Purification effect and microbial community structure of bio filter on rural dispersed sewage.

Taking rural dispersed sewage for research objects, the treatment effect and microbial community structure characteristics of a bio filter (BF) reactor was studied. At fixed time and location, the removal efficiencies of common pollutants were investigated. By using high-throughput sequencing method, the heterogeneities of microbial community structure in fillers and plant roots were analyzed. The results showed that the average annual removal rates of CODCr, NH3-N, TN, and TP by the BF were 83.10 %, 65.67 %, 60.25 %, and 80.32 % respectively, and the effluent could reach the first grade of the water pollutant discharge standard of rural sewage treatment facility (DB51/2626-2019). During the sewage treatment process, Scindapsus could effectively establish complex and stable microbial communities, and could better degrade pollutants, especially nitrogen removal. The dominant microbial communities were more than 11 phyla and 19 classes. At the genus level, the dominant bacteria included Nitrospira, Arthrobacter, Rhodoplanes, etc.

Elucidation of antioxidant activities of intracellular and extracellular polysaccharides from Cordyceps militaris in vitro and their protective effects on ulcerative colitis in vivo.

In this study, we extracted the polysaccharides from C. militaris fruiting bodies (CFIPs), mycelial intracellular polysaccharides (CMIPs), and fermentation broth extracellular polysaccharides (CFEPs) to investigate their physicochemical properties, antioxidant capacities, and effects on oxazolone-induced zebrafish ulcerative colitis (UC). Our results revealed differences in monosaccharide composition and surface structure among CFIPs, CMIPs, and CFEPs. The molar ratios of glucose to mannose in CFIPs, glucose to xylose in CMIPs, and xylose to glucose in CFEPs were 7.57: 1.6, 7.26: 1.81, and 5.44: 2.98 respectively. Moreover, CFEPs exhibited significantly (p < 0.05) higher chemical antioxidant capacity compared to CMIPs and CFIPs. Surprisingly, CFEP treatment didn't show a significant effect in protecting against H2O2-induced oxidative damage in RAW 264.7 cells. After 3 d of treatment, the levels of ROS, MDA, and MPO in the CFIPs group exhibited a significant (p < 0.05) reduction by 37.82 %, 68.15 %, and 22.77 % respectively. Additionally, the ACP and AKP increased by 60.33 % and 96.99 %. Additionally, C. militaris polysaccharides (CMPs) were found to effectively improve UC by activating the MyD88/NF-κB signaling pathway in vivo. These findings confirm the distinct physicochemical properties of these three types of CMP and their potential for development into antioxidant-rich anti-inflammatory health foods.

The effect of sequential extraction on the physicochemical and rheological properties of Naematelia aurantialba polysaccharides.

To overcome the difficulty of separation and low rate of extraction caused by highly viscous polysaccharides from Naematelia aurantialba (NA), four N. aurantialba polysaccharides (NAPs) were sequentially extracted using water (enzyme-/ultrasound-assisted extraction), alkali (0.1 mol/L NaOH), and acid (0.1 mol/L HCl), and named E-NAP, U-NAP, Al-NAP, and Ac-NAP. The properties of four NAPs were different. The yields of NAPs were 26.05 % (Ac-NAP) > 20.33 % (Al-NAP) > 17.99 % (U-NAP) > 12.77 % (E-NAP), respectively. The monosaccharide composition of NAPs was composed primarily of mannose, xylose, glucose, glucuronic acid, and galactose. Sequential extraction improved the purity and solubility of NAPs, but decreased the particle size, thermal stability, water retention, and crystallinity. Two polysaccharides, U-NAP and Al-NAP, had a triple helix structure. All the NAPs were pseudoplastic fluids with concentration/frequency-dependent entangled structure. Al-NAP with the highest viscosity exhibited an elastic gel, while Ac-NAP with the lowest viscosity was a viscous gel. The behavior of NAPs differed from that predicted using the Cox-Merz rule, and in particular, E-NAP and U-NAP more significantly deviated from the rule. In this study, four NAPs with different properties were extracted sequentially, which provided a theoretical basis for the down-stream processing with high added-value and utilization of NA and NAP.

Polysaccharide from Clitocybe squamulosa: Gel-forming properties and its compound effect with food thickener.

To study the gel-forming properties of polysaccharide from the fruiting body of Clitocybe squamulosa (CSFP) and its degradation product (UH-CSFP), the changes in steady-state and dynamic rheological properties of CSFP and UH-CSFP under different conditions (polysaccharide mass fraction, temperature, pH, and salt ion concentration) were studied. Polysaccharides with good gel-forming properties were selected and mixed with common edible thickeners (gelatin, guar gum, and locust bean gum), after which the properties of the composite gel were assessed. The steady-state rheological results showed that CSFP and UH-CSFP were pseudoplastic fluids, their apparent viscosity decreased with increasing temperature, the viscosity was greatest when the pH was 7. The addition of Na+ and Ca2+ could increase the viscosity, and the viscosity of UH-CSFP was lower than that of CSFP at the same mass fraction. The results of dynamic rheology indicated that G´ and G´´ of CSFP and UH-CSFP increased with increasing mass fraction, pH, and ion concentration (0.01 M to 1 M), and G´´ was always smaller than G´ indicating weak gel behavior. The thixotropy-related experimental results showed that the thixotropy ring area of CSFP and UH-CSFP increased with increasing mass fraction, the ring area of CSFP was larger than that of UH-CSFP, and the gel strength of CSFP was greater than that of UH-CSFP. The results of CSFP and three types of edible gels showed that the composite gels were pseudoplastic fluids, and their apparent viscosity was ranked (in descending order) as follows: guar bean gum, locust bean gum, and gelatin. The addition of CSFP improved the gel-forming properties of guar gum but did not significantly improve the gel properties of locust bean gum and gelatin. This study provides a theoretical basis for the selection of processing methods and the application of polysaccharides.

Polysaccharides from an edible mushroom, Hericium erinaceus, alleviate ulcerative colitis in mice by inhibiting the NLRP3 inflammasomes and reestablish intestinal homeostasis.

This study aimed to assess the effects of polysaccharides extracted from Hericium erinaceus fruiting bodies (HEFPs) on the inflammatory response to oxidative stress in a mouse model of ulcerative colitis (UC) induced by ingestion of dextran sodium sulfate. The results indicated reduced oxidative damage in the HEFPs groups, as evidenced by significantly decreased malondialdehyde levels and significantly increased levels of the antioxidant enzymes superoxide dismutase and catalase in colon homogenates, compared with those in the Model Control (MC) group. Additionally, compared with the levels in the MC group, the levels of the pro-inflammatory factors IL-6, IL-1ß, and TNF-α in the positive-control (PC) and HEFPs groups were significantly lower, and that of the anti-inflammatory factor IL-10 was significantly higher. qRT-PCR analyses revealed that the colon expression patterns of IL-6, IL-1ß, TNF-α, and IL-18 were consistent with the serum levels. Western-blotting results indicated significantly lower levels of NLRP3, ASC, and caspase 1 P20 in the HEFPs and PC groups than in the MC group. These findings suggest that HEFPs alleviate UC by suppressing the NLRP3 inflammasome/Caspase-1 pathway. Lachnospiraceae, Clostridiales, Parabacteroides, Oscillibacter, and Clostridium XlVa genera were more abundant in the gut microbiota of the HEFPs group than that of the MC group.

All-natural polysaccharide and protein complex nanoparticles from Clitocybe squamulosa as unique Pickering stabilizers for oil-in-water emulsions.

This study aimed to develop novel nanoparticles that can serve as an excellent oil-in-water (O/W) Pickering stabilizer. The polysaccharide-protein complex nanoparticles (PPCNs-20 and PPCNs-40) were prepared at different ultrasonication amplitudes (20 % and 40 %, respectively) from the polysaccharide-protein complexes (PPCs) which were extracted from the residue of Clitocybe squamulose. Compared with PPCs and PPCNs-20, the PPCNs-40 exhibited dispersed blade and rod shape, smaller average size, and larger zeta potential, which indicated significant potential in O/W Pickering emulsion stabilizers. Subsequently, PPCNs-40 stabilized Pickering emulsions were characterized at different concentrations, pHs, and oil phase contents. The average size, micromorphology, rheological properties, and storage stability of the emulsions were improved as the concentration of PPCNs-40, the ratio of the soybean oil phase and pH value increased. Pickering emulsions showed the best stability when the concentration of PPCNs-40 was 3 wt%, and the soybean oil fraction was 30 % under both neutral and alkaline conditions. The emulsions demonstrated shear thinning and gelation behavior. These findings have implications for the use of eco-friendly nanoparticles as stabilizers for Pickering emulsions and provide strategies for increasing the added value of C. squamulosa.

Sparassis latifolia polysaccharide alleviated lipid metabolism abnormalities in kidney of lead-exposed mice by regulating oxidative stress-mediated inflammation and autophagy based on multi-omics.

Lead is a common environmental pollutant which can accumulate in the kidney and cause renal injury. However, regulatory effects and mechanisms of Sparassis latifolia polysaccharide (SLP) on lipid metabolism abnormality in kidney exposed to lead are not clarified. In this study, mice were used to construct an animal model to observe the histopathological changes in kidney, measure lead content, damage indicators, differentially expressed metabolites (DEMs) and genes (DEGs) in key signaling pathways that cause lipid metabolism abnormalities based on lipidomics and transcriptomics, which were later validated using qPCR and western blotting. Co-treatment of Pb and N-acetylcysteine (NAC) were used to verify the link between SLP and oxidative stress. Our results indicated that treatment with SLP identified 276 DEMs (including metabolism of glycerophospholipid, sphingolipid, glycerolipid and fatty acid) and 177 DEGs (including genes related to oxidative stress, inflammation, autophagy and lipid metabolism). Notably, regulatory effects of SLP on abnormal lipid metabolism in kidney were mainly associated with oxidative stress, inflammation and autophagy; SLP could regulate abnormal lipid metabolism in kidney by reducing oxidative stress and affecting its downstream-regulated autophagy and inflammatory to alleviate renal injury caused by lead exposure. This study provides a theoretical basis for SLP intervention in lead injury.

Functional Properties, Rheological Characteristics, Simulated Digestion, and Fermentation by Human Fecal Microbiota of Polysaccharide from Morchella importuna.

Morchella importuna polysaccharide (MIP) has been proven to have obvious hypoglycemic effects on mice with type 2 diabetes (T2DM). This study looked at the functional and rheological characteristics of MIP, and investigated the effects of MIP on the human fecal microbiota through in vitro fermentation experiments. The outcomes demonstrate the excellent oil-holding capacity, emulsifying, foaming, and rheological characteristics of MIP. After salivary gastrointestinal digestion, the Mw of MIP decreased from 398.2 kDa and 21.5 kDa to 21.9 kDa and 11.7 kDa. By 16S rRNA sequencing of bacteria fermented in vitro, it was found that MIP did not improve the richness and diversity of intestinal microorganisms, but it may exert an anti-T2DM function by significantly increasing the relative abundance of Firmicutes and promoting Ruminococcaceae_UCG_014, Bacteroides, and Blautia proliferation. Escherichia-Shigella could also be inhibited to improve the intestinal microenvironment. In addition, the fermentation of MIP increased the total short-chain fatty acid (SCFA) concentration from 3.23 mmol/L to 39.12 mmol/L, and the propionic acid content increased significantly. In summary, MIP has excellent processing performance and is expected to exert potential anti-T2DM activity through the human intestinal microbiota, which has broad market prospects.

Effect of Different Drying Methods on the Quality of Oudemansiella raphanipes.

In this study, we used fresh Oudemansiella raphanipes as raw materials and pre-treated through hot air drying (HD), infrared radiation drying (ID), and vacuum freeze drying (VD) to investigate the effects of different drying methods on the rehydration rate, appearance quality, microstructure, and volatile flavor components of the dried products, as well as to determine the physicochemical properties and bioactivities of the polysaccharides in the dried O. raphanipes. The results showed that the VD O. raphanipes had the highest rehydration rate and the least shrinkage in appearance, and it better maintained the original color of the gills, but their aroma was not as strong as that of the HD samples. The scanning electron microscopy results indicate that VD maintains a good porous structure in the tissue, while HD and ID exhibit varying degrees of shrinkage and collapse. Seventy-five common volatile substances were detected in the three dried samples, mainly alkanes, alcohols, and esters. The polysaccharides (PS-H, PS-I, and PS-V) extracted from the dried samples of these three species of O. raphanipes had similar infrared spectral features, indicating that their structures are basically consistent. The highest yield was obtained for PS-V, and the polysaccharide content and glucuronic acid content of PS-I were higher than those of the remaining two polysaccharides. In addition, PS-V also showed better antioxidant activity and inhibitory activity against α-glucosidase as well as α-amylase. In conclusion, among the above three drying methods, the quality of O. raphanipes obtained by vacuum freeze drying is the best, and this experiment provides a theoretical basis for the selection of drying methods for O. raphanipes.

Effects of different extraction methods on the physico-chemical characteristics and biological activities of polysaccharides from Clitocybe squamulosa.

This study comparatively evaluated the effects of the commonly used six extraction methods (acidic, alkaline, enzymatic, ultrasonic, high-pressure, and microwave) on the physico-chemical properties, processing characteristics, and biological activities of polysaccharides from Clitocybe squamulosa (CSFPs). The results show that polysaccharides extracted using an enzyme-assisted extraction method has a relatively high extraction yield (4.46 ± 1.62 %) and carbohydrate content (70.79 ± 6.25 %) compared with others. Furthermore, CSFPs were all composed of glucose, galactose, mannose, xylose, and glucosamine hydrochloride. Only ultrasonic-assisted extraction of polysaccharides (CSFP-U) has a triple helix chain conformation. Scanning electron microscopy (SEM) revealed significant differences in the microstructure of polysaccharides prepared using different methods. Besides that, the polysaccharides prepared by alkali extraction (CSFP-B) and high-pressure assisted extraction (CSFP-H) have good water (2.86 ± 0.29 g/g and 3.15 ± 0.29 g/g) and oil (8.13 ± 0.32 g/g and 7.97 ± 0.04 g/g) holding properties. The rheological behavior demonstrated that CSFPs solutions were typical non-Newtonian fluid. Apart from this, the antioxidant capacity (clearing DPPH (IC50 = 0.29) and ABTS free radicals (IC50 = 0.19), total reduction ability (IC50 = 3.02)) of polysaccharides prepared by the microwave-assisted extraction (CSFP-M) method was significantly higher than that of other extraction methods. By contrast, the polysaccharide prepared by acid extraction (CSFP-A) has the optimum binding capacity (bile acid salt (71.30 ± 6.78 %) and cholesterol (57.07 ± 3.26 mg/g)). The antibacterial activity of CSFPs was positively correlated with their concentration. Thus, the research results can provide a theoretical basis for the development and utilization of polysaccharides from C. squamulosa.

The Effects of Naematelia aurantialba on the Pasting and Rheological Properties of Starch and the Research and Development of Soft Candy.

To study the effects of Naematelia aurantialba (NA) on the rheological and gelatinization properties of starch, the processing methods of NA were diversified. In this study, the gelatinization and rheological properties of corn starch (CS) and edible cassava starch (ECS) were investigated by adding NA with different mass fractions. Starch soft candy was prepared using NA, CS, and ECS as the main raw materials. Rheological studies showed that both CS-NA and ECS-NA exhibited elastic modulus (G') > viscosity modulus (G″), implying elastic behavior. G' was such that CS+1%NA > CS+5%NA > CS+3%NA > CS > CS+2%NA > CS+4%NA > ECS+4%NA > ECS+3%NA > ECS+5%NA > ECS+2%NA > ECS+1%NA > ECS. The gelatinization implied showed that after adding NA, the pasting temperature of CS-NA and ECS-NA increased by 1.33 °C and decreased by 2.46 °C, while their breakdown values decreased by 442.35 cP and 866.98 cP, respectively. Through a single-factor test and orthogonal test, the best formula of starch soft candy was as follows: 0.4 f of NA, 10 g of white granulated sugar, a mass ratio of ECS to CS of 20:1 (g:g), 0.12 g of citric acid, 1 g of red date power, and 16 mL of water. The soft candy was stable when stored for two days. This study offers a new direction for the research and development of NA starch foods.

MAC Family Transcription Factors Enhance the Tolerance of Mycelia to Heat Stress and Promote the Primordial Formation Rate of Pleurotus ostreatus.

Pleurotus ostreatus is a typical tetrapolar heterologous edible mushroom, and its growth and development regulatory mechanism has become a research hotspot in recent years. The MAC1 protein is a transcription factor that perceives copper and can regulate the expression of multiple genes, thereby affecting the growth and development of organisms. However, its function in edible mushrooms is still unknown. In this study, two transcription factor genes, PoMCA1a and PoMAC1b, were identified. Afterwards, PoMAC1 overexpression (OE) and RNA interference (RNAi) strains were constructed to further explore gene function. The results showed that the PoMAC1 mutation had no significant effect on the growth rate of mycelia. Further research has shown that OE-PoMAC1a strains and RNAi-PoMAC1b strains exhibit strong tolerance under 32 °C heat stress. However, under 40 °C heat stress, the OE of PoMAC1a and PoMAC1b promoted the recovery of mycelial growth after heat stress. Second, the OE of PoMAC1a can promote the rapid formation of primordia and shorten the cultivation cycle. In summary, this study indicated that there are functional differences between PoMAC1a and PoMAC1b under different heat stresses during the vegetative growth stage, and PoMAC1a has a positive regulatory effect on the formation of primordia during the reproductive growth stage.