaginosa were investigated under different light irradiation conditions. The results indicated that irradiation with 1700 lx could promote the growth and glucose assimilation of R. mucilaginosa, compared to the dark control, while the trial with 3500 lx had certain inhibiting effects. The carotenoids concentrations and percentages of unsaturated fatty acid (USFA, C16:1 and C18:1) increased with the improvement of irradiation intensity. Conversely, the proportions of saturated fatty acids (C16:0, C18:0 and C20:0) were decreased. The relative contents of amino acid and total protein were reduced under illumination compared to dark control. Conclusively, irradiation could change the cell growth and metabolites of the pigmented fungus, which implied that there may be a photoinduced mode exists in R. mucilaginosa similar to that of Neurospora crassa, and it also could be applied to regulate the biosynthesis and production of valuable components such as carotenoids and USFA.

Enhancing peptaibols production in the biocontrol fungus Trichoderma longibrachiatum SMF2 by elimination of a putative glucose sensor

Trichoderma spp. are main producers of peptide antibiotics known as peptaibols. While peptaibols have been shown to possess a range of biological activities, molecular understanding of the regulation of their production is largely unclear, which hampers the production improvement through genetic engineering. Here, we demonstrated that the orthologue of glucose sensors in the outstanding biocontrol fungus Trichoderma longibrachiatum SMF2, TlSTP1, participates in the regulation of peptaibols production. Deletion of Tlstp1 markedly impaired hyphal growth and conidiation, but significantly increased peptaibols yield by 5-fold for Trichokonins A and 2.6-fold for Trichokonins B. Quantitative real-time polymerase chain reaction analyses showed that the increased peptaibols production occurs at the transcriptional levels of the two nonribosomal peptide synthetase encoding genes, tlx1 and tlx2. Transcriptome analyses of the wild type and the Tlstp1 mutant strains indicated that TlSTP1 exerts a regulatory effect on a set of genes that are involved in a number of metabolic and cellular processes, including synthesis of several other secondary metabolites. These results suggest an important role of TlSTP1 in the regulation of vegetative growth and peptaibols production in T. longibrachiatum SMF2 and provide insights into construction of peptaibol-hyperproducing strains through genetic engineering.

The second International Symposium on Fungal Stress: ISFUS

The topic of 'fungal stress' is central to many important disciplines, including medical mycology, chronobiology, plant and insect pathology, industrial microbiology, material sciences, and astrobiology. The International Symposium on Fungal Stress (ISFUS) brought together researchers, who study fungal stress in a variety of fields. The second ISFUS was held in May 8-11 2017 in Goiania, Goiás, Brazil and hosted by the Instituto de Patologia Tropical e Saúde Pública at the Universidade Federal de Goiás. It was supported by grants from CAPES and FAPEG. Twenty-seven speakers from 15 countries presented their research related to fungal stress biology. The Symposium was divided into seven topics: 1. Fungal biology in extreme environments; 2. Stress mechanisms and responses in fungi: molecular biology, biochemistry, biophysics, and cellular biology; 3. Fungal photobiology in the context of stress; 4. Role of stress in fungal pathogenesis; 5. Fungal stress and bioremediation; 6. Fungal stress in agriculture and forestry; and 7. Fungal stress in industrial applications. This article provides an overview of the science presented and discussed at ISFUS-2017.