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The isolation and selection of yeast strains to improve the quality of the cachaça -Brazilian Spirit-have been studied in our research group. Our strategy considers Saccharomyces cerevisiae as the predominant species involved in sugarcane juice fermentation and the presence of different stressors (osmolarity, temperature, ethanol content, and competition with other microorganisms). It also considers producing balanced concentrations of volatile compounds (higher alcohols and acetate and/or ethyl esters), flocculation capacity, and ethanol production. Since the genetic bases behind these traits of interest are not fully established, the whole genome sequencing of 11 different Saccharomyces cerevisiae strains isolated and selected from different places was analyzed to identify the presence of a specific genetic variation common to cachaça yeast strains. We have identified 20,128 single-nucleotide variants shared by all genomes. Of these shared variants, 37 were new variants (being six missenses), and 4,451 were identified as missenses. We performed a detailed functional annotation (using enrichment analysis, protein-protein interaction network analysis, and database and in-depth literature searches) of these new and missense variants. Many genes carrying these variations were involved in the phenotypes of flocculation, tolerance to fermentative stresses, and production of volatile compounds and ethanol. These results demonstrate the existence of a genetic profile shared by the 11 strains under study that could be associated with the applied selective strategy. Thus, this study points out genes and variants that may be used as molecular markers for selecting strains well suited to the fermentation process, including genetic improvement by genome editing, ultimately producing high-quality beverages and adding value.IMPORTANCEThis work demonstrates the existence of new genetic markers related to different phenotypes used to select yeast strains and mutations in genes directly involved in producing flavoring compounds and ethanol, and others related to flocculation and stress resistance., Competing Interests: The authors declare no conflict of interest.

Brazil would benefit from a long-term strategy for science and innovation that improves the standing of both science and scientists in the country., Competing Interests: GC, JM, RC, FW No competing interests declared, (© 2023, Crestana et al.)

Due to an increasing demand for sustainable agricultural practices, the adoption of microbial volatile organic compounds (VOCs) as antagonists against phytopathogens has emerged as an eco-friendly alternative to the use of agrochemicals. Here, we identified three Pseudomonas strains that were able to inhibit, in vitro, up to 80% of mycelial growth of the phytopathogenic fungus Thielaviopsis ethacetica, the causal agent of pineapple sett rot disease in sugarcane. Using GC/MS, we found that these bacteria produced 62 different VOCs, and further functional validation revealed compounds with high antagonistic activity to T. ethacetica. Transcriptomic analysis of the fungal response to VOCs indicated that these metabolites downregulated genes related to fungal central metabolism, such as those involved in carbohydrate metabolism. Interestingly, genes related to the DNA damage response were upregulated, and micro-FTIR analysis corroborated our hypothesis that VOCs triggered DNA damage. Electron microscopy analysis showed critical morphological changes in mycelia treated with VOCs. Altogether, these results indicated that VOCs hampered fungal growth and could lead to cell death. This study represents the first demonstration of the molecular mechanisms involved in the antagonism of sugarcane phytopathogens by VOCs and reinforces that VOCs can be a sustainable alternative for use in phytopathogen biocontrol., (© 2022 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Background: Sugarcane is one of the world's most profitable crops. Waste steam-exploded sugarcane bagasse (SEB) is a cheap, abundant, and renewable lignocellulosic feedstock for the next-generation biofuels. In nature, fungi seldom exist as planktonic cells, similar to those found in the nutrient-rich environment created within an industrial fermenter. Instead, fungi predominantly form biofilms that allow them to thrive in hostile environments., Results: In turn, we adopted an RNA-sequencing approach to interrogate how the model fungus, Aspergillus nidulans, adapts to SEB, revealing the induction of carbon starvation responses and the lignocellulolytic machinery, in addition to morphological adaptations. Genetic analyses showed the importance of hydrophobins for growth on SEB. The major hydrophobin, RodA, was retained within the fungal biofilm on SEB fibres. The StuA transcription factor that regulates fungal morphology was up-regulated during growth on SEB and controlled hydrophobin gene induction. The absence of the RodA or DewC hydrophobins reduced biofilm formation. The loss of a RodA or a functional StuA reduced the retention of the hydrolytic enzymes within the vicinity of the fungus. Hence, hydrophobins promote biofilm formation on SEB, and may enhance lignocellulose utilisation via promoting a compact substrate-enzyme-fungus structure., Conclusion: This novel study highlights the importance of hydrophobins to the formation of biofilms and the efficient deconstruction of lignocellulose.

A novel ustilaginomycetous yeast isolated from the intestinal tract of an insect pest of sugarcane roots in Ribeirão Preto, São Paulo State, Brazil, represents a novel species of the genus Pseudozyma based on molecular analyses of the D1/D2 rDNA large subunit and the internal transcribed spacer (ITS1+ITS2) regions. The name Pseudozyma brasiliensis sp. nov. is proposed for this species, with GHG001(T) ( = CBS 13268(T) = UFMG-CM-Y307(T)) as the type strain. P. brasiliensis sp. nov. is a sister species of Pseudozyma vetiver, originally isolated from leaves of vetiver grass and sugarcane in Thailand. P. brasiliensis sp. nov. is able to grow well with xylan as the sole carbon source and produces high levels of an endo-1,4-xylanase that has a higher specific activity in comparison with other eukaryotic xylanases. This enzyme has a variety of industrial applications, indicating the great biotechnological potential of P. brasiliensis., (© 2014 IUMS.)