Production, effects, and applications of fructans with various molecular weights

New biological strategies for preventing and controlling food contaminants in the supply chain: Smart use of common plant-derived substances

Traditional means of contaminant management that rely on chemical additives and high-temperature processing have raised concerns about long-term safety and environmental issues in the modern food supply chain. Therefore, sustainable, safe, and innovative strategies are urgently needed. Plant-derived substances are known for their biological activity and antifouling potential as natural alternatives for contamination control. This review examines the sources of various contaminants, the categories of plant-derived substances, the action mechanisms, and their feasibility in the food supply chain. The smart use of plant-derived substances to improve microbial, chemical, and metal contamination in the food blockchain is not only a profound fusion of nature and technology, but also a mutual combination of ecological preservation and food safety. However, the realization of its commercialization is subject to multiple sanctions, but as the thorny issues are gradually resolved, the consolidation and market for the new strategies will thrive.

Production and characterization of levans with different molecular weights synthesized by Bacillus licheniformis ZM107

Levan, a fructan-type polysaccharide with diverse applications in food, pharmaceuticals, and biotechnology, has garnered significant attention for its functional properties, such as prebiotic, immunomodulatory, antioxidant, and antimicrobial activities. In this study, the effects of fermentation temperature, sucrose concentration, and incubation time on the molecular weight of levan produced by Bacillus licheniformis fermentation were investigated. The results showed that as the temperature (37°C-50°C) and sucrose concentration (300-500 g l-1) increased, the molecular weight of levan produced by the strain during fermentation decreased. At the same time, the molecular weight initially increased and then decreased with longer culture times, indicating that levan within a specific size range could be produced by controlling the fermentation conditions. In addition, the properties and characteristics of levan produced by fermentation at two molecular weights (HML and LML) were compared. The results showed that molecular weight significantly affected the micromorphology, thermal behavior, rheological properties, and prebiotic activity of levan. Therefore, this study demonstrated that Bacillus licheniformis SFLV-ZM107 can produce low molecular weight levan, and its molecular weight can be controlled through fermentation conditions. Consequently, the properties and functions of levan can be influenced, allowing the production of levans with the desired characteristics.

Recent advances in Artemisia argyi Levl. et Vant. polysaccharides: Extractions, purifications, structural characteristics, pharmacological activities, and existing and potential applications

Artemisia argyi Levl. et Vant. (A. argyi) is an important member of Asteraceae (Compositae) family, which has good medicinal potential and edible value. Phytochemical studies have shown that the A. argyi has a variety of bioactive components, mainly including polysaccharides, flavonoids, alkaloids, and volatile oil. More and more evidences show that A. argyi polysaccharide is a kind of representative pharmacological and biological active macromolecules, which has a variety of pharmacological activities in vitro and in vivo, such as estrogen-like effect, anti-bacterial, anti-tumor, anti-oxidant and immune regulation effect. As far as we know, there are few comprehensively reviews on A. argyi polysaccharide. This review aims to comprehensively and systematically review the research progress on the extractions and purifications, structural characteristics, pharmacological activities, structure-activity relationships, existing and potential applications of A. argyi polysaccharides in the past 12 years, in order to support their therapeutic potential and health functions. Finally, prospects were made for the further development and utilization of A. argyi polysaccharides in four fields: food, medicine, packaging materials, and daily chemicals.

Improving the activity of an inulosucrase by rational engineering for the efficient biosynthesis of low-molecular-weight inulin

Inulin, a widely recognized prebiotic, has diverse applications across various industrial sectors. Although inulin is primarily produced through plant extraction, there is growing interest in enzymatic synthesis as an alternative. The enzymatic production of inulin from sucrose, which yields polymers with degrees of polymerization similar to those of plant-derived inulin, shows potential as a viable replacement for traditional extraction methods. In this study, an inulosucrase from Neobacillus bataviensis was identified, demonstrating a non-processive mechanism specifically tailored for synthesizing inulin with polymerization degrees ranging from 3 to approximately 40. The enzyme exhibited optimal activity at pH 6.5 and 55 °C, efficiently producing inulin with a yield of 50.6%. Ca2+ can improve the activity and thermostability of this enzyme. To enhance catalytic total activity, site-directed and truncated mutagenesis techniques were applied, resulting in the identification of a mutant, T149S, displaying a significant 57% increase in catalytic total activity. Molecular dynamics simulations unveiled that the heightened flexibility observed in three surface regions positively influenced enzymatic activity. This study not only contributes to the theoretical foundation for inulosucrase engineering but also presents a potential avenue for the production of inulin.

Evaluation of the anti-atherosclerotic effect for Allium macrostemon Bge. Polysaccharides and structural characterization of its a newly active fructan

Allium Macrostemon Bge. (AMB) is a well-known homology of herbal medicine and food that has been extensively used for thousands of years to alleviate cardiovascular diseases. It contains a significant amount of polysaccharides, yet limited research exists on whether these polysaccharides are responsible for its cardiovascular protective effects. In this study, the anti-atherosclerosis effect of the crude polysaccharides of AMB (AMBP) was evaluated using ApoE-/- mice fed a high-fat diet, along with ox-LDL-induced Thp-1 foam cells. Subsequently, guided by the inhibitory activity of foam cells formation, a major homogeneous polysaccharide named AMBP80-1a was isolated and purified, yielding 11.1 % from AMB. The molecular weight of AMBP80-1a was determined to be 10.01 kDa. AMBP80-1a was firstly characterized as an agavin-type fructan with main chains consisting of →1)-β-d-Fruf-(2→ and →1,6)-β-d-Fruf-(2→ linked to an internal glucose moiety, with →6)-β-d-Fruf-(2→ and β-d-Fruf-(2→ serving as side chains. Furthermore, the bio-activity results indicated that AMBP80-1a reduced lipid accumulation and cholesterol contents in ox-LDL-induced Thp-1 foam cell. These findings supported the role of AMBP in alleviating atherosclerosis in vivo/vitro. AMBP80-1a, as the predominant homogeneous polysaccharide in AMB, was expected to be developed as a functional agent to prevent atherosclerosis.

Multistrategy Engineering of an Inulosucrase to Enhance the Activity and Thermostability for Efficient Production of Microbial Inulin

Inulin has found commercial applications in the pharmaceutical, nutraceutical, and food industries due to its beneficial health effects. The enzymatic biosynthesis of microbial inulin has garnered increasing attention. In this study, molecular modification was applied to Lactobacillus mulieris UMB7800 inulosucrase, an enzyme that specifically produces high-molecular weight inulin, to enhance its catalytic activity and thermostability. Among the 18 variable regions, R5 was identified as a crucial region significantly impacting enzymatic activity by replacing it with more conserved sequences. Site-directed mutagenesis combined with saturated mutagenesis revealed that the mutant A250 V increased activity by 68%. Additionally, after screening candidate mutants by rational design, four single-point mutants, S344D, H434P, E526D, and G531P, were shown to enhance thermostability. The final combinational mutant, M5, exhibited a 66% increase in activity and a 5-fold enhancement in half-life at 55 °C. These findings are significant for understanding the catalytic activity and thermostability of inulosucrase and are promising for the development of microbial inulin biosynthesis platforms.

Advances in the treatment of type 2 diabetes mellitus by natural plant polysaccharides through regulation of gut microbiota and metabolism: A review

The prevalence and impact of type 2 diabetes mellitus (T2DM) is a major global health problem. The treatment process of T2DM is long and difficult to cure. Therefore, it is necessary to explore alternative or complementary methods to deal with the various challenges brought by T2DM. Natural plant polysaccharides (NPPs) have certain potential in the treatment of T2DM. However, many studies have not considered the relationship between the structure of NPPs and their anti-T2DM activity. This paper reviews the relevant anti-T2DM mechanisms of NPPs, including modulation of insulin action, promotion of glucose metabolism and modulation of postprandial glucose levels, anti-inflammation and modulation of gut microbiota (GM) and metabolism. This paper provides an in-depth study of the conformational relationships of NPPs and facilitates the development of anti-T2DM drugs or dietary supplements with NPPs.

PGPB Consortium Formulation to Increase Fermentable Sugar in Agave tequilana Weber var. Blue: A Study in the Field

Agave tequilana Weber var. Blue is used as the primary raw material in tequila production due to its fructans (inulin) content. This study evaluates the formulation of a plant-growth-promoting bacteria (PGPB) consortium (Pseudomonas sp. and Shimwellia sp.) to increase sugars in A. tequilana under field conditions. A total of three doses were tested: low (5 L ha-1), medium (10 L ha-1), and high (15 L ha-1), with a cellular density of 1 × 108 CFU mL-1 and one control treatment (without application). Total reducing sugars (TRS), inulin, sucrose, glucose, fructose, and plant growth were measured in agave plants aged 4-5 years at 0 (T0), 3 (T3), 6 (T6), and 12 (T12) months. Yield was recorded at T12. The TRS increased by 3%, and inulin by 5.3% in the high-dose treatment compared to the control at T12. Additionally, a low content of sucrose, glucose, and fructose (approximately 1%) was detected. At T12, the weight of agave heads increased by 31.2% in the medium dose and 22.3% in the high dose compared to the control. The high dose provided a higher inulin content. The A. tequilana plants were five years old and exhibited growth comparable to the standards for 6-7-year-old plants. This study demonstrates a sustainable strategy for tequila production, optimizing the use of natural resources and enhancing industry performance through increased sugar content and yield.

Levan Production by Suhomyces kilbournensis Using Sugarcane Molasses as a Carbon Source in Submerged Fermentation

The valorization of byproducts from the sugarcane industry represents a potential alternative method with a low energy cost for the production of metabolites that are of commercial and industrial interest. The production of exopolysaccharides (EPSs) was carried out using the yeast Suhomyces kilbournensis isolated from agro-industrial sugarcane, and the products and byproducts of this agro-industrial sugarcane were used as carbon sources for their recovery. The effect of pH, temperature, and carbon and nitrogen sources and their concentration in EPS production by submerged fermentation (SmF) was studied in 170 mL glass containers of uniform geometry at 30 °C with an initial pH of 6.5. The resulting EPSs were characterized with Fourier-transform infrared spectroscopy (FT-IR). The results showed that the highest EPS production yields were 4.26 and 44.33 g/L after 6 h of fermentation using sucrose and molasses as carbon sources, respectively. Finally, an FT-IR analysis of the EPSs produced by S. kilbournensis corresponded to levan, corroborating its origin. It is important to mention that this is the first work that reports the production of levan using this yeast. This is relevant because, currently, most studies are focused on the use of recombinant and genetically modified microorganisms; in this scenario, Suhomyces kilbournensis is a native yeast isolated from the sugar production process, giving it a great advantage in the incorporation of carbon sources into their metabolic processes in order to produce levan sucrose, which uses fructose to polymerize levan.