Common Sugars Research Articles

A dual-mode strategy for early detection of sugarcane pokkah boeng disease pathogen: A portable sensing device based on Cross-N DNA framework and MoS2@GDY

Sucrose, a common sugar primarily derived from sugarcane, is a crucial national strategic resource. However, its yield is significantly affected by various serious diseases, with pokkah boeng disease being one of the most damaging. Therefore, developing a sensitive method for the accurate detection of the pokkah boeng disease pathogen is crucial for ensuring the safety of sugar. This work presents a portable dual-modal detection device, assisted by a smartphone, which is based on MoS2@GDY, Mn3O4@Au nanomenzyme, cross-N DNA framework and Exo III exonuclease-assisted CHA signal amplification technology. The cross-N DNA framework provides many binding sites and is not restricted by AuNPs scattering positions, enhancing the signal output strength of the sensor. Additionally, the detection system incorporates a high-power-density capacitor to further amplify the electrochemical detection signal, increasing sensitivity by 9.1 times. Moreover, the use of electrochemical and colorimetric dual-mode detection effectively avoids mutual interference, reducing the likelihood of false positives from a single signal. Under optimized conditions, the proposed method has a linear range of 0.0001–10,000 pM, and with a detection limit of 6.1 aM (S/N=3). This high-sensitivity, high-reliability portable sensing method shows significant potential for the early detection and real-time on-site monitoring of the pokkah boeng disease pathogen.

Detection of sugar syrup adulteration in UK honey using DNA barcoding

Honey is a valuable and nutritious food product, but it is at risk to fraudulent practices such as the addition of cheaper syrups including corn, rice, and sugar beet syrup. Honey authentication is of the utmost importance, but current methods are faced with challenges due to the large variations in natural honey composition (influenced by climate, seasons and bee foraging), or the incapability to detect certain types of plant syrups to confirm the adulterant used. Molecular methods such as DNA barcoding have shown great promise in identifying plant DNA sources in honey and could be applied to detect plant-based sugars used as adulterants. In this work DNA barcoding was successfully used to detect corn and rice syrup adulteration in spiked UK honey with novel DNA markers. Different levels of adulteration were simulated (1 – 30%) with a range of different syrup and honey types, where adulterated honey was clearly separated from natural honey even at 1% adulteration level. Moreover, the test was successful for multiple syrup types and effective on honeys with different compositions. These results demonstrated that DNA barcoding could be used as a sensitive and robust method to detect common sugar adulterants and confirm syrup species origin in honey, which can be applied alongside current screening methods to improve existing honey authentication tests.

Metabolome and Transcriptome Unveil the Correlated Metabolites and Transcripts with 2-acetyl-1-pyrroline in Fragrant Rice.

Fragrance is a valuable trait in rice varieties, with its aroma significantly influencing consumer preference. In this study, we conducted comprehensive metabolome and transcriptome analyses to elucidate the genetic and biochemical basis of fragrance in the Shangsixiangnuo (SSXN) variety, a fragrant indica rice cultivated in Guangxi, China. Through sensory evaluation and genetic analysis, we confirmed SSXN as strongly fragrant, with an 806 bp deletion in the BADH2 gene associated with fragrance production. In the metabolome analysis, a total of 238, 233, 105 and 60 metabolic compounds exhibited significant changes at the seedling (S), reproductive (R), filling (F), and maturation (M) stages, respectively. We identified four compounds that exhibited significant changes in SSXN across all four development stages. Our analyses revealed a significant upregulation of 2-acetyl-1-pyrroline (2AP), the well-studied aromatic compound, in SSXN compared to the non-fragrant variety. Additionally, correlation analysis identified several metabolites strongly associated with 2AP, including ethanone, 1-(1H-pyrrol-2-yl)-, 1H-pyrrole, and pyrrole. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) analysis highlighted the magenta and yellow modules as particularly enriched in aroma-related metabolites, providing insights into the complex aromatic compounds underlying the fragrance of rice. In the transcriptome analysis, a total of 5582, 5506, 4965, and 4599 differential expressed genes (DEGs) were identified across the four developmental stages, with a notable enrichment of the common pathway amino sugar and nucleotide sugar metabolism in all stages. In our correlation analysis between metabolome and transcriptome data, the top three connected metabolites, phenol-, 3-amino-, and 2AP, along with ethanone, 1-(1H-pyrrol-2-yl)-, exhibited strong associations with transcripts, highlighting their potential roles in fragrance biosynthesis. Additionally, the downregulated expression of the P4H4 gene, encoding a procollagen-proline dioxygenase that specifically targets proline, in SSXN suggests its involvement in proline metabolism and potentially in aroma formation pathways. Overall, our study provides comprehensive insights into the genetic and biochemical mechanisms underlying fragrance production in rice, laying the foundation for further research aimed at enhancing fragrance quality in rice breeding programs.

Succinate-mediated symbiosis between Dialister hominis and an uncharacterized Segatella-like pectinophile

ObjectivesSyntrophy has been documented between pectinophiles and methanol-utilizing bacteria, along with instances of cross-feeding between pectinophiles and methanogens. However, studies on the ecology of pectinophiles in anaerobic digestion (AD) are lacking. Therefore, in this study, we aimed to elucidate the ecology of pectinophiles by isolating novel pectinophile forms and conducting a comprehensive analysis of their physiology and ecology. MethodsComplex microbial communities from AD systems were enriched in a pectin-containing medium; subsequently, specific strains were isolated using a pectinophile isolation method. The carbon source assimilation and growth ability of the isolates, along with their symbiotic relationships, were evaluated using batch tests. ResultsStrain LPYR103-Pre exhibited 16S rRNA gene sequence similarity and average nucleotide identity values of 94.3 % and 77.9 %, respectively, compared to its closest related species, Segatella cerevisiae. Strain LPYR103-Pre demonstrated attenuated growth in the presence of eight common sugars but exhibited remarkably high growth in the presence of pectin, d-galacturonate, and d-glucuronate, with succinate being identified as a primary metabolite. Accumulation of succinate inhibited the growth of strain LPYR103-Pre. However, this growth impediment was alleviated by Dialister hominis LPYG114-Dih, whose growth required succinate. ConclusionsOur results elucidate the specific carbon source requirements of the Segatella-like strain LPYR103-Pre and succinate-mediated symbiosis involving D. hominis. These findings provide new insights into the degradation of pectin and its degradation products during AD, contributing to the identification of unknown pectinophiles.

Effect of Hydrocarbon Pollution on the Fungal Communities of the White and Barents Sea Littoral Sediments

The effect of hydrocarbon pollution on the fungal communities of littoral sediments of the cold-water White and Barents seas was investigated. The samples were collected at locations with different levels of pollution with oil products, from ports to relatively undisturbed areas. Using the diesel fuel-containing medium resulted in detection of hydrocarbon-degrading fungi in almost all studied samples, although in all cases they were less diverse than sugar-degrading fungi. In this relatively small group, Penicillium chrysogenum and Penicillium brevicompactum were the most common organisms. Fungal communities isolated on a sugar-containing medium exhibited higher diversity and abundance, with being the most common sugar degraders. The major factors affecting the structure of the fungal communities were the percentage of hydrocarbons in the total mass of organic carbon in the samples in the case of hydrocarbon-degrading fungi and location, for sugar degraders. In the experiment, the highest hydrocarbon-degrading activity was shown for Penicillium chrysogenum (the loss of residual hydrocarbons was 77.4%), Cadophora fastigiata (72%), and Tolypocladium inflatum (67.2%).

Multidimensional Uses of Bitter Melon (Momordica charantia L.) Considering the Important Functions of its Chemical Components

Abstract: Bitter melon (Momordica charantia L.) is a member of the Cucurbitaceae, which is also known as bitter squash, bitter gourd, karela, Goya melon and balsam pear. It is a rich source of different vitamins, potassium, zinc and other nutrients. The main pharmaceutical benefits of bitter melon are “antiinflammatory”, “antioxidant activity”, “antimicrobial characteristic”, “anticancer activity”, and “antihelmintic activity”, “antidiabetic effects”, “antiinflammation activity” and “treat skin conditions”. Its fruit is the main part of the plant which has been used for medicinal and food purposes. The primary metabolites in bitter gourd are common sugars, chlorophyll and proteins while secondary metabolites are carotenoids, alkaloids, phenolics, curcubitane triterpenoids, saponins, etc. The present review aims to study and survey on the nearly up-to-date results and findings regarding the pharmaceutical advantages and health benefits of bitter melon in an organic life.

Solid-State Fermentation of Ganoderma lucidum on the Soluble Sugar Metabolism of Three Summer–Autumn Black Tea Varieties

Soluble sugar is one of the important characteristic metabolites contributing to the flavor quality of tea. However, little is known about the changes and metabolic pathways of sugar in summer–autumn black tea varieties during the solid-state fermentation of Ganoderma lucidum. Therefore, this study is aimed at investigating the effects of the solid-state fermentation of Ganoderma lucidum on soluble sugar metabolism in three summer–autumn black tea varieties. In this study, we combined targeted metabolomics technology, gas chromatography-mass spectrometry, and multivariate statistical analysis to reveal the metabolic rules of 13 different sugars in three varieties of summer–autumn black tea under the action of Ganoderma lucidum. Using multivariate statistical analysis, 8 common key sugar differential metabolites were selected from the three groups of samples: D-fructose, trehalose, lactose, maltose, D-galactose, glucose, L-rhamnose, and xylitol. The eight different sugars contributed to the quality difference between Ganoderma lucidum tea and black tea in this study. To better explore the patterns of sugar changes, the metabolic pathways of 13 different sugars were screened and analyzed. The result revealed that the solid-state fermentation of Ganoderma lucidum increased the sweet characteristics and decreased the bitter characteristics of the three summer–autumn black tea varieties. In addition, these results showed that the solid-state fermentation of Ganoderma lucidum could produce lactose in tea, reduce glucose and fructose contents, and increase xylitol content. The solid-state fermentation of Ganoderma lucidum can regulate soluble sugar metabolism in three summer–autumn black tea varieties, leading to an improvement in their quality. This study has potential practical significance for regulating the flavor quality of summer–autumn tea.

A Critical Review on Immobilized Sucrose Isomerase and Cells for Producing Isomaltulose.

Isomaltulose is a novel sweetener and is considered healthier than the common sugars, such as sucrose or glucose. It has been internationally recognized as a safe food product and holds vast potential in pharmaceutical and food industries. Sucrose isomerase is commonly used to produce isomaltulose from the substrate sucrose in vitro and in vivo. However, free cells/enzymes were often mixed with the product, making recycling difficult and leading to a significant increase in production costs. Immobilized cells/enzymes have the following advantages including easy separation from products, high stability, and reusability, which can significantly reduce production costs. They are more suitable than free ones for industrial production. Recently, immobilized cells/enzymes have been encapsulated using composite materials to enhance their mechanical strength and reusability and reduce leakage. This review summarizes the advancements made in immobilized cells/enzymes for isomaltulose production in terms of refining traditional approaches and innovating in materials and methods. Moreover, innovations in immobilized enzyme methods include cross-linked enzyme aggregates, nanoflowers, inclusion bodies, and directed affinity immobilization. Material innovations involve nanomaterials, graphene oxide, and so on. These innovations circumvent challenges like the utilization of toxic cross-linking agents and enzyme leakage encountered in traditional methods, thus contributing to enhanced enzyme stability.

A phosphatase gene is linked to nectar dihydroxyacetone accumulation in mānuka (Leptospermum scoparium).

Floral nectar composition beyond common sugars shows great diversity but contributing genetic factors are generally unknown. Mānuka (Leptospermum scoparium) is renowned for the antimicrobial compound methylglyoxal in its derived honey, which originates from the precursor, dihydroxyacetone (DHA), accumulating in the nectar. Although this nectar trait is highly variable, genetic contribution to the trait is unclear. Therefore, we investigated key gene(s) and genomic regions underpinning this trait. We used RNAseq analysis to identify nectary-associated genes differentially expressed between high and low nectar DHA genotypes. We also used a mānuka high-density linkage map and quantitative trait loci (QTL) mapping population, supported by an improved genome assembly, to reveal genetic regions associated with nectar DHA content. Expression and QTL analyses both pointed to the involvement of a phosphatase gene, LsSgpp2. The expression pattern of LsSgpp2 correlated with nectar DHA accumulation, and it co-located with a QTL on chromosome 4. The identification of three QTLs, some of the first reported for a plant nectar trait, indicates polygenic control of DHA content. We have established plant genetics as a key influence on DHA accumulation. The data suggest the hypothesis of LsSGPP2 releasing DHA from DHA-phosphate and variability in LsSgpp2 gene expression contributing to the trait variability.

Preliminary characterization of gut mycobiome enterotypes reveals the correlation trends between host metabolic parameter and diet: a case study in the Thai Cohort

The association between the gut mycobiome and its potential influence on host metabolism in the Thai Cohort was assessed. Two distinct predominant enterotypes, Saccharomyces (Sa) and Aspergillus/Penicillium (Ap/Pe) showed differences in gut mycobiota diversity and composition. Notably, the Sa enterotype exhibited lower evenness and richness, likely due to the prevalence of Saccharomyces, while both enterotypes displayed unique metabolic behaviors related to nutrient metabolism and body composition. Fiber consumption was positively correlated with adverse body composition and fasting glucose levels in individuals with the Sa enterotype, whereas in the Ap/Pe enterotype it was positively correlated with fat and protein intake. The metabolic functional analysis revealed the Sa enterotype associated with carbohydrate metabolism, while the Ap/Pe enterotype involved in lipid metabolism. Very interestingly, the genes involved in the pentose and glucuronate interconversion pathway, such as polygalacturonase and l-arabinose-isomerase, were enriched in the Sa enterotype signifying a metabolic capacity for complex carbohydrate degradation and utilization of less common sugars as energy sources. These findings highlight the interplay between gut mycobiome composition, dietary habits, and metabolic outcomes within the Thai cohort studies.

Biosynthesis of UDP-α-N-Acetyl-d-mannosaminuronic Acid and CMP-β-N-Acetyl-d-neuraminic Acid for the Capsular Polysaccharides of Campylobacter jejuni.

Campylobacter jejuni is a human pathogen and a leading cause of food poisoning in North America and Europe. The exterior surface of the bacterial cell wall is attached to a polymeric coat of sugar molecules known as the capsular polysaccharide (CPS) that helps protect the organism from the host immune response. The CPS is composed of a repeating sequence of common and unusual sugar residues. In the HS:11 serotype of C. jejuni, we identified two enzymes in the gene cluster for CPS formation that are utilized for the biosynthesis of UDP-α-N-acetyl-d-mannosaminuronic acid (UDP-ManNAcA). In the first step, UDP-α-N-acetyl-d-glucosamine (UDP-GlcNAc) is epimerized at C2 to form UDP-α-N-acetyl-d-mannosamine (UDP-ManNAc). This product is then oxidized by a NAD+-dependent C6-dehydrogenase to form UDP-ManNAcA. In the HS:6 serotype (C. jejuni strain 81116), we identified three enzymes that are required for the biosynthesis of CMP-β-N-acetyl-d-neuraminic acid (CMP-Neu5Ac). In the first step, UDP-GlcNAc is epimerized at C2 and subsequently hydrolyzed to form N-acetyl-d-mannosamine (ManNAc) with the release of UDP. This product is then condensed with PEP by N-acetyl-d-neuraminate synthase to form N-acetyl-d-neuraminic acid (Neu5Ac). In the final step, CMP-N-acetyl-d-neuraminic acid synthase utilizes CTP to convert this product into CMP-Neu5Ac. A bioinformatic analysis of these five enzymes from C. jejuni serotypes HS:11 and HS:6 identified other bacterial species that can produce UDP-ManNAcA or CMP-Neu5Ac for CPS formation.

Healthcare Burden in Greenland of Gastrointestinal Symptoms in Adults with Inherited Loss of Sucrase-Isomaltase Function.

Congenital sucrase isomaltase deficiency (CSID) is in general a very rare disease. However, 2-3% of the Greenlandic population are homozygous (HO) carriers of an Arctic-specific loss-of-function (LoF) variant in the sucrase-isomaltase (SI) encoding gene, causing CSID. The condition is characterized by gastrointestinal symptoms such as stomachache, diarrhea, and weight loss when consuming sucrose, the most common dietary sugar. However, the awareness of the condition in the population and the healthcare system seems to be limited, potentially leading to a higher healthcare burden. Hence, we aimed to investigate whether HO-carriers visit the healthcare system more with gastrointestinal symptoms compared to the control groups by using registry data. We performed a case-control study identifying cases and controls using genotype information from the 1999-2001 and 2005-2010 Greenlandic health population cohorts. The cases were defined as HO LoF SI-carriers and controls were defined as non-carriers and were matched (1:1) on sex, age, place of residence, and European genetic admixture. We used electronic medical records to assess the number of electronic medical record contacts (EMRc) related to gastrointestinal symptoms and the number of gastrointestinal-related diagnostic procedures. A total of 80 HO-carriers and 80 non-carriers were included. The HO-carriers had 19% more EMRc related to gastrointestinal symptoms (IRR, 1.19, 95% CI [1.02;1.40], p=0.02) and had a 41% higher incidence of gastrointestinal related diagnostic procedures compared to controls (IRR, 1.41, 95% CI [1.05-1.92], p=0.02). Only one HO-carrier was aware of the condition according to the electronic medical records. HO-carriers of the LoF SI-variant had both significantly more gastrointestinal-related EMRc and significantly more diagnostic procedures conducted due to gastrointestinal symptoms. Only one HO-carrier was aware of the condition. Given the high prevalence of HO-carriers in the Greenlandic population, we anticipate that diagnosing more patients with CSID and providing dietary advice could potentially reduce symptom burden and healthcare visits among HO-carriers.

Dietary galactose exacerbates autoimmune neuroinflammation via advanced glycation end product-mediated neurodegeneration.

Recent studies provide increasing evidence for a relevant role of lifestyle factors including diet in the pathogenesis of neuroinflammatory diseases such as multiple sclerosis (MS). While the intake of saturated fatty acids and elevated salt worsen the disease outcome in the experimental model of MS by enhanced inflammatory but diminished regulatory immunological processes, sugars as additional prominent components in our daily diet have only scarcely been investigated so far. Apart from glucose and fructose, galactose is a common sugar in the so-called Western diet. We investigated the effect of a galactose-rich diet during neuroinflammation using myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (MOG-EAE) as a model disease. We investigated peripheral immune reactions and inflammatory infiltration by ex vivo flow cytometry analysis and performed histological staining of the spinal cord to analyze effects of galactose in the central nervous system (CNS). We analyzed the formation of advanced glycation end products (AGEs) by fluorescence measurements and investigated galactose as well as galactose-induced AGEs in oligodendroglial cell cultures and induced pluripotent stem cell-derived primary neurons (iPNs). Young mice fed a galactose-rich diet displayed exacerbated disease symptoms in the acute phase of EAE as well as impaired recovery in the chronic phase. Galactose did not affect peripheral immune reactions or inflammatory infiltration into the CNS, but resulted in increased demyelination, oligodendrocyte loss and enhanced neuro-axonal damage. Ex vivo analysis revealed an increased apoptosis of oligodendrocytes isolated from mice adapted on a galactose-rich diet. In vitro, treatment of cells with galactose neither impaired the maturation nor survival of oligodendroglial cells or iPNs. However, incubation of proteins with galactose in vitro led to the formation AGEs, that were increased in the spinal cord of EAE-diseased mice fed a galactose-rich diet. In oligodendroglial and neuronal cultures, treatment with galactose-induced AGEs promoted enhanced cell death compared to control treatment. These results imply that galactose-induced oligodendrocyte and myelin damage during neuroinflammation may be mediated by AGEs, thereby identifying galactose and its reactive products as potential dietary risk factors for neuroinflammatory diseases such as MS.

Оценка токсикологической и биологической безопасности кормовой добавки из продуктов переработки стевии

The fullness of feeding is inextricably connected with the concept of the nutritional status of cows and the normalized feeding of animals. Feed nutrition refers to the ability of the feed to meet the animal's natural food needs. One of the main conditions for the effective use of feed is the balance of diets in vitamins, macro- and micronutrients and feed value. Ensuring a balanced diet for all nutrients, in farm conditions, is very difficult. Normalized feeding in the practice of animal husbandry is carried out due to the use of full-fledged feed, as well as various feed additives and premixes. We conducted a chemical analysis of the nutritional, toxicological and biological safety of stevia processing products. Having a low energy and nutritional value, stevia processing products compensated for these products by the fact that they had a high content of common sugars, mine and organic-mineral compounds, as well as biologically active substances. When determining level of toxic elements – nitrates, nitrites, residual amounts of pesticides, mycotoxins, radionuclides, in new feed additive weren't revealed excesses of the maximum allowed levels. The results of the test of the solution from stevia processing products in white rats indicate that there is no toxic effect on the animal body and indicate its complete biological safety.

Novel multienzyme cascade for efficient synthesis of d-allulose from inexpensive sucrose

d-Allulose is one of the most common rare sugars with low calorie and is extensively applied in the food, cosmetic, and pharmaceutical fields. Here, a novel in vitro multienzyme cascade route (MCAS) was designed to produce d-allulose from sucrose. The MCAS route comprised three modules (sucrose phosphorolysis, phosphorylation–dephosphorylation, and ATP regeneration), including five enzymes (sucrose phosphorylase, fructokinase, d-allulose 6-phosphate 3-epimerase, d-allulose 6-phosphatephosphatase, and polyphosphate kinase). As a rate-limiting enzyme, d-allulose 6-phosphate 3-epimerase from Pantoea sp. was semi-rationally engineered, and variant Y143F led to 88.8% yield of d-allulose from 10 mM sucrose using one-pot strategy. ATP consumption was reduced to 5% of the sucrose concentration after introducing ATP-regeneration system. At elevated sucrose concentration of 100 mM by two-step strategy, a d-allulose yield of 70.4% was achieved with a space-time yield of 1.06 g L−1·h−1. This study provides an efficient and cost-effective approach for producing d-allulose from sucrose.

Differential biochemical and metabolic responses of contrast rice cultivars (<i>Oryza sativa</i> L.) under salt stress

More than half of the global population uses rice as the fundamental staple food; therefore, it is one of the most popular crops in the world. However, it is susceptible to salt stress, particularly among monocot crops, which reduces rice cultivation yield and threatens global food security. This research investigates the role of some factors, including amino acids, antioxidant enzymes, and sugars, in the response to the salinity stress of three contrasting rice cultivars, Dai Thom 8 (salt-sensitive), OC 10 (moderately salt-tolerant), and OM 9577 (salt-tolerant) in the seedling stage. The salt-tolerant varieties exhibited remarkable differences in physiological and biochemical traits, including enhancement of growth capacity, reduction of cell membrane damage via lowering lipid peroxidation, minimization of ROS generation, enhancement of free radical scavenging activity, and SOD, POD, and CAT enzyme activities. Additionally, the study analyzed the presence of 13 sugars using GC-MS and found that all three rice cultivars shared seven common sugars in similar quantities. However, OM 9577 had a higher content of the other six sugars compared to OC 10 and Dai Thom 8. It is one of the important biochemical factors responsible for the difference in the response mechanism to NaCl stress among rice varieties, specifically lyxofuranose (3.268%), a-D-xylopyranose (5.727%), mannopyranose (12.86%), α-D-glucopyranose (6.399%), ß-D-glucopyranose (5.509%), and D-arabinose (1.512%). Furthermore, the quantification of 20 amino acids through HPLC-DAD revealed that the salt-tolerant rice cultivars had higher concentrations of 11 amino acids than the salt-sensitive ones, including proline, isoleucine, serine, ornithine, histidine, glutamic acid, asparagine, alpha-alanine, aspartic acid, glutamine, and valine. These findings provide promising biochemical indicators for selecting salt-tolerant rice cultivars or improving existing varieties through traditional hybridization or gene transfer methods. Understanding these responses can significantly contribute to enhancing rice cultivation and ensuring food security in regions facing salinity challenges.

Engineering Escherichia coli for Isobutanol Production from Xylose or Glucose-Xylose Mixture.

Aiming to overcome the depletion of fossil fuels and serious environmental pollution, biofuels such as isobutanol have garnered increased attention. Among different synthesis methods, the microbial fermentation of isobutanol from raw substrate is a promising strategy due to its low cost and environmentally friendly and optically pure products. As an important component of lignocellulosics and the second most common sugar in nature, xylose has become a promising renewable resource for microbial production. However, bottlenecks in xylose utilization limit its wide application as substrates. In this work, an isobutanol synthetic pathway from xylose was first constructed in E. coli MG1655 through the combination of the Ehrlich and Dahms pathways. The engineering of xylose transport and electron transport chain complexes further improved xylose assimilation and isobutanol production. By optimizing xylose supplement concentration, the recombinant E. coli strain BWL4 could produce 485.35 mg/L isobutanol from 20 g/L of xylose. To our knowledge, this is the first report related to isobutanol production using xylose as a sole carbon source in E. coli. Additionally, a glucose-xylose mixture was utilized as the carbon source. The Entner-Doudorof pathway was used to assimilate glucose, and the Ehrlich pathway was applied for isobutanol production. After carefully engineering the recombinant E. coli, strain BWL9 could produce 528.72 mg/L isobutanol from a mixture of 20 g/L glucose and 10 g/L xylose. The engineering strategies applied in this work provide a useful reference for the microbial production of isobutanol from xylose or glucose-xylose mixture.

N-linked glycoproteins and host proteases are involved in swine acute diarrhea syndrome coronavirus entry.

Gaining insight into the cell-entry mechanisms of swine acute diarrhea syndrome coronavirus (SADS-CoV) is critical for investigating potential cross-species infections. Here, we demonstrated that pretreatment of host cells with tunicamycin decreased SADS-CoV attachment efficiency, indicating that N-linked glycosylation of host cells was involved in SADS-CoV entry. Common N-linked sugars Neu5Gc and Neu5Ac did not interact with the SADS-CoV S1 protein, suggesting that these molecules were not involved in SADS-CoV entry. Additionally, various host proteases participated in SADS-CoV entry into diverse cells with different efficiencies. Our findings suggested that SADS-CoV may exploit multiple pathways to enter cells, providing insights into intervention strategies targeting the cell entry of this virus.

Multifactorial characterization of nutritional and quality profiles of organically-sweetened Kunun-zaki beverage

Increased risk of non-communicable diseases (NCDs) such obesity, Type-2 diabetes, cardiovascular illnesses, and dental health issues has been associated with excessive added-sugar consumption. The objective of this study was to develop Kunun-zaki - a non-carbonated, non-alcoholic, cereal-based fermented beverage, using natural plant-based sweeteners Thaumatococcus daniellii (Miracle fruits) and Dioscoreophyllum cumminsii (Serendipity berry) in place of table sugar at various concentrations (1.0 – 5.0 g/100 mL). The beverages' quality characteristics, nutritional, antinutrients, minerals and sensory profiles were determined. With regard to the majority of the variables examined, the main factors and interaction effects were significant (p < 0.05). Beverage sweetened with both fruits showed improved physical characteristics and quality indicators, and they also retained more micronutrients (vitamins and minerals). Although at tolerable level, alkaloids and tannins, however, were somewhat more prevalent these organically-sweetened samples, whereas phytates were more in sucrose ones. Application of robust (R2 > 0.80) Principal Component Analysis (PCA) and Orthogonal Projection to Latent Structure Discriminant Analysis (OPLS-DA) clearly partitioned all the desirable physicochemical and sensory attributes of the beverages mainly between miracle fruits and serendipity-sweetened Kunun-zaki, with just overall consumer acceptability favoring the sucrose-sweetened beverage. Hence, these further reiterate the superiority of these organic sweeteners over common table sugar in the formulation of Kunun-zaki and their potential expanded application in food systems.

First Report of Beet Yellows Virus Causing Virus Yellows in Sugar Beet in Serbia.

Several viruses have been described to infect sugar beet (Beta vulgaris var. saccharifera L.), but virus yellows disease is one of the most important diseases in many sugar beet growing areas. It is caused by four viruses either in single or mixed infection, including the poleroviruses beet western yellows virus (BWYV), beet mild yellowing virus (BMYV), and beet chlorosis virus (BChV), and a closterovirus beet yellows virus (BYV) (Stevens et al. 2005; Hossain et al. 2021). In August 2019, five samples of sugar beet plants showing yellowing on interveinal leaf tissue were collected in a sugar beet crop in the Novi Sad locality (Vojvodina Province, Serbia). Double-antibody sandwich (DAS)-ELISA commercial antisera (DSMZ, Braunschweig, Germany) were used to test the collected samples for the presence of the most common sugar beet viruses: beet necrotic yellow vein virus (BNYVV), BWYV, BMYV, BChV, and BYV. Commercial positive and negative controls were included in each ELISA test. BYV was serologically detected in all sugar beet samples, but no other viruses tested were found. The presence of BYV in sugar beet plants was further confirmed by conventional reverse transcription (RT)-PCR. Total RNAs were extracted using the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany), according to the manufacturer's instructions, and used as template in the RT-PCR. Total RNAs extracted from healthy sugar beet leaves and molecular-grade water were included as negative controls in the RT-PCR analysis. RT-PCR confirmed the presence of BYV in all naturally infected plants using four sets of specific primers (Kundu and Ryšánek 2004), whereas no amplification products were obtained in the negative controls. The RT-PCR products derived from isolate 209-19 were purified and directly sequenced in both directions using the same primer pairs as in RT-PCR (accession numbers OQ686792 to OQ686794). Multiple sequence alignment of the L-Pro and N-terminal part of the MET genes showed that the Serbian BYV isolate had the highest nucleotide identity (99.01% and 100%, respectively) with several BYV isolates in GenBank originating from different parts of the world. Sequence analysis of the HSP70 gene showed the highest similarity (99.79%) with the BYV-Cro-L isolate found in Croatia. In a semi-persistent type of transmission test, aphids (Myzus persicae Sulzer) were allowed to feed on BYV-infected leaves of an ELISA-positive sample (209-19) for 48 hours, and then the aphids were transferred to five plants each of Spinacia oleracea cv. Matador and B. vulgaris ssp. vulgaris cv. Eduarda for a three-day inoculation access period. All test plants were successfully infected and exhibited symptoms in the form of interveinal yellowing up to three weeks postinoculation. RT-PCR confirmed the presence of BYV in all inoculated plants. A study by Nikolić (1951) suggested a possible presence of BYV based on symptoms observed on sugar beet plants in fields, but to our knowledge this is the first report of BYV in sugar beet in Serbia. As sugar beet is one of the most important industrial crops in Serbia, the presence of BYV could lead to significant losses, considering that aphid vectors are widespread under Serbian environmental conditions. The discovery of BYV on sugar beet should prompt a more detailed survey and subsequent testing of susceptible hosts to determine the distribution and incidence of BYV in Serbia.