Immunomodulatory Effect of Polysaccharides from the Mushroom-Forming Basidiomycete Gymnopilus imperialis (Agaricomycetes, Basidiomycota).

Gymnopilus consists of a widely distributed genus of basidiomycetes, especially in tropical regions of the world, such as Japan, Australia, Paraguay, and Brazil. This genus biosynthesizes interesting bioactive compounds, such as sesquiterpenoids, oligoisoprenoids, styrylpyrones, and lectins. In the present study, the aqueous extract of the basidiomata of Gymnopilus imperialis (Basidiomycota, Agaricomycetes, Agaricales, Hymenogastraceae) was obtained by using the accelerated solvent extraction (ASE) technique, followed by the precipitation of polysaccharide fraction with ethanol. Further purification by freeze-thawing processes, Fehling solution precipitation, and membrane dialysis with different pore sizes yield three main polysaccharide fractions (Gi-MRSW, Gi-PFME, and Gi-SFME). According to monosaccharide composition and 13C-NMR data, the Gi-MRSW and Gi-SFME fractions showed to be composed mainly of ß-glucans and Gi-PFME by a heterogalactan. Moreover, the immunomodulatory potential of Gi-MRSW was evaluated using RAW 264.7 murine macrophage as a study model. The nitric oxide production was significantly increased in treated samples, and the expression of inducible nitric oxide synthase (iNOS) showed that the fraction Gi-MRSW from G. imperialis induces the M1 polarization phenotype.

Rheological and biochemical properties of Solanum lycocarpum starch.

This study was conducted to evaluate the rheological and physicochemical properties of Solanum lycocarpum starch. The thermogravimetric analysis of S. lycocarpum starch showed a typical three-step weight loss pattern. Microscopy revealed significant changes in the granule morphology after hydrothermal treatment. Samples hydrothermally treated at 50°C for 10 min lost 52% of their crystallinity, which was recovered after storage for 7 days at 4°C. However, samples hydrothermally treated at 65°C were totally amorphous. This treatment was sufficient to completely disrupt the starch granule, as evidenced by the absence of an endothermic peak in the DSC thermogram. The RVA of S. lycocarpum starch revealed 4440.7cP peak viscosity, 2660.5cP breakdown viscosity, 2414.1cP final viscosity, 834.3cP setback viscosity, and a pasting temperature of 49.6°C. The low content of resistant starch (10.25%) and high content of digestible starch (89.78%) in S. lycocarpum suggest that this starch may be a good source for the production of hydrolysates, such as glucose syrup and its derivatives.

Effects of organic and conventional management of sugar cane crop on soil physicochemical characteristics and phosphomonoesterase activity.

Soil enzymes play an important role in agriculture and particularly in nutrient cycling. They are also involved in the degradation, transformation, and mineralization of organic matter and availability of nutrients in soil. It is believed that organic agriculture causes fewer losses to soil quality and is less aggressive to the environment than conventional management. In this study, the effects of conventional (CM) and organic management (OM) on phosphomonoesterases, an important enzyme for soil fertility, were evaluated and compared to those results from native Cerrado (Brazilian Savanna) soil (NS), because they are the most common phosphatases in soils. The results showed that there were both acid (AcP) and alkaline (AkP) phosphatases in all soils tested and that AcP activity was higher than that of AkP. In contrast to AkP, AcP had its activity affected by land use. In the cultivated areas there was a reduction of almost 50% of AcP activity respect to native unexploited soils and there was no significant difference between organic and CM, demonstrating that independent of the management chosen, there was an impact of land use on AcP activity. Principal component analysis indicated that characteristics related to pH such as alkali saturation (V%), aluminum saturation (M%), Al(3+), soil total acidity (H+Al), and Ca(2+) are the main factors that permit distinguishing NS from OM and CM.

Extraction and chemical characterization of starch from S. lycocarpum fruits.

In this study the pulp from Solanum lycocarpum fruits was used as raw material for extraction of starch, resulting in a yield of 51%. The starch granules were heterogeneous in size, presenting a conical appearance, very similar to a high-amylose cassava starch. The elemental analysis (CHNS) revealed 64.33% carbon, 7.16% hydrogen and 0.80% nitrogen. FT-IR spectroscopy showed characteristic peaks of polysaccharides and NMR analysis confirmed the presence of the α-anomer of d-glucose. The S. lycocarpum starch was characterized by high value of intrinsic viscosity (3515 mPa s) and estimated molecular weight around 645.69 kDa. Furthermore, this starch was classified as a B-type and high amylose content starch, presenting 34.66% of amylose and 38% crystallinity. Endothermic transition temperatures (To=61.25 °C, Tp=64.5 °C, Tc=67.5 °C), gelatinization temperature (ΔT=6.3 °C) ranges and enthalpy changes (ΔH=13.21 J g(-1)) were accessed by DCS analysis. These results make the S. lycocarpum fruit a very promising source of starch for biotechnological applications.