Invertase Activity Research Articles

Xylanase Supplement Enhances the Growth Performance of Broiler by Modulating Serum Metabolism, Intestinal Health, Short-Chain Fatty Acid Composition, and Microbiota

This study aimed to investigate the effects of different levels of xylanase supplementation in a wheat-based diet on growth performance, short-chain fatty acids, intestinal health, microbial composition, and serum metabolism. A total of 1200 male chicks were randomly assigned to four wheat-based diet treatments: Group C (adding 0 mg/kg of xylanase), Group L (adding 50 mg/kg of xylanase), Group M (adding 100 mg/kg of xylanase), and Group H (adding 150 mg/kg of xylanase). The experiment lasted for 56 days. The results indicated that Group H broilers experienced a decreased feed-to-gain ratio throughout the study period. Additionally, dietary supplementation with xylanase led to an increase in the physical barrier, as indicated by increased VH and VH/CD in the gut (p < 0.05). Furthermore, levels of D-lactic acid and endotoxin were reduced. Xylanase supplementation also increased the abundance of Muc-2, ZO-1, and Occludin (p < 0.05). Moreover, xylanase supplementation enhanced the activity of sucrase and maltase in the duodenum (p < 0.05), which may be attributable to the upregulation of the abundance of SI and MGA (p < 0.05). Furthermore, xylanase addition promoted propionic acid produced by specific bacteria, such as Phascolarctobacterium, and influenced the microbial composition to some extent, promoting intestinal health. Additionally, 150 mg/kg of xylanase supplementation increased the amino acid, peptide, and carbohydrate content and upregulated the metabolism of amino acids related to histidine, cysteine, methionine, and other pathways (p < 0.05). These findings suggest adequate xylanase supplementation can enhance nutritional digestibility and absorption, improve growth performance, stimulate endogenous enzyme activity, optimize intestinal morphology and barrier function, and positively influence acid-producing bacteria and amino acid metabolic pathways.

The role of afforestation with diverse woody species in enhancing and restructuring the soil microenvironment in polymetallic coal gangue dumps.

To elucidate the effects of long-term (20years) afforestation with different woody plant species on the soil microenvironment in coal gangue polymetallic contaminated areas. This study analyzed the soil physicochemical properties, soil enzyme activities, soil ionophore, bacterial community structure, soil metabolite, and their interaction relationships at different vertical depths. Urease, sucrase, and acid phosphatase activities in the shallow soil layers increased by 4.70-7.45, 3.83-7.64, and 3.27-4.85 times, respectively, after the restoration by the four arboreal plant species compared to the plant-free control soil. Additionally, it reduced the content of available elements in the soil and alleviated the toxicity stress for Cd, Ni, Co, Cr, As, Fe, Cu, U, and Pb. After the long-term restoration of arboreal plants, the richness and Shannon indices of soil bacteria significantly increased by 4.77-23.81% and 2.93-7.93%, respectively, broadening the bacterial ecological niche. The bacterial community structure shaped by different arboreal plants exhibited high similarity, but the community similarity decreased with increasing vertical depth. Soils Zn, U, Sr, S, P, Mg, K, Fe, Cu, Ca, Ba, and pH were identified as important influencing factors for the community structure of Sphingomonas, Pseudarthrobacter, Nocardioides, and Thiobacillus. The metabolites such as sucrose, raffinose, L-valine, D-fructose 2, 6-bisphosphate, and oxoglutaric acid were found to have the greatest effect on the bacterial community in the rhizosphere soils for arboreal plants. The results of the study demonstrated that long-term planting for woody plants in gangue dumps could regulate microbial abundance and symbiotic patterns through the accumulation of rhizosphere metabolites in the soil, increase soil enzyme activity, reduce heavy metal levels, and improve the soil environment in coal gangue dumps.

Comparative analysis of metabolites and in vitro hypoglycemic activity of Taiwanofungus camphoratus cultured using various methods

Taiwanofungus camphoratus has attracted much attention because it can abundantly produce various active substances that exhibit blood-sugar lowering, immunity improving, and antioxidant properties. Currently, T. camphoratus is cultured using four main methods: cutting wood culture, solid-state fermentation, submerged fermentation, and dish culture. T. camphoratus produces different metabolites under different culture methods. In this study, nontargeted metabolomics was used to compare the metabolites of T. camphoratus produced under these four culture methods. Principal component analysis and supervised partial least squares-discriminant analysis were used to analyze the differences in the metabolites. Moreover, in vitro hypoglycemic activity of T. camphoratus extracts produced under four culture methods was compared by assessing their ability to inhibit the activity of α-glucosidase, α-amylase, and sucrase. A total of 186 metabolites were identified. In total, 127 metabolites were common under the four culture methods. Under solid-state fermentation, submerged fermentation, and cutting wood culture, 12, 1, and 4 metabolites were unique, respectively. The differential metabolites produced by T. camphoratus under four culture methods were mainly triterpenoids, phenolic compounds, and fatty acid compounds. α-glucosidase, α-amylase, and sucrase activity inhibition was the best using T. camphoratus extract obtained under cutting wood culture; the inhibition rates were 55.97%, 51.96%, and 78.02%, respectively, which were comparable to those exhibited by 0.001, 3, and 12 mg/mL acarbose (positive control). The metabolites produced by T. camphoratus and α-glucosidase, α-amylase, and sucrase inhibitory activities were different under the four culture methods. Cutting wood culture exhibited the best enzyme inhibitory activity. This study provided a theoretical basis for further use and development of various culture methods for the rational production of active metabolites of T. camphoratus.

First report of Pseudomonas cichorii causing bacterial leaf blight of pocketbook plant (Calceolaria hybrida) in Taiwan.

Pocketbook plants (Calceolaria spp.) are flowering ornamentals often grown as potted plants (Poesch 1937). In December 2022, leaf blight symptoms were observed on 2-mo-old plants of C. hybrida F1 'Dainty'. The disease was found in a nursery in Ren'ai Township, Nantou, and about 20% of the plants exhibited symptoms. Symptomatic plants had brown or gray necrotic lesions of different sizes and shapes, mostly around leaf margins. Lower leaf wilting was also observed (Fig. S1, A and B). Three plants were sampled. Leaf lesions were surface-disinfected with 75% ethanol and cut into smaller pieces in 10 mM MgCl2. After observing bacterial streaming under a microscope, the bacteria were streaked onto nutrient agar (NA). Following 2 days at 28°C, a type of round, creamy white colony predominated on all the plates. Three strains (Calc-A, Calc-B, and Calc-C) were obtained, one from each plant. The strains produced fluorescent pigments on King's B medium and were tested Gram-negative. The strains were characterized with the LOPAT scheme (Schaad et al. 2001). They did not exhibit activities of pectic enzymes, arginine dihydrolase and levan sucrase, but produced oxidase and induced the hypersensitive response in tobacco. DNA was extracted from the strains for PCR amplification of the 16S rDNA with primer pair 27f/1492r as described by Lane (1991). The 16S rDNA sequences were compared with entries in the GenBank database. The sequences obtained (GenBank accession no. OR824302) matched that of Pseudomonas cichorii MAFF 301158 (accession no. AB724288; 1,403/1,403 bp) and were 99% identical to that of DSM 50259T (accession no. CP074349; 1,391/1,405 bp). The strains were also tested with the species-specific primers hrp1a and hrp2a (Cottyn et al. 2011). The amplicons were sequenced and a BLASTn search showed that the sequences (accession no. OR827305) shared the highest identity (99.3%) with that of P. cichorii strain 83-1 (accession no. DQ168848; 848/854 bp) and were 97.3% identical to the sequence of DSM 50259T (accession no. CP074349; 831/854 bp). Calc-A was selected as a representative strain and deposited in the Bioresource Collection and Research Center, Taiwan (reference no. BCRC 81432). Koch's postulates were fulfilled by spray-inoculating a suspension of Calc-A on three 2-mo-old C. hybrida F1 'Dainty' plants. The inoculum was prepared by suspending NA-grown cells in 10 mM MgCl2 including 0.02% Silwet L-77 (OD600 = 0.3; 1.5 x 108 CFU/ml). For the controls, three plants were sprayed with bacteria-free solution. The plants were bagged throughout the experiment and kept in a growth chamber (14/10 h light/dark; 26/24°C day/night). Leaf blight and wilting symptoms developed on all leaves of the inoculated plants after 30 h, but not the controls (Fig. S1, C and D). The pathogen was reisolated from the treatment group, and colony PCR with hrp1a/hrp2a showed that the reisolated strain shared the same sequence with Calc-A to Calc-C. Repeating the inoculation assay produced consistent results. This is the first report of P. cichorii affecting Calceolaria in Taiwan. The bacterium has been reported infecting diverse crops in Taiwan, such as tomato and lettuce (Tsai et al. 2014). Expanding the understanding of the pathogen's potential hosts could help prevent its spread across important crops.

Co-inoculation of fungi and desert cyanobacteria facilitates biological soil crust formation and soil fertility

The inoculation of cyanobacteria for enriching soil nutrients and forming biological soil crusts (BSCs) is considered an effective means to restore degraded soil. However, there are limited studies on the application of co-inoculation of fungi and cyanobacteria for degraded soil remediation. In this study, a high exopolysaccharide-secreting fungi Zh2 was isolated from lichen BSCs in Hobq Desert, and co-inoculated with a cyanobacterial strain identified as Phormidium tenue in different proportions to form BSCs on sand during a 35 days incubation period. Results revealed significant differences in crust biomass and soil properties among crusts with different cyanobacterial/fungal inoculation ratios. Microbial biomass, soil nutrient content and enzyme activities in crusts co-inoculated with cyanobacteria and fungi were higher than those inoculated with cyanobacteria and fungi alone. The inoculation of cyanobacteria contributed to the fulvic-like accumulation, and the inoculated fungi significantly increased the humic-like content and soil humification. Redundancy analysis showed that the inoculation of cyanobacteria was positively correlated with the activities of urease and phosphatase, and the content of fulvic-like. Meanwhile, the inoculation of fungi was positively correlated with the contents of total carbon, total nitrogen and humic-like, the activities of catalase and sucrase. Cyanobacteria and fungi play distinct roles in improving soil fertility and accumulating dissolved organic matter. This study provides new insights into the effects of cyanobacteria and fungi inoculations on the formation and development of cyanobacterial-fungus complex crusts, offering a novel method for accelerating induced crust formation on the surface of sand.

Effects of variable-temperature drying on the qualities and sweet-substance profile of Zizyphus jujuba Mill. cv. Junzao

The changes in the qualities and sweet-substance levels of Junzao jujube during variable-temperature drying (VTD) were investigated. The results showed that VTD retains the original color of jujube, reduces its hardness and chewiness, and decreases its wrinkling while shortening the drying time by 13.2% compared with that of constant temperature drying (CTD). “Electronic-tongue” taste analysis showed that the sweetness of VTD jujube is significantly higher than that for CTD. This is shown to be related to the contents of sucrose, fructose, and glucose, as well as the activities of invertase and sucrose synthase enzymes. In addition, the content trends for sweet amino acids are correlated with the temperature gradient used in VTD. Thus, the present study elucidates the factors governing the transformation of sugar substances in jujube during VTD, as well as providing a practical reference for the application of VTD in the jujube industry.

Unperforated film-covered planting contributes to improved film recovery rates and foxtail millet grain yields in sandy soils

Plastic film mulching improves the soil water content and temperature and, thus, contributes to enhanced grain yield in arid and semi-arid areas, such as Northwest China. However, in traditional film-covering methods, plastic films are difficult to recycle, causing environmental issues. Therefore, developing cultivation methods with enhanced film recovery rates is important for sustainable agricultural development. Here, we evaluated how the planting method affected the soil temperature, water content, film recovery rate, and grain yield by applying the following three planting patterns to the traditional crop, foxtail millet, in 2021–2022: no plastic film mulching (NP), plastic film mulching (MP), and planting on the film edge (PFE); in the latter, holes were not punched in the film and crops were planted approximately 5 cm from the film edge. The results for 2021 showed that the biomass ranged from 27.69 g to 33.76 g per plant, and the biomass was increased by 21.9% and 3.2% in PFE compared with NP and MP, respectively. However, in 2022, the biomass increased in PFE by 52.5% and 17.7% compared with NP and MP, respectively. In 2021, the highest grain yield was observed in PFE (2480 kg/hm2), followed by MP (2470 kg/hm2) and NP (2343 kg/hm2); in 2022, a significantly higher grain yield was observed in PFE than that in MP and NP. Although the soil temperature increased in PFE, it was not as high as in MP. The relatively higher soil temperature increased the root growth process, stimulated the production of root exudates (acetic acid and citric acid), and increased the soil enzyme (sucrase and urease) activity. Increases in organic acids and soil enzymes assisted in the decomposition of soil organic matter and induced relatively higher levels of available nutrients, such as nitrogen and phosphorus, and the higher root reuse rates contributed to higher grain yields. In addition, fewer holes were punched in the film of the PFE model, which improved film recovery, and the recovery rate of PFE was higher than that of MP. These results indicate that the proposed unperforated film-covered planting pattern is suitable for millet production in sandy soil.

Short-term high-temperature pretreated compost increases its application value by altering key bacteria phenotypes

Short-term high-temperature pretreatment can effectively shorten the maturity period of organic waste composting and improve the fertilizer efficiency and humification degree of products. To investigate the effect and mechanism of the end products on the saline–alkali soil improvement and plant growth, the short-term high-temperature pretreatment composting (SHC) and traditional composting (STC) were separately blended with saline–alkali soil in a ratio of 0–40 % to establish a soil–fertilizer blended matrix for cultivating Lolium perenne L. The pot experiments combined with principal component analysis showed Lolium perenne L. planted in 20 % SHC-blended saline–alkali soil had the best growth effect, and its biomass, chlorophyll content, and plant height were 109–113 % higher than STC. The soil physicochemical property analysis showed that SHC and STC increased the soil nutrient content, humification degree, and enzyme activity at any blending ratio. The microbial analysis showed that 20 % SHC in the saline–alkali soil stimulated the growth of functional microorganisms and the addition of SHC promoted the sulfur cycle, nitrogen fixation, and carbon metabolism in the soil–plant system. The correlation analysis showed that pH; nutrient contents; and urease, catalase, sucrase, and phosphatase activities in the saline–alkali soil were significantly correlated with plant growth indexes (p < 0.05). Georgenia and norank_f__Fodinicurvataceae had a stronger correlation with four types of enzyme activities (p < 0.01). SHC improved the saline–alkali soil and promoted plant growth by adjusting soil pH, increasing soil nutrients, and influencing soil enzyme activity and dominant flora. This study provides a theoretical basis for applying SHC products in soil improvement.

A novel magnetic graphene-loaded biochar gel for the remediation of arsenic- and antimony-contaminated mining soil

Metalloid co-contamination such as arsenic (As) and antimony (Sb) in soils has posed a significant threat to ecological balance and human well-being. In this study, a novel magnetic graphene-loaded biochar gel (FeBG) was developed, and its remediation potential for the reclamation of AsSb spoiled soil was assessed through a six-month soil incubation experiment. Results showed that the incorporation of iron substances and graphene imparted FeBG with enhanced surface characteristics, such as the formation of a new FeO bond and an enlarged surface area compared to the pristine biochar (BC) (80.5 m2 g−1 vs 57.4 m2 g−1). Application of FeBG significantly decreased Na2HPO4-extractable concentration of As in soils by 9.9 %, whilst BC addition had a non-significant influence on As availability, compared to the control. Additionally, both BC (8.2 %) and FeBG (16.4 %) treatments decreased the Na2HPO4-extractable concentration of Sb in soils. The enhanced immobilization efficiency of FeBG for As/Sb could be attributed to FeBG-induced electrostatic attraction, complexation (Fe–O(H)–As/Sb), and π-π electron donor-acceptor coordination mechanisms. Additionally, the FeBG application boosted the activities of sucrase (9.6 %) and leucine aminopeptidase (7.7 %), compared to the control. PLS-PM analysis revealed a significant negative impact of soil physicochemical properties on the availability of As (β = −0.611, P < 0.01) and Sb (β = −0.848, P < 0.001) in soils, in which Sb availability subsequently led to a suppression in soil enzyme activities (β = −0.514, P < 0.01). Overall, the novel FeBG could be a potential amendment for the simultaneous stabilization of As/Sb and the improvement of soil quality in contaminated soils.

Carbohydrase activity in proximal and distal segments of small intestine in health, irritated bowel syndrome and enteropathy with membrane digestion disturbance

Diagnostics of enteropathy with membrane digestion disturbance (EMDD) is based on the evaluation of carbohydrase activity in duodenal mucosa (DM). There is no information about diagnostic value of ileum mucosa (IM) carbohydrases.&#x0D; Aim. Assess the diagnostic value of carbohydrases activity in mucous membrane of duodenum and distal ileum in patients with EMDD and irritable bowel syndrome (IBS).&#x0D; Materials and methods. The study includes 12 patients with EMDD, 16 patients with IBS and 12 relatively healthy persons (control group). Study design included analysis of food tolerance and evaluation of activity of sucrase, glucoamylase, maltase and lactase in mucous membrane of duodenum and ileum based on the method of Dahlquist with N.I. Belostotsky modification. Microsoft Office Excel and Statistica 10.0 were used for statistical evaluation of material. Mann–Whitney criterion was used to evaluate the differences between quantitative parameters. The differences were considered to be significant at p0.05. Control group was used for comparison.&#x0D; Results. In control group the carbohydrases activity in duodenum mucosa was not significantly statistically different from the one in IM. In patients of the IBS group, the activity of glucoamylase and maltase in the IM was significantly higher than in the duodenum: glucoamylase by 2.2 times, maltase by 2 times. In patients with EMDD the activity of glucoamylase, maltase and sucrase in IM is higher than in DM by 5.2, 3.8 and 2 times respectively, which signifies the formation of compensatory reaction of adaptive shift, initially described by A.M. Ugolev in 1985.&#x0D; Conclusion. The evaluation of carbohydrase activity in IM provides more information about pathogenesis of EMDD and its differential diagnosis with IBS.

Distinctive properties of the pine, oak, chestnut and multifloral blossom and honeydew honeys

AbstractAlthough blossom and honeydew honeys are produced from different nectar sources, it is very difficult to distinguish them. In this study, physicochemical and biochemical properties were compared to distinguish honeydew and blossom honeys obtained from different botanical sources. The honeys of pine (Pinus spp.) and oak (Quercus, spp.) were used as honeydew honey, and chestnut (Castania sativa L.) and highland honey were used as blossom honey. Turbidity, specific optical rotation (SOR) [α]20, electrical conductivity (EC), CIEL* a*b color parameters, and moisture and pH were assessed as physical parameters. Proline, invertase activity, sugar composition, total phenolic and flavonoid contents, and antioxidant capacity were used as biochemical properties. It was determined that SOR values were the most important parameters in distinguishing honeydew and blossom honeys. Turbidity stands out as a crucial factor in differentiating between pine and oak honeys. Except for chestnut honey, electrical conductivity, CIE color Lab values, and sugar profiles were identified as additional distinguishing factors among the tested honeys.

Identification of Cell Wall Invertase Activities in Selected Wheat Cultivars from Sindh for Crop Improvement

CWI markers, also known as Cell Wall Invertase markers, play a pivotal role in wheat breeding and crop improvement. These markers help identify wheat varieties with desirable traits related to yield potential, stress tolerance, drought tolerance, and overall crop performance. The CWI gene, found in bread wheat, has been identified on chromosomes 4A, 5B, and 5D, all of which contain the conserved WECPDF domain. The main role of the Cell wall invertase (CWI) gene is to hydrolyze sucrose into glucose and fructose. Harnessing the power of CWI markers contributes to the advancement of sustainable agriculture practices and the development of high-performing wheat varieties to meet the demands of diverse agricultural landscapes. In this study, we investigated the prevalence of CWI markers, specifically CWi21 and CWi22, in wheat varieties cultivated in Sindh, Pakistan. We collected a set of thirteen wheat genotypes cultivated in the Sindh province for the screening of Cell Wall Invertase markers through polymerase chain reactions. Our analysis revealed the diversity of the markers CWi21 and CWi22 in wheat genotypes. The marker CWi21 was present in 30% of the wheat varieties, while CWi22 was detected in 70% of the wheat varieties.

Effects of dietary pectin on the growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss)

To evaluate the effects of dietary pectin on growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss), 10-week feeding trial was conducted. Five isoproteic and isoenergetic diets were formulated to contain 0% (P0), 4% (P4), 8% (P8), and 16% (P16) pectin as well as 0.02% pectinase (PE) at the expense of wheat starch, respectively. Dietary inclusion of 416% pectin linearly promoted the feed intake and growth performance but depressed the feed efficiency, but significant differences were only observed between the P16 and P0 groups. Similarly, dietary inclusion of 816% pectin significantly increased the foregut trypsin and amylase activities but decreased the foregut and midgut sucrase activity. The midgut muc2 gene expression level was significantly down-regulated by the inclusion of 16% pectin. Dietary inclusion of 2% pectin increased the abundance of Proteobacteria and Stenotrophomonas but reduced the abundance of Actinobacteria, Bacteroides and Helicobacter; while the lowest values of observed species, Chao1 and ACE indices of intestinal flora were found in the P8 group. Fish fed with the P8 diet exhibited the lowest plasma catalase and midgut glutathione S-transferase activities as well as malondialdehyde content, but the highest midgut malondialdehyde content. Dietary inclusion of 816% pectin significantly depressed the plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and mechanistic target of rapamycin contents as well as alanine aminotransferase activity, the hepatic adenosine monophosphate deaminase and glutamate dehydrogenase (GDH) activities. Dietary treatment with 0.02% pectinase did not affect the growth performance, but depressed the foregut sucrase activity, the midgut amylase and sucrase activities, increased the plasma GH and IGF-1 contents as well as hepatic GDH and aspartate aminotransferase activities. In conclusion, high-dose of dietary pectin (816%) may promote the feed intake and intestinal digestive enzyme activities and thereby improve the growth performance of rainbow trout.

Effects of slow-release nitrogen and urea combined application on soil physicochemical properties and fungal community under total straw returning condition

Under the system of full straw returning, the relationship between soil fungal community diversity and soil physiochemical properties, and the combined application of slow-release nitrogen and urea is unclear. To evaluate its effect and provide an effective strategy for sustainable agricultural production, a 2-year field positioning trial was conducted using maize as the research object. The experiment was designed with two factors: straw treatment(S) and nitrogen fertilizer treatment(N),Six experimental treatments were set up,S1N0,S1N1,S1N2,S1N3,S1N4,S0N2,respectively.Analysis of 54 soil samples revealed 15 fungal phyla and 49 fungal classes. The composition of fungal communities in each treatment was basically the same, but there were significant differences in species abundance. Under total straw returning conditions, the combined application of slow-release nitrogen fertilizer and normal nitrogen fertilizer significantly increased the relative abundance of Ascomycota. During the jointing stage, tasseling stage and maturity stage, S1N4, S1N3 and S1N2 increased by 25.76%, 22.97%, 20.74%; 25.11%, 30.02%, 23.64% and 22.47%, 28.14%, 22.71% respectively compared with S0N2.The relative abundance of Basidiomycota was significantly reduced. Alpha diversity analysis showed that the straw returning mode significantly increased the Shannon index and decreased the Simpson index, which was obvious in the jointing stage and tasseling stage. The principal coordinate analysis analysis results showed that the fungal communities formed different clusters in the horizontal and vertical directions at the three growth stages of corn jointing, tasseling and maturity. At the jointing stage and tasseling stage, the communities of the straw return treatment and the straw removal treatment were separated, and the community distribution of each treatment was not significantly different in the mature stage. Total straw returning combined with slow-release fertilizer significantly (P＜0.05) increased the soil organic carbon, nitrate nitrogen and ammonia nitrogen content in each growth period, and increased the soil total nitrogen and hydrolyzable nitrogen content (P＞0.05).After the straw was returned to the field, the combined application of slow-release nitrogen fertilizer and common urea had a significant impact on soil urease, catalase, and sucrase activities. Among them, the three enzyme activities were the highest in the S1N3 treatment at the jointing stage and maturity stage, and the S1N4 treatment at the tasseling stage had the highest enzyme activity. Fungal community composition is closely related to environmental factors. Soil organic carbon, urease and catalase are positively correlated with Ascomycota and negatively correlated with Basidiomycota.

Fluorinated complexes doped nanodot with high brightness and dual emission for ratiometric detection of glucose-related enzymes

Fluorescence detection of enzymes have attracted considerable interest due to their promise in biological applications, while suffering from the limitation of rigorous demand on the structure design of enzyme substrates. Herein, we report a simple and convenient approach for fluorescence detection of multiple enzymes by developing a fluorescence/phosphorescence dual-emissive nanodot, which is composed of fluorinated organic dyes and fluorinated Pt (II) porphyrin complexes, and exhibits ratiometric luminescence response toward oxygen. We characterized the optical properties of the nanodot, which showed high brightness and sensitive oxygen-response luminescence. Based on the oxygen-consumed enzymatic reaction of glucose oxidase and the glucose-generated enzymatic reaction of the enzymes related to glucose metabolism, and using this presented nanodot, the concentration of glucose and the enzymatic activity of invertase, β-galactosidase, and maltase in aqueous solution were successfully determined quantitatively. To the best of our knowledge, the strategy proposed here for enzyme detection is the first demonstration of an optical probe for monitoring the enzymatic activity of multiple enzymes. Significantly, the strategy presented here may provide a general design principle to develop a kind of luminescent probe for detecting various enzymes.

Effects of antimony on the soil enzymes, microbial, and rhizobial activity of legumes

ABSTRACT Leguminous farmland in China is severely polluted by antimony. Here, to explore the effects of antimony stress on rhizobia and soil microorganisms in leguminous plants, mung beans, kidney beans, and peanuts were grown in soil with different concentrations of Sb3+, Sb5+, and Sb3++Sb5+. Antimony had a promotional effect on soil sucrase and catalase activities and an inhibitory effect on urease activity. The effects of Sb3+ on sucrase, catalase, and urease activities were 3.3–11.1, 1.27–1.29, and 1.24–3.05 times those of Sb5+, respectively. Antimony reduced the rhizobial activity by 20.63–57.84%, with the inhibitory effect positively related to the antimony content. Additionally, the inhibitory effect of Sb3+ was 1.10–2.22 times that of Sb5+. This inhibition decreased the total nitrogen and ammonia nitrogen content in the soil. However, the decrease in Sb3+ was 0.46–1.54 times that of Sb5+. Sb3+ significantly altered the microbial activity.

The role of microplastics in the process of Paraclostridium sp. DLY7-assisted phytoremediation of phenanthrene contaminated soil

Microplastics can absorb polycyclic aromatic hydrocarbons (PAHs), decrease the bioavailability of pollutants, alter the soil microbial community, and thus might affect the dissipation of soil pollutants. However, whether microplastics could alter the remediation efficiency of PGPR-assisted plants for PAHs-contaminated soil has not been studied. This study assessed the remediation potential of PGPR exhibiting phenanthrene (PHE) degradation ability in assisting maize for PHE-contaminated soil. Especially, the role of microplastics involved in this remediation process was also investigated. The results showed that strain Paraclostridium sp. DLY7 (DLY7) significantly increased the PHE removal efficiency (63.4%) from soil by maize and reduced the content of PHE in maize leaves and roots with no microplastics addition. However, the presence of microplastics significantly inhibited the PHE removal from soil and increased the PHE accumulation in maize issues, in comparison with PHE + DLY7 treatment. Microplastics also significantly reduced soil sucrase and alkaline phosphatase activities, and the content of soil nitrate nitrogen and ammonium nitrogen under non-inoculation with strain conditions. Inoculation with strain DLY7 also altered the rhizosphere soil microbial community, enriched some beneficial bacteria and increased activities of some crucial soil enzymes, thus facilitating PHE removal from soil. On the whole, compared with conventional soil contamination remediation studies, this study innovatively pointed out that microplastics significantly reduced the removal efficiency of soil PHE and increased the uptake of PHE by maize in the PGPR-assisted phytoremediation process. However, the effects of microplastics on microorganisms might be related to the particle size, concentration and type of microplastics in the environment, which would be studied in our future research. These findings proposed new perspectives for revealing the role of microplastics on the efficiency of microbe-assisted phytoremediation of PAHs-contaminated soil.

Versatility of copper-iron bimetallic nanoparticles fabricated using Hibiscus rosa-sinensis flower phytochemicals: various enzymes inhibition, antibiofilm effect, chromium reduction and dyes removal.

Bimetallic nanoparticles (NPs) are considered superior in terms of stability and function with respect to its monometallic counterparts. Hence, in the present study Hibiscus rosa-sinensis flower extract was used to synthesis copper-iron bimetallic nanoparticles (HF-FCNPs). HF-FCNPs was characterized and its applications (biological and environmental) were determined. HF-FCNPs were spherical in shape with high percentage of copper inducted into the NPs. HF-FCNPs inhibited mammalian glucosidases [maltase (IC50: 548.71 ± 61.01µg/mL), sucrase (IC50: 441.34 ± 36.03µg/mL), isomaltase (IC50: 466.37 ± 27.09µg/mL) and glucoamylase (IC50: 403.12 ± 14.03µg/mL)], alpha-amylase (IC50: 16.27 ± 1.73µg/mL) and acetylcholinesterase [AChE (IC50: 0.032 ± 0.004µg/mL)] activities. HF-FCNPs showed competitive inhibition against AChE, maltase and sucrase activities; mixed inhibition against isomaltase and glucoamylase activities; whereas non-competitive inhibition against α-amylase activity. HF-FCNPs showed zone of inhibition of 16 ± 2mm against S. mutans at 100µg/mL concentration. HF-FCNPs inhibited biofilm formation of dental pathogen, S. mutans. SEM and confocal microscopy analysis revealed the disruption of network formation and bacterial cell death induced by HF-FCNPs treatment on tooth model of S. mutans biofilm. HF-FCNPs efficiently removed hexavalent chromium in pH-independent manner and followed first order kinetics. Through Langmuir isotherm fit the qmax (maximum adsorption capacity) was determined to be 62.5mg/g. Further, HF-FCNPs removed both anionic and cationic dyes. Altogether, facile synthesis of HF-FCNPs was accomplished and its biological (enzyme inhibition and antibiofilm activity) and environmental (catalyst to remove pollutants) applications have been understood.

Magnesium oxide nanoparticles reduce clubroot by regulating plant defense response and rhizosphere microbial community of tumorous stem mustard (Brassica juncea var. tumida).

Clubroot, caused by Plasmodiophora brassicae, is a major disease that significantly impairs the yield of cruciferous crops and causes significant economic losses across the globe. The prevention of clubroot, especially in tumorous stem mustard (without resistant varieties), are is limited and primarily relies on fungicides. Engineered nanoparticles have opened up new avenues for the management of plant diseases, but there is no report on their application in the prevention of clubroot. The results showed that the control efficacy of 500 mg/L MgO NPs against clubroot was 54.92%. However, when the concentration was increased to 1,500 and 2,500 mg/L, there was no significant change in the control effect. Compared with CK, the average fresh and dry weight of the aerial part of plants treated with MgO NPs increased by 392.83 and 240.81%, respectively. Compared with the F1000 treatment, increases were observed in the content of soil available phosphorus (+16.72%), potassium (+9.82%), exchangeable magnesium (+24.20%), and water-soluble magnesium (+20.64%) in the 1,500 mg/L MgO NPs treatment. The enzyme-linked immune sorbent assay (ELISA) results showed that the application of MgO NPs significantly increased soil peroxidase (POD, +52.69%), alkaline protease (AP, +41.21%), alkaline phosphatase (ALP, +79.26%), urease (+52.69%), and sucrase (+56.88%) activities; And also increased plant L-phenylalanine ammonla-lyase (PAL, +70.49%), polyphenol oxidase (PPO, +36.77%), POD (+38.30%), guaiacol peroxidase (POX, +55.46%) activities and salicylic acid (SA, +59.86%) content. However, soil and plant catalase (CAT, -27.22 and - 19.89%, respectively), and plant super oxidase dismutase (SOD, -36.33%) activities were significantly decreased after the application of MgO NPs. The metagenomic sequencing analysis showed that the MgO NPs treatments significantly improved the α-diversity of the rhizosphere soil microbial community. The relative abundance of beneficial bacteria genera in the rhizosphere soil, including Pseudomonas, Sphingopyxis, Acidovorax, Variovorax, and Bosea, was significantly increased. Soil metabolic functions, such as oxidative phosphorylation (ko00190), carbon fixation pathways in prokaryotes (ko00720), indole alkaloid biosynthesis (ko00901), and biosynthesis of various antibiotics (ko00998) were significantly enriched. These results suggested that MgO NPs might control clubroot by promoting the transformation and utilization of soil nutrients, stimulating plant defense responses, and enriching soil beneficial bacteria.

Effects of water stress on nutrients and enzyme activity in rhizosphere soils of greenhouse grape.

In grape cultivation, incorrect water regulation will lead to significant water wastage, which in turn will change soil structure and disrupt soil nutrient cycling processes. This study aimed to investigate the effects of different water regulation treatments [by setting moderate water stress (W1), mild water stress (W2), and adequate water availability (CK)] on soil physical-chemical properties and enzyme activity in greenhouse grape during the growing season. The result showed that the W2 treatment had a negative impact on the build-up of dissolved organic carbon (DOC), nitrate nitrogen (NO3-N), and available phosphorus (AP). Throughout the reproductive period, the W1 and W2 treatments decreased the soil's microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents, and MBC was more vulnerable to water stress. During the growth period, the trends of urease, catalase, and sucrase activities in different soil depth were ranked as 10-20 cm > 0-10 cm > 20-40 cm. The urease activity in 0-10 cm soil was suppressed by both W1 and W2 treatments, while the invertase activity in various soil layers under W1 treatment differed substantially. The W1 treatment also reduced the catalase activity in the 20-40 cm soil layer in the grape growth season. These findings suggested that W2 treatment can conserve water and enhance microbial ecology of greenhouse grape soils. Therefore, W2 treatment was the most effective water regulation measure for local greenhouse grape cultivation.