Combination of citrus peel-derived essential oils with acarbose to inhibit amylolytic enzymes - A potential type II diabetes treatment approach.

Type 2 diabetes (T2D) can be managed by inhibiting amylolytic enzymes, α-amylase and α-glucosidase, reducing the impact of dietary carbohydrates on blood glucose elevation. Acarbose, a current α-glucose inhibitor (AGI), has excessive α-amylase inhibition, resulting in side effects associated with large amounts of undigested starch being fermented in the colon. This study evaluated the AGI efficacy of citrus peel-derived essential oils, where they were first tested in silico against the target amylolytic enzymes, and then their AGI activity was tested in vitro.

In vitro evaluation of the application of an optimized xylanase cocktail for improved monogastric feed digestibility.

Xylanases from glycoside hydrolase (GH) families 10 and 11 are common feed additives for broiler chicken diets due to their catalytic activity on the nonstarch polysaccharide xylan. This study investigated the potential of an optimized binary GH10 and GH11 xylanase cocktail to mitigate the antinutritional effects of xylan on the digestibility of locally sourced chicken feed. Immunofluorescence visualization of the activity of the xylanase cocktail on xylan in the yellow corn of the feed showed a substantial collapse in the morphology of cell walls.

Towards an understanding of the enzymatic degradation of complex plant mannan structures.

Plant cell walls are composed of a heterogeneous mixture of polysaccharides that require several different enzymes to degrade. These enzymes are important for a variety of biotechnological processes, from biofuel production to food processing. Several classical mannanolytic enzyme functions of glycoside hydrolases (GH), such as β-mannanase, β-mannosidase and α-galactosidase activities, are helpful for efficient mannan hydrolysis.

Bioconversion of spent coffee grounds to prebiotic mannooligosaccharides - an example of biocatalysis in biorefinery.

Spent coffee ground (SCG), an agro-industrial waste, have a high content of polysaccharides such as mannan, making it ideal for utilisation for the production of nutraceutical oligosaccharides. Recently, there has been growing interest in the production of mannooligosaccharides (MOS) for health promotion in humans and animals. MOS are reported to exhibit various bioactive properties, including prebiotic and antioxidant activity.

Analysis of the galactomannan binding ability of β-mannosidases, BtMan2A and CmMan5A, regarding their activity and synergism with a β-mannanase.

Both β-mannanases and β-mannosidases are required for mannan-backbone degradation into mannose. In this study, two β-mannosidases of glycoside hydrolase (GH) families 2 (BtMan2A) and 5 (CmMan5A) were evaluated for their substrate specificities and galactomannan binding ability. BtMan2A preferred short -oligomers, while CmMan5A preferred longer ones; DP >2, and galactomannans.

A Combination Approach in Inhibiting Type 2 Diabetes-Related Enzymes Using Fucoidan and Acarbose.

Although there are chemotherapeutic efforts in place for Type 2 diabetes mellitus (T2DM), there is a need for novel strategies (including natural products) to manage T2DM. Fucoidan, a sulphated polysaccharide was extracted from . The integrity of the fucoidan was confirmed by structural analysis techniques such as FT-IR, NMR and TGA.

Unraveling Synergism between Various GH Family Xylanases and Debranching Enzymes during Hetero-Xylan Degradation.

Enzymes classified with the same Enzyme Commission (EC) that are allotted in different glycoside hydrolase (GH) families can display different mechanisms of action and substrate specificities. Therefore, the combination of different enzyme classes may not yield synergism during biomass hydrolysis, as the GH family allocation of the enzymes influences their behavior. As a result, it is important to understand which GH family combinations are compatible to gain knowledge on how to efficiently depolymerize biomass into fermentable sugars.

Enzymatic Conversion of Mannan-Rich Plant Waste Biomass into Prebiotic Mannooligosaccharides.

A growing demand in novel food products for well-being and preventative medicine has attracted global attention on nutraceutical prebiotics. Various plant agro-processes produce large amounts of residual biomass considered "wastes", which can potentially be used to produce nutraceutical prebiotics, such as manno-oligosaccharides (MOS). MOS can be produced from the degradation of mannan.

Production and in vitro evaluation of prebiotic manno-oligosaccharides prepared with a recombinant Aspergillus niger endo-mannanase, Man26A.

In this study, a GH26 endo-mannanase (Man26A) from an Aspergillus niger ATCC 10864 strain, with a molecular mass of 47.8 kDa, was cloned in a yBBH1 vector and expressed in Saccharomyces cerevisiae Y294 strain cells. Upon fractionation by ultra-filtration, the substrate specificity and substrate degradation pattern of the endo-mannanase (Man26A) were investigated using ivory nut linear mannan and two galactomannan substrates with varying amounts of galactosyl substitutions, guar gum and locust bean gum.

Feruloyl esterase (FAE-1) sourced from a termite hindgut and GH10 xylanases synergy improves degradation of arabinoxylan.

Cereal feedstocks have high arabinoxylan content as their main hemicellulose, which is linked to lignin by hydroxycinnamic acids such as ferulic acid. The ferulic acid is linked to arabinoxylan by ester bonds, and generally, the high substitution of ferulic acid leads to a loss of activity of xylanases targeting the arabinoxylan. In the current study, a feruloyl esterase (FAE-1) from a termite hindgut bacteria was functionally characterised and used in synergy with xylanases during xylan hydrolysis.

Fucoidan Structure and Its Impact on Glucose Metabolism: Implications for Diabetes and Cancer Therapy.

Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade.

Delineating functional properties of a cello-oligosaccharide and β-glucan specific cellobiohydrolase (GH5_38): Its synergism with Cel6A and Cel7A for β-(1,3)-(1,4)-glucan degradation.

Cellulase cocktails formulated to degrade crystalline cellulose generally contain cellobiohydrolases (CBHs), referred to as CBHI (Cel7A) and CBHII (Cel6A), as the major constituents. The combined hydrolytic activities of CBHI and CBHII improve the release of fermentable sugars (β-1,4-cellobiose as the main product) from crystalline cellulose. In this study, a novel cellobiohydrolase (Exg-D) sourced from a metagenome of hindgut bacterial symbionts of a termite was heterologouly expressed, purified, and functionally characterised.

Lignocellulosic pretreatment-mediated phenolic by-products generation and their effect on the inhibition of an endo-1,4-β-xylanase from VAPS-24.

The inhibitory effect of eight model lignin derivatives (ferulic acid, guaiacol, kraft lignin (alkali, low sulfonate content), -coumaric acid, gallic acid, syringic acid, vanillin and vanillic acid) on XynA activity was evaluated. The model lignin derivatives viz. gallic acid, vanillic acid and vanillin were inhibitory to XynA activity, with an over 50% reduction in activity at concentrations as low as 0.

Tryptic Mapping Based Structural Insights of Endo-1, 4-β-Xylanase from VAPS-24.

An endo-1,4-β-xylanase, XynA, from VAPS-24, was purified to homogeneity and exhibited a molecular mass of approximately 20 kDa. The protein sequence of XynA was found to be similar to those of other derived xylanases and, as a result, could be used as a model enzyme for understanding the protein structure-activity relationship and facilitating protein engineering to design enzyme variants with desirable properties. Therefore, this xylanase will be an attractive candidate for applications in the biofuel and fine chemical industries for the degradation of xylans in steam pre-treated biomass.

Fucoidan from Ecklonia maxima is a powerful inhibitor of the diabetes-related enzyme, α-glucosidase.

Ecklonia maxima, an endemic South African seaweed, is a potential source of beneficial bioactive compounds. Among these compounds, fucoidan, a sulphated polysaccharide has a wide range of bioactivities including anti-diabetic activity. In this study, fucoidan was extracted from E.

A Novel Dimeric Exoglucanase (GH5_38): Biochemical and Structural Characterisation towards its Application in Alkyl Cellobioside Synthesis.

An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.

A mini review of xylanolytic enzymes with regards to their synergistic interactions during hetero-xylan degradation.

This review examines the recent models describing the mode of action of various xylanolytic enzymes and how these enzymes can be applied (sequentially or simultaneously) with their distinctive roles in mind to achieve efficient xylan degradation. With respect to homeosynergy, synergism appears to be as a result of β-xylanase and/or oligosaccharide reducing-end β-xylanase liberating xylo-oligomers (XOS) that are preferred substrates of the processive β-xylosidase. With regards to hetero-synergism, two cross relationships appear to exist and seem to be the reason for synergism between the enzymes during xylan degradation.

The effect of an oligosaccharide reducing-end xylanase, BhRex8A, on the synergistic degradation of xylan backbones by an optimised xylanolytic enzyme cocktail.

Xylan, the most abundant hemicellulose in lignocellulosic biomass, requires a consortium of xylanolytic enzymes to achieve its complete de-polymerisation. As global interest in using xylan-containing lignocellulosic feedstocks for biofuel production increases, an accompanying knowledge on how to efficiently depolymerise these feedstocks into fermentable sugars is required. Since it has been observed that the same enzyme [i.

Time dependence of enzyme synergism during the degradation of model and natural lignocellulosic substrates.

Cellulosic ethanol production relies on the biochemical (enzymatic) conversion of lignocellulose to fermentable sugars and ultimately to bioethanol. However, the cost of lignocellulolytic enzymes is a limiting factor in the commercialisation of this technology. This therefore necessitates the optimisation of lignocellulolytic enzyme cocktails through the elucidation of synergistic interactions between enzymes so as to improve lignocellulose hydrolysis and also lower protein loadings in these reactions.

A review of the enzymatic hydrolysis of mannans and synergistic interactions between β-mannanase, β-mannosidase and α-galactosidase.

Mannan is an important polysaccharide found in softwoods and many other plant sources. Mannans from various sources display large differences in composition, structure and complexity. To hydrolyse mannan into its monomer sugars requires a number of enzymes working in synergy.

β-mannanase (Man26A) and α-galactosidase (Aga27A) synergism - a key factor for the hydrolysis of galactomannan substrates.

This study investigated the behavior of mannan-degrading enzymes, specifically focusing on differences with respect to their substrate specificities and their synergistic associations with enzymes from different glycoside hydrolase (GH) families. Galactosidases from Cyamopsis tetragonolobus seeds (Aga27A, GH27) and Aspergillus niger (AglC, GH36) were evaluated for their abilities to synergistically interact with mannanases from Clostridium cellulovorans (ManA, GH5) and A. niger (Man26A, GH26) in hydrolysis of guar gum and locust bean gum.