Optimised methodology for carboxymethylation of (1→3)-β-d-glucan from Yeast (Saccharomyces cerevisiae) and promotion of mechanical activation

Circular economyeast: Saccharomyces cerevisiae as a sustainable source of glucans and its safety for skincare application

Glucans, a polysaccharide naturally present in the yeast cell wall that can be obtained from side streams generated during the fermentation process, have gained increasing attention for their potential as a skin ingredient. Therefore, this study focused on the extraction method to isolate and purify water-insoluble glucans from two different Saccharomyces cerevisiae strains: an engineered strain obtained from spent yeast in an industrial fermentation process and a wild strain produced through lab-scale fermentation. Two water-insoluble extracts with a high glucose content (> 90 %) were achieved and further subjected to a chemical modification using carboxymethylation to improve their water solubility. All the glucans' extracts, water-insoluble and carboxymethylated, were structurally and chemically characterized, showing almost no differences between both yeast-type strains. To ensure their safety for skin application, a broad safety assessment was undertaken, and no cytotoxic effect, immunomodulatory capacity (IL-6 and IL-8 regulation), genotoxicity, skin sensitization, and impact on the skin microbiota were observed. These findings highlight the potential of glucans derived from spent yeast as a sustainable and safe ingredient for cosmetic and skincare formulations, contributing to the sustainability and circular economy.

An important polysaccharide from fermentum

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Extraction, structure and modification of polysaccharides from fermentum were summarized.

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Structure-activity relationship and application of polysaccharides from fermentum were reviewed.

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It provided a strong basis for the development and application of polysaccharides from fermentum.

Fermentum is a common unicellular fungus with many biological activities attributed to β-polysaccharides. Different in vivo and in vivo experimental studies have long proven that fermentum β-polysaccharides have antioxidant, anti-tumor, and fungal toxin adsorption properties. However, there are many uncertainties regarding the relationship between the structure and biological activity of fermentum β-polysaccharides, and a systematic summary of fermentum β-polysaccharides is still lacking. Herein, we reviewed the research progress about the extraction, structure and modification, structure–activity relationship, activity and application of fermentum β-polysaccharides, compared the extraction methods of fermentum β-polysaccharide, and paid special attention to the structure–activity relationship and application of fermentum β-polysaccharide, which provided a strong basis for the development and application of fermentum β-polysaccharide.

Structure, preparation, modification, and bioactivities of β-glucan and mannan from yeast cell wall: A review

In order to solve the antibiotic resistance, the research on antibiotic substitutes has received an extensive attention. Many studies have shown that β-glucan and mannan from yeast cell wall have the potential to replace antibiotics for the prevention and treatment of animal diseases, thereby reducing the development and spread of antibiotic-resistant bacterial pathogens. β-Glucan and mannan had a variety of biological functions, including improving the intestinal environment, stimulating innate and acquired immunity, adsorbing mycotoxins, enhancing antioxidant capacity, and so on. The biological activities of β-glucan and mannan can be improved by chemically modifying its primary structure or reducing molecular weight. In this paper, the structure, preparation, modification, and biological activities of β-glucan and mannan were reviewed, which provided future perspectives of β-glucan and mannan.

Structural Features, Modification, and Functionalities of Beta-Glucan

Β-glucan is a strongly hydrophilic non-starchy polysaccharide, which, when incorporated in food, is renowned for its ability to alter functional characteristics such as viscosity, rheology, texture, and sensory properties of the food product. The functional properties of β-glucans are directly linked to their origin/source, molecular weight, and structural features. The molecular weight and structural/conformational features are in turn influenced by method of extraction and modification of the β-glucan. For example, whereas physical modification techniques influence only the spatial structures, modification by chemical agents, enzyme hydrolysis, mechanical treatment, and irradiation affect both spatial conformation and primary structures of β-glucan. Consequently, β-glucan can be modified (via one or more of the aforementioned techniques) into forms that have desired morphological, rheological, and (bio)functional properties. This review describes how various modification techniques affect the structure, properties, and applications of β-glucans in the food industry.

Chemical modifications of polysaccharides and their anti-tumor activities

With the rising trend of incidence of cancers, effective therapies are urgently needed to control human malignancies. However, the chemotherapy drugs currently on the market cause serious side effects. Polysaccharides belong to a class of biomacromolecules, which have drawn considerable research interest over the years as it possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs with fewer side effects. The antitumor activity of many polysaccharides was significantly increased after modification. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and modified derivatives for the development of effective therapeutics for various human cancers. This review highlights recent advances on the major chemical modification methods of polysaccharides, and discusses the effect of molecular modification on the physicochemical properties and anti-tumor activities of polysaccharides. Meanwhile, the underlying anti-tumor mechanisms of polysaccharide and its modified derivatives were also discussed.

Synthesis of Carboxymethyl Flaxseed Gum and Study of Nonlinear Rheological Properties of Its Solutions

Flaxseed gum (FG) was carboxymethylated by reacting it with monochloroacetic acid (MCA). The effects of concentrations of NaOH and MCA, reaction temperature and reaction time, on the degree of substitution (DS) were investigated. Reaction between the FG and MCA at NaOH and MCA concentrations of 0.06 g/mL and 0.08 g/mL, respectively, at 70 °C for 60 min produced carboxymethyl flaxseed gum (CMFG) with a DS of 0.969. Carboxymethylation of FG increased its solubility and light transmittance in water. The nonlinear rheological properties of CMFG solutions were studied using large amplitude oscillatory shear (LAOS) tests, Fourier transform (FT) rheology and Chebyshev stress decomposition methods. The different nonlinear rheological behaviors observed were related to the microstructures of the CMFG solutions as a function of concentration and DS.

Mechanochemical phosphorylation and solubilisation of β-D-glucan from yeast Saccharomyces cerevisiae and its biological activities

To obtain a water-soluble β-D-glucan derivative cleanly and conveniently, a highly efficient mechanochemical method, planetary ball milling, was used to phosphorylate β-D-glucan isolated from yeast Saccharomyces cerevisiae in solid state. Soluble β-D-glucan phosphate (GP) with a high degree of substitution (0.77-2.09) and an apparent PEAK molecular weight of 6.6-10.0 kDa was produced when β-D-glucan was co-milled with sodium hexametaphosphate at 139.5-186.0 rad/s for 12-20 min. The energy transferred was 3.03-11.98 KJ/g. The phosphorylation of GPs was demonstrated by Fourier transform infrared spectroscopy and 13C and 31P Nuclear magnetic resonance spectroscopy. Three GP products with different degree of substitution (DS) and degree of polymerisation (DP) were able to upregulate the functional events mediated by activated murine macrophage RAW264.7 cells, among which GP-2 with a DS of 1.24 and DP of 30.5 exerted the highest immunostimulating activity. Our results indicate that mechanochemical processing is an efficient method for preparing water-soluble and biologically active GP with high DS.