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Polysialic acid (PSA) is a long-chain linear amino polysaccharide with broad application prospects; however, its relatively low molecular weight limits its application range. This study aims to explore a new fermentation method of combining the three-phase pH control strategy, three-phase mixing speed control strategy, and exogenous substance to produce high molecular weight PSA. In brief, Escherichia coli K235 6E61 (CCTCC M208088) was used as a fermentation strain. 3 g·L

This study introduces a facile method for synthesizing O-benzoylselenoglycolic chitosan with a high selenium concentration of 45.32 mg/g. The characterizations of the chemical structure via FTIR, 1H NMR, 13C NMR, TGA, and XRD analyses indicated that benzoylselenoglycolic acid was successfully grafted onto the C6 hydroxyl group of chitosan. The anti-cancer activity of the O-benzoylselenoglycolic chitosan was investigated in vitro using a HepG2 cell model, and the results indicated that it has excellent anticancer activity against HepG2 cancer cells with an IC50 value of 0.53 μg/mL while exhibiting non-toxicity against normal cells (L-02). Furthermore, a mechanistic study revealed that the O-benzoylselenoglycolic chitosan could induce early apoptosis, G2/M, S phase arrest, and activation of caspase-3 activity to inhibit the HepG2 cell growth. This study has led to novel organic selenium species, and the results suggest its potential to be used as an effective ingredient for cancer prevention and therapy in the food and pharmaceutical fields.

Malto-oligosaccharides (MOS) are α-1,4 glycosidic linked linear oligosaccharides of glucose, which have a diverse range of functional applications in the food, pharmaceutical, and other industries. They can be used to modify the physicochemical properties of foods thereby improving their quality attributes, or they can be included as prebiotics to improve their nutritional attributes. The degree of polymerization of MOS can be controlled by using specific enzymes, which means their functionality can be tuned for specific applications. In this article, we review the chemical structure, physicochemical properties, preparation, and functional applications of MOS in the food, health care, and other industries. Besides, we offer an overview for this saccharide from the perspective of prospect functional ingredient, which we feel lacks in the current literature. MOS could be expected to provide a novel promising substitute for functional oligosaccharides.

In recent years, the biological functions of human milk oligosaccharides and the potential toxic effects of red meat on human health have attracted considerable attention. Sialic acid is an important carbohydrate in milk and red meat, corresponding to sialylated oligosaccharides and N-glycolylneuraminic acid (NeuGc, one type of sialic acid). Herein, we reviewed the metabolic fate of dietary sialic acid in the body and their effects on gut and oral microbes. In summary, dietary NeuAc monomer is directly excreted through urine after being assimilated through the intestines and is not utilized by the human body; in contrast, dietary NeuGc from red meat is easily utilized by the human body and can be incorporated into the brain and other organs. Sialoglycans can be partially utilized by the human body, but they do not affect the cognitive development and growth of children. Dietary sialic acid may mainly regulate the growth and metabolism of gastrointestinal microbiota and human health and development through the gut–brain axis.

β-1,3-oligoglucoside is widely used as a functional food additive and a physiologically active compound. To efficiently produce β-1,3-oligoglucosides through curdlan hydrolysis, the endo-β-1,3-glucanase gene from Trichoderma harzianum was expressed in Pichia pastoris KM71 for the first time in order to construct a high-yield endo-β-1,3-glucanase strain. Optimal conditions for cell culture and endo-β-1,3-glucanase induction were subsequently determined in shake flask experiments. Recombinant endo-β-1,3-glucanase activity was then evaluated in a 7 L bioreactor, reaching a maximum of 198.57 U/mL after of 118 h fermentation. The recombinant endo-β-1,3-glucanase optimally functioned at pH 5.5 and 50 °C in addition to being stable over a pH range of 4.0–6.0 and a temperature range of 30 °C – 50 °C. In addition, the expressed glucanase could efficiently hydrolyze scleroglucan and schizophyllan to produce branched oligoglucosides exhibiting different degrees of polymerization (DP 3–10) and structures. The high enzyme activity and specificity towards polysaccharides with β-1,3-linked glucose residues as primary chains renders recombinant endo-β-1,3-glucanase an ideal candidate enzyme for the industrial production of oligoglucosides.

The production of curdlan oligosaccharides, a multifunctional and valuable carbohydrate, by hydrolyzing polysaccharides is of great interest. The endo-β-1,3-glucanase derived from Trichoderma harzianum was expressed in Pichia pastoris with three commonly used promoters (AOX1, GAP and FLD1). The purified recombinant endo-β-1,3-glucanase expressed by Pichia pastoris with GAP promoter displayed high specific activity at pH 5.5 and 50 °C. Thereafter, a co-culture system of Pichia pastoris GS115 (GAP promoter) and Agrobacterium sp. was constructed in which Agrobacterium sp.-metabolized curdlan can be directly hydrolyzed by Pichia pastoris-secreted endo-β-1,3-glucanase to produce functional curdlan oligosaccharides. The co-culture conditions were optimized and the process was carried out in a 7-L bioreactor. The maximum yield of curdlan oligosaccharides reached 18.77 g/L with 3–10 degrees of polymerization. This study presents a novel and easy curdlan oligosaccharide production strategy that can replace traditional sophisticated production procedures and could potentially be implemented for production of other oligosaccharides.

Background As a kind of potential probiotic, Akkermansia muciniphila abundance in human body is directly causally related to obesity, diabetes, inflammation and abnormal metabolism. In this study, A. muciniphila dynamic cultures using five different media were implemented in an in vitro bionic intestinal reactor for the first time instead of the traditional static culture using brain heart infusion broth (BHI) or BHI + porcine mucin (BPM). Results The biomass under dynamic culture using BPM reached 1.92 g/L, which improved 44.36% compared with the value under static culture using BPM. The biomass under dynamic culture using human mucin (HM) further increased to the highest level of 2.89 g/L. Under dynamic culture using porcine mucin (PM) and HM, the main metabolites were short-chain fatty acids (acetic acid and butyric acid), while using other media, a considerable amount of branched-chain fatty acids (isobutyric and isovaleric acids) were produced. Under dynamic culture Using HM, the cell diameters reached 999 nm, and the outer membrane protein concentration reached the highest level of 26.26 μg/mg. Conclusions This study provided a preliminary theoretical basis for the development of A. muciniphila as the next generation probiotic.

This study investigated the influence of the geometry of the draft tube on the mass transfer and energy efficiency in the airlift reactor with helical sieve plate (ALR-HSP). The power consumption efficiency was 46%–53% higher than the control condition by optimizing the draft tube. A set of empirical equations was used to describe the gas holdup and volumetric mass transfer coefficients corresponding to the geometry of draft tubes in the ALR-HSP for the water–air system. The comparative cultivation of Pichia pastoris was carried out using the ALR-HSP and the conventional airlift reactor (CALR). The biomass increased by 20%, the maximal specific growth rate during the logarithmic growth phase nearly doubled, and volumetric oxygen transfer coefficient increased by 21%–47% under the same culture conditions. Results preliminarily demonstrated the superior performance and practicability of the ALR-HSP in enhancing oxygen transfer efficiency and aerobic biological reaction efficiency.

Endo-β-1,3-glucanase is used to hydrolyze curdlan in a wide range of oligosaccharides production processes. Using pachymaran as the sole carbon source resulted in an endo-β-1,3-glucanase activity of 86.1 U/mL and an Eendo/Etotal ratio of 0.43, which were 3.2 and 1.65 folds of the values from control (glucose as the sole carbon source), due to the inductive effect of pachymaran as a polysaccharide. However, the cell concentration decreased from 25 to 12 g/L during the late fermentation phase. Therefore, a novel multi-stage feeding strategy was developed wherein glucose was fed twice during the cell logarithmic growth phase (24 and 48 h) and pachymaran once during the early stage of the enzyme accumulation phase (72 h). Consequently, the cell concentration remained around 30 g/L during the late fermentation phase. Endo-β-1,3-glucanase activity and Eendo/Etotal reached 160.0 U/mL and 0.76, respectively, which were 6.0 and 2.92 folds of the values from control. In addition, three typical polysaccharides with β-1,3-linked glucose residues were successfully hydrolyzed by endo-β-1,3-glucanase to produce multifunctional β-1,3-oligoglucosides.

Nisin is a high-efficiency Gram-positive bacterium-targeted antimicrobial peptide widely used in the food industry. However, its antibacterial activity can be attenuated in specific niches, and its biomedical applications are limited. Herein, nisin was covalently bonded with gellan gum, a biocompatible polysaccharide. The antibacterial stability of nisin was also verified to be effectively enhanced. After nisin was conjugated with gellan, the antibacterial duration of nisin against Staphylococcus epidermidis increased from 96 h to 216 h under acidic conditions and from 48 h to 144 h under alkaline conditions. The antibacterial activity of gellan–nisin conjugate was also not lost with either heat alkali treatment at 80 °C or chymotrypsin digestion. Hemolysis and cytotoxicity tests also confirmed the good biocompatibility of this conjugate. This conjugate could be a promising biomaterial for medical applications, such as wound dressings and implant coatings.

Proteins from Bacillus thuringiensis are widely used as biopesticides but little is known about its exopolysaccharides. The exopolysaccharide BPS-2 was extracted from B. thuringiensis IX-01 after high-cell-density fermentation. BPS-2 is a heteropolysaccharide (molecular weight 29.36 kDa) composed of D-galactosamine, arabinose, glucosamine, glucose, and mannose in molar ratios 5.53: 1.77:4.74:3.24:1. In vitro upper gastrointestinal simulations showed that BPS-2 has strong anti-digestive capacity, with scavenging of DPPH, hydroxyl, ABTS, and superoxide anions radicals of 31.34 ± 1.67 %, 32.43 ± 3.01 %, 34.31 ± 2.12 %, and 48.53 ± 3.55 %, respectively, after BPS-2 entered the colon. It significantly inhibited production of lipopolysaccharide-induced nitric oxide and multiple pro-inflammatory cytokines and had proliferative effects on RAW 264.7 cells. BPS-2 inhibited malondialdehyde secretion and elevated activities of glutathione peroxidase, superoxide dismutase, and total antioxidants, significantly improving the antioxidant status of inflammation model cells. This first report of the in vitro anti-inflammation and antioxidant properties of BPS-2 from B. thuringiensis provides a basis for biopharmaceutical applications.

Textiles can be contaminated with pathogens during household laundering, potentially leading to human sickness. In this work, chitosan (CTS) was used as a substrate to prepare Ag/Cu-CTS composite, which was applied in laundering and showed a remarkable antibacterial effect on Escherichia coli and Staphylococcus aureus. The mechanical strength of Ag/Cu-CTS composite beads was higher than 400 MPa. The Ag/Cu-CTS composite were further characterized by scanning electron microscopy and energy dispersive spectroscopy. This composite had a strong inhibitory effect on several laundry pathogens, such as Acinetobacter sp., Pseudomonas aeruginosa, and Candida albicans. Using a standard laundering program and 15 g of Ag/Cu-CTS composite beads, the antibacterial rates reached 99.9%, and no silver emission was detected, thereby satisfying the Chinese requirement for washing machines. After 160 runs of laundering tests, this composite still has an excellent antibacterial effect. For the first time, chitosan is successfully applied as an antibacterial material on household electric appliances.

A gellan-polylysine (GPL) fiber was prepared by wet spinning molding with gellan solution containing glucose, soybean peptide, fish collagen peptide as spinning liquid, and ε-poly-l-lysine as fixative liquid. Results showed that the material addition order affects the spinning and an acceptable material addition order was as follows: soybean peptides →glucose → fish collagen peptides. The mechanical strength of the GPL fiber decreased with the collagen peptide titer and the fiber strength can reach 0.99 cN/dtex. In addition, the GPL fiber showed comparable water absorption capacity. The GPL fiber demonstrated good antibacterial properties against Escherichia coli and Staphylococcus aureus. The GPL fiber also had no cytotoxicity on mouse embryo fibroblast L-929 cells and could effectively promote wound healing for rats. As a result, the bifunctional edible GPL fiber is potentially used as a military and rescue emergency equipment.

Curdlan is a neutral, water-insoluble, unbranched, linear β-(1,3)-glucan. This study explored the roles of exoR and exoX in curdlan biosynthesis in Agrobacterium sp. ATCC 31749. The microcapsule biosynthesis of ΔexoR strain was reduced, and the motility of this strain increased remarkably compared with the wild-type (WT) strain during the cell growth phase. The curdlan yields of ΔexoR and ΔexoX strains enhanced by 19% and 17%, and the glucose utilization increased by 12% and 11%, respectively, compared with the WT strain during batch fermentation. By contrast, the curdlan yields of exoR and exoX overexpression strains decreased by 28% and 33%, respectively. The gel strength produced by ΔexoR and exoX overexpression strains decreased compared with the WT strain. RT-qPCR analysis at the transcriptional level revealed that key genes in exopolysaccharide synthesis and central metabolic pathways were up-regulated in ΔexoX and ΔexoR strains during gel production. Metabolomics analysis of ΔexoR and ΔexoX mutants proved the rates of central metabolic and electron transport chain were accelerated.

The current study aimed to determine the rheological properties of welan gum produced by Sphingomonas sp. ATCC 31555 using different nitrogen sources. The viscosity and rheological properties of welan gum produced by Sphingomonas sp. ATCC 31555 from different ratios of inorganic, organic, and mixture of organic and inorganic nitrogen sources were measured under different conditions of pH, rotational speeds, and temperatures and also in the presence of various metal ions. Increasing the proportion of sodium nitrate (NaNO3 ) as the nitrogen source enhanced the viscosity and the ability of welan gum solution to resist high temperatures and salinity. The viscosity of welan gum solution derived from all three nitrogen sources gradually declined when the rotational speed was increased and stabilized at rotational speeds >30 rpm. The elastic modulus and viscous modulus were highest for a welan gum solution derived from 4.0 g/L NaNO3 . The viscosity, temperature, and salt tolerance were superior when a welan gum solution was produced from NaNO3 in comparison with that produced from organic nitrogen source.

Polymyxins, as strong antibiotics with high liposaccharide deactivation abilities, are rarely used as neuronal anti-inflammatory agent because of their high cytotoxicity. In this study, polymyxin B (PMB) was conjugated with deacylated gellan gum for the sustained release of PMB to reduce its cytotoxicity at high concentration without affecting the antibacterial and liposaccharide binding activities. For the conjugate of original PMB/GN ratio of 1.0 (GPC), the conjugating rate was 96.40%, and the releasing ratio of PMB was 30.12% within 60 h. The FT-IR spectra of GPC indicated that the amino groups of PMB were covalently bonded with the COOH groups of gellan and other PMB molecules. Most GPCs were micelle shaped regardless of whether they were under dry conditions or in an aqueous solution. The inhibition zones of PMB against Escherichia coli and Pseudomonas aeruginosa were small, but the half maximal inhibitory concentration value against BV-2 cells increased from 15.63 μg/mL to 2000.00 μg/mL after conjugation. GPC can also effectively depress the liposaccharide-stimulated overexpression of cytotoxic nitric oxide by BV-2 cells. This study revealed the possibility of using polymyxins for neuronal anti-inflammation and that this gellan/PMB conjugate can potentially be applied to wound healing and implants.

Chitosan and kojic acid composite films (CHn-KAm) utilizing three chitosan with differing molecular weights and kojic acid in different ratios were investigated. Results showed that chitosan with higher molecular weights presented higher viscosity, mechanical properties and lower water vapor permeability. Furthermore, kojic acid addition further significantly decreased apparent viscosity, water content, water vapor permeability as well as increasing the antibacterial activity of the films. Increasing the kojic acid concentration resulted in increased levels of a*, b*, ΔE*, opacity values and a decreased L* value, as compared to chitosan films. The mechanical properties of CHn-KAm films increased significantly with kojic acid addition into chitosan. FTIR spectral analyses revealed a strong interaction in the film matrix consistent with composite film mechanical and physical properties. The CHn-KAm films showed significant antibacterial effectiveness. The results suggested that the use of chitosan with a higher molecular weight as CHn-KAm films is expected to be a promising material for food packaging.

The aim of this work was to develop a novel, nontoxic, bioactive antimicrobial material based on a natural polymer, chitosan oligosaccharides (COS), a natural pyrone compound, kojic acid (KA), and piperazine. The COS-based polymer (COS-O-MB) has been synthesized by selective partial alkylation reaction to graft kojic acid, KA, and piperazine onto the COS molecular chain. Then, physicochemical properties and bioactivity of the COS-O-MBs were evaluated and it was characterized by FT-IR, NMR spectroscopy, Mw, PID, antimicrobial activity, hemolysis assay, biocompatibility, animal toxicity, and antimicrobial action mode studies. The results revealed that the alkylation reaction took place at the C-6 position of COS, and the as-prepared COS-O-MB significantly enhanced the antimicrobial activity and biocompatibility and reduced the hemolytic activity in vitro in comparison with that of the free COS and KA. Meanwhile, the antimicrobial action mode studies proved that COS-O-MB can pass through the anionic microbial membrane, destroy the cytomembrane integrity, and potentially affect protein denaturation, demonstrating that exposure to COS-O-MB results in the death of microbial cells. But importantly, COS-O-MB is not toxic to human cells. Hence, low hemolytic activity to human red blood cells, and nontoxic nature to female mice of SLAC KM strain, made this novel polymer material a promising and effective compound for food and pharmaceutical industries.

In current study, a polysaccharide (GPP) was successfully extracted from Gynostemma pentaphyllum herb. Monosaccharide composition of GPP was rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid and glucuronic acid in a molar ratio of 4.11: 7.34: 13.31: 20.99: 1.07: 0.91: 4.75: 0.36. Molecular weight and polydispersity (Mw/Mn) of GPP were 4.070 × 104 Da and 1.037, respectively. Primary structure features of GPP were determined to be a polysaccharide by FT-IR and NMR. Fasting blood sugar of diabetic mice decreased from 17.56 mmol/L to 7.42 mmol/L by orally administration of 0.5 mL GPP (1 mg/mL) for 30 days. GPP exhibited a dose-dependent inhibition effect on α-glucosidase activity. Moreover, GPP could inhibit the glucose absorption and affect the protein expression of GLUT2, but not the protein expression of SGLT1. These results indicated GPP could be used as an effective ingredient to prevent and cure diabetes.

Though great efforts have been made to develop selenium polysaccharides with unique properties using HNO

Biologically active gellan oligosaccharides (GOSs), newly found plant elicitors and biostimulants, are produced from the hydrolysis of gellan gum. Traditional hydrolysis with concentrated acid suffers from the problems of high pollution and low functional oligosaccharide yield because the process is difficult to control. Irradiation (

Carbohydrates play an important role in the life cycle. Among them, functional oligosaccharides show a complex and diverse structures with unique physiological activities and biological functions. However, different preparation methods directly affect the structure, molecular weight, and other functions of oligosaccharides, as well as their application fields and manufacturing costs. In the preparation of β-1,3-glucan oligosaccharides (OBGs), water insolubility of β-1,3-glucans hampers the hydrolysis efficiency. The synthesis of some functional oligosaccharides requires the consumption of energy substrates, such as ATP, CTP, and uridine triphosphate, for sugar nucleotide synthesis, leading to increased capital costs. A more economical solution to solve energy supply is to adopt microbial cocultivation or cellular nucleoside triphosphate regeneration. This review focused on the sources, preparation methods, biological activities of OBG, and the cultivation methods and applications of microbial cocultivation and fermentation. We also reviewed the preparation methods of other functional oligosaccharides, such as sialylated oligosaccharides, β-nicotinamide mononucleotide, and α-galacto-oligosaccharides.

The large molecular weight and poor water solubility of β-1,3-glucan impede its potential applications. In this study, the β-1,3-glucan producing fungi and Trichoderma harzianum capable of secreting endo-β-1,3-glucanase were co-cultivated to produce branched β-1,3-glucan oligosaccharides (bOβGs) by fermentation with Sclerotium rolfsii and Schizophyllum commune. The highest bOβG yields from S. rolfsii in flasks were 4.53 and 9.94 g/L in a 7 L fermenter. Structural analysis proved that bOβG from S. rolfsii had a narrow degree of polymerization of 5–12, whereas bOβG from S. commune had a degree of polymerization of 5–15. Antioxidant tests showed that both bOβGs had remarkable DPPH radical scavenging activity and hydroxyl radical scavenging activity, and the activity of bOβG from S. commune was better than that of bOβG from S. rolfsii. In addition, bOβGs could promote the secretion of NO by mouse macrophages and increase the production of TNF-α, IL-1β, and IL-6 in RAW264.7.

In vitro digestion of curdlan oligosaccharides (COSs), pullulan oligosaccharides (POSs), xanthan gum oligosaccharides (XGOSs) and gellan gum oligosaccharides (GGOSs) was investigated. These four oligosaccharides showed resistance to simulated saliva and gastric and small intestinal fluid. In further fermentation with faecal microbiota from healthy subjects and type 2 diabetes (T2D) patients, COS fermentation significantly increased the abundance of Bifidobacterium spp. and Lactobacillus spp. and the production of short-chain fatty acids in healthy and T2D groups. Digestion of XGOS enhanced the growth of the Clostridium leptum subgroup and significantly increased butyric acid production in healthy and T2D groups. Sole fermentation with COS, POS, XGOS and GGOS exhibited different metabolic profiles between healthy and T2D groups, and more small molecule polyols were produced in the T2D group than in the healthy group. This study provides a novel perspective on the reconstruction of gut microbiota and metabolism by POS, COS, GGOS and XGOS intervention.

Carbohydrates play an important role in the life cycle. Among them, functional oligosaccharides show a complex and diverse structures with unique physiological activities and biological functions. However, different preparation methods directly affect the structure, molecular weight, and other functions of oligosaccharides, as well as their application fields and manufacturing costs. In the preparation of β-1,3-glucan oligosaccharides (OBGs), water insolubility of β-1,3-glucans hampers the hydrolysis efficiency. The synthesis of some functional oligosaccharides requires the consumption of energy substrates, such as ATP, CTP, and uridine triphosphate, for sugar nucleotide synthesis, leading to increased capital costs. A more economical solution to solve energy supply is to adopt microbial cocultivation or cellular nucleoside triphosphate regeneration. This review focused on the sources, preparation methods, biological activities of OBG, and the cultivation methods and applications of microbial cocultivation and fermentation. We also reviewed the preparation methods of other functional oligosaccharides, such as sialylated oligosaccharides, β-nicotinamide mononucleotide, and α-galacto-oligosaccharides.

Highly resistant starch rice (HRSR) is of particular interest in terms of its capacity to deliver short-chain fatty acids (SCFAs) to the colon in the prevention of diabetes mellitus and obesity. In this study, HRSR was processed into cooked rice, rice milk, rice cake, and rice popcorn, and the in vitro digestion and fermentation processes were monitored. The results showed that the starch digestibility of the four samples conformed to a first-order two-phase equation, and the resistant starch content of rice cake was the highest (11.98%). Compared with inulin, rice cake had a slower fermentation rate, and the butyrate concentration increased by 67.85%. The abundances of Prevotellaceae, which promotes the synthesis of SCFAs, and anti-inflammatory Faecalibacterium increased. The abundances of Proteobacteria and Megamonas, markers of gut microbiota imbalance, decreased. The results might facilitate the design and production of functional food products for type 2 diabetic and obese patients and improving colonic health.

As a kind of potential probiotic, Akkermansia muciniphila abundance in human body is directly causally related to obesity, diabetes, inflammation and abnormal metabolism. In this study, A. muciniphila dynamic cultures using five different media were implemented in an in vitro bionic intestinal reactor for the first time instead of the traditional static culture using brain heart infusion broth (BHI) or BHI + porcine mucin (BPM). The biomass under dynamic culture using BPM reached 1.92 g/L, which improved 44.36% compared with the value under static culture using BPM. The biomass under dynamic culture using human mucin (HM) further increased to the highest level of 2.89 g/L. Under dynamic culture using porcine mucin (PM) and HM, the main metabolites were short-chain fatty acids (acetic acid and butyric acid), while using other media, a considerable amount of branched-chain fatty acids (isobutyric and isovaleric acids) were produced. Under dynamic culture Using HM, the cell diameters reached 999 nm, and the outer membrane protein concentration reached the highest level of 26.26 μg/mg. This study provided a preliminary theoretical basis for the development of A. muciniphila as the next generation probiotic.

In this study, a polysaccharide (CGP-BG) was successfully produced from waste distillers' grain by Chaetomium globosum CGMCC 6882. Chemical analysis demonstrated that CGP-BG contained 3.49 ± 0.51 % protein. The molecular weight of CGP-BG was 52.37 KDa, which was composed of rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid in the molar ratio of 4.11:7.34:13.31:20.99:1.07:0.91:4.75:0.36. In vitro assay showed that CGP-BG had scavenging activities on hydroxyl radical, DPPH radical, superoxide anion, and ABTS radical in a dose-dependent manner. Meanwhile, CGP-BG significantly inhibited nitric oxide and pro-inflammatory cytokine (TNF-α, IL-6, and IL-1β) production in the lipopolysaccharide (LPS)-induced RAW 264.7 cells. Moreover, CGP-BG notably improved the antioxidant status of LPS-treated macrophages by enhancing superoxide dismutase, glutathione peroxidase, and antioxidant capacity and mitigating malondialdehyde. This work provided the basis for the application of CGP-BG as an anti-inflammatory and antioxidant agent.

Endotoxemia, a life-threatening disease affecting people worldwide, can be treated by hemoperfusion alone. New hemoperfusion materials with high biocompatibility and endotoxin-combination ability are always in demand. Herein, polymyxin B (PMB), a specific endotoxin binding molecule, was loaded onto gellan–polylysine polyion complex, and the obtained material was used in preparing wet-spun fibers. The tensile strength of the as-spun yarns (100 fibers) ranged from 1.49 N to −1.58 N and that of the dried and rewetted yarns ranged from 1.45 N to 1.56 N. The adsorption ability of the fibers with lipopolysaccharides from E. coli was 2.784 ± 0.036 EU/mg in simulated human body fluid and 2.452 ± 0.107 EU/mg in mouse plasma. The fibers showed no cytotoxicity toward U2OS cells and no hemolysis toward mouse blood. The influence of the fibers on the clotting time of mouse blood was negligible, and the blood cells were not adhesive to the fibers. Thus, the PMB-loaded gellan–polylysine complex fiber and its derivate fabrics can be used in hemoperfusion.

Cyclodextrins (CDs) are yielded by cyclodextrin glycosyltransferase (CGTase) using starches or their derivatives as substrates. However, how starch fine structure affects it production is still ambiguous. This study aimed to decipher the relevance between the external chain length (ECL) and CD production. The waxy maize starch was hydrolyzed by β-amylase to prepare starchy substrates with regular gradient ECL for CGTase. The HPAEC results reflected that β-amylolysis lower the starch chain fractions with DP range of 13-24 by 30%, while the fractions with DP 6 promoted by 30%. The molecular weight distribution and iodine binding results reflected that this process had limited impact on overall starch molecular size parameters. After CGTase conversion, it is interesting to find that the ECL was positively correlated with CD contents, which also has a high consistency among α-CD, β-CD, and γ-CD. This research would provide a favorable perspective for CD production improvement.

Rhodium is one of the most used precious metals in catalysis both in laboratory reactions and industrial processes. However, the adsorption of Rh(III) by microorganisms has been seldomly reported. In this work, waste P. pastoris and recombinant P. pastoris with surface-displayed Rh metal peptides (P. pastoris GS-R) from high-density culture were used as novel adsorbents to study Rh(III) adsorption. Under the optimal adsorption conditions of biomass of 0.25 g L

Fungal polysaccharides are mainly taken orally, so it is very important to study the absorption mechanism of which in vivo for understanding its biological activities. In this work, a polysaccharide fraction (GLP) was purified from G. lucidum by water extraction and alcohol precipitation. Physicochemical characterization indicated that GLP had a molecular weight of 108 kDa and consisted of glucose (35.56%), xylose (40.11%), rhamnose (16.45%) and l -arabinose (7.88%) in a molar radio of 4.51: 5.09: 2.88: 1.0. GLP was taken by Caco-2 cells through the pathway of macropinocytosis and it was a well-absorbed biological macromolecule testified by Papp value. Sugar transporters (SGLT1 and GLUT2) played different roles at different absorption stages of GLP, and the absorption of GLP during digestion in mice model was a time-dependent process. All these results could contribute to explore the absorption mechanism of polysaccharides in body.