Enzymatic Attack Research Articles

Physicochemically protected organic carbon release is the rate-limiting step of rhizosphere priming in paddy soils

Iron oxides affect the stability of soil organic matter (SOM), which in turn affects greenhouse gas emissions in paddy soils. They also regulate the direction and magnitude of the rhizosphere priming effect (RPE) by restricting SOM accessibility and microbial activity. However, the controlling steps and key factors that regulate the RPE magnitude under anoxic conditions are unknown. In this study, we investigated the mechanisms through which Fe(III) reduction affects the RPE using humic acid as an electron shuttle in paddy soils and conducting continuous 13CO2 labeling of rice plants. The RPE, measured via CO2 emission, was approximately 25 % greater in soils with humic acid than in soils without. A rapid increase in the RPE of CH4 emissions after 41 days was attenuated in soils containing humic acid. Root growth and Fe(III) reduction stimulated the total primed CO2 emissions from the rhizosphere independent of the microbial biomass and enzyme activities. Humic acid accelerated Fe(III) reduction, leading to a decrease in Fe-bound organic carbon and an increase in RPE (CO2 emissions). The rhizosphere-primed CO2 emissions decreased with increasing amounts of reactive Fe(III) (oxyhydr)oxides, which protected the SOM from microbial and enzymatic attacks. Biochemical Fe(III) reduction and physical aggregate destruction controlled the abiotic transformation of inaccessible SOM into bioavailable organic carbon, thereby regulating the RPE. The results suggest that the reduction of reactive Fe(III) minerals is the rate-limiting step in the release of the physicochemically protected SOM, which in turn determines the magnitude of rhizosphere priming in paddy soils.

Enzymatic biocatalysis processes on the semicrystalline and morphological order of native cassava starches (Manihot esculenta)

Enzymatic biocatalysis has emerged as a green technology in starch modification with divergent results at the morphological level depending on the origin of the starch source. Therefore, various enzymatic biocatalysts were implemented to evaluate their effect on the morphological and semi-crystalline characteristics of native cassava starches. The degree of affinity of the biocatalysts and the conversion rate on native cassava starches were determined by kinetic parameters such as the Michaelis-Menten constant, whose results revealed the following order of affinity from highest to lowest: α-amylase, amyloglucosidase, pullulanase, and β-amylase. In addition, greater biocatalytic activity of α-amylase and β-amylase was evidenced on the amorphous zones of the polymer associated with the decrease in the amylose content and a significant increase in the degree of relative crystallinity. According to morphological analyses and XDR, the action of amyloglucosidase promoted exo-erosion phenomena and the appearance of lacerations on the granular surface of starch with the consequent decrease in the semicrystalline order. The pullulanase caused slightly eroded fragmented granules with greater biocatalytic activity on the crystalline lamellae, associated with a significant increase in the apparent amylose content. FTIR analysis in the 1,200-900 cm-1 region, corresponding to the starch fingerprint, allowed us to detect notable changes in the degree of molecular order after the enzymatic attack; this result was consistent with the degree of relative crystallinity estimated by X-ray diffraction. Likewise, the results allowed us to notice significant changes in the semi-crystalline order and morphological characteristics during the modification with α-amylase (AAM) and amyloglucosidase (AMG) associated with their greater affinity and preferential action on the amorphous structures located on the granular surface of native cassava starch.

Crosslinking of base-modified RNAs by synthetic DYW-KP base editors implicates an enzymatic lysine as the nitrogen donor for U-to-C RNA editing

Sequence-specific cytidine to uridine (C-to-U) and adenosine to inosine editing tools can alter RNA and DNA sequences and utilize a hydrolytic deamination mechanism requiring an active site zinc ion and a glutamate residue. In plant organelles, DYW-PG domain containing enzymes catalyze C-to-U edits through the canonical deamination mechanism. Proteins developed from consensus sequences of the related DYW-KP domain family catalyze what initially appeared to be uridine to cytidine (U-to-C) edits leading to this investigation into the U-to-C editing mechanism. The synthetic DYW-KP enzyme KP6 was found sufficient for C-to-U editing activity stimulated by the addition of carboxylic acids invitro. Despite addition of putative amine/amide donors, U-to-C editing by KP6 could not be observed in vitro. C-to-U editing was found not to be concomitant with U-to-C editing, discounting a pyrimidine transaminase mechanism. RNAs containing base modifications were highly enriched in interphase fractions consistent with covalent crosslinks to KP6, KP2, and KP3 proteins. Mass spectrometry of purified KP2 and KP6 proteins revealed secondary peaks with mass shifts of 319Da. A U-to-C crosslinking mechanism was projected to explain the link between crosslinking, RNA base changes, and the ∼319Da mass. In this model, an enzymatic lysine attacks C4 of uridine to form a Schiff base RNA-protein conjugate. Sequenced RT-PCR products from the fern Ceratopteris richardii indicate U-to-C base edits do not preserve proteinaceous crosslinks in planta. Hydrolysis of a protonated Schiff base conjugate releasing cytidine is hypothesized to explain the completed pathway in plants.

Interfacial kinetics reveal enzymatic resistance mechanisms behind granular starch with smooth surfaces

Heterogeneous (interfacial) enzyme catalyzed hydrolysis of starch granules occurs in various biological systems, including plants, animal/human digestion, and microorganisms. Factors such as granular size, surface area, pores, and smoothness play crucial roles in influencing this process. However, limited understanding persists regarding the high enzymatic resistance of starch granules with smooth surfaces. In this study, we investigated the hydrolysis mechanism of glucoamylase (GA) on three different types of starch granules with smooth surfaces, extracted from Curcuma zedoaria (zedoary) rhizomes, Solanum tuberosum (potato) tubers, and Manihot esculenta (tapioca or cassava) roots. We compared the Langmuir adsorption, interfacial kinetics, and the multi-level structure of the three starches. Our data demonstrate that the lower enzymatic resistance observed in tapioca starch stems from the higher density of enzymatic attack sites (kinΓmax) recognized by GA on tapioca starch (1.0 nmol/g) compared to potato (0.6 nmol/g) and zedoary (0.3 nmol/g) starch granules. The high kinΓmax for tapioca starch was significantly influenced by its relatively lower B-type crystallinity, which is disrupted by the presence of short fa chains (degree of polymerization (DP) < 12) and long amylose chains. Furthermore, the relatively higher proportion of longer chains (fb1 and fb2 chains) on the surface of tapioca starch also contributed to higher kinΓmax for GA, resulting in lower enzymatic resistance. These findings enhance our understanding of how the structure of starch granules affects enzymatic catalysis, particularly in granular starches with smooth surfaces devoid of pores. Such insights are crucial for elucidating the digestion and utilization of starch granules.

In Silico Analysis of Natural Plant-Derived Cyclotides with Antifungal Activity against Pathogenic Fungi.

Fungal infections in plants, animals, and humans are widespread across the world. Limited classes of antifungal drugs to treat fungal infections and loss of drug efficacy due to rapidly evolving fungal strains pose a challenge in the agriculture and health sectors. Hence, the search for a new class of antifungal agents is imperative. Cyclotides are cyclic plant peptides with multiple bioactivities, including antifungal activity. They have six conserved cysteine residues forming three disulfide linkages (CI-CIV, CII-CV, CIII-CVI) that establish a Cyclic Cystine Knot (CCK) structure, making them extremely resistant to chemical, enzymatic, and thermal attacks. This in silico analysis of natural, plant-derived cyclotides aimed to assess the parameters that can assist and hasten the process of selecting the cyclotides with potent antifungal activity and prioritize them for in vivo/ in vitro experiments. The objective of this study was to conduct in silico studies to compare the physicochemical parameters, sequence diversity, surface structures, and membrane-cyclotide interactions of experimentally screened (from literature survey) potent (MIC ≤ 20 μM) and non-potent (MIC > 20 μM) cyclotides for antifungal activity. Cyclotide sequences assessed for antifungal activity were retrieved from the database (Cybase). Various online and offline tools were used for sequence-based studies, such as physicochemical parameters, sequence diversity, and neighbor-joining trees. Structure-based studies involving surface structure analysis and membrane-cyclotide interaction were also carried out. All investigations were conducted in silico. Physicochemical parameter values, viz. isoelectric point, net charge, and the number of basic amino acids, were significantly higher in potent cyclotides compared to non-potent cyclotides. The surface structure of potent cyclotides showed a larger hydrophobic patch with a higher number of hydrophobic amino acids. Furthermore, the membrane-cyclotide interaction studies of potent cyclotides revealed lower transfer free energy (ΔG transfer) and higher penetration depth into fungal membranes, indicating higher binding stability and membrane-disruption ability. These in silico studies can be applied for rapidly identifying putatively potent antifungal cyclotides for in vivo and in vitro experiments, which will ultimately be relevant in the agriculture and pharmaceutical sectors.

The synergistic effect of lactic acid bacteria fermentation combined with gluten on the starch digestive properties of highland barley

In this study, the synergistic effect of fermentation and gluten on highland barley starch digestibility was investigated, and the possible mechanisms were explored. The addition of gluten during fermentation increased the resistant starch content from 16.03% to 28.57% in highland barley. Both fermentation and the addition of gluten inhibited starch swelling and gelatinization. The combination of fermentation and gluten exhibited the most pronounced synergistic effect. Fermentation, with/without gluten addition, had a significant influence on the long-range ordered structure, while only fermentation with gluten addition influenced the short-range ordered structure. Furthermore, confocal laser scanning microscopy images indicated that fermentation facilitated the interaction between exogenously added gluten and starch, forming a dense protective layer around starch granules. This protective layer limited starch gelatinization and protected the starch from enzymatic attack. The results of rheological analyses suggested that the interaction between gluten and starch was primarily driven by hydrogen bonding. These findings will enrich the theory that the synergistic effect of fermentation and gluten improves the digestive properties of cereal starch and facilitates the development of healthy cereal products.

Are biological pretreatments of lignocellulosic residues a real option for biofuels production?

The use of lignocellulosic residues as feedstocks for biofuels production represents an economic and ecofriendly option, since they are generated as byproducts or wastes from different industrial areas. Nevertheless, a pretreatment method aimed at eliminating the lignin content of these residues must be performed. This is required in order to increase cellulose bioavailability, which favors the production of reducing sugars through microbial or enzymatic attack. Some performed pretreatments can be classified as physical, chemical, and physicochemical methods. Although such methods are the most used pretreatments, they are expensive and generate or make use of harmful compounds. Biological methods, by the action of microorganisms or their enzymes for lignin content reduction, may be regarded as an alternative, being cheaper and more friendly to the environment than the aforementioned methods. However, until now, biological pretreatments have not shown the same yield as the previously mentioned methods in both sugar recovery and biofuel production. In that sense, the aim of this work is to review the efficiency of these methods, with the goal of clarifying their advantages and disadvantages for improvement of biofuel production.

In vitro study on the inflammatory response of chitosan nanoparticles as a potential siRNA carrier targeting towards osteosarcoma cells

Abstract There have been significant developments in the use of siRNA in the silencing of cancer-allied target proteins with substantial apoptotic effects. Nevertheless, the challenges regarding siRNA delivery for cancer therapy remain a major concern for taking these therapies successfully from laboratory to in vivo studies. Biomaterials are defined traditionally as any material that is used for either medical or dental applications that contact the host cells in any form, such as a drug carrier a device, or as a prosthesis towards the replacement of damaged tissues. The main issues to be fulfilled by the biomaterial for clinical applications are biocompatibility, bioactivity, ability to carry drug to target site, inflammatory responses and other factors based on its application. The present study focuses on the in vitro inflammatory response to the CS nanoparticles using RAW 264.7 and bone marrow derived macrophage cells. Additionally, the in vitro release kinetics of siRNA with varying concentrations and pH, transfection efficacy and biocompatibility were also investigated. The results of siRNA cumulative release increased at pH 5 and 3, which may be corresponding to the protonation, and a delayed release was seen at 7, which was ascribed to unprotonated amine groups inside the CS. The results of release kinetics confirmed a sustained release of siRNA from CS NPs. Considering that CS is a biocompatible polymer, it typically has little impact/damage on cells, as numerous researchers have observed during in vitro experiments. Inflammatory studies were carried out in vitro with RAW 264.7 and BMC cells derived from mice. The gene and protein expression studies showed that the materials might cause some slight inflammation on exposure with both RAW 264.7 and BMC cells in vitro, which is completely negligible. However, putting together the overall data it can be concluded that CS NPs can be a promising material for in vivo applications, which is in agreement with the results of other researchers, but the only concern being its ability to carry siRNA and protect it from nuclease and other enzymatic attacks.

BIOPROCESS OPTIMIZATION FOR PECTINASE PRODUCTION IN A SUBMERGED CULTIVATION SYSTEM USING VARIOUS FILAMENTOUS FUNGI.

The pectinase enzymes attack in several ways; the pectin is widely used in processing fruit juices, extracting vegetable oil, processing alcoholic drinks, and various uses in food industries. The present study was carried out to utilize an agro-industrial by-product (date syrup) as a carbon source for the growth of different fungi and the production of the pectinase enzyme. Four types of fungi (Penicillium lilacinum, Mucor geophillus, Aspergillus niger and Aspergillus fumigatus) were used in this study. The maximum production rate of pectinase was observed by A. niger when grown on a mineral medium incorporated with 2.5% and 5% date syrup compared to other fungi used. The highest rate of pectinase, 5.68 units/ml, was produced after 72 hours when A. niger was grown on 5% date syrup.

The Interplay of Protein Hydrolysis and Ammonia in the Stability of Hevea Rubber Latex during Storage.

Natural rubber (NR) latex derived from Hevea brasiliensis is a complex colloid comprising mainly rubber hydrocarbons (latex particles) and a multitude of minor non-rubber constituents such as non-rubber particles, proteins, lipids, carbohydrates, and soluble organic and inorganic substances. NR latex is susceptible to enzymatic attack after it leaves the trees. It is usually preserved with ammonia and, to a lesser extent, with other preservatives to enhance its colloidal stability during storage. Despite numerous studies in the literature on the influence of rubber proteins on NR latex stability, issues regarding the effect of protein hydrolysis in the presence of ammonia on latex stability during storage are still far from resolved. The present work aims to elucidate the interplay between protein hydrolysis and ammoniation in NR latex stability. Both high- and low-ammonia (with a secondary preservative) NR latexes were used to monitor the changes in their protein compositions during storage. High-ammonia (FNR-A) latex preserved with 0.6% (v/v) ammonia, a low 0.1% ammonia/TMTD/ZnO (FNR-TZ) latex, and a deproteinized NR (PDNR) latex were labeled with fluorescence agents and observed using confocal laser scanning microscopy to determine their protein composition. Protein hydrolysis was confirmed via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results revealed that protein hydrolysis increased with the storage duration. The change in protein composition accompanying hydrolysis also allows the spatial distribution of allergenic proteins to be estimated in the latex. Concurrently, the latex stability increased with the storage duration, as measured by the latex's mechanical stability time (MST) and the zeta potential of the latex particles. As monitored by AFM, the surface roughness of the NR latex film increased markedly during extended storage compared with that of the DPNR latex, which remained smooth. These results underscore the pivotal role of ammonia in bolstering NR latex stability brought on by protein hydrolysis, which greatly impacts latex film's formation behavior. NR latex stability underpins the quality of latex-dipped goods during manufacturing, particularly those for medical gloves.

Enzymatic degradation of poly(ethylene terephthalate) (PET): Identifying the cause of the hypersensitive enzyme kinetic response to increased PET crystallinity

Plastic pollution poses a significant environmental challenge, with poly(ethylene terephthalate) (PET) being a major contributor due to its extensive use in single use applications such as plastic bottles and other packaging material. Enzymatic degradation of PET offers a promising solution for PET recycling, but the enzyme kinetics in relation to the degree of crystallinity (XC) of the PET substrate are poorly understood. In this study, we investigated the hypersensitive enzyme kinetic response on PET at XC from ∼8.5–12% at 50 °C using the benchmark PET hydrolysing enzyme LCCICCG. We observed a substantial reduction in the maximal enzymatic reaction rate (invVmax) with increasing XC, corresponding to a 3-fold reduction in invVmax when the XC of PET increased from 8.6% to 12.2%. The kinetic analysis revealed that the level of the Mobile Amorphous Fraction (XMAF) was a better descriptor for the enzymatic degradation rate response than XC (or (100%-XC)). By continuous monitoring of the enzymatic reaction progress, we quantified the lag phase prolongation in addition to the steady-state kinetic rates (vss) of the reactions and found that the duration of the lag phase of a reaction could be predicted from the vss and XC by multiple linear regression modeling. The linear correlation between the duration of the lag phase and the vss of the enzymatic PET degradation affirmed that the LCCICCG worked via a random/endo-type enzymatic attack pattern. The longer lag phase at increased XC of PET is proposed to be due to increased substrate entanglement density as well as unproductive enzyme binding to the crystalline regions of PET. The findings enhance our understanding of PET enzymatic degradation kinetics and its dependence on substrate composition, i.e., XMAF and XC.

Physicochemical properties of fortified flour based modified cassava flour blended with bacterial poly-glutamic acid

Cassava is one of the most important staple crops worldwide. However, cassava flour needs to meet the high-quality requirements in terms of physicochemical characteristics. The present study was designed to investigate properties of fortified cassava flour produced from co-processing of modified cassava flour with poly-glutamic acid (PGA) derived from protein of beans that had been fermented by Bacillus natto. Proximate analysis, cyanide content, swelling power, solubility, and viscosity of modified cassava flour (MCF) which was fortified with poly-glutamic acid (PGA) was found to indicate improvements as compared to the native flour. The modified flours were further investigated for their physicochemical properties after addition of poly- -glutamic acid ( -PGA) at different levels. All flour samples showed no significant (p&gt;0.05) differences in terms of lightness (L*), while greenness to redness (a*) of native flours was significantly (p&lt;0.05) higher than modified flours with -PGA. There were significant (p&lt;0.05) differences in the swelling power and solubility measured at various temperatures. From the pasting profiles, there were significant (p&lt;0.05) increases in peak viscosity, final viscosity and pasting temperature of cassava flours due to addition of -PGA. Observation by scanning electron microscopy (SEM), pronounced cracks were observed in starch granules indicative of enzyme attack. It indicated that starch granules of modified and fortified cassava flour were depolymerized by enzymatic hydrolysis which led to cause change and degrade exterior surface of the granules within corrosion via pores of small granules.

Modeling of the Peptide Release during Proteolysis of β-Lactoglobulin by Trypsin with Consideration of Peptide Bond Demasking.

Prospects for predicting the fragmentation of polypeptide chains during their enzymatic hydrolysis using proteolysis models are considered. The opening of the protein substrate during proteolysis and the exposure of its internal peptide bonds for a successful enzymatic attack, the so-called demasking process, were taken into account. The two-step proteolysis model was used, including the parameters of demasking and the rate constants of hydrolysis of enzyme-specific peptide bonds. Herein, we have presented an algorithm for calculating the concentrations of intermediate and final peptide fragments depending on the time of hydrolysis or the degree of hydrolysis. The intermediate peptide fragments with two or one internal specific peptide bond were considered. The fragmentation of β-lactoglobulin (β-LG) by trypsin was predicted, and the calculated concentration curves for peptide fragments were compared with the experimental dependences of the concentrations on the degree of hydrolysis. Numerical parameters were proposed that characterize the concentration curves for intermediate and final peptide fragments, and they were used to compare the calculated and experimental dependences. The predicted distribution of the peptide fragments corresponded to the experimental data on the peptide release during the proteolysis of β-LG by trypsin.

Profound structural conservation of chemically cross-linked HIV-1 envelope glycoprotein experimental vaccine antigens

Chemical cross-linking is used to stabilize protein structures with additional benefits of pathogen and toxin inactivation for vaccine use, but its use has been restricted by the potential for local or global structural distortion. This is of particular importance when the protein in question requires a high degree of structural conservation for inducing a biological outcome such as the elicitation of antibodies to conformationally sensitive epitopes. The HIV-1 envelope glycoprotein (Env) trimer is metastable and shifts between different conformational states, complicating its use as a vaccine antigen. Here we have used the hetero-bifunctional zero-length reagent 1-Ethyl-3-(3-Dimethylaminopropyl)-Carbodiimide (EDC) to cross-link two soluble Env trimers, selected well-folded trimer species using antibody affinity, and transferred this process to good manufacturing practice (GMP) for experimental medicine use. Cross-linking enhanced trimer stability to biophysical and enzyme attack. Cryo-EM analysis revealed that cross-linking retained the overall structure with root-mean-square deviations (RMSDs) between unmodified and cross-linked Env trimers of 0.4–0.5 Å. Despite this negligible distortion of global trimer structure, we identified individual inter-subunit, intra-subunit, and intra-protomer cross-links. Antigenicity and immunogenicity of the trimers were selectively modified by cross-linking, with cross-linked ConS retaining bnAb binding more consistently than ConM. Thus, the EDC cross-linking process improves trimer stability whilst maintaining protein folding, and is readily transferred to GMP, consistent with the more general use of this approach in protein-based vaccine design.

Rational design of novel compounds to serve as potential NDM-1 inhibitors using molecular docking, molecular dynamics simulation, and physicochemical studies

ABSTRACT New Delhi Metallo-β-lactamase (NDM-1) is an enzyme that hydrolyses a wide range of β-lactam antibiotics, including most carbapenems, leading to antimicrobial resistance. The development of a novel NDM-1 inhibitor for use in combination with carbapenems may help to combat drug-resistant pathogens. Twenty compounds were designed based on the structural features of the NDM-1 active site to inhibit bacterial NDM-1 and protect β-lactam antibiotics from enzyme attack. The designed molecules were naphthalene, thiazole, and sulfone derivatives because they could coordinate with the zinc ions and form hydrophobic contracts with the enzyme’s active site. A molecular docking protocol was used to identify potential inhibitor(s) of the NDM-1 target protein. Furthermore, drug-likeness and pharmacokinetic properties of the designed molecules were predicted. Three compounds with the more negative ΔGbinding results were selected for further investigation using molecular dynamic (MD) simulations. T016 had a significantly more negative binding free energy than the positive control and other designed molecules, had stable MD simulations (Root-mean-square deviation < 0.5 Å), passed Lipinski’s rule of five, and had favourable physicochemical and pharmacokinetic properties. The findings can be used to inform the synthesis and in vitro testing of the selected molecules.

Candida auris: a growing threat to global health

Candida auris (C. auris) belongs to the Candida genus and is a fungal yeast resistant to multiple drugs. It is highly virulent and evades current therapeutic remedies. It was first discovered in a Japanese hospital in 2009 from a patient’s external auditory canal1. C. auris infection has a high worldwide mortality, which ranges from 30% to 60%, and is frequently associated with bloodstream infections2. The rapid spread of C. auris infection occurred after 2009. The Centers for Disease Control and Prevention (CDC) has estimated the presence of C. auris isolates in 41 countries, typically in hospital settings, as of March 20203. CDC also reported outbreaks of infections with C. auris in 47 countries globally on February 15, 20214. The United States reported 2377 clinical cases and 5754 screening cases from January 2022 to December 20225. Twenty-six isolates of C. auris from India were different genetically and phenotypically from the ones found in Japan and Korea, which provided evidence for C. auris’s ability to mutate and its resistance to Azoles6. The mechanism of C. auris virulence factors is relatively unknown. According to genomic comparison, C. auris has the ability to adapt to different environments. Two mechanisms of its pathogenesis have been identified, which include hydrolytic enzyme production and attack host cells and tissues. It can also form biofilms that protect it from antifungal drugs and increase its ability in nosocomial transmission4. C. auris can be spread in health care facilities such as hospitals and nursing homes through direct patient-to-patient contact. Contaminated surfaces are a significant culprit in the spread when a person comes in contact with them. As C. auris colonizes the skin and can be transmitted into the environment, both properties make it easily transmissible. Population susceptible are immunocompromised people, recently hospitalized patients in areas where C. auris is endemic; catheter use, extended stay in ICU, previous history of antimicrobial exposure, and resistance to antifungal therapy7. Identifying this pathogen is tricky as the methods used to determine the yeast in laboratories often must be corrected for other fungi. Detection of C. auris requires reliable sampling procedures from the most common sites of colonization, including the axillae and groin. Nares, external auditory canals, urine, rectum, catheter sites, and vagina also serve as colonization sites8. Making use of water and soaps or using a hand sanitizer with a 60% alcohol content is effective in preventing infection. Health care workers should take proper precautions to use gowns and gloves in the hospital setting. Regular disinfection and cleaning of surfaces prevent the survival of C. auris. When referring a patient with C. auris, the health care facility on the receiving end should be informed of the patient’s infection or colonization status to take appropriate measures promptly9. The steadily rising incidence of C. auris outbreaks poses a significant public health threat. C. auris outbreaks are a challenge to control due to poor routine diagnostic detection, prompt transmission, and resistance to disinfection techniques. It is now a leading cause of fungal infections in many medical setups with high mortality rates. Rapid detection methods that provide reliable identification and diagnosis, as well as control measures and necessary precautions, will help contain the spread of C. auris in health care systems. Ethical approval None. Consent for publication None. Sources of funding None. Author contributions The conceptualization was done by H.F. and H.S.R. The literature and drafting of the manuscript were conducted by H.F., A.M.S., F.R., and B.S.R. The editing and supervision were performed by H.S.R. All authors have read and agreed to the final version of the manuscript. Conflict of interest disclosures The authors declare that they have no financial conflict of interest with regard to the content of this report. Research registration unique identifying number (UIN) Not applicable. Guarantor All authors take responsibility for the work, access to data and decision to publish. Provenancer and Peer review Not commissioned, externally peer reviewed.

The Effect of Chemical Treated Spent Mushroom Substrate (SMS) on Lignocellulosic Content

A by-product of the mushroom industry, spent mushroom substrate (SMS) is primarily made of lignocellulosic agricultural waste. SMS contains cellulose (38–46.6%), lignin (25–34.5%), and hemicellulose (19–27.7%) and is nutrient-rich. The primary objectives of this study included the characterization of SMS, analysis of lignocellulosic content prior to and following pre-treatment, analysis of the effects of various NaOH concentrations with varying molarities (1.0 to 5.0 Molar), and analysis of surface morphology using a scanning electron microscope (SEM). The result that comparison between untreated and treated sample The result for untreated are contain high amount of lignin from 23.85% to 27.39% and for treated are amount reduce from 20.6% to 23.85%. The difference of NaOH concentration from 1.0 to 5.0 Molar, so the best pre-treatment is alkaline pre-treatment from 1.0 to 3.0 M are the best concentration to treat SMS sample from alkaline pre-treatment and proved sodium hydroxide pre-treatment as an effective method to reduce the hemicellulose and lignin contents. Images clearly showed how the pre-treatment could alter the biomass’s structural makeup and distort it, increasing the surface area that was open to enzymatic attack. The pre-treated SMS’s surface had numerous sporadic pores and cracks. The study’s findings demonstrated that SMS from the P. sajor-caju species has the potential to provide a new source of glucose for bioethanol production.

Structural changes of thermally treated starch during digestion and the impact on postprandial glucose homeostasis

Intake of foods upon thermal treatment is typically associated with an elevated postprandial glycemic response, which is one of the risk factors for type 2 diabetes development and progression. In this study, rice starch was thermally treated using aqueous phase (boil), air phase (bake), and lipid phase (fry). Peak blood glucose levels in C57 mice increased by 16.94 %, 12.60 %, and 8.1 % after ingestion of thermally treated starch (20.23, 19.48, and 18.70 mmol/L), compared with raw starch (17.30 mmol/L). The insulin response to the intake of thermally treated starch increased (4.73 %–6.83 % higher than the control), whereas the concentration of GLP-1, a hormone used to promote insulin secretion, decreased (1.54 %–8.56 % lower than the control). Furthermore, thermally treated starch accelerated food absorption by enhancing gastrointestinal digestion, exacerbating postprandial glucose fluctuation at the next meal. Structural characterization showed thermal treatment reduced starch branching density and degree of structure order, which were not conducive to preventing the attack of enzymes. During digestion, they were highly hydrolyzed into low-molecular-weight fragments, and the proportion of ultrashort chains substantially increased. These findings provide a better understanding of the fine structure of starch that promotes hypoglycemia and initially explain how diets high in thermally treated starch impair glucose balance.

Study of morphological, structural, pasting, thermal, and vibrational changes in maize and isolated maize starch during germination

The germination process has already been studied in detail, but the changes in the different starch components have not yet been entirely elucidated. Therefore, this work focused on evaluating the changes in physicochemical properties, fat, protein, ash, and moisture content, nanocrystalline structures, and macromolecules such as amylose and amylopectin during germination of maize kernels over a nine-day period. The protein and ash contents were significantly reduced after 5 and 6 days of germination, respectively. The final viscosity of the isolated starch increased which was accompanied by an increase in fat content on day 7. One of the most important results is that the X-ray diffraction patterns showed no changes in the nanocrystalline structure of the maize starch due to the gemination. The DSC thermograms showed a transition between order to disorder of the orthorhombic structure. Pasting profiles showed strong changes in peak and final viscosity values due to fractionation of amylose and amylopectin chains by enzymatic attack, which was confirmed by scanning electron microscopy and infrared analysis (IR). In addition, reducing sugars supported the degradation of amorphous starch (amylose and amylopectin) in a dynamic process that served to generate energy for the formation of radicle and plumule.

Degradation and Failure Phenomena at the Dentin Bonding Interface.

Damage in the bonding interface is a significant factor that leads to premature failure of dental bonded restorations. The imperfectly bonded dentin-adhesive interface is susceptible to hydrolytic degradation and bacterial and enzyme attack, severely jeopardizing restorations' longevity. Developing caries around previously made restorations, also called "recurrent or secondary caries," is a significant health problem. The replacement of restorations is the most prevailing treatment in dental clinics, leading to the so-called "tooth death spiral". In other words, every time a restoration is replaced, more tooth tissue is removed, increasing the size of the restorations until the tooth is eventually lost. This process leads to high financial costs and detriment to patients' quality of life. Since the complexity of the oral cavity makes prevention a challenging task, novel strategies in Dental Materials and Operative fields are required. This article briefly overviews the physiological dentin substrate, features of dentin bonding, challenges and clinical relevance. We discussed the anatomy of the dental bonding interface, aspects of the degradation at the resin-dentin interface, extrinsic and intrinsic factors affecting dental bonding longevity, perspectives on resin and collagen degradation and how these subjects are connected. In this narrative review, we also outlined the recent progress in overcoming dental bonding challenges through bioinspiration, nanotechnology and advanced techniques to reduce degradation and improve dental bonding longevity.