Effect of Different Pretreatment of Birch Sawdust on the Production of Active Polysaccharides by Inonotus obliquus Under Submerged Fermentation and Its Structural Mechanism

Necessity of Different Lignocellulose on Exopolysaccharide Synthesis and Its Hypoglycemic Activity In Vitro of Inonotus obliquus

Current work proposes elm sawdust, poplar sawdust, pine sawdust, and cotton straw with different lignocellulose compositions and structures as the research objects to investigate the relationship between the hypoglycemic activity of mycelium polysaccharides from Inonotus obliquus and lignocellulose biodegradation. Four kinds of lignocellulosic materials could significantly increase the exopolysaccharide content and α-glucosidase inhibition rate and advance the occurrence time of α-glucosidase inhibition activity. Among all groups, the polysaccharide synthesis promotion effect of the cotton straw group was the best, which exopolysaccharide yield was 92.05% higher than that of the control group after 11-day fermentation. Meanwhile, the highest α-glucosidase inhibitory activity was found in the elm sawdust group on the 11th day (30.99%, which was 137.47% higher than control), and the exopolysaccharide in the elm sawdust group showed its effectiveness on glucose consumption of insulin resistant HepG2 cells at the concentration of 20 µg/mL, significantly higher than that of the metformin group (P < 0.05). The cellulose in the non-crystalline region of elm and pine and the hemicellulose of poplar were mainly used in the fermentation of I. obliquus, while the cellulose in the crystalline zone and amorphous zone of cotton straw was degraded to improve the exopolysaccharide content of I. obliquus. This paper revealed the necessity of different kinds of lignocellulose for the synthesis of active polysaccharide from I. obliquus and provided a new idea for the regulation of polysaccharide synthesis pathway.

Bioprospecting CAZymes repertoire of Aspergillus fumigatus for eco-friendly value-added transformations of agro-forest biomass

BACKGROUND

Valorizing waste residues is crucial to reaching sustainable development goals and shifting from a linear fossil-based economy to a circular economy. Fungal cell factories, due to their versatility and robustness, are instrumental in driving the bio-transformation of waste residues. The present work isolated a potent strain, i.e., Aspergillus fumigatus (ZS_AF), from an ancient Złoty Stok gold mine, which showcased distinctive capabilities for efficient hydrolytic enzyme production from lignocellulosic wastes.

RESULTS

The present study optimized hydrolytic enzyme production (cellulases, xylanases, and β-glucosidases) from pine sawdust (PSD) via solid-state fermentation using Aspergillus fumigatus (ZS_AF). The optimization, using response surface methodology (RSM), produced a twofold increase with maximal yields of 119.41 IU/gds for CMCase, 1232.23 IU/gds for xylanase, 63.19 IU/gds for β-glucosidase, and 31.08 IU/gds for FPase. The secretome profiling validated the pivotal role of carbohydrate-active enzymes (CAZymes) and auxiliary enzymes in biomass valorization. A total of 77% of carbohydrate-active enzymes (CAZymes) were constituted by glycoside hydrolases (66%), carbohydrate esterases (9%), auxiliary activities (3%), and polysaccharide lyases (3%). The saccharification of pretreated wheat straw and PSD generated high reducing sugar yields of 675.36 mg/g and 410.15 mg/g, respectively.

CONCLUSION

These findings highlight the significance of an efficient, synergistic, and cost-effective arsenal of fungal enzymes for lignocellulosic waste valorization and their potential to contribute to waste-to-wealth creation through solid-waste management. The utilization of Aspergillus fumigatus (ZS_AF) from an unconventional origin and optimization strategies embodies an innovative approach that holds the potential to propel current waste valorization methods forward, directing the paradigm toward improved efficiency and sustainability.

Research progress on the hypoglycemic activity and mechanisms of natural polysaccharides

The incidence of diabetes, as a metabolic disease characterized by high blood sugar levels, is increasing every year. The predominantly western medicine treatment is associated with certain side effects, which has prompted people to turn their attention to natural active substances. Natural polysaccharide is a safe and low-toxic natural substance with various biological activities. Hypoglycemic activity is one of the important biological activities of natural polysaccharides, which has great potential for development. A systematic review of the latest research progress and possible molecular mechanisms of hypoglycemic activity of natural polysaccharides is of great significance for better understanding them. In this review, we systematically reviewed the relationship between the hypoglycemic activity of polysaccharides and their structure in terms of molecular weight, monosaccharide composition, and glycosidic bonds, and summarized underlying molecular mechanisms the hypoglycemic activity of natural polysaccharides. In addition, the potential mechanisms of natural polysaccharides improving the complications of diabetes were analyzed and discussed. This paper provides some valuable insights and important guidance for further research on the hypoglycemic mechanisms of natural polysaccharides.

Pigment Production by Paracoccus spp. Strains through Submerged Fermentation of Valorized Lignocellulosic Wastes

Due to the increasing emphasis on the circular economy, research in recent years has focused on the feasibility of using biomass as an alternative energy source. Plant biomass is a potential substitute for countering the dependence on depleting fossil-derived energy sources and chemicals. However, in particular, lignocellulosic waste materials are complex and recalcitrant structures that require effective pretreatment and enzymatic saccharification to release the desired saccharides, which can be further fermented into a plethora of value-added products. In this context, pigment production from waste hydrolysates is a viable ecological approach to producing safe and natural colorings, which are otherwise produced via chemical synthesis and raise health concerns. The present study aims to evaluate two such abundant lignocellulosic wastes, i.e., wheat straw and pinewood sawdust as low-cost feedstocks for carotenoid production with Paracoccus strains. An alkali pretreatment approach, followed by enzymatic saccharification using an indigenous lab-isolated fungal hydrolase, was found to be effective for the release of fermentable sugars from both substrates. The fermentation of the pretreated sawdust hydrolysate by Paracoccus aminophilus CRT1 and Paracoccus kondratievae CRT2 resulted in the highest carotenoid production, 631.33 and 758.82 μg/g dry mass, respectively. Thus, the preliminary but informative research findings of the present work exhibit the potential for sustainable and economically feasible pigment production from lignocellulosic feedstocks after optimal process development on the pilot scale.

Evaluation of Toxicity and Efficacy of Inotodiol As an Anti-Inflammatory Agent Using Animal Model

Chaga mushroom (Inonotus obliquus) comprises polyphenolic compounds, triterpenoids, polysaccharides, and sterols. Among the triterpenoid components, inotodiol has been broadly examined because of its various biological activities. The purpose of this study is to examine inotodiol from a safety point of view and to present the potential possibilities of inotodiol for medical usage. From chaga mushroom extract, crude inotodiol (INO20) and pure inotodiol (INO95) were produced. Mice were treated with either INO20 or INO95 once daily using oral administration for repeated dose toxicity evaluation. Serum biochemistry parameters were analyzed, and the level of pro-inflammatory cytokines in the serum was quantified. In parallel, the effect of inotodiol on food allergic symptoms was investigated. Repeated administration of inotodiol did not show any mortality or abnormalities in organs. In food allergy studies, the symptoms of diarrhea were ameliorated by administration with INO95 and INO20. Furthermore, the level of MCPT-1 decreased by treatment with inotodiol. In this study, we demonstrated for the first time that inotodiol does not cause any detrimental effect by showing anti-allergic activities in vivo by inhibiting mast cell function. Our data highlight the potential to use inotodiol as an immune modulator for diseases related to inflammation.

Improved production and antioxidant activity of exopolysaccharides by submerged culture of Lentinula edodes by the addition of lignocellulose

The objective of this study was to investigate the effect of addition of four different lignocellulose (water-treated corn straw, water-treated xylosma sawdust, alkali-treated corn straw and alkali-treated xylosma sawdust) on the production and antioxidant activity of exopolysaccharides by Lentinula edodes. To evaluate the antioxidant activity of polysaccharides, the analyses of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity, lipid peroxidation inhibition rate and erythrocyte hemolysis inhibition rate were carried out. The result clearly indicated that the exo-polysaccharide production and antioxidant activity by L. edodes mycelium was enhanced in varying degrees via the decomposition of lignocellulose. The yield of exo-polysaccharide in alkali-treated corn straw group was the highest (0.351 g/L), which was 31.06% higher than that in control group after 5 days of submerged fermentation. High DPPH radical scavenging activity was observed in water-treated xylosma sawdust group, which decreased with the extension of fermentation time (23.15%-44.06%). Alkali-treated groups performed better than water-treated groups in terms of lipid peroxidation inhibitory activity. As for hemolysis inhibition activity toward erythrocytes, xylosma sawdust groups showed stronger oxidation resistance than corn straw groups.

Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.