Fructose affecting morphology and inducing β-fructofuranosidases in Penicillium janczewskii

Comparative proteomics reveals the mechanism of cyclosporine production and mycelial growth in Tolypocladium inflatum affected by different carbon sources

Cyclosporine A (CsA) is a secondary cyclopeptide metabolite produced by Tolypocladium inflatum that is widely used clinically as an immunosuppressant. CsA production and mycelial growth differed when T. inflatum was cultured in different carbon source media. During early fermentation, CsA was preferred to be produced in fructose medium, while the mycelium preferred to accumulate in sucrose medium. On the sixth day, the difference was most pronounced. In this study, high-throughput comparative proteomics methods were applied to analyze differences in protein expression of mycelial samples on day 6, revealing the proteins and mechanisms that positively regulate CsA production related to carbon metabolism. The differences included small molecule acid metabolism, lipid metabolism, organic catabolism, exocrine secretion, CsA substrate Bmt synthesis, and transcriptional regulation processes. The proteins involved in the regulation of mycelial growth related to carbon metabolism were also revealed and were associated with waste reoxidation processes or coenzyme metabolism, small molecule synthesis or metabolism, the stress response, genetic information or epigenetic changes, cell component assembly, cell wall integrity, membrane metabolism, vesicle transport, intramembrane localization, and the regulation of filamentous growth. This study provides a reliable reference for CsA production from high-efficiency fermentation. This study provides key information for obtaining more CsA high-yielding strains through metabolic engineering strategies.

Ganoderma lucidum Mycelia Mass and Bioactive Compounds Production through Grape Pomace and Cheese Whey Valorization

Numerous compounds obtained from the medicinal mushroom Ganoderma lucidum have evidenced renowned bioactive characteristics. Controlled fermentation to generate fungal mycelia confers several advantages, specifically when the valorization of agro-industrial streams as fermentation feedstocks is included. Submerged fermentation of a newly isolated Greek strain of G. lucidum was performed using conventional synthetic media and, also, grape pomace extract (GPE) and cheese whey permeate (CWP) under static and shaking conditions. Under shaking conditions, maximum biomass with GPE and supplementation with organic nitrogen reached 17.8 g/L. The addition of an elicitor in CWP resulted in a significant improvement in biomass production that exceeded synthetic media. Overall, agitation demonstrated a positive impact on biomass productivity and, therefore, on process optimization. Crude intracellular and extracellular polysaccharides were extracted and evaluated regarding antioxidant activity and polysaccharide and protein content. FTIR analysis confirmed the preliminary chemical characterization of the crude extracts. This study introduces the design of a bioprocessing scenario to utilize food industry by-products as onset feedstocks for fungal bioconversions to obtain potential bioactive molecules within the concept of bioeconomy.

Fructose-induced topographical changes in fructophilic, pseudofructophilic and non-fructophilic lactic acid bacterial strains with genomic comparison

Fructophilic Lactic Acid Bacteria (FLAB), Fructobacillus fructosus DPC7238 and pseudofructophilic Leuconostoc mesenteroides DPC7261 and non-FLAB Limosilactobacillus reuteri DSM20016 strains were studied for their growth and morphological evolution as a function of increased fructose concentrations (0, 25, and 50% w/v) in the media. A comparison of the genomics of these strains was carried out to relate observed changes and understand fructose-rich adaptations. The viability of FLAB strains were reduced by approx. 50% at a 50% fructose concentration, while the Limosilactobacillus reuteri strain was reduced to approx. 98%. Electron microscopy demonstrated that FLAB strain, Fructobacillus. fructosus and pseudofructophilic Leuc. mesenteroides, were intact but expanded in the presence of high fructose in the medium. Limosilactobacillus reuteri, on the other hand, ruptured as a result of excessive elongation, resulting in the formation of cell debris when the medium contained more than 25% (w/v) fructose. This was entirely and quantitatively corroborated by three-dimensional data obtained by scanning several single cells using an atomic force microscope. The damage caused the bacterial envelope to elongate lengthwise, thus increasing width size and lower height. The cell surface became comparatively smoother at 25% fructose while rougher at 50% fructose, irrespective of the strains. Although Fructobacillus fructosus was highly fructose tolerant and maintained topological integrity, it had a comparatively smaller genome than pseudofructophilic Leuc. mesenteroides. Further, COG analysis identified lower but effective numbers of genes in fructose metabolism and transport of Fructobacillus fructosus, essentially needed for adaptability in fructose-rich niches.

A comparative study between Fusarium solani and Neocosmospora vasinfecta revealed differential profile of fructooligosaccharide production

Fructooligosaccharides (FOS) are fructose-based oligosaccharides employed as additives to improve the food's nutritional and technological properties. The rhizosphere of plants that accumulate fructopolysaccharides as inulin has been revealed as a source of filamentous fungi. These fungi can produce FOS either by inulin hydrolysis or by biosynthesis from sucrose, including unusual FOS with enhanced prebiotic properties. Here, we investigated the ability of Fusarium solani and Neocosmospora vasinfecta to produce FOS from different carbon sources. Fusarium solani and N. vasinfecta grew preferentially in inulin instead of sucrose, resulting in the FOS production as the result of endo-inulinase activities. N. vasinfecta was also able to produce the FOS 1-kestose and 6-kestose from sucrose, indicating transfructosylating activity, absent in F. solani. Moreover, the results showed how these carbon sources affected fungal cell wall composition and the expression of genes encoding for β-1,3-glucan synthase and chitin synthase. Inulin and fructose promoted changes in fungal macroscopic characteristics partially explained by alterations in cell wall composition. However, these alterations were not directly correlated with the expression of genes related to cell wall synthesis. Altogether, the results pointed to the potential of both F. solani and N. vasinfecta to produce FOS at specific profiles.

High-Mobility Fungus-Triggered Biodegradable Ultraflexible Organic Transistors

Biodegradable organic field-effect transistors (OFETs) have drawn tremendous attention for potential applications such as green electronic skins, degradable flexible displays, and novel implantable devices. However, it remains a huge challenge to simultaneously achieve high mobility, stable operation and controllable biodegradation of OFETs, because most of the widely used biodegradable insulating materials contain large amounts of hydrophilic groups. Herein, it is firstly proposed fungal-degradation ultraflexible OFETs based on the crosslinked dextran (C-dextran) as dielectric layer. The crosslinking strategy effectively eliminates polar hydrophilic groups and improves water and solvent resistance of dextran dielectric layer. The device with spin-coated 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) semiconductor and C-dextran dielectric exhibits the highest mobility up to 7.72 cm² V^-1 s^-1 , which is higher than all the reported degradable OFETs. Additionally, the device still maintains high performance regardless of in an environment humidity up to 80% or under the extreme bending radius of 0.0125 mm. After completion of their mission, the device can be controllably biodegraded by fungi without any adverse environmental effects, promoting the natural ecological cycles with the concepts of "From nature, for nature". This work opens up a new avenue for realizing high-performance biodegradable OFETs, and advances the process of the "green" electrical devices in practical applications.

Estimation of glucosamine in biomass of Trichoderma reesei cultivated on lignocellulosic substrates

Effects of the compositions of lignocellulosic substrate including hemicellulose, cellulose, lignin, and protein on the glucosamine content in biomass of Trichoderma reesei TISTR3080 were studied. A synthetic solid surface media containing different ratios of xylan (hemicellulose), carboxymethyl cellulose (cellulose), lignin, and various concentrations of yeast extract (source of protein) were used to cultivated T. reesei. Regression analysis identified significant individual and interaction factors that affected glucosamine quantity in T. reesei biomass. A regression model was developed to estimate the glucosamine content in biomass of T. reesei from the compositions of the lignocellulosic substrate. An acceptable error (not more than 10%) of the regression model was obtained from validation with the experimental results of glucosamine content in biomass of T. reesei cultivated on lignocellulosic solid surface media made from copra waste and banana peel.

Continuous production of enzymes under carbon-limited conditions by Trichoderma harzianum P49P11

Carbon-limited chemostat cultures were performed using different carbon sources (glucose, 10 and 20 g/L; sucrose, 10 g/L; fructose/glucose, 5.26/5.26 g/L; carboxymethyl cellulose, 10 g/L; and carboxymethyl cellulose/glucose, 5/5 g/L) to verify the capability of the wild type strain Trichoderma harzianum to produce extracellular enzymes. All chemostat cultures were carried out at a fixed dilution rate of 0.05 h^-1. Experiments using glucose, fructose/glucose and sucrose were performed in duplicate. Glucose condition was found to induce the production of enzymes that can catalyse the hydrolysis of p-nitrophenyl-β-d-glucopyranoside (PNPGase). A concentration of 20 g/L of glucose in the feed provided the highest productivity (1048 ± 16 U/mol h). Extracellular polysaccharides were considered the source of inducers. Based on the obtained results, a new PNPGase production process was developed using mainly glucose. This process raises interesting possibilities of synthesizing the inducer substrate and the induced enzymes in a single step using an easily assimilated carbon source under carbon-limited conditions.

Sequential statistical optimization of lactose-based medium and process variables for inulinase production from Penicillium oxalicum BGPUP-4

A statistical tool of response surface methodology was used sequentially to optimise lactose-based medium and process variables for inulinase production from Penicillium oxalicum BGPUP-4. Two-level CCRD with four variables, for each design, was used for the optimization study. The independent variables: lactose 1-3%, NH4H2PO4 0.2-0.5%, NaNO3 0.2-0.5%, pH 5.0-7.0 (design-1); temperature 25-35 °C, incubation time 4.0-6.0 days, inoculum size 1.0-3.0 mycelial agar discs and agitation 100-200 rpm (design-2) were selected for the present investigation. The optimised medium variables (lactose 3.70%, NH4H2PO4 0.35%, NaNO3 0.35% and pH 6.0) produced 44.44 (IU/ml) and 0.38 (g dry wt./50 ml) of inulinase and biomass yield, respectively. Thereafter, the optimization of process conditions (temperature 25 °C, incubation time 5 days, inoculum size 2 mycelial agar discs and agitation 150 rpm), increased the inulinase production 50.45 (IU/ml) and biomass yield 0.26 (g dry wt./50 ml). The good agreement between experimental and predicted values in both the designs, the coefficient of determination (R2 ) greater than 0.90 and very close to 1.0 shows an appropriate fitness of the polynomial quadratic models.