Hydrolytic Activity Research Articles

Site-directed mutagenesis leads to the optimized transglycosylation activity of endo-beta-N-acetylglucosaminidase from Trypanosoma brucei.

Endo-β-N-acetylglucosaminidases (ENGases) are pivotal enzymes in the degradation and remodeling of glycoproteins, which catalyze the cleavage or formation of β-1,4-glycosidic bond between two N-acetylglucosamine (GlcNAc) residues in N-linked glycan chains. It was investigated that targeted mutations of amino acids in ENGases active site may modulate their hydrolytic and transglycosylation activities. Endo-Tb, the ENGase derived from Trypanosoma brucei, belongs to the glycoside hydrolase family 85 (GH85). Our group previously demonstrated that Endo-Tb exhibits hydrolytic activity toward high-mannose and complex type N-glycans and preliminarily confirmed its transglycosylation potential. In this study, we further optimized the transglycosylation activity of recombinant Endo-Tb by focusing on the N536A, E538A and Y576F mutants. A comparative analysis of their transglycosylation activity with that of the wild-type enzyme revealed that all mutants exhibited enhanced transglycosylation capacity. The N536A mutant exhibited the most pronounced improvement in transglycosylation activity with a significant reduction in hydrolytic activity. It is suggested that Endo-Tb N536A possesses the potential as a tool for synthesizing a wide array of glycoconjugates bearing high-mannose and complex type N-glycans.

Integrative approach to assessing bioactivity from hempseed protein isolate extracted and dehydrated by different methods: Synergising in silico prediction and in vitro validation

This study demonstrated a comprehensive workflow combining in silico screening and prediction with in vitro validation to investigate the bioactivity of hempseed protein isolate (HPI) extracted and dehydrated using different methods. By adopting an in silico approach, 13 major proteins of HPI were hydrolysed by 20 selected enzymes, leading to the prediction of 20 potential bioactivities. With papain hydrolysis, dipeptidyl peptidase-IV (DPP4) and angiotensin-converting enzyme (ACE) inhibitory activities emerged as having the highest potential. In vitro experiments confirmed these predictions, with DPP4 and ACE inhibitory activities displaying IC50 values of 0.32–0.42 mg/mL and 6.8–9.17 μg/mL, respectively. A strong correlation (r2 = 0.96) was observed between in vitro protein inhibitory results and in silico predicted data. This study demonstrated an effective integrative approach for predicting bioactive peptides in food protein, providing valuable guidance on its processing to create value-added products.

Multienzyme Immobilization on PVDF Membrane via One-Step Mussel-Inspired Method: Enhancing Fouling Resistance and Self-Cleaning Efficiency.

Immobilizing different enzymes on membranes can result in biocatalytic active membranes with a self-cleaning capacity toward a complex mixture of foulants. The membrane modification can reduce fouling and enhance filtration performance. Protease, lipase, and amylase were immobilized on poly(vinylidene fluoride) (PVDF) microfiltration membranes using a polydopamine coating in a one-step method. The concentrations of polydopamine precursor and enzymes were optimized during the immobilization. The higher hydrolytic activities were obtained using 0.2 mg/mL of dopamine hydrochloride and 4 mg/mL of enzymes: 0.90 mgstarch/min·cm2 for amylase, 10.16 nmoltyrosine/min·cm2 for protease, and 20.48 µmolp-nitrophenol/min·cm2 for lipase. Filtration tests using a protein, lipid, and carbohydrate mixture showed that the modified membrane retained 41%, 29%, and 28% of its initial water permeance (1808 ± 39 L/m2·h·bar) after three consecutive filtration cycles, respectively. In contrast, the pristine membrane (initial water permeance of 2016 ± 40 L/m2·h·bar) retained only 23%, 12%, and 8%. Filtrations of milk powder solution were also performed to simulate dairy industry wastewater: the modified membrane maintained 28%, 26%, and 26% of its initial water permeance after three consecutive filtration cycles, respectively, and the pristine membrane retained 34%, 21%, and 7%. The modified membrane showed increased fouling resistance against a mixture of foulants and presented a similar water permeance after three cycles of simulated dairy wastewater filtration. Membrane fouling is reduced by the immobilized enzymes through two mechanisms: increased membrane hydrophilicity (evidenced by the reduced water contact angle after modification) and the enzymatic hydrolysis of foulants as they accumulate on the membrane surface.

Unravelling of cellulolytic fungal consortium from humus soil for efficient lignocellulosic waste degradation

Cellulose is a complex polysaccharide composed of β 1, 4 glycosidic linkages and these linkages are broken down by a complex enzyme system called cellulase. Cellulase is an enzyme complex associated with β 1, 4 endoglucanase, β 1, 4 exoglucanase, and β glucosidase. The fungal strains were isolated from decomposed humus soil and screened for the best cellulolytic activity. Thirty-two isolates were screened among these; three were selected based on their morphological characters and hydrolytic capacity, viz, Cladosporium oxysporum N5, Aspergillus sigurros N6, and Cladosporium cladosporioides N12. Among these fungi, Cladosporium oxysporum N5 shows potential hydrolytic activity and was selected for optimization studies and evaluation of their cellulolytic capability. Cellulolytic strain Cladosporium oxysporum N5 produced maximum amount of cellulase enzyme at 5 days of incubation at 30 ℃ and pH 7, viz, β 1, 4 endoglucanase (167.83± U/ml), β 1, 4 exoglucanase (29.04± U/ml), and β glucosidase (34.07± U/ml). SEM coupled Energy dispersive X-ray and FTIR spectroscopy methods revealed the cellulose degradation efficiency of fungal cellulase by microscopic, elemental percentage, and functional group, respectively. An affordable and eco-friendly fungal-based cellulase that will boost industrially important commodity production such as food, beverages, pharmaceuticals, fertilisers, and biofuels.

Biological Activities of Soy Protein Hydrolysate Conjugated with Mannose and Allulose.

The non-enzymatic conjugation of peptides through the Maillard reaction has gained attention as an effective method to enhance biological functions. This study focuses on two conjugate mixtures: crude soy protein hydrolysate (SPH) conjugated with mannose (SPHM) and crude soy protein hydrolysate conjugated with allulose (SPHA). These two mixtures were products of the Maillard reaction, also known as non-enzymatic glycation. In vitro experiments were conducted to evaluate the antioxidant, anti-pancreatic lipase, inhibition of Bovine Serum Albumin (BSA) denaturation, and anti-angiotensin converting enzyme (ACE) activities of these conjugated mixtures. The results indicate that conjugated mixtures significantly enhance the antioxidant potential demonstrated via the DPPH and FRAP assays. SPHA exhibits superior DPPH scavenging activity (280.87 ± 16.39 µg Trolox/mL) and FRAP value (38.91 ± 0.02 mg Trolox/mL). Additionally, both conjugate mixtures, at a concentration of 10 mg/mL, enhance the BSA denaturation properties, with SPHM showing slightly higher effectiveness compared to SPHA (19.78 ± 2.26% and 5.95 ± 3.89%, respectively). SPHA also shows an improvement in pancreatic lipase inhibition (29.43 ± 1.94%) when compared to the SPHM (23.34 ± 3.75%). Furthermore, both the conjugated mixtures and rare sugars exhibit ACE inhibitory properties on their own, effectively reducing ACE activity. Notably, the ACE inhibitory effects of the individual compounds and their conjugate mixtures (SPHM and SPHA) are comparable to those of positive control (Enalapril). In conclusion, SPHM and SPHA demonstrate a variety of bioactive properties, suggesting their potential use in functional foods or as ingredients in supplementary products.

New Insights into the Structure-Activity Relationship of a Novel Immunomodulatory Peptide (HPHPHLSF) from Casein Hydrolyzed by Kluyveromyces marxianus JY-1: Molecular Docking, Interaction Evaluation, and HOMO Analysis.

Casein is rich in immunomodulatory peptides. In this study, the release of casein-derived immunomodulatory peptides by Kluyveromyces marxianus JY-1 was investigated for the first time, and an immunosuppressive mouse model was used to evaluate the immunomodulatory activity in the casein hydrolysate. The results showed that the cellular and humoral immunity of immunosuppressed mice could be significantly enhanced by casein hydrolysate. Peptide HPHPHLSF with high immunomodulatory activity from casein hydrolysate was screened using the virtual screening technique. HPHPHLSF possessed strong immunomodulatory activity and significantly upregulated the expression of IL-6, IL-1β, and TNF-α. Next, the interaction of HPHPHLSF with TLR2/4 on the cell surface of RAW264.7 cells was further elucidated by molecular docking and combined analysis of double-stranded small interfering RNA and receptor inhibitors. Further, the results of the highest occupied molecular orbital energy distribution elucidated that the histidine active site C48═O49 played an important role in the immunomodulatory activity of HPHPHLSF. This study confirmed that casein hydrolyzed by K. marxianus JY-1 was a natural immunomodulator, while the structure-activity relationship analysis provided new theoretical and technical support for the targeted preparation and screening of casein-derived immunomodulatory peptides.

Novel Feruloyl Esterase for the Degradation of Polyethylene Terephthalate (PET) Screened from the Gut Microbiome of Plastic-Degrading Mealworms (Tenebrio Molitor Larvae).

Mealworms (Tenebrio molitor) larvae can degrade both plastics and lignocellulose through synergistic biological activities of their gut microbiota because they share similarities in chemical and physical properties. Here, a total of 428 genes encoding lignocellulose-degrading enzymes were screened from the gut microbiome of T. molitor larvae to identify poly(ethylene terephthalate) (PET)-degrading activities. Five genes were successfully expressed in E. coli, among which a feruloyl esterase-like enzyme named TmFae-PETase demonstrated the highest PET degradation activity, converting PET into MHET (0.7 mgMHETeq ·h-1·mgenzyme-1) and TPA (0.2 mgTPAeq ·h-1·mgenzyme-1) at 50 °C. TmFae-PETase showed a preference for the hydrolysis of ferulic acid methyl ester (MFA) in the presence of both PET and MFA. Site-directed mutagenesis and molecular dynamics simulations of TmFae-PETase revealed similar catalytic mechanisms for both PET and MFA. TmFae-PETase effectively depolymerized commercial PET, making it a promising candidate for application. Additionally, the known PET hydrolases IsPETase, FsC, and LCC also hydrolyzed MFA, indicating a potential origin of PET hydrolytic activity from its lignocellulosic-degrading abilities. This study provides an innovative strategy for screening PET-degrading enzymes identified from lignocellulose degradation-related enzymes within the gut microbiome of plastic-degrading mealworms. This discovery expands the existing pool of plastic-degrading enzymes available for resource recovery and bioremediation applications.

Antioxidant Activity of Protein Hydrolysates from Redlip Mullet (Chelon haematocheilus) Muscle and Byproducts.

Fish muscle and byproducts represent a valuable source of bioactive compounds, with their protein hydrolysates exhibiting noteworthy antioxidant properties. This study assessed the antioxidant activity of protein hydrolysates derived from the muscle and byproducts of redlip mullet (Chelon haematocheilus), utilizing different proteases (Neutrase, Alcalase, and Protamex). Hydrolysates were prepared from various parts of the fish, including muscle (white and red meat) and byproducts (frames, head, viscera, fins, skin, and scales). The enzymatic hydrolysis resulted in the highest degree of hydrolysis, achieving 83.24 ± 1.45% for skin at 60 min and 82.14 ± 4.35% for head at 30 min, when treated with Neutrase. Frames treated with Neutrase exhibited the highest protein concentration, measured at 1873.01 ± 71.11 µg/mL at 15 min. Significantly, skin hydrolysates treated with Protamex showed the highest DPPH• scavenging activity (70.07 ± 3.99% at 120 min), while those treated with Alcalase demonstrated the highest ABTS• scavenging activity (93.47 ± 0.02% at 15 min). The highest superoxide dismutase (SOD) activity (92.01 ± 1.47%) was observed in head hydrolysates treated with Protamex after 90 min. These results suggest that C. haematocheilus protein hydrolysates possess significant antioxidant activity within a short time frame of less than 120 min.

A Novel Self-Amplifying mRNA with Decreased Cytotoxicity and Enhanced Protein Expression by Macrodomain Mutations.

The efficacy and safety of self-amplifying mRNA (saRNA) have been demonstrated in COVID-19 vaccine applications. Unlike conventional non-replicating mRNA (nrmRNA), saRNA offers a key advantage: its self-replication mechanism fosters efficient expression of the encoded protein, leading to substantial dose savings during administration. Consequently, there is a growing interest in further optimizing the expression efficiency of saRNA. In this study, in vitro adaptive passaging of saRNA is conducted under exogenous interferon pressure, which revealed several mutations in the nonstructural protein (NSP). Notably, two stable mutations, Q48P and I113F, situated in the NSP3 macrodomain (MD), attenuated its mono adenosine diphosphate ribose (MAR) hydrolysis activity and exhibited decreased replication but increased payload expression compared to wild-type saRNA (wt saRNA). Transcriptome sequencing analysis unveils diminished activation of the double-stranded RNA (dsRNA) sensor and, consequently, a significantly reduced innate immune response compared to wt saRNA. Furthermore, the mutant saRNA demonstrated less translation inhibition and cell apoptosis than wt saRNA, culminating in higher protein expression both in vitro and in vivo. These findings underscore the potential of reducing saRNA replication-dependent dsRNA-induced innate immune responses through genetic modification as a valuable strategy for optimizing saRNA, enhancing payload translation efficiency, and mitigating saRNA cytotoxicity.

Characterization of Peptide Profiles and the Hypoallergenic and High Antioxidant Activity of Whey Protein Hydrolysate Prepared Using Different Hydrolysis Modes.

Food proteins and peptides are generally considered a source of dietary antioxidants. The aim of this study was to investigate the antioxidant activity, allergenicity, and peptide profiles of whey protein hydrolysates (WPHs) using different hydrolysis methods. The results demonstrated that the degrees of hydrolysis of the hydrolysates with one-step (O-AD) and two-step (T-AD) methods reached 16.25% and 17.64%, respectively. The size exclusion chromatography results showed that the O-AD had a higher content of >5 and <0.3 kDa, and the distribution of peptide profiles for the two hydrolysates was significantly different. Furthermore, 5 bioactive peptides and 15 allergenic peptides were identified using peptidomics. The peptide profiles and the composition of the master proteins of the O-AD and T-AD were different. The DPPH and ABTS radical scavenging abilities of WPHs were measured, and hydrolysates were found to exhibit a strong radical scavenging ability after being treated using different hydrolysis methods. An enzyme-linked immunosorbent assay showed that the sensitization of WPHs was significantly reduced. This study may provide useful information regarding the antioxidant properties and allergenicity of WPHs.

Soy protein processing impacts the ice recrystallization inhibition activity of protein hydrolysates

Soy protein processing impacts the ice recrystallization inhibition activity of protein hydrolysates

The role of duel hydrolysis of soybean on functional properties and protein digestibility: a sustainable approach.

Protein hydrolysates derived from food sources contains enormous number of peptides which are composed of amino acid possessess various bioactive properties. However, the use of protein hydrolysates as a nutraceutical is hindered due to their unpleasant flavour. The study aims to enhance the biological activity and palatability of protein hydrolysates. In the present study, soybean protein hydrolysate (SPH) was prepared using alcalase for 4 h (control). Modification of hydrolysis (MPH) was carried out by reiterating the hydrolysis of the supernatant obtained after 2 h of hydrolysis using an enzyme to 50% of alcalase during each successive hydrolysis. Samples were characterised by their physio-chemical and functional properties. Furthermore, the effect of modification on the protein digestibility and bitterness intensity using e-tongue was studied. The suppressive effect on retrogradation of corn starch was analysed using texture profile analysis. The results demonstrated increased protein content by 1.6 and 1.9% in MPH compared to SPH and UNH, respectively. MPH showed 1.5- and 1.6-fold higher DH% than SPH before and after gastrointestinal digestion (p < 0.05). A decrease in molecular weight was found in the order of UNH > SPH > MPH. Nevertheless, MPH displayed significantly higher functional properties (p ≤ 0.05). The hardness of retrograded corn starch was significantly reduced in the MPH (1.21N) than SPH (1.55 N) and UNH (1.81N) compared to control (1.71N) during 7-day storage at 4°C (p ≤ 0.05). E-tongue analysis of MPH showed a 4-fold reduction in bitterness than SPH. Modification of hydrolysis of soybean has demonstrated its significance in improved DH% functional properties and palatability. In addition, improved protein digestibility with promising benefits in deferral action on retrogradation of starch over the traditional process of hydrolysis was observed. The outcome of this study contributes to the potential utilisation of MPH as an ingredient in the formulation of nutraceutical products.

Integrated HS-SPME-GC–MS and UHPLC-O-TOF-MS-based metabolomics revealed the characteristics flavor and nonvolatile metabolites during the hydrolysis process of Boletus edulis

This research aimed to investigate the flavor characteristic, metabolites and bioactivities of Boletus edulis hydrolysates via HS-SPME-GC-MS and UHPLC-MS/MS. The Maillard reaction (MR) significantly enhanced the sensory qualities of Boletus edulis, including like-meat, caramel, continuity, and complete acceptance. The accumulation of browning precursors during MR was verified through spectral analysis. We also found that the MR enhanced the antioxidant and hypoglycemic activities of Boletus edulis hydrolysates. Furthermore, 11 VOCs were also identified as key aromatic compounds and had important impact on the flavor characteristics of Maillard reaction products (MRPs). Non-targeted metabolomics analyses revealed that the formation of MRPs was affected through amino acid metabolism, lipid metabolism and plant secondary metabolism. Briefly, the flavor and biological activity of Boletus edulis were improved through enzymolysis and MR. The results provided a theoretical foundation for deep processing and resource utilization of Boletus edulis.

Antifungal, Hydrolytic Enzyme Activity, and Identification of Gut Bacterial in Feces of Black Soldier Fly (Hermetia illucens) Larvae

AbstractBlack soldier fly (BSF) (Hermetia illucens) is a type of fly that has larvae called maggots with potential as a waste bioremediation agent. Maggot from BSF has unique digestive characteristics with a diversity of bacteria in it which helps maggot digest organic materials by producing various hydrolytic enzymes. Fecal bacteria in maggots also have potential antifungal activity. This research aimed to identify the hydrolytic and antifungal enzyme activity of maggot fecal bacteria (Hermetia illucencs). Hydrolytic enzyme activity is carried out by measuring the hydrolytic zone in the test medium. The antifungal antagonist test was carried out on Phytophthora sp. using the dual agar culture method. The results of the enzyme activity test showed that isolate MNM 001 had proteolytic enzyme activity, MNM 002 had amylolytic, and proteolytic enzyme activity, and was able to dissolve P elements. MNM 003 had cellulolytic, amylolytic, and proteolytic enzyme activity. From the results of the antagonist test, MNM 001, MNM 002, and MNM 003 have antifungal activity against Phytophthora sp. of the three isolates, isolates MNM 002 and MNM 003 had the best hydrolytic enzyme activity and were identified using the 16S rRNA gene. The results of amplification of the 16S rRNA gene from MNM 002 and MNM 003 indicated that the two isolates were close to the genus Brevibacterium.AbstrakBlack soldier fly (BSF) (Hermetia illucens) adalah jenis lalat yang memiliki larva disebut maggot dengan potensi sebagai agen bioremediasi sampah. Maggot dari BSF memiliki karakterisitik pencernaan unik dengan keragaman bakteri di dalamnya yang membantu maggot mencerna bahan organik dengan menghasilkan beragam enzim hidrolitik. Bakteri pada feses maggot juga memiliki potensi aktivitas antifungi. Tujuan dari penelitian ini adalah untuk mengidentifikasi aktivitas enzim hidrolitik dan antifungi dari bakteri feses maggot (Hermetia illucens). Aktivitas enzim hidrolitik dilakukan dengan mengukur zona hidrolitik pada medium uji. Uji antagonis antifungi dilakukan terhadap Phytophthora sp. dengan metode dual culture agar. Hasil uji aktivitas enzyme menunjukkan isolat MNM 001 memiliki aktivitas enzim proteolitik, MNM 002 memiliki aktivitas enzim amilolitik, proteolitik, dan mampu melarutkan unsur P. MNM 003 memiliki aktivitas enzim selulolitik, amilolitik, dan proteolitik. Hasil uji antagonis MNM 001, MNM 002, dan MNM 003 memiliki aktivitas antifungi terhadap Phytophthora sp. Ketiga isolat tersebut, isolate MNM 001, MNM 002, dan MNM 003 memiliki aktivitas enzim hidrolitik terbaik dan diidentifikasi menggunakan gen 16S rRNA. Hasil amplifikasi gen 16S rRNA dari MNM 002 dan MNM 003 mengindikasikan bahwa kedua isolat tersebut memiliki kedekatan dengan genus Brevibacterium.

IF1 is a cold-regulated switch of ATP synthase hydrolytic activity to support thermogenesis in brown fat

While mechanisms controlling uncoupling protein-1 (UCP1) in thermogenic adipocytes play a pivotal role in non-shivering thermogenesis, it remains unclear whether F1Fo-ATP synthase function is also regulated in brown adipose tissue (BAT). Here, we show that inhibitory factor 1 (IF1, encoded by Atp5if1), an inhibitor of ATP synthase hydrolytic activity, is a critical negative regulator of brown adipocyte energy metabolism. In vivo, IF1 levels are diminished in BAT of cold-adapted mice compared to controls. Additionally, the capacity of ATP synthase to generate mitochondrial membrane potential (MMP) through ATP hydrolysis (the so-called “reverse mode” of ATP synthase) is increased in brown fat. In cultured brown adipocytes, IF1 overexpression results in an inability of mitochondria to sustain the MMP upon adrenergic stimulation, leading to a quiescent-like phenotype in brown adipocytes. In mice, adeno-associated virus-mediated IF1 overexpression in BAT suppresses adrenergic-stimulated thermogenesis and decreases mitochondrial respiration in BAT. Taken together, our work identifies downregulation of IF1 upon cold as a critical event for the facilitation of the reverse mode of ATP synthase as well as to enable energetic adaptation of BAT to effectively support non-shivering thermogenesis.

Phase-Separated Nano-Antibiotics Enhanced Survival in Multidrug-Resistant Escherichia coli Sepsis by Precise Periplasmic EcDsbA Targeting.

Disulfide bond (Dsb) proteins, especially DsbA, represent a promising but as-yet-unrealized target in combating multidrug-resistant (MDR) bacteria because their precise subcellular targeting through multibarrier remains a significant challenge. Here, a novel heterogenization-phase-separated nano-antibiotics (NCefoTs) is proposed, through the co-assembly of enzyme-inhibiting lipopeptides (ELp component), membrane-recognizing and disrupting lipopeptides (MLp component), and cefoperazone. The self-sorting components of MLp"concentrated island-liked clusters"on the surface of NCefoTs promote the efficient penetration of NCefoTs through the outer membrane. Triggered by the DsbA, the precisely spatiotemporal engineered NCefoTs transform to nanofibers insitu and further significantly enhance the inhibition of DsbA. The hydrolytic activity of β-lactamase and the motility function of flagella are thereby impeded, confirming the efficacy of NCefoTs in restoring susceptibility to antibiotics and inhibiting infection dissemination. By these synergistic effects of NCefoTs, the minimum inhibitory concentration of antibioticsdecreases from over 300 µM to 1.56 µM for clinically isolated E. coli MDR. The survival rate of sepsis-inflicted mice is significantly enhanced from 0% to 92% upon encapsulation of cefoperazone in NCefoTs, which rapidly eliminates invading pathogens and mitigates inflammation. The universally applicable delivery system, based on an "on demands" strategy, presents a promising prospect for undruggable antibiotic targets in the periplasm to combat MDR bacteria.

Rate of hydrolysis of the phosphate esters of B vitamins is reduced by zinc deficiency: Invitro and invivo.

Extracellular hydrolysis of the phosphate esters of B vitamins (B1, B2, and B6) is crucial for their cellular uptake and metabolism. Although a few zinc-dependent enzymes have been implicated in these processes, their exact mechanisms of action remain largely unknown. This study investigated the potential involvement of phosphate group hydrolyzing enzymes in the hydrolysis of B vitamin phosphate esters. We evaluated enzyme activity in membrane lysates prepared from cells transiently transfected with these enzymes or those endogenously expressing them. Specifically, we investigated how zinc deficiency affects the rate of hydrolysis of B vitamin phosphate esters in cellular lysates. Assessment of the activities of zinc-dependent ectoenzymes in the lysates prepared from cells cultured in zinc-deficient conditions and in the serum of rats fed zinc-deficient diets revealed that zinc deficiency reduced the extracellular hydrolysis activity of B vitamin phosphate esters. Furthermore, our findings explain the similarities between several symptoms of B vitamin and zinc deficiencies. Collectively, this study provides novel insights into the diverse symptoms of zinc deficiency and could guide the development of appropriate clinical strategies.

Enzymatic hydrolysis and biological activities of Konjac glucomannan hydrolysate in different degree of polymerisation

SummaryThe study explores the enhanced functional and bioactive properties of Konjac Glucomannan Hydrolysate (KGMH) by partially degrading Konjac Glucomannan (KGM) using β‐mannanase over 60 min. KGM concentrations (40% and 50% w/w) were treated with 200–300 U g−1 of the enzyme over 60 min. The hydrolysis of KGM was monitored by colorimetry, with DP values ranging from 4.20 to 6.16 for 40% KGM and 4.10 to 4.60 for 50% KGM. MALDI‐TOF‐MS analysis confirmed typical oligosaccharides with DP values from 2 to 9 and some acetyl substitutions. The optimal conditions of 40% KGM with 250 U g−1 enzyme and varying hydrolysis times produced KGMHs with a wide range of DPs, demonstrating in vitro antioxidant and anti‐glycation activities. The results showed significant bioactivities (P &lt; 0.05) positively correlated with lower DP values. This study emphasises the potential of KGMH as a novel functional food ingredient, highlighting its bioactive properties and the significant impact of DPs on the biological functionality of saccharides.

High Salt-Resistant Urethanase Degrades Ethyl Carbamate in Soy Sauce.

Urethanase is a promising biocatalyst for degrading carcinogen ethyl carbamate (EC) in fermented foods. However, their vulnerability to high ethanol and/or salt and acidic conditions severely limits their applications. In this study, a novel urethanase from Alicyclobacillus pomorum (ApUH) was successfully discovered using a database search. ApUH shares 49.4% sequence identity with the reported amino acid sequences. It belongs to the Amidase Signature family and has a conserved "K-S-S" catalytic triad and the characteristic "GGSS" motif. The purified enzyme overexpressed in Escherichia coli exhibits a high EC affinity (Km, 0.306 mM) and broad pH tolerance (pH 4.0-9.0), with an optimum pH 7.0. Enzyme activity remained at 58% in 12% (w/v) NaCl, and 80% in 10% (v/v) ethanol or after 1 h treatment with the same ethanol solution at 37 °C. ApUH has no hydrolytic activity toward urea. Under 30 °C, the purified enzyme (200 U/L) degraded about 15.4 and 43.1% of the EC in soy sauce samples (pH 5.0, 6.0), respectively, in 5 h. Furthermore, the enzyme also showed high activity toward the class 2A carcinogen acrylamide in foods. These attractive properties indicate their potential applications in the food industry.

Enhancing concrete self-healing capabilities of Bacillus sphaericus spores through the encapsulation in biopolymeric microcapsules

This study examined the encapsulation of Bacillus sphaericus LMG 22257 spores in biopolymeric microcapsules (MCs) for use in cement mortar, with a focus on enhancing self-healing properties. Biopolymers, including alginate (ALG), chitosan (CTS), carboxymethyl cellulose (CMC), and ALG/CMC blends at various ratios, were employed to fabricate the MCs through ionotropic gelation and freeze–drying. The physicochemical properties of MCs, including size, morphology, and swelling behavior under simulated concrete conditions, were assessed. Among these, ALG/CMC-MCs exhibited superior characteristics and demonstrated the highest urea hydrolysis activity when incorporated into the mortar, indicating optimal spore protection. Despite an initial decrease in compressive strength, the ALG/CMC blend with an ALG:CMC mass ratio of 6:4 achieved a crack healing efficiency of 96.7% over 28 days under cyclic wet-dry conditions. These findings highlight the potential of biopolymer encapsulation for embedding functional microorganisms in construction materials, contributing to a more durable and sustainable infrastructure.