Characterizing the mycelial cultures of the Morchella specimens, alongside multilocus sequence analysis for identification, facilitated comparisons with undisturbed environment specimens. In our assessment, these results, as far as we can determine, present the initial evidence for the presence of the species Morchella eximia and Morchella importuna in Chile, and notably, the latter species is recorded for the first time in South America. These species were, for the most part, confined to the harvested or burned coniferous plantations. Growth medium and incubation temperature influenced the observed inter- and intra-specific variations in mycelial morphology, specifically pigmentation, mycelium type, and the development and formation of sclerotia, as revealed by in vitro characterization. Mycelial biomass (mg) and the growth rates (mm/day) were significantly affected by the temperature conditions (p 350 sclerotia/dish) over the ten-day growth cycle. Expanding the geographical reach of Morchella species in Chile to include those flourishing in disturbed environments provides a significant contribution to our understanding of the species diversity. In vitro cultures of different Morchella species are also subject to molecular and morphological characterization. The initial exploration of M. eximia and M. importuna, recognized for their cultivability and adaptability to Chile's local climate and soil conditions, may lay the groundwork for the development of artificial Morchella cultivation techniques in the country.
The production of industrially valuable bioactive compounds, encompassing pigments, is being studied globally within the context of filamentous fungi. Employing a strain of Penicillium sp. (GEU 37), isolated from Indian Himalayan soil and exhibiting cold and pH tolerance, this study explores the effects of varying temperature conditions on the production of natural pigments. When the temperature is maintained at 15°C, the fungal strain exhibits increased sporulation, exudation, and red diffusible pigment production within the Potato Dextrose (PD) medium compared to 25°C. The observation of a yellow pigment occurred in PD broth at 25 degrees Celsius. A study of the impact of temperature and pH on the red pigment production of GEU 37 indicated that the optimum conditions were 15°C and pH 5. By parallel means, the effect of external carbon, nitrogen, and mineral salt additives on pigment synthesis by GEU 37 was determined employing PD broth as the culture medium. In spite of efforts, no substantial change in pigmentation was detected. Pigment extracted with chloroform was separated using thin-layer chromatography (TLC) and column chromatography techniques. Fractions I and II, each possessing Rf values of 0.82 and 0.73, respectively, displayed the highest light absorbance at 360 nm and 510 nm. Employing GC-MS, pigment characterization from fraction I exhibited phenol, 24-bis(11-dimethylethyl), and eicosene, and fraction II displayed the presence of coumarin derivatives, friedooleanan, and stigmasterol. LC-MS analysis, however, uncovered the presence of carotenoid derivatives from fraction II, in addition to chromenone and hydroxyquinoline derivatives appearing as significant constituents from both fractions, together with several other noteworthy bioactive compounds. The strategic role of bioactive pigments in ecological resilience, as displayed by fungal strains operating at low temperatures, might yield biotechnological benefits.
While trehalose's role as a stress solute has long been acknowledged, recent research suggests some of its protective effects may stem from the distinct non-catalytic function of the trehalose biosynthesis enzyme, trehalose-6-phosphate (T6P) synthase. Our study utilizes Fusarium verticillioides, a maize-infecting fungus, as a model to explore the relative contributions of trehalose and a potential secondary role for T6P synthase in stress protection. This research also aims to decipher why, according to previous findings, the deletion of the TPS1 gene, coding for T6P synthase, reduces virulence against maize. A TPS1-deficient F. verticillioides mutant demonstrates a compromised ability to withstand simulated oxidative stress, characteristic of the oxidative burst in maize defense responses, and suffers greater ROS-mediated lipid damage than its wild-type counterpart. Eliminating T6P synthase expression negatively impacts the ability to withstand water stress, but its defense mechanism against phenolic acids does not suffer. In TPS1-deleted strains, the introduction of a catalytically-inactive T6P synthase partially recovers the sensitivity to oxidative and desiccation stress, suggesting an autonomous function of T6P synthase beyond trehalose production.
Xerophilic fungi store a substantial quantity of glycerol inside their cytosol to offset the external osmotic pressure. Yet, under heat stress (HS), the vast majority of fungi store the thermoprotective osmolyte trehalose. Considering that glycerol and trehalose are derived from the same glucose precursor in cellular metabolism, we conjectured that, during heat shock, xerophiles cultured in media with a high concentration of glycerol would develop enhanced thermotolerance compared to those grown in media containing high NaCl. An investigation into the acquired thermotolerance of Aspergillus penicillioides was conducted, examining the composition of membrane lipids and osmolytes in this fungus cultivated in two distinct media under high-stress circumstances. Observations in salt-rich media indicated a shift towards higher phosphatidic acid levels and lower phosphatidylethanolamine levels in membrane lipids, accompanied by a substantial sixfold decrease in intracellular glycerol. In contrast, media supplemented with glycerol showed minimal alteration in membrane lipid profiles and a glycerol decrease not exceeding thirty percent. Mycelium trehalose levels saw an increase in both growth media, but never surpassing 1% of the dry mass. L(+)-Monosodium glutamate monohydrate mouse Subsequent to HS exposure, the fungus displays greater thermotolerance in a medium containing glycerol as opposed to a medium containing salt. Data gathered show a correlation between alterations in osmolyte and membrane lipid makeup and the adaptive response to HS, including the combined action of glycerol and trehalose.
Grape postharvest losses are significantly impacted by blue mold decay, a consequence of Penicillium expansum. L(+)-Monosodium glutamate monohydrate mouse Considering the expanding demand for pesticide-free agricultural products, this investigation targeted the identification of yeast strains capable of managing blue mold issues affecting table grapes. Fifty yeast strains were examined for their ability to antagonize P. expansum using a dual-culture approach, and six strains proved to significantly inhibit fungal growth. The fungal growth (296-850%) and decay severity of wounded grape berries inoculated with P. expansum were mitigated by six yeast strains (Coniochaeta euphorbiae, Auerobasidium mangrovei, Tranzscheliella sp., Geotrichum candidum, Basidioascus persicus, and Cryptococcus podzolicus). Geotrichum candidum stood out as the most effective biocontrol agent. Due to their antagonistic effects, strains were further characterized using in vitro assays, including the inhibition of conidial germination, the production of volatile substances, the competition for iron, the production of hydrolytic enzymes, biofilm formation, and exhibited at least three potential mechanisms. Initial reports suggest that yeasts might be viable biocontrol agents against grapevine blue mold, however, a more comprehensive evaluation of their efficiency in a real-world context is essential.
Environmentally friendly electromagnetic interference shielding devices can be developed by combining polypyrrole one-dimensional nanostructures with cellulose nanofibers (CNF) in flexible films, while precisely tuning the mechanical and electrical properties. Films of polypyrrole nanotubes (PPy-NT) and CNF, exhibiting a thickness of 140 micrometers, were synthesized using two distinct approaches for conductive applications. The first approach encompassed a one-pot synthesis through the in situ polymerization of pyrrole guided by a structure-directing agent while incorporating CNF. The second approach involved a two-step process, combining physically blended CNF and PPy-NT. Films fabricated via a one-pot synthesis process using PPy-NT/CNFin displayed higher conductivity than those prepared by physical blending. This conductivity was significantly enhanced to 1451 S cm-1 through post-treatment redoping using HCl. The PPy-NT/CNFin composite with the minimal PPy-NT loading (40 wt%), and the corresponding minimum conductivity (51 S cm⁻¹), unexpectedly exhibited the highest shielding effectiveness (-236 dB, signifying more than 90% attenuation). A well-rounded combination of mechanical and electrical properties contributed to this superior performance.
The conversion of cellulose to levulinic acid (LA), a promising bio-based platform chemical, faces a major obstacle in the substantial formation of humins, especially at high cellulose concentrations above 10 wt%. We detail a highly effective catalytic system, utilizing a 2-methyltetrahydrofuran/water (MTHF/H2O) biphasic solvent, augmented by NaCl and cetyltrimethylammonium bromide (CTAB) additives, for converting cellulose (15 wt%) into lactic acid (LA) in the presence of a benzenesulfonic acid catalyst. The depolymerization of cellulose and the formation of lactic acid were observed to be accelerated by the presence of sodium chloride and cetyltrimethylammonium bromide. Although sodium chloride encouraged humin formation via degradative condensation processes, cetyltrimethylammonium bromide prevented humin formation by impeding both degradative and dehydration condensation routes. L(+)-Monosodium glutamate monohydrate mouse The synergistic effect of NaCl and CTAB on inhibiting humin formation is vividly illustrated. Combining NaCl and CTAB led to a noteworthy increment in LA yield (608 mol%) from microcrystalline cellulose in a MTHF/H2O mixture (VMTHF/VH2O = 2/1) at 453 Kelvin for 2 hours duration. Moreover, its efficacy extended to converting cellulose fractions isolated from various sources of lignocellulosic biomass, yielding an exceptional LA yield of 810 mol% when processing wheat straw cellulose.