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Aims: Sugarcane plants infected with Leifsonia xyli subsp. xyli (Lxx) have their primary metabolism affected with decreased levels of sugars and amino acids. Cysteine and methionine are sulfur-containing essential amino acids used for bacterial growth and the Lxx titer in sugar cane leaves could affect the animo acid concentrations. The goal of this study was to evaluate how the increase in Lxx titer affects the nutritional status and sulfur metabolism in sugar cane leaves. Methods: Susceptible sugar cane (Saccharum officinarum) genotype: CB49260 was used in this study with low (256 cells) and high (2090 cells) Lxx titers and macronutrients and primary metabolites assessed from leaves and culms. Results: Plants with high Lxx titers accumulated more biomass in the main culm, leaves, and shoots than plants with low Lxx titers. Additionally, plants with high Lxx titers had 26% more sulfur content in leaves than plants with low Lxx titers. Higher levels of sulfate, sucrose, maltose, raffinose, shikimic acid, malate, putrescine, glycerol, and, erythritol were also present in plants with high Lxx titers; but decreased levels of methionine and glutathione in leaves. In the culm, plants with high Lxx titers also had increased levels of maltose; but decreased levels of threonine, ornithine, phenylalanine and myo-inositol when compared with plants with low Lxx titers. Conclusions: This study demonstrated that high bacterial titers increase sulfur demand in sugar cane; however, the increased S content in the leaf did not result in higher sulfur assimilation, verified by increased sulfate but decreased methionine and glutathione levels. Therefore, our study showed that lower methionine availability, and methionine catabolism to putrescine in the leaves may fail to meet the increased sulfur organic compound demand of Lxx. The decrease in glutathione biosynthesis may reflect impaired biosynthesis or a drain on this antioxidant resulting from oxidative stresss by pathogenesis of Lxx. [ABSTRACT FROM AUTHOR]

The integrated approach of biocatalytic conversion coupled with purification using selective enzyme was developed to achieve continuous trehalose production. The activity of trehalose synthase (TS) derived from three different bacteria— Deinococcus radiodurans , Pseudomonas stutzeri , and Thermus thermophillus —immobilized with chitin-binding domain (ChBD-DrTS, ChBD-PsTS, and ChBD-TtTS, respectively) was compared for the production of trehalose from maltose syrup. The trehalose production yield using ChBD-PsTS was 2.4 and 1.7-fold higher than those using ChBD-DrTS and ChBD-TtTS, respectively, after 24 h at 30 °C and pH 7.0. In this study, a continuous bioconversion system was developed for trehalose production using ChBD-PsTS in a fixed-bed bioreactor, resulting in an approximate yield of 72%, and a productivity of 4 g/L/h. Additionally, residual maltose was converted into glucose using glucoamylase, and the 37% of bioethanol was produced. The integrated approach demonstrated remarkable biocatalytic performance, biocatalyst reusability, and high production yield. [Display omitted] • Immobilizing trehalose synthase from Pseudomonas stutzeri enhances its activity. • The continuous system yielded 72% trehalose at pH 7.0 and 30 °C. • Residual maltose was converted to glucose for subsequent bioethanol fermentation. [ABSTRACT FROM AUTHOR]

In the current global energy crisis scenario, microalgae are considered an efficient feedstock for the green synthesis of biofuels. Therefore, it is a dire need of time to screen, select and optimizes the growth conditions of indigenous microalgal strains for enhanced biofuel production. This study was designed to optimize the physicochemical conditions required for the growth of indigenous microalgal strains (n=10). All strains were grown in BG-11 media and optimized for different physical requirements, i.e., pH, temperatures, light intensity, NaCl, and chemical requirements, i.e., carbon source (glucose, glycerol, maltose, acetic acid), nitrogen source (urea, ammonium chloride, potassium nitrate, sodium nitrate), Nitrogen levels, phosphorus level, sodium bicarbonate concentration, and CO2. All strains were grown for 10 days, and growth was monitored by measuring optical density at 650 nm. Results revealed that out of 10 strains, the optimum growth of most of the strains was at 35oC (5/10, 50%), pH 7 (8/10, 80%), light intensity of 2000 lux (5/10, 50%), and 1% NaCl (5/10, 50%). Similarly, most of the strains had higher growth in media supplemented with 40 mM of NaNO3 (7/10, 70%), 2 mM phosphorus (5/10, 50%), 1% glycerol (9/10, 90%) in autotrophic conditions, and 1% glucose (5/10, 50%) in mixotrophic conditions. The overall finding of the study revealed that Scenedesmus AIN01 showed significantly higher growth at 35oC, pH 7, 2000 lux light, 1% NaCl, 40 mM NaNO3, 1.5 mM phosphorus, 1% glycerol, and 0.1% bicarbonate as compared to other strains grown at their optimum conditions. It is concluded that the strains in this study, especially Scenedesmus AIN01, may be grown using their optimum physicochemical conditions for enhanced growth for subsequent use in biofuel production. [ABSTRACT FROM AUTHOR]

Escherichia coli, a well-known prokaryotic organism, has been widely employed as a versatile host for heterologous overexpression of proteins/biocatalysts and the production of pharmaceutically important intermediates/small molecules. However, some E. coli endogenous enzymes showing substrate promiscuity may disturb the heterologous metabolic flux, which will result in the reduction of substrates, intermediates, and target products. Here we reported an unexpected E. coli-catalyzed regioselective O-acetylation of various glucosides. The regioselectively O-acetylated products, 6′-O-acetyl-loganin and 6′-O-acetyl-loganic acid, were obtained and characterized from the enzymatic reaction in which the supernatants of E. coli expressing either CaCYP72A565 and CaCPR, the key enzymes involved in camptothecin biosynthesis, or empty vector were used as catalyst and loganin and loganic acid as independent substrate. An alkaloidal glucoside strictosamide was converted into the regioselectively O-acetylated product 6′-O-acetyl-strictosamide, implying substrate promiscuity of the E. coli-catalyzed O-acetylation reaction. Furthermore, 8 glucosides, including 5 iridoid glucosides and 3 flavonoid glucosides, were successfully converted into the regioselectively O-acetylated products by E. coli, indicating the wide substrate range for the unexpected E. coli-catalyzed O-acetylation. E. coli maltose O-acetyltransferase was demonstrated to be responsible for the mentioned regioselective O-acetylation at the 6-OH of the glucopyranosyl group of multiple classes of natural product glucosides through candidate acetyltransferase-encoding gene analysis, gene knock-out, gene complementation, and the relevant enzymatic reaction activity assays. The present study not only provides an efficient biocatalyst for regioselective O-acetylation but also notifies cautions for metabolic engineering and synthetic biology applications in E. coli. Key points: • 6-OH of glucosyl of multiple glucosides was regioselectively O-acetylated by E. coli. • Endogenous EcMAT is responsible for the regioselective O-acetylation reaction. [ABSTRACT FROM AUTHOR]

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A novel cellulose microfibril swelling (Cms) gene of Bacillus sp. AY8 was successfully cloned and sequenced using a set of primers designed based on the conserved region of the gene from the genomic database. The molecular cloning of the Cms gene revealed that the gene consisted of 679 bp sequences encoding 225 amino acids. Further in silico analysis unveiled that the Cms gene contained the NlpC/P60 conserved region that exhibited a homology of 98% with the NlpC/P60 family proteins found in both the strains, Burkholderialata sp. and Burkholderia vietnamiensis. The recombinant Cms enzyme had a significant impact on the reduction of crystallinity indices (CrI) of various substrates including a 3%, a 3.97%, a 4.66%, and a substantial 14.07% for filter paper, defatted cotton fiber, avicel, and alpha cellulose, respectively. Additionally, notable changes in the spectral features were observed among the substrates treated with recombinant Cms enzymes compared to the untreated control. Specifically, there was a decrease in band intensities within the spectral regions of 3000–3450 cm−1, 2900 cm−1, 1429 cm−1, and 1371 cm−1 for the treated filter paper, cotton fiber, avicel, and alpha cellulose, respectively. Furthermore, the recombinant Cms enzyme exhibited a maximum cellulose swelling activity at a pH of 7.0 along with a temperature of 40 °C. The molecular docking data revealed that ligand molecules, such as cellobiose, dextrin, maltose 1-phosphate, and feruloyated xyloglucan, effectively bonded to the active site of the Cms enzyme. The molecular dynamics simulations of the Cms enzyme displayed stable interactions with cellobiose and dextrin molecules up to 100 ns. It is noteworthy to mention that the conserved region of the Cms enzyme did not match with those of the bioadditives like expansins and swollenin proteins. This study is the initial report of a bacterial cellulose microfibril swellase enzyme, which could potentially serve as an additive to enhance biofuel production by releasing fermentable sugars from cellulose. [ABSTRACT FROM AUTHOR]

In this study, PQQ-dependent glucose dehydrogenase (PQQ-GDH) was immobilized onto reduced graphene oxide (rGO) modified with organic dyes from three different classes (acridine, arylmethane, and diazo); namely, neutral red (NR), malachite green (MG), and congo red (CR) formed three types of biosensors. All three rGO/organic dye composites were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The impact of three rGO/organic dye modifications employed in bioelectrocatalytic systems on changes in enzyme activity and substrate selectivity was investigated. The highest sensitivity of 39 µA/cm2 was obtained for 1 mM of glucose when a rGO_MG/PQQ-GDH biosensor was used. A significant improvement in the electrochemical response of biosensors was attributed to the higher amount of pyrrolic nitrogen groups on the surface of the rGO/organic dye composites. Modifications of rGO by NR and MG not only improved the surfaces for efficient direct electron transfer (DET) but also influenced the enzyme selectivity through proper binding and orientation of the enzyme. The accuracy of the biosensor's action was confirmed by the spectrophotometric analysis. Perspectives for using the proposed bioelectrocatalytic systems operating on DET principles for total or single monosaccharide and/or disaccharide determination/bioconversion systems or for diagnoses have been presented through examples of bioconversion of D-glucose, D-xylose, and maltose. [ABSTRACT FROM AUTHOR]

Starch enzymatic hydrolysis is a key technology for preparing plant-based dairy alternative beverages, preferred for its low energy consumption, high product yield, and quality. However, the high-temperature requirement to terminate reactions and challenges in continuous operations hinder enzyme applicability. Therefore, encapsulation techniques have been explored to address these limitations, enhancing the enzyme's stability and facilitating process control. This study developed a novel amyloglucosidase encapsulation system based on chitosan-SDS hydrogel capsules produced by simple coacervation. The enzymatic activity of free and immobilised amyloglucosidase was assessed using corn starch and maltose as substrates. The encapsulation process successfully yielded self-supporting structured and spherical capsules, achieving an immobilisation yield of 71% and an enzyme efficiency of 83%. The residual enzymatic activity after 28 days of storage remained at 76%. A feedback inhibition investigation was performed by varying the concentration of corn starch, and favourable applicability of encapsulated amyloglucosidase for continuous processes was found. The encapsulation process offered several advantages, such as a straightforward separation step to halt enzymatic reactions and no need for high temperatures that may affect food product attributes. Lastly, the amyloglucosidase-chitosan-SDS coacervates show promise in improving enzyme stability, facilitating hydrolysis control, and expanding enzyme utilisation in dairy alternative plant beverage manufacture. [ABSTRACT FROM AUTHOR]

Abstract Trehalose is a functional sugar that has numerous applications in food, cosmetic, and pharmaceutical products. Production of trehalose from maltose via a single-step enzymatic catalysis using trehalose synthase (TreS) is a promising method compared with the conventional two-step process due to its simplicity with lower formation of byproducts. In this study, a cold-active trehalose synthase (PaTreS) from Pseudarthrobacter sp. TBRC 2005 was heterologously expressed and characterized. PaTreS showed the maximum activity at 20 °C and maintained 87% and 59% of its activity at 10 °C and 4 °C, respectively. The enzyme had remarkable stability over a board pH range of 7.0–9.0 with the highest activity at pH 7.0. The activity was enhanced by divalent metal ions (Mg2+, Mn2+ and Ca2+). Conversion of high-concentration maltose syrup (100–300 g/L) using PaTreS yielded 71.7–225.5 g/L trehalose, with 4.5–16.4 g/L glucose as a byproduct within 16 h. The work demonstrated the potential of PaTreS as a promising biocatalyst for the development of low-temperature trehalose production, with the advantages of reduced risk of microbial contamination with low generation of byproduct. Graphical abstract

Microorganisms often live in complex habitats, where changes in the environment are predictable, providing an opportunity for microorganisms to learn, anticipate the upcoming environmental changes and prepare in advance for better survival and growth. One such environment is the mammalian intestine, where the abundance of different carbon sources is spatially distributed. In this study, we identified seven spatially distributed carbon sources in the mammalian intestine and tested whether Escherichia coli exhibits phenotypes that are consistent with an anticipatory response given their spatial order and abundance within the mammalian intestine. Through RNA-Seq and RT-PCR validation measurements, we found that there was a 67% match in the expression patterns between the measured phenotypes and what would otherwise be expected in the case of anticipatory behavior, while 83% and 0% were in agreement with the homeostatic and random response, respectively. To understand the genetic and phenotypic basis of the discrepancies between the expected and measured anticipatory responses, we thoroughly investigated the discrepancy in D-galactose treatment and the expression of maltose operon in E. coli. Here, the expected anticipatory response, based on the spatial distribution of D-galactose and D-maltose, was that D-galactose should upregulate the maltose operon, but it was the opposite in experimental validation. We performed whole genome random mutagenesis and screening and identified E. coli strains with positive expression of maltose operon in D-galactose. Targeted Sanger sequencing and mutation repair identified that the mutations in the promoter region of malT and in the coding region of the crp gene were the factors responsible for the reversion in the association. Further, to identify why positive association in the D-galactose treatment and the expression of the maltose operon did not evolve naturally, fitness measurements were performed. Fitness experiments demonstrated that the fitness of E. coli strains with a positive association in the D-galactose treatment and the expression of the maltose operon was 12% to 20% lower than that of the wild type strain.

This letter discusses two cases of classic galactosemia in infants that presented with pseudohyperglycemia due to interference from a glucometer. The cases highlight the limitations of point-of-care glucometers for diagnosing hyperglycemia and emphasize the need for confirmation using an alternative method, such as a hexokinase assay in the central laboratory. Galactosemia should be considered in the differential diagnosis for infants with pseudohyperglycemia. The letter also mentions the risks of iatrogenic insulin-induced hypoglycemia and the FDA's notification about potentially fatal errors with GDH-PQQ glucose monitoring technology. [Extracted from the article]

This study investigated the effects of electron beam irradiation (EBI) on the structural, physicochemical, and functional properties of lentil starch with varying maltose content. EBI did not significantly disrupt the starch’s surface structure or cause amorphization of starch and maltose crystals, but it significantly reduced the intensity of starch’s XRD peaks. The presence of maltose intensified internal growth ring damage, leading to more cross-link and rearrangement between short chains, improving short-range ordering of lentil starch and enhancing starch’s solubility and thermal stability. Additionally, adding maltose that EBI then treats can lead to an increased content of slowly digestible starch in samples.

The β-Glucans are exceptionally important polysaccharide compounds in the cell wall of a higher plants, fungi and bacteria. Due to having functional types of bioactive β-glucans, fungi are one of the foremost important sources of β-glucans. In the present study, Pleurotus ostreatus was considered as a source of β-glucan production, which can also evaluate the effect of the stirring method during mass production. Also the effect of the types of 4 carbon sources namely; xylose, glucose, maltose and lactose (at 3 levels) and 4 different sources of nitrogen including; Malt extract, yeast extract, peptone and rice bran extract (at 1 level) were investigated. The efficiency of the process was calculated by measuring the amount of produced dry mycelium per unit volume. According to the results continuous stirring at a speed of 220 rpm per minute increased the mycelium production and the highest amounts of produced biomass were obtained in the presence of maltose as a carbon source and malt extract and rice bran extract as nitrogen sources. β-glucan extraction was also evaluated by acid and acid-alkaline methods extracted by acid-alkali method showed a statistically significant difference of about 94% compared to β-glucan extraction by acid method (P

Carbohydrate compounds are widely used as fillers and stabilisers in biological products. When present, these compounds guarantee that the active pharmaceutical ingredient will remain stable during production, transportation, and storage. At the same time, pharmacopoeias standardise the excipient content and require that excipients should be quantified for assessing the quality of biological products.The aim of the study was to identify promising methods for the development of quantification procedures for carbohydrate compounds in biological products.The authors analysed regulatory documents for biological products approved in the Russian Federation. The most widely used excipients, both individually and in combinations, are polyols (sorbitol and mannitol), monosaccarides (glucose), and disaccharides (trehalose, sucrose, lactose, and maltose). Using literature data, the authors reviewed the methods used for quantifying polyols, monosaccharides, and disaccharides to assess the quality of biological products. Quantitative determination of carbohydrate stabilisers employs titrimetric, spectrophotometric, enzymatic, and chromatographic methods. This review presents an analysis of the advantages and disadvantages of these methods. It highlights the advantages of ionic HPLC with amperometric detection and hydrophilic HPLC with refractometric and evaporative light scattering detection, which are sufficiently selective and can identify substances without prior derivatisation. In conclusion, ionic and hydrophilic HPLC methods are a promising base for the development of quantification procedures for carbohydrate stabilisers.

Water is essential for metabolism and all life processes. Despite this, many organisms distributed across the kingdoms of life survive near-complete desiccation or anhydrobiosis. Increased intracellular viscosity, leading to the formation of a vitrified state is necessary, but not sufficient, for survival while dry. What properties of a vitrified system make it desiccation-tolerant or -sensitive are unknown. We have analyzed 18 different in vitro vitrified systems, composed of one of three protective disaccharides (trehalose, sucrose, or maltose) and glycerol, quantifying their enzyme-protective capacity and their material properties in a dry state. Protection conferred by mixtures containing maltose correlates strongly with increased water content, increased glass-transition temperature, and reduced glass former fragility, while the protection of glasses formed with sucrose correlates with increased glass transition temperature and the protection conferred by trehalose glasses correlates with reduced glass former fragility. Thus, in vitro different vitrified sugars confer protection through distinct material properties. Next, we examined the material properties of a dry desiccation tolerant and intolerant life stage from three different organisms. The dried desiccation tolerant life stage of all organisms had an increased glass transition temperature and reduced glass former fragility relative to its dried desiccation intolerant life stage. These results suggest in nature organismal desiccation tolerance relies on a combination of various material properties. This study advances our understanding of how protective and non-protective glasses differ in terms of material properties that promote anhydrobiosis. This knowledge presents avenues to develop novel stabilization technologies for pharmaceuticals that currently rely on the cold-chain. Statement of significance: For the past three decades the anhydrobiosis field has lived with a paradox, while vitrification is necessary for survival in the dry state, it is not sufficient. Understanding what property(s) distinguishes a desiccation tolerant from an intolerant vitrified system and how anhydrobiotic organisms survive drying is one of the enduring mysteries of organismal physiology. Here we show in vitro the enzyme-protective capacity of different vitrifying sugars can be correlated with distinct material properties. However, in vivo, diverse desiccation tolerant organisms appear to combine these material properties to promote their survival in a dry state.

ABSTRACT Bacterial utilization of starch is increasingly of interest as the importance and contributions of animal gut microbiomes become more defined. Consequently, identifying and characterizing the bacterial enzymes responsible for the degradation, transport, and metabolism of starch will enable developments in pharmaceutical, biotechnological, and culinary industries searching for novel prebiotics, carrier molecules, and low glycemic index sweeteners. The current challenge is that bacteria proficient at starch utilization often have hundreds of carbohydrate active enzymes, and it is unclear which are essential for starch utilization using only homology-based bioinformatics or computational methods. Complementary experimental data are also needed, especially to understand the regulation of bacterial starch utilization. We have completed an RNAseq analysis of the Gram-negative bacterium Cellvibrio japonicus and found that it has sophisticated regulation that includes substrate sensing and growth rate components for genes that encode starch-degrading enzymes. Among the 22 genes predicted to encode starch-active enzymes, C. japonicus has 10 alpha-amylases, 4 alpha-glucosidases, 2 pullulnases, and 2 cyclomaltodextrin glucanotransferases, 15 of which were up-regulated during exponential growth on starch and 8 up-regulated in stationary phase. Growth analyses with an enzyme secretion deficient mutant of C. japonicus suggested that secreted amylases are essential for this bacterium to degrade starch. Our approach of coupling a physiological growth assay with transcriptomic data provides a platform to identify targets for further genetic or biochemical analysis that can be broadly applied to other starch-utilizing bacteria. IMPORTANCE Understanding the bacterial metabolism of starch is important as this polysaccharide is a ubiquitous ingredient in foods, supplements, and medicines, all of which influence gut microbiome composition and health. Our RNAseq and growth data set provides a valuable resource to those who want to better understand the regulation of starch utilization in Gram-negative bacteria. These data are also useful as they provide an example of how to approach studying a starch-utilizing bacterium that has many putative amylases by coupling transcriptomic data with growth assays to overcome the potential challenges of functional redundancy. The RNAseq data can also be used as a part of larger meta-analyses to compare how C. japonicus regulates carbohydrate active enzymes, or how this bacterium compares to gut microbiome constituents in terms of starch utilization potential.

To improve the storage quality of adzuki bean paste from starch aging, the effects of glycolipid addition on the properties of gelatinization and retrogradation properties of adzuki flour obtained by the retrogradation inside adzuki bean during storage and transportation are investigated. The results indicate the significant differences in the gelatinization and the distribution of starch granules for different varieties of beans. The higher gelatinization temperature of adzuki flour results in the lower enthalpy of gelatinization with an undulating tendency of the retrogradation due to the short-term aging of amylose and long-term aging of amylopectin within adzuki flour. In the early stage of aging, the coexistence of protein, fat, and starch inside adzuki flour hinder the aging of starch. An Avrami equation is introduced to characterize the aging process of the starch–protein–fat–water system of different varieties of adzuki flours. The nucleation mode of the crystal nucleus has a significant effect on the aging rate of different varieties of adzuki flour. The fat in the system fails to demonstrate a significant effect on the nucleation mode of starch retrogradation. The addition of glycolipids increases the gelatinization enthalpy of adzuki flour. Glycolipids can reduce the aging degree of adzuki flour, and the inhibition effect on the retrogradation of sucrose monoester is greater than that of maltose monoester. The research results provide the valuable guidance for the high-quality processing and storage of adzuki bean paste from starch aging. [ABSTRACT FROM AUTHOR]

A rod-shaped, motile, Gram-negative bacterial strain named DM-R-R2A-13T was isolated from the plant Cannabis sativa L. 'Cheungsam'. The phylogenetic analysis of the 16S rRNA gene sequence revealed that strain DM-R-R2A-13T belongs to the family Oxalobacteraceae and is closely related to members of the genus Massilia, with Massilia flava (97.58% sequence similarity) and Massilia armeniaca (97.37% sequence similarity) being the closest members. The digital DNA-DNA hybridization (dDDH) values between strain DM-R-R2A-13T and Massilia flava CGMCC 1.10685T and Massilia armeniaca ZMN-3Twere 22.2% and 23.3%, while the average nucleotide identity (ANI) values were 78.85% and 79.63%, respectively. The DNA G+C content was measured to be 64.6 mol%. Moreover, the bacterium was found to contain polyhydroxyalkanoate (PHA) granules based on transmission electron microscopy, indicating its potential to produce bioplastic. Genome annotation revealed the presence of PHA synthase genes (phaC, phaR, phaP, and phaZ), and the biopolymer was identified as poly-3-hydroxybutyrate (PHB) based on nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) analyses. Using maltose as a carbon source, the strain produced PHB of up to 58.06% of its dry cell weight. Based on the phenotypic, chemotaxonomic, and phylogenetic characteristics, it has been determined that DM-R-R2A-13T represents a novel species belonging to the genus Massilia. As such, the name Massilia endophytica sp. nov. is proposed for this newly identified species. The type strain is DM-R-R2A-13T (= KCTC 92072T = GDMCC 1.2920T). [ABSTRACT FROM AUTHOR]

Intermittent (or bolus) feeding regimens in critically ill patients have been of increasing interest to clinicians and scientists. Changes in amino acid, fat and carbohydrate metabolites over time might yet deliver other benefits (e.g. modulation of the circadian rhythm and sleep, and impacts on ghrelin secretion, insulin resistance and autophagy). We set out to characterise these changes in metabolite concentration. The Intermittent versus Continuous Feeding in Critically Ill paitents study (NCT02358512) was an eight-centre single-blinded randomised controlled trial. Patients were randomised to received a continuous (control arm) or intermittent (6x/day, intervention arm) enteral feeding regimen. Blood samples were taken on trial days 1, 7 and 10 immediately before and 30 min after intermittent feeds, and at equivalent timepoints in the control arm. A pre-planned targeted metabolomic analysis was performend using Nuclear Resonance Spectroscopy. Five hundred and ninety four samples were analysed from 75 patients. A total of 24 amino acid-, 19 lipid based-, and 44 small molecule metabolite features. Across the main two axes of variation (40–60% and 6–8% of variance), no broad patterns distinguished between intermittent or continuous feeding arms, across intra-day sampling times or over the 10 days from initial ICU admission. Logfold decreases in abundance were seen in metabolites related to amino acids (Glutamine − 0.682; Alanine − 0.594), ketone body metabolism (Acetone − 0.64; 3-Hydroxybutyric Acid − 0.632; Acetonacetic Acid − 0.586), fatty acid (carnitine − 0.509) and carbohydrate metabolism (Maltose − 0.510; Citric Acid − 0.485). 2–3 Butanediol, a by-product of sugar-fermenting microbial metabolism also decreased (− 0.489). No correlation was seen with change in quadriceps muscle mass for any of the 20 metabolites varying with time (all p > 0.05). Increasing severity of organ failure was related to increasing ketone body metabolism (3 Hydroxybutyric Acid-1 and − 3; p = 0.056 and p = 0.014), carnitine deficiency (p = 0.002) and alanine abundancy (p − 0.005). A 6-times a day intermittent feeding regimen did not alter metabolite patterns across time compared to continuous feeding in critically ill patients, either within a 24 h period or across 10 days of intervention. Future research on intermittent feeding regimens should focus on clinical process benefits, or extended gut rest and fasting. [ABSTRACT FROM AUTHOR]

Olive Mill Wastewater (OMWW) is produced in large quantities and contains high levels of nutrients that can be reused for irrigation, reducing the demand for freshwater resources. However, OMWW is phytotoxic and expensive to treat, making it important to develop more cost-effective treatment methods. This study aims to investigate an integrated detoxification treatment sequence consisting of acid precipitation, Fenton oxidation, and electrical coagulation to safely reuse OMWW for barley germination. Raw, treated and diluted OMWW (25% and 50% OMWW) were tested. The results showed that raw and diluted OMWW suppressed seed germination at all concentrations, while diluted treated OMWW enhanced seed germination and plant growth. In addition, treated OMWW (acid precipitation treatment) at 25% dilution reported 0% phytotoxicity significantly improved plant growth, where plant fresh weight (FW) reached 123.33 mg. Moreover, α-amylase, lipase, and protease enzyme activity confirmed the superior enhancement of barley growth parameters, where the highest enzyme activity value recoded 0.870 mg maltose/g FW. The integrated treatments reduced detoxification by 97.90% for total phenolic, 98.37% for total flavonoids, and 99.18% for total tannins. Reductions of around 95.78%, 60.00%, and 78.90% in total organic carbon, electric conductivity, and total solids, respectively, were achieved. A significant decrease in heavy metals was observed with removal ratios 98.64%, 94.80%, 96.88%, and 95.72% for Fe, Cu, Mn, and Zn, respectively. Seedling Vigor Index as an indicator of crop productivity was successfully predicted using neural network modeling. Therefore, the applied method can be used as a fertilizer to support plant growth and reduce fertilization costs. [ABSTRACT FROM AUTHOR]

The present research is undertaken to study the effect of ozonation on isolated pearl millet starch (PMS) and sorghum starch (SS), at various concentrations (0.06, 0.08, and 0.1 L min−1) for 60 minutes. The ozonated starches is evaluated for the techno‐functional properties, in vitro starch digestibility, pasting properties, morphological characteristics, X‐ray diffraction, and FTIR interactions. Functional properties such as water and oil absorption capacity and solubility, paste clarity (PC), gel consistency (GC), and freeze‐thawing stability (FTS) increased significantly (p ≤ 0.05). However, swelling power (SP) increased for all treatments with rise in temperature but a reverse trend is observed with an increase in ozone treatment. Although, reduction in vitro starch digestibility (IVSD) for treated PMS i.e. 44.59 to 29.20 g 100 g−1 maltose and 30.80–28.76 g 100 g−1 maltose for SS is observed. Slight difference is observed for the color values is observed. Higher values of peak and final viscosity whereas, lower breakdown viscosity, and setback viscosity are observed for all treatments. The crystalline pattern of PMS and SS remained unaffected with ozone treatment, whereas relative crystallinity (RC) decreased with ozone treatment. SEM images confirmed indentations, and enlargement of surface pores for ozonated starches. While, FTIR spectroscopy revealed a slight decrease in the peak intensity. [ABSTRACT FROM AUTHOR]

Herein, we present a novel biosensor based on nature-inspired poly(caffeic acid) (PCA) grafted to magnetite (Fe3O4) nanoparticles with glucose oxidase (GOx) from Aspergillus niger via adsorption technique. The biomolecular corona was applied to the fabrication of a biosensor system with a screen-printed electrode (SPE). The obtained results indicated the operation of the system at a low potential (0.1 V). Then, amperometric measurements were performed to optimize conditions like various pH and temperatures. The SPE/Fe3O4@PCA-GOx biosensor presented a linear range from 0.05 mM to 25.0 mM, with a sensitivity of 1198.0 μA mM−1 cm−2 and a limit of detection of 5.23 μM, which was compared to other biosensors presented in the literature. The proposed system was selective towards various interferents (maltose, saccharose, fructose, L-cysteine, uric acid, dopamine and ascorbic acid) and shows high recovery in relation to tests on real samples, up to 10 months of work stability. Moreover, the Fe3O4@PCA-GOx biomolecular corona has been characterized using various techniques such as Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Bradford assay. [ABSTRACT FROM AUTHOR]

Several alkyl glucosides exhibit various bioactivities. 1-Octyl β- d -glucopyranoside produced by organic synthesis is used as a nonionic surfactant. However, no convenient method has been developed for the selective production of alkyl α-glucosides (α-AGs), such as 1-octyl α- d -glucopyranoside (α-OG). Therefore, we developed a simple method for selective production of α-AGs using the glucosyl transfer enzyme XgtA, (E.C. 3.2.1.20), derived from Xanthomonas campestris WU-9701. When 0.80 M alkyl alcohol and 2.5 units XgtA were incubated in 2.0 mL of 30 mM HEPES-NaOH buffer (pH 8.0) containing 1.2 M maltose at 45 °C, a specific α-AG corresponding to each alkyl alcohol (C2–C10) was detected. Under the standard conditions, we examined the selective production of α-OG from 1-octanol and maltose using XgtA. The reaction product was isolated and identified as α-OG via 1H nuclear magnetic resonance and nuclear overhauser effect spectroscopy analyses. No other glucosylated products, such as maltotriose, were detected in the reaction mixture. Under the standard conditions at 45 °C for 96 h, 243 mM α-OG (71 g/L) was produced in one batch production. Moreover, the addition of glucose isomerase to the reaction mixture decreased the concentration of glucose released via the reaction and increased the amount of α-OG produced; 359 mM α-OG (105 g/L) was maximally produced at 96 h. In conclusion, this study demonstrates the selective production of α-AGs using a simple enzymatic reaction, and XgtA has the potential to selectively produce various α-AGs. [Display omitted] [ABSTRACT FROM AUTHOR]

The β-amylase (BAM) gene family encodes important enzymes that catalyze the conversion of starch to maltose in various biological processes of plants and play essential roles in regulating the growth and development of multiple plants. So far, BAMs have been extensively studied in Arabidopsis thaliana (A. thaliana). However, the characteristics of the BAM gene family in the crucial economic crop, cotton, have not been reported. In this study, 27 GhBAM genes in the genome of Gossypium hirsutum L (G. hirsutum) were identified by genome-wide identification, and they were divided into three groups according to sequence similarity and phylogenetic relationship. The gene structure, chromosome distribution, and collinearity of all GhBAM genes identified in the genome of G. hirsutum were analyzed. Further sequence alignment of the core domain of glucosyl hydrolase showed that all GhBAM family genes had the glycosyl hydrolase family 14 domain. We identified the BAM gene GhBAM7 and preliminarily investigated its function by transcriptional sequencing analysis, qRT-PCR, and subcellular localization. These results suggested that the GhBAM7 gene may influence fiber strength during fiber development. This systematic analysis provides new insight into the transcriptional characteristics of BAM genes in G. hirsutum. It may lay the foundation for further study of the function of these genes. [ABSTRACT FROM AUTHOR]

Novacetimonas cocois WE7 (formally named Komagataeibacter cocois WE7) is a strain isolated from contaminated coconut milk, capable of producing bacterial cellulose (BC). We sequenced its genome to investigate why WE7 cannot synthesize BC from glucose efficiently. It contains about 3.5 Mb and six plasmid DNAs. N. cocois WE7 contains two bcs operons (bacterial cellulose operon, bcs I and bcs II); the absence of bcs III operons may lead to reduced BC production. From genome predictions, glucose, sucrose, fructose, maltose, and glycerol can be utilized to generate BC, with WE7 unable to metabolize carbohydrate carbon sources through the Embden–Meyerhof–Parnas (EMP) pathway, but rather through the Hexose Monophosphate Pathway (HMP) and tricarboxylic acid (TCA) pathways. It has a complete gluconic acid production pathway, suggesting that BC yield might be very low when glucose, maltose, and trehalose are used as carbon sources. This study represents the first genome analysis of N. cocois. This information is crucial for understanding BC production and regulation mechanisms in N. cocois and lays a foundation for constructing engineered strains tailored for diverse BC application purposes. [ABSTRACT FROM AUTHOR]

Celiac patients tend to have an unbalanced diet, because gluten-free products typically contain a high amount of fats and carbohydrates and a low amount of proteins, minerals, and dietary fiber. This research focused on the development of gluten-free functional breads using pseudocereals, psyllium, and gluten-free sourdough to replace commercial yeast, fortifying them with Moringa oleifera. Six different gluten-free breads were made with sourdough: three control breads differentiated by sourdough (quinoa, amaranth, and brown rice) and three breads enriched with moringa leaf differentiated by sourdough. The antioxidant capacity, phenolic compounds, nutritional composition, physicochemical parameters (color, pH, and acidity), folate content, amino acid profile, reducing sugars, mineral composition, mineral bioaccessibility, fatty acid profile, and sensory acceptability were evaluated. A commercial gluten-free (COM) bread was included in these analyses. Compared with COM bread, the reformulated breads were found to have better nutritional properties. Moringa leaf increased the nutritional properties of bread, and highlighted the QM (quinoa/moringa) bread as having increased protein, fiber, sucrose, glucose, maltose, phenylalanine, and cysteine. The AM (amaranth/moringa) bread was also shown to have a higher total folate content, antioxidant capacity, phenolic compounds, 9t,11t-C18:2 (CLA), and 9t-C18:1. Reformulated breads enriched with moringa could meet nutritional requirements and provide health benefits to people with celiac disease. [ABSTRACT FROM AUTHOR]

β‐galactosidase dosing and transport powders offer benefits for people with specific digestive deficiencies. They can be produced by immobilization in solid materials by sol–gel methods. The challenge is to maintain enzyme activity under processing conditions. The objective here is to design and optimize the calcium chloride and carboxymethylchitosan concentrations at 25°C and 7.3 pH for preparing active β‐galactosidase powders. This optimization was performed using a Response Surface Methodology with Central Composite Design, selecting lyoprotectants for preserving activity during the lyophilization. Glucose, galactose, maltose, sucrose, and β‐cyclodextrin lyoprotectants were assayed in different weight proportions. The optimal conditions to obtain a biocatalyst with maximum expressed activity were 473 mM CaCl2 and 402 ppm carboxymethylchitosan, obtaining a biocatalyst with 57.8% ±.7% recovered activity and 92.3% ± 2.1% immobilization yield. The galactose, maltose, and sucrose in a 1:5 ratio increased 1.2 times the expressed activity of this biocatalyst, protecting the active site during lyophilization due to favorable interactions with the enzyme as shown by docking analysis. Practical applications: This work shows the implementation of production methodologies of mixed enzyme‐mineral biocatalysts, based on the experimental, statistical, and docking studies of β‐galactosidase interactions with mono‐, di‐ and polysaccharides under ionic and thermal stress. The obtained powders could be candidates as dietary supplements of calcium, silicon minerals, and β‐galactosidase. [ABSTRACT FROM AUTHOR]

Differences in taste perception between species are thought to reflect evolutionary adaptations to dietary specialization. White-faced sakis (Pithecia pithecia) are commonly considered as frugivores but are unusual among primates as they do not serve as seed dispersers but rather prey upon the seeds of the fruits they consume and are thought to exploit the lipids and proteins that these seeds contain in high amounts. Using a two-bottle preference test of short duration we therefore assessed whether this dietary specialization affects the taste responsiveness of four adult white-faced sakis for five food-associated carbohydrates. We found that the sakis significantly preferred concentrations as low as 10 mM sucrose, 10–40 mM fructose, 20–30 mM glucose and maltose, and 30–40 mM lactose over tap water. When given the choice between all binary combinations of these five saccharides presented at equimolar concentrations of 100, 200, and 300 mM, respectively, the sakis displayed significant preferences for individual saccharides in the following order: sucrose > fructose > glucose ≥ maltose = lactose. These results demonstrate that seed-predating white-faced sakis have a well-developed taste sensitivity for food-associated carbohydrates which is not inferior to that of most other primates including seed-dispersing frugivores, but rather ranks among the more sweet-taste sensitive species. Further, they show that their pattern of relative preference for the five carbohydrates is similar to that found in other frugivorous primate species. These findings may represent an example of Liem's paradox as the sakis' morphological adaptations to efficiently predate on and exploit the lipid- and protein-rich hard-shelled seeds of fruits does not compromise their ability to detect the carbohydrates found in the pulp of fruits at low concentrations. [ABSTRACT FROM AUTHOR]

Saccharides are increasingly used as biomarkers and for therapeutic purposes. Their characterization is challenging due to their low ionization efficiencies and inherent structural heterogeneity. Here, we illustrate how the coupling of online droplet-based reaction, in a form of contained electrospray (ES) ion source, with liquid chromatography (LC) tandem mass spectrometry (MS/MS) allows the comprehensive characterization of sucrose isomers. We used the reaction between phenylboronic acid and cis-diols for on-the-fly derivatization of saccharides eluting from the LC column followed by in situ MS/MS analysis, which afforded diagnostic fragment ions that enabled differentiation of species indistinguishable by chromatography or mass spectrometry alone. For example, chromatograms differing only by 2% in retention times were flagged to be different based on incompatible MS/MS fragmentation patterns. This orthogonal LC-contained-ES-MS/MS method was applied to confirm the presence of turanose, palatinose, maltulose, and maltose, which are structural isomers of sucrose, in three different honey samples. The reported workflow does not require modification to existing mass spectrometers, and the contained-ES platform itself acts both as the ion source and the reactor, all promising widespread application. [ABSTRACT FROM AUTHOR]

Background: A high concentration of CO2 will stagnate the development of the newly formed primordia of Hypsizygus marmoreus, hinder the development of the mushroom cap, thereby inhibiting the normal differentiation of the fruiting body. Moreover, in the previous experiment, our research group obtained the mutant strain HY68 of H. marmoreus, which can maintain normal fruiting under the condition of high concentration of CO2. Our study aimed to evaluate the CO2 tolerance ability of the mutant strain HY68, in comparison with the starting strain HY61 and the control strain HY62. We analyzed the mycelial growth of these strains under various conditions, including different temperatures, pH levels, carbon sources, and nitrogen sources, and measured the activity of the cellulose enzyme. Additionally, we identified and predicted β-glucosidase-related genes in HY68 and analyzed their gene and protein structures. Results: Our results indicate that HY68 showed superior CO2 tolerance compared to the other strains tested, with an optimal growth temperature of 25 °C and pH of 7, and maltose and beef paste as the ideal carbon and nitrogen sources, respectively. Enzyme activity assays revealed a positive correlation between β-glucosidase activity and CO2 tolerance, with Gene14147 identified as the most closely related gene to this activity. Inbred strains of HY68 showed trait segregation for CO2 tolerance. Conclusions: Both HY68 and its self-bred offspring could tolerate CO2 stress. The fruiting period of the strains resistant to CO2 stress was shorter than that of the strains not tolerant to CO2 stress. The activity of β-GC and the ability to tolerate CO2 were more closely related to the growth efficiency of fruiting bodies. This study lays the foundation for understanding how CO2 regulates the growth of edible fungi, which is conducive to the innovation of edible fungus breeding methods. The application of the new strain HY68 is beneficial to the research of energy-saving production in factory cultivation. [ABSTRACT FROM AUTHOR]

As an important characteristic crop in China, sweetpotato plays an important role in the intake and supplement of nutrients. The saccharification characteristics of sweetpotato determine the edible quality and processing type. Exploring the saccharification characteristics of sweetpotato is of great significance to the selection of processing materials and the formation mechanism of service quality, but there are few relevant studies. A comparison study of two high saccharification varieties (Y25 and Z13) and one low saccharification variety (X27) was conducted to analyze their storage roots physical and chemical properties. The results show that the dry matter content, starch, and amylose content of Y25 and Z13 were significantly different from those of X27. Furthermore, the total amylase activity was significantly higher than that of X27. On the other hand, the starch gelatinization temperature was significantly lower than that of X27. The starch reduction in Y25 and Z13 is four times more than that in X27, and the maltose content of Y25 and Z13 is more than two times that of X27. Finally, the scores of sensory evaluation and physiological sweetness were significantly higher than those of X27. The results provide a theoretical basis for understanding the saccharification characteristics of sweetpotato varieties and are of guiding significance for the selection of sweetpotato parents. [ABSTRACT FROM AUTHOR]

Regulated Ire1-dependent decay (RIDD) is a feedback mechanism in which the endoribonuclease Ire1 cleaves endoplasmic reticulum (ER)-localized mRNAs encoding secretory and membrane proteins in eukaryotic cells under ER stress. RIDD is artificially induced by chemicals that generate ER stress; however, its importance under physiological conditions remains unclear. Here, we demonstrate the occurrence of RIDD in filamentous fungus using Aspergillus oryzae as a model, which secretes copious amounts of amylases. α-Amylase mRNA was rapidly degraded by IreA, an Ire1 ortholog, depending on its ER-associated translation when mycelia were treated with dithiothreitol, an ER-stress inducer. The mRNA encoding maltose permease MalP, a prerequisite for the induction of amylolytic genes, was also identified as an RIDD target. Importantly, RIDD of malP mRNA is triggered by inducing amylase production without any artificial ER stress inducer. Our data provide the evidence that RIDD occurs in eukaryotic microorganisms under physiological ER stress. Regulated IRE1-dependent mRNA decay in eukaryotic microorganisms under physiological endoplasmic reticulum stress is demonstrated to occur by using Aspergillus oryzae as a model, which produces copious amounts of amylolytic enzymes. [ABSTRACT FROM AUTHOR]

YcjT is a kojibiose phosphorylase found in Escherichia coli. We found that sucrose was a good acceptor of YcjT in reverse phosphorolysis using β-d-glucose 1-phosphate as a donor. The product was identified as β-d-fructofuranosyl α-d-glucopyranosyl-(1→2)-α-d-glucopyranoside. This sugar was also synthesized from sucrose and maltose using YcjT and maltose phosphorylase and promoted the growth of the probiotic Bifidobacterium breve. [ABSTRACT FROM AUTHOR]

The mechanism by which glycoside hydrolases control the reaction specificity through hydrolysis or transglycosylation is a key element embedded in their chemical structures. The determinants of reaction specificity seem to be complex. We looked for structural differences in domain B between the 4-α-glucanotransferase from Thermotoga maritima (TmGTase) and the α-amylase from Thermotoga petrophila (TpAmylase) and found a longer loop in the former that extends towards the active site carrying a W residue at its tip. Based on these differences we constructed the variants W131G and the partial deletion of the loop at residues 120-124/128-131, which showed a 11.6 and 11.4-fold increased hydrolysis/transglycosylation (H/T) ratio relative to WT protein, respectively. These variants had a reduction in the maximum velocity of the transglycosylation reaction, while their affinity for maltose as the acceptor was not substantially affected. Molecular dynamics simulations allow us to rationalize the increase in H/T ratio in terms of the flexibility near the active site and the conformations of the catalytic acid residues and their associated pKas. [ABSTRACT FROM AUTHOR]

Lignocellulose biomass, as a renewable and biodegradable carbon source, provides a wide range of valuable bioproducts. Their utilization requires an efficient conversion process to break down the complex and variable chemical structure of lignocellulose. In this work, a solid-state fermentation-based pretreatment method for the release of fermentable sugars from corn silage was investigated. The optimal process conditions for water-soluble sugar extraction were initially explored by response surface methodology with the aim to achieve the maximum sugar concentration in the extracts. The optimal extraction conditions were determined: t = 30 min; the liquid-solid ratio L/S = 25 mL g-1; n = 170 rpm; and T = 30 °C. The changes in the content of water-soluble sugars (glucose, fructose, sucrose, maltose, maltotriose) were analyzed during seven days of fungal treatment. [ABSTRACT FROM AUTHOR]

As a potent, pleiotropic regulatory protein in Gram-positive bacteria, catabolite control protein A (CcpA) mediates the transcriptional control of carbohydrate metabolism in Streptococcus bovis, a lactate-producing bacterium that plays an essential role in rumen acidosis in dairy cows. Although the rumen uptake of carbohydrates is multi-substrate, the focus of S. bovis research thus far has been on the glucose. With the aid of gene deletion, whole-genome sequencing, and transcriptomics, we have unraveled the role of CcpA in carbohydrate metabolism, on the one hand, and acidosis, on the other, and we show that the S. bovis strain S1 encodes "Carbohydrate-Active Enzymes" and that ccpA deletion slows the organism's growth rate and modulates the organic acid fermentation pathways toward lower lactate, higher formate, and acetate in the maltose and cellobiose. Furthermore, this study revealed the different regulatory functions of the CcpA protein in rumen metabolism and acidosis. [ABSTRACT FROM AUTHOR]

For growth and energy, Corynebacterium glutamicum has the ability to assimilate numerous carbon sources in the form of either single or combined substrates. During the growth of C. glutamicum on substrate mixtures, it has shown the ability to co-metabolize the majority of these carbon sources and displays monophasic growth, unlike other microorganisms such as Escherichia coli and Bacillus subtilis, which exhibit either diauxic or biphasic growth. Here, a recombinant strain of C. glutamicum ATCC 13032 was selected for the use in the production of itaconic acid (IA), which is a promising biochemical building block that could be an alternative material for polymer synthesis. For this purpose, an engineered C. glutamicum ATCC 13032 pCH-cadAopt was constructed by introducing the plasmid pCH-cadAopt, which expressed a cis-aconitate dehydrogenase gene (cadA) that originated from Aspergillus terreus. The production of IA was evaluated using a combined mixture of maltose and sodium acetate. The monophasic growth of C. glutamicum in the presence of maltose and sodium acetate was observed and showed final IA titer of 12.63 g/L, and a molar yield of 0.38 mol/mol after 240 h of cultivation. The present study suggests the possibility of utilizing a mixture of carbon sources by C. glutamicum to improve IA production. [ABSTRACT FROM AUTHOR]

Vacuum frying (VF) is a selective technique for producing high-quality fried food that is mostly used on vegetables, fruits, and potato chips. It is rarely applied to the production of aquatic (especially fish) products. The purpose of this study is to explore whether VF technology can be applied to the preparation of dried silver herring products and to obtain the optimal VF conditions. The response surface methodology (RSM) was used to examine the factors affecting the quality of silver herring (Spratelloides gracilis) products after VF, namely temperature (75, 90, and 105 °C), duration (25, 35, and 45 min), and concentration (0, 15, and 30%) of maltose solution used to immerse the samples during pre-processing. The results indicated that VF temperatures had significant impacts on water activity (Aw), moisture content, yield, oil content, lightness (L* value), and colour difference (ÄE). The higher the VF temperature, the lower the Aw, moisture content, yield, and oil content of the product, but the higher the L* value and ΔE. Next, a longer VF duration resulted in higher oil content of the product. Maltose concentration was significantly and positively correlated with the yield and fracturability of the product. RSM analysis indicated that the optimal combination of processing conditions was a VF temperature of 105 °C, VF duration of 25 min, and maltose concentration of 27%. Under these VF conditions, the silver herring products had a moisture content of 3.91%, Aw of 0.198, oil content of 21.69%, L* value of 28.19, ΔE of 27.31, and fracturability of 359 g/s. In summary, vacuum frying technology is suitable for the preparation of dried silver herring products, and this study can provide the optimal processing conditions for seafood processors to obtain better quality. [ABSTRACT FROM AUTHOR]

Trehalose is a functional sugar that has numerous applications in food, cosmetic, and pharmaceutical products. Production of trehalose from maltose via a single-step enzymatic catalysis using trehalose synthase (TreS) is a promising method compared with the conventional two-step process due to its simplicity with lower formation of byproducts. In this study, a cold-active trehalose synthase (PaTreS) from Pseudarthrobacter sp. TBRC 2005 was heterologously expressed and characterized. PaTreS showed the maximum activity at 20 °C and maintained 87% and 59% of its activity at 10 °C and 4 °C, respectively. The enzyme had remarkable stability over a board pH range of 7.0–9.0 with the highest activity at pH 7.0. The activity was enhanced by divalent metal ions (Mg2+, Mn2+ and Ca2+). Conversion of high-concentration maltose syrup (100–300 g/L) using PaTreS yielded 71.7–225.5 g/L trehalose, with 4.5–16.4 g/L glucose as a byproduct within 16 h. The work demonstrated the potential of PaTreS as a promising biocatalyst for the development of low-temperature trehalose production, with the advantages of reduced risk of microbial contamination with low generation of byproduct. [ABSTRACT FROM AUTHOR]

Malto-oligosaccharides (MOSs) from starch conversion is advantageous for food and pharmaceutical applications. In this study, an efficient malto-oligosaccharide-forming α-amylase AmyCf was identified from myxobacter Cystobacter sp. strain CF23. AmyCf is composed of 417 amino acids with N-terminal 41 amino acids as the signal peptide, and conserved glycoside hydrolase family 13 (GH13) catalytic module and predicted C-terminal domain with β-sheet structure are also identified. Phylogenetic and functional analysis demonstrated that AmyCf is a novel member of GH13_6 subfamily. The special activity of AmyCf toward soluble starch and raw wheat starch is 9249 U/mg and 11 U/mg, respectively. AmyCf has broad substrate specificity toward different types of starches without requiring Ca2+. Under ideal circumstances of 60 °C and pH 7.0, AmyCf hydrolyzes gelatinized starch into maltose and maltotriose and maltotetraose as the main hydrolytic products with more than 80% purity, while maltose and maltotriose are mainly produced from the hydrolysis of raw wheat starch with more than 95% purity. The potential applicability of AmyCf in starch processing is highlighted by its capacity to convert gelatinized starch and raw starch granules into MOSs. This enzymatic conversion technique shows promise for the low-temperature enzymatic conversion of raw starch. [ABSTRACT FROM AUTHOR]

Recent interest in the special beer category has encouraged the search for novel brewing materials, including new ingredients and novel yeast strains, in order to differentiate the finished products. The aim of this work was to select non-brewing S. cerevisiae strains for the production of a fruit beer with raspberry. The in vitro tests and the wort fermentations allowed the selection of two sourdough S. cerevisiae strains, showing high maltose and maltotriose consumption, high ethanol production, and high viability. Fruit beers (FB) and control beers (CB) without raspberries were prepared. Fruit addition accelerated sugar consumption (7 days compared to 13 days) and increased ethanol and glycerol production by yeasts. Raspberry addition and the inoculated yeast strongly affected the aroma profile of beers. FB samples showed a higher amount of volatile organic compounds (VOCs); the most represented classes were alcohols, followed by esters and acids. FB inoculated by the selected S. cerevisiae SD12 showed the highest VOCs concentration (507.33 mg/L). Results highlighted the possible application of sourdough yeast strains for the brewing process, which, combined with raspberry addition, can be exploited for the production of beers with enhanced aromatic features and suitable chemical properties. [ABSTRACT FROM AUTHOR]

Yeasts are ubiquitously present in different natural sources. Some of these yeasts have interesting characteristics for the production of fermented food products. This study characterized Lachancea thermotolerans and L. quebecensis isolated from insects to determine their brewing potential. The yeasts were evaluated according to their fermentative potential in glucose and maltose-defined media and their resistance to ethanol and hop. Finally, craft beer was elaborated at a laboratory scale (10 L). The yeasts utilized glucose as the only carbon source and produced 3.25 ± 1.77, and 4.25 ± 1.06% (v/v), of ethanol for L. thermotolerans and quebecensis, respectively. While in the maltose-defined medium, ethanol content reached 3.25 ± 0.45, and 3.92 ± 0.36, respectively. The presence of alpha acids and ethanol affected the growth of L. quebecensis, which showed lower growth at 90 IBU and 8 ethanol% (v/v) mixtures. The craft beer brewed with L. quebecensis in monoculture experiments showed fruity flavors associated with ethyl acetate and isoamyl acetate. The ethanol content reached 3.50 ± 0.46% (v/v). The beer pH was 4.06 ± 0.20, with a lactic acid concentration of 1.21 ± 0.05 g/L. The sensory panel identified the beer as "fruity", "floral", "hoppy", "sweet", and "sour". To our knowledge, this is the first time L. quebecensis was reported as a potential candidate for sour beer production with reduced ethanol content. [ABSTRACT FROM AUTHOR]

The biosynthetic process of selenium nanoparticles (SeNPs) by specific bacterial strain, whose growth directly affects the synthesis efficiency, has attracted great attentions. We previously reported that Bacillus paralicheniformis SR14, a SeNPs-producing bacteria, could improve intestinal antioxidative function in vitro. To further analyze the biological characteristics of SR14, whole genome sequencing was used to reveal the genetic characteristics in selenite reduction and sugar utilization. The results reviewed that the genome size of SR14 was 4,448,062 bp, with a GC content of 45.95%. A total of 4300 genes into 49 biological pathways was annotated to the KEGG database. EC: 1.1.1.49 (glucose-6-phosphate 1-dehydrogenase) and EC: 5.3.1.9 (glucose-6-phosphate isomerase), were found to play a potential role in glucose degradation and EC:2.7.1.4 (fructokinase) might be involved in the fructose metabolism. Growth profile and selenite-reducing ability of SR14 under different sugar supplements were determined and the results reviewed that glucose had a better promoting effect on the reduction of selenite and growth of bacteria than fructose, sucrose, and maltose. Moreover, RT-qPCR experiment proved that glucose supplement remarkably promoted the expressions of thioredoxin, fumarate reductase, and the glutathione peroxidase in SR14. Analysis of mRNA expression showed levels of glucose-6-phosphate dehydrogenase and fructokinase significantly upregulated under the supplement of glucose. Overall, our data demonstrated the genomic characteristics of SR14 and preliminarily determined that glucose supplement was most beneficial for strain growth and SeNPs synthesis. Keypoints: Whole genome sequencing was used to reveal the genetic characteristics of SR14 in selenite reduction and sugar utilization. Supplementing glucose had the best promoting effect on growth and selenite reduction of SR14, and the effect was better than supplementing sucrose, fructose, or maltose. EC:1.1.1.49 (glucose-6-phosphate 1-dehydrogenase) and EC:2.7.1.4 (fructokinase) might be associated with the metabolic process of SR14. SR14 might rely on multiple enzymes, such as thioredoxin, fumarate reductase, and glutathione peroxidase, to reduce selenite when supplementing with glucose. [ABSTRACT FROM AUTHOR]

Summary: Starch digestion is typically evaluated using in‐vitro techniques. During and after the in‐vitro digestion, samples are collected (gastric and intestinal phases) at allotted time intervals where starch digestion is quantified through the analysis of sugars using routine chemical and enzymatic analysis. This paper reports the use of mid‐infrared (MIR) spectroscopy as rapid method to measure the concentration of maltose and % digested starch during the digestion of rice and potato starch, maize starch namely Gelose 50 (50% amylose), Gelose 80 (80% amylose) and pregelatinized corn starch collected at different time points (5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 90, 105 and 120 min) from two in‐vitro digestion experiments. Two types of samples, turbid and supernatant were also evaluated. The coefficient of determination (R2) and the standard error in cross‐validation (SECV) ranged between 0.74 to 0.93 and 163 to 360 μg mL−1 for the prediction of the concentration of maltose. The use of turbid samples showed a better predictive ability when compared with the regression models developed using the supernatant samples. This method showed potential to significantly decrease the time and effort associated to determining maltose concentration and % digested starch during in‐vitro digestion. [ABSTRACT FROM AUTHOR]

Reductive dehalogenases are corrinoid and iron–sulfur cluster–containing enzymes that catalyze the reductive removal of a halogen atom. The oxygen-sensitive and membrane-associated nature of the respiratory reductive dehalogenases has hindered their detailed kinetic study. In contrast, the evolutionarily related catabolic reductive dehalogenases are oxygen tolerant, with those that are naturally fused to a reductase domain with similarity to phthalate dioxygenase presenting attractive targets for further study. We present efficient heterologous expression of a self-sufficient catabolic reductive dehalogenase from Jhaorihella thermophila in Escherichia coli. Combining the use of maltose-binding protein as a solubility-enhancing tag with the btuCEDFB cobalamin uptake system affords up to 40% cobalamin occupancy and a full complement of iron–sulfur clusters. The enzyme is able to efficiently perform NADPH-dependent dehalogenation of brominated and iodinated phenolic compounds, including the flame retardant tetrabromobisphenol, under both anaerobic and aerobic conditions. NADPH consumption is tightly coupled to product formation. Surprisingly, corresponding chlorinated compounds only act as competitive inhibitors. Electron paramagnetic resonance spectroscopy reveals loss of the Co(II) signal observed in the resting state of the enzyme under steady-state conditions, suggesting accumulation of Co(I)/(III) species prior to the rate-limiting step. In vivo reductive debromination activity is readily observed, and when the enzyme is expressed in E. coli strain W, supports growth on 3-bromo-4-hydroxyphenylacetic as a sole carbon source. This demonstrates the potential for catabolic reductive dehalogenases for future application in bioremediation. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the effects of different carbon sources (glucose, sucrose, and maltose) on laccase production from mycelium of Ganoderma multistipitatum grown on malt extract agar plates. The preliminary screening test was performed on the guaiacol plate, where a maroon brown zone formed after laccase oxidation. A few pure mycelial discs of Ganoderma species were transferred into submerged fermentation nutrient broth. The nutrient medium of submerged fermentation at 20 g of glucose revealed the highest laccase activities (2300 U/L) than other carbon sources. The interesting results also shown by inorganic NaNO3 in the production of maximum laccase (7800 ± 1.1 U/L). The organic nitrogen inducer, namely yeast extract, exhibited 5834 U/L laccase activity and a potential source of laccase secretion. The results concluded that C and N inducers enhanced the laccase production. This production process is eco-friendly and effective in the removal of dye from water. Laccase from the cultural broth was partially purified by SDS-PAGE for molecular weight determination, while Native-PAGE confirmed the laccase band after staining with guaiacol. The Km and Vmax values of Lacc134 were 1.658 mm and 2.452 mM min−1, respectively. The Lacc134 of this study effectively removed the Remazol Brilliant Blue R (RBBR) dye (extensively used in textile industries and wastewater). For dye removal capacity, 2.0 mg, 4.0 mg, 5.0 mg, and 6.0 mg were used, from which 6.0 mg was most effective in removal (85% and 88%) dye concentration in 1st and 2nd h interval treatment, respectively. Total organic carbon (TOC) quantity after dye removal percentage in the first- and second-hour time interval was 62% and 89%, respectively, at 30 g glucose. According to the experimental finding of this study, the breakdown products catalyzed by Lacc134 are less hazardous due to lower molecular weight than the dye itself. [ABSTRACT FROM AUTHOR]

The ideal yeast for the production of alcohol-free beer does not form ethanol, produces a distinct and pleasant taste and has probiotic properties. This study characterized the potential of a wine yeast, Saccharomyces cerevisiae CCM 9181, to be an ideal alcohol free beer strain. It was found to be maltose-negative, and the ethanol content in fermented all-malt wort has never exceeded the legal limit of 0.5% v/v. Its specific growth rate (µ) was the highest at 25 °C (μ = 0.41 ± 0.01 h−1) and it was not affected by iso-α-bitter acids (15–50 IBU, international bitterness units). A response surface methodology was used to optimize the temperature and pitching rate affecting the formation of total higher alcohols and esters. A statistical analysis of the experimental data revealed that temperature affected esters most significantly, while both temperature and pitching rate had the most significant effects on higher alcohols. The sensory properties of beers were evaluated by trained panelists and they were described as malty, clove-like, having a very mild bitterness and a bouquet of white wine. The survival rate of S. cerevisiae CCM 9181 after simulated passage through the gastrointestinal tract was investigated as a first step to evaluate its probiotic properties. Our analyses show that Saccharomyces cerevisiae CCM9181 is a suitable candidate for the large-scale commercial production of alcohol-free beer and has probiotic potential that needs to be studied further. [ABSTRACT FROM AUTHOR]