Changes In Enzyme Activities Research Articles

P-limitation regulates the accumulation of soil aggregates organic carbon during the restoration of Pinus tabuliformis forest

Artificial forest restoration is widely recognized as a crucial approach to enhance the potential of soil carbon sequestration. Nevertheless, there is still limited understanding regarding the dynamics of aggregate organic carbon (OC) and the underlying mechanisms driving these dynamics after artificial forest restoration. To address this gap, we studied Pinus tabuliformis forests and adjacent farmland in three recovery periods (13, 24 and 33 years) in the Loess Plateau region. Samples of undisturbed soil from the surface layer were collected and divided into three aggregate sizes: >2 mm (large aggregate), 0.25–2 mm (medium aggregate), and <0.25 mm (small aggregate). The aim was to examine the distribution of OC and changes in enzyme activity within each aggregate size. The findings revealed a significant increase in OC content for all aggregate sizes following the restoration of Pinus tabuliformis forests. After 33 years of recovery, the OC of large aggregates, medium aggregates and micro-aggregates increased by (30.23 ± 9.85)%, (36.71 ± 21.60)% and (37.88 ± 16.07)% respectively compared with that of farmland. Moreover, the restoration of Pinus tabuliformis forests lead to increased activity of hydrolytic enzymes and decreased activity of oxidative enzymes. It is noteworthy that the regulation of carbon in all aggregates is influenced by soil P-limitation. In large aggregates, P-limitation promotes the enhancement of hydrolytic enzyme activity, thereby facilitate OC accumulation. Conversely, in medium and small aggregates, P-limitation inhibits the increase in oxidative enzyme activity, resulting in OC accumulation. The results emphasize the importance of P-limitation in regulating OC accumulation during the restoration of Pinus tabulaeformis forest, in which large aggregates play a leading role.

A Study of the Relationship between Initial Grape Yield and Soil Properties Based on Organic Fertilization

Increasing the use of organic fertilizers is an effective measure to improve, increase soil fertility and maintain crop yields. The aim of this study was to investigate the influence of different types of organic fertilizers on the early yield of grapes and soil parameters, as well as the relationship between soil parameters and grape yield under fertilization conditions. The ‘Shine Muscat’ grape was used as the material, with early maturing cultivation in the solar greenhouse. From the time of grape planting, three-year continuous fertilization management was carried out using five types of base fertilizers: chemical fertilizer (CK), fermented corn stalk residue (A1), mature sheep manure (A2) and two types of commercial organic fertilizers (B1 and B2). In the third year, berry and soil samples were collected to determine grape yield and evaluate soil physicochemical properties, nutrient status and changes in enzyme activity, studying the relationship between grape yield and soil indicators. The results show that compared to CK, the grape yields with B1 and B2 increased by 19.04% and 16.26%, respectively, while A1 and A2 decreased by 24.09% and 18.97%. Organic fertilizer application reduced soil bulk density, increased soil porosity, enhanced soil organic matter content and effectively buffered soil pH levels. Two types of commercial fertilizers (B1 and B2) improved soil total nitrogen, total phosphorus, total potassium, available nitrogen and available phosphorus content to varying degrees. All organic fertilizer treatments effectively increased soil enzyme activity, except for soil sucrase activity. Through correlation and regression analyses, it was found that in this study, the levels of available nitrogen, available potassium and soil saccharase activity were most closely related to early grape yield. Their influence on grape yield was in the order of available nitrogen &gt; soil saccharase activity &gt; available potassium. Therefore, with a combined organic and inorganic basal fertilization system, the fertilizer nutrients are more comprehensive and help to increase the productivity of grapes at the beginning of the fruiting period. Nitrogen and phosphorus are very important in the maintaining of grape yields and improving sucrose activity in the soil through the application of organic fertilizers cannot be ignored when increasing yields.

Involvement of ROS and calcium ions in developing heat resistance and inducing antioxidant system of wheat seedlings under melatonin's effects.

The stress-protective effect of melatonin (N-acetyl-5-methoxytryptamine) on plant cells is mediated by key signaling mediators, in particular calcium ions and reactive oxygen species (ROS). However, the links between changes in calcium and redox homeostasis and the formation of adaptive responses of cultivated cereals (including wheat) to the action of high temperatures have not yet been studied. In the present study, we investigated the possible involvement of ROS and calcium ions as signaling mediators in developing heat resistance in wheat (Triticum aestivum L.) seedlings and activating their antioxidant system. Treatment of 3-day-old etiolated seedlings with melatonin solutions at concentrations 0.01-10µM increased their survival after exposure to 45°C for 10min. The most significant stress-protective effect was exerted by melatonin treatment at 1µM concentration. Under the influence of melatonin, a transient enhancement of superoxide anion radical (O2•-) generation and an increase in hydrogen peroxide content were observed in roots, with a maximum at 1h. Four hours after treatment with melatonin, the activity of catalase and guaiacol peroxidase increased in roots, while the activity of superoxide dismutase did not change significantly. After exposure to 45°C, the activity of catalase and guaiacol peroxidase was higher in the roots of melatonin-treated wheat seedlings, and the indices of ROS generation, content of the lipid peroxidation product malonic dialdehyde, and cell membrane damage were lower than in control seedlings. Melatonin-induced changes in root ROS generation and antioxidant enzyme activities were eliminated by pretreatment with the hydrogen peroxide scavenger dimethylthiourea (DMTU), NADPH oxidase inhibitor imidazole, and calcium antagonists (the extracellular calcium chelator EGTA and phospholipase C inhibitor neomycin). Treatment with DMTU, imidazole, EGTA, and neomycin also abolished the melatonin-induced increase in survival of wheat seedlings after heat stress. The role of calcium ions and ROS, generated with the participation of NADPH oxidase, as signaling mediators in the melatonin-induced antioxidant system and heat stress resistance of wheat seedlings have been demonstrated.

Non-specific animal esterases as biomarkers of pesticide pollution of aquatic ecosystems (review)

Pollution of water resources with pesticides negatively affects aquatic organisms and makes water bodies unsuitable for use by humans. Chemical analysis methods do not provide information about the impact of a detected substance and its individual components on the ecosystem. The article presents an analysis and synthesis of published data on the possibilities and features of the use of aquatic enzymes as biomarkers of pollution of aquatic ecosystems with pesticides. Publications over the past 20 years, indexed in the PubMed, Crossref, Web of Science, Scopus, and RSCI databases devoted to the issues of pesticide pollution of water bodies and the use of enzymes, in particular nonspecific esterases, in biomonitoring were analyzed. The concept of “biomarker” is revealed, groups of biomarkers, the purposes of their use, advantages and disadvantages as a source of information about the state of the ecosystem are listed. Particular attention is paid to study of nonspecific esterases in aquatic organisms (fish, mollusks, crustaceans, amphibians). The main types of substrates used to measure the activity of esterase isoforms and the features of changes in enzymatic activity in response to exposure to pesticides from different chemical groups (organophosphorus compounds, carbamates, pyrethroids) are considered. The factors influencing the activity of nonspecific esterases of aquatic organisms and limiting their use for assessing pollution of aquatic ecosystems are identified.

Physiologically Based Pharmacokinetic Modelling of UGT Substrate Drugs Lamotrigine and Raltegravir during Pregnancy

Pregnancy is associated with various physiological changes that can significantly impact the disposition of drugs. To further the insight into how pregnancy affects the pharmacokinetics of drugs at different stages, clinical studies can be simulated using Physiologically Based Pharmacokinetic modelling. PBPK modelling of drugs metabolised by Phase I enzymes (CYPs) in pregnant population models had been reported in the past, while its use in Phase II (UGTs) is not known. In this study, based on the results of a recent meta-analysis, lamotrigine (UGT1A4) and raltegravir (UGT1A1) were selected as candidate drugs, and pregnancy-specific models were developed for both using the Simcyp v.21 simulator. A middle-out strategy was used where previously published drug parameters were adapted from a minimal to a full PBPK model to allow their application for the pregnancy population models using Simcyp PBPK software. Adapted models were successfully validated against observed clinical data both qualitatively (visual overlay of plasma concentrations on graphs) and quantitatively (calculating the predicted/observed ratios for AUC, Cmax and CL as well as statistical analysis using model prediction power metrics). They were then applied to predict the PKs of both drugs in pregnancy population models. The temporal changes in maternal enzymatic activities during gestation were modelled based on in vitro data reported in literature and default relationships encoded in the Simcyp platform for UGT1A1 and UGT1A4, respectively. Our study demonstrates the successful development and validation of a PBPK model for LTG and RTG in pregnancy population models. Future work with additional UGT1A4 substrate drugs using the proposed changes in UGT1A4 activity may enable validating the pregnancy population model and its subsequent use for the prospective prediction of PK.

A Comparative Study of Five Apple Cultivars Linking Biochemical Changes at Different Developmental Stages with Storage Textural Quality

Biochemical changes in the cell wall composition and activity of cell wall-modifying enzymes of five apple cultivars, Royal Gala (Gala), Aurora Golden Gala (Aur), Splendour (Spl), Honeycrisp (HC), and Ambrosia (Amb), collected from the 2016 growing season in the early growth phases, namely 40 and 70 days after full bloom (DAFB), at harvest maturity, and after 20 weeks of storage were investigated in relation to the textural changes at harvest maturity through to 20 weeks of storage. Assessing apple texture with a single-point measurement of firmness using a penetration test to a depth of approximately 8 mm in apples may not be an ideal measurement for assessing apple textural quality. Pectin methyl esterase (PME) activity at early developmental stages may be predictive of textural quality after storage. This work also found that β-D-galactosidase (BGAL) and α-L-arabinofuranosidase (AFAS) activities at early developmental stages may be important factors affecting textural quality after storage. Additionally, the degree of methylesterification (DME) assessed with FTIR on apple flesh material at the early developmental stages was strongly positively correlated (r2 ≥ +0.891 to +0.963, p ≤ 0.05) with textural quality after storage, including crispness, indicating that FTIR could serve as a rapid screening tool for textural quality at early developmental stages on minimally processed starting material.

Effect and Mechanism of L-Arginine against Alternaria Fruit Rot in Postharvest Blueberry Fruit.

This study aimed to explore the impact of L-arginine (Arg) on the development of resistance to Alternaria tenuissima (A. tenuissima) in blueberries. The metabolism of reactive oxygen species, pathogenesis-related proteins (PRs), and jasmonic acid (JA) biosynthesis pathways were analyzed, including changes in activity and gene expression of key enzymes. The results indicated that Arg treatment could prevent the development of Alternaria fruit rot in postharvest blueberries. In addition, it was also found to induce a burst of hydrogen peroxide in the blueberries early on during storage, thereby improving their resistance to A. tenuissima. Arg treatment was observed to increase the activity of antioxidant enzymes (peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase) and related gene expression, as well as the total levels of phenolics, flavonoids, and anthocyanin in the blueberries. The activity and gene expression of the PRs (chitinase and β-1,3-glucanase) were elevated in Arg-treated blueberries, boosting their resistance to pathogens. Additionally, a surge in endogenous JA content was detected in Arg-treated blueberries, along with upregulated expression of key genes related the JA biosynthesis pathway (VcLOX1, VcAOS1, VcAOC, VcAOC3, VcOPR1, VcOPR3, VcMYC2, and VcCOI1), thereby further bolstering disease resistance. In conclusion, Arg treatment was determined to be a promising prospective method for controlling Alternaria fruit rot in blueberries.

Chronic effect of copper on biology, immunity, and biochemical assessment of Helicoverpa armigera (Lepidoptera; Noctuidae) in laboratory bioassays.

Although copper is an essential element for any organism's well-being, it becomes toxic if present in excess. In the present study, copper was provisioned at 25, 50, and 75 mg/kg in an artificial diet and fed to juvenile larvae of cotton bollworm, Helicoverpa armigera (Lepidoptera; Noctuidae), for 4 generations. The results of this investigation exhibited shortening of larval life in the first 2 generations, but extended duration was observed in third and fourth generations compared to controls, and dietary copper caused reduced total hemocyte counts in all treatments. The number of immunocytes (i.e., granulocytes and plasmatocytes) were also significantly reduced. The changes in activities of certain important enzymes, including catalase, superoxide dismutase, and peroxidases, were seen. Furthermore, after treatment, an increase in the activity of 2 detoxifying enzymes, glutathione s-transferase and acetylcholinesterase, was observed. It is clear that metallothioneins are important in maintaining essential and nonessential metal ion homeostasis. While copper is typically regarded as an important essential metal in an organism's life, excessive amounts can have deteriorating effects. This heavy metal is being used as a nano-based pesticide. Therefore, the present investigation aims to determine the fate of Cu in insects receiving them in new formulations.

Effects of fire smoke on soil microorganisms: results of a modelling experiment

ABSTRACT Wildfires are widespread and have major effects on ecosystems. The sensitivity of soil microorganisms to smoke was studied in experimental conditions using smoke generated from burning pine sawdust. High concentrations of toxicants such as NO (40 mg/m3), NO2 (60 mg/m3), CO (3570 mg/m3), C2H4O (241 mg/m3), CH2O (9.5 mg/m3), C6H6O (4.4 mg/m3), and C6H14 (238 mg/m3) were measured in the smoke. Reduced abundance of Azotobacter chroococcum by 9–62% and of microscopic fungi by 25–57% was found when the soil was treated with smoke for 30–120 min. The abundance of soil microorganisms after exposure to smoke depended on time. Several species of soil fungi (Fusarium oxysporum, Venturia inaequalis, Fusarium moniliforme, Fusarium graminearum, Cladosporium cucumerinum, Penicillium chrysogenum, Rhodotorula rubra, Lipomyces starkeyi), and bacteria (Acinetobacter calcoaceticus, Streptomyces violaceus, Kocuria rosea) were studied. The lowest smoke exposure time at which growth inhibition was registered was 1–5 min. The effect of smoke on the enzymatic activity of Haplic Chernozem soils was also evaluated. Catalase activity was found to decrease by 25%, and peroxidase and polyphenol oxidase by 15% and 33%, respectively. High smoke toxicity contributed to changes in microbial abundance and enzymatic activity.

Molecular mechanisms of cytochrome P450-mediated detoxification of tetraniliprole, spinetoram, and emamectin benzoate in the fall armyworm, Spodoptera frugiperda (J.E. Smith).

The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is a highly damaging invasive omnivorous pest that has developed varying degrees of resistance to commonly used insecticides. To investigate the molecular mechanisms of tolerance to tetraniliprole, spinetoram, and emamectin benzoate, the enzyme activity, synergistic effect, and RNA interference were implemented in S. frugiperda. The functions of cytochrome P450 monooxygenase (P450) in the tolerance to tetraniliprole, spinetoram, and emamectin benzoate in S. frugiperda was determined by analysing changes in detoxification metabolic enzyme activity and the effects of enzyme inhibitors on susceptibility to the three insecticides. 102 P450 genes were screened via transcriptome and genome, of which 67 P450 genes were differentially expressed in response to tetraniliprole, spinetoram, and emamectin benzoate and validated by quantitative real-time PCR. The expression patterns of CYP9A75, CYP340AA4, CYP340AX8v2, CYP340L16, CYP341B15v2, and CYP341B17v2 were analysed in different tissues and at different developmental stages in S. frugiperda. Silencing CYP340L16 significantly increased the susceptibility of S. frugiperda to tetraniliprole, spinetoram, and emamectin benzoate. Furthermore, knockdown of CYP340AX8v2, CYP9A75, and CYP341B17v2 significantly increased the sensitivity of S. frugiperda to tetraniliprole. Knockdown of CYP340AX8v2 and CYP340AA4 significantly increased mortality of S. frugiperda to spinetoram. Knockdown of CYP9A75 and CYP341B15v2 significantly increased the susceptibility of S. frugiperda to emamectin benzoate. These results may help to elucidate the mechanisms of tolerance to tetraniliprole, spinetoram and emamectin benzoate in S. frugiperda.

Differential responses of photosynthesis, yield and soil properties 4 years after a single application of zeolites and biochar in a rainfed olive orchard

AbstractOlive orchards represent a key agricultural system in the Mediterranean Basin. Soil degradation processes associated with unsustainable agronomic practices and climate change could severely impact the sustainability of Mediterranean rainfed olive orchards. In this context, soil amendments are important tools that can be used to enhance soil fertility for sustained environmental quality and plant performance. In this study, a field trial was conducted for 4 years in olive tree (Olea europaea L.) to assess the effects of a mineral fertilizer compound and the combination with a single application of zeolites or biochar on the physiological and biochemical performance, tree nutritional status, crop yield and soil chemical and biological properties to gain knowledge towards more sustainable management. Our results showed that the addition of zeolites and biochar to mineral fertilizer ameliorated the physiological and biochemical performance, as evidenced by consistent increments of relative water content, stomatal conductance and net photosynthesis and by lower signs of oxidative stress during the periods of greater climate adversity. However, crop yield was not significantly different among soil treatments. On the other hand, soil chemical and biological traits at the surface layer (0–10 cm) have shown different and relevant responses after 4 years of soil amendment application. In fact, zeolite supply stood out as increased pH, extractable K, cation exchange capacity, microbial biomass carbon and microbial biomass quotient and reduced extractable Cu. Furthermore, zeolites induced positive changes in soil enzymatic activity, leading to increases in 10 enzymes involved in C, N and P cycles. In contrast, the effects of biochar on soil properties were much more reduced, given that it decreased the microbial biomass nitrogen and enhanced the activities of three P‐cycle enzymes. In summary, our data demonstrated that both soil amendments can be an interesting complement to mineral fertilization, in order to increase trees' resilience under rainfed conditions and to promote soil health, although the use of zeolites appears to be a more promising strategy because of the induction of higher soil sustainability.

Revealing the mechanism of post-harvest processing on rose quality based on dynamic changes in water content, enzyme activity, volatile and non-volatile metabolites

Existing studies on post-harvest processing of edible roses have mainly focused on processing techniques and physicochemical properties of the final dried products, with limited studies on how changes in metabolites during processing affect the quality of these products. This study investigated changes in water content and status, enzyme activity, phenolic compounds, and volatile and non-volatile compounds during processing and revealed the mechanisms by which post-harvest processing (drying without blanching (WBD) and drying with blanching (BD)) affects the quality of dried roses by establishing their correlations. Results showed that the blanching reduced the relative content of free water and water activity, thus reducing the subsequent drying time and enzyme activity. The BD method caused higher levels of phenolic compounds than the WBD method in terms of gallic acid, ellagic acid, epicatechin, and quercetin. The OPLS-DA analysis identified 6 differential volatiles out of 72 detected volatiles, contributing to the unique aroma of dried roses by activating olfactory receptors through hydrogen bonding and hydrophobic interactions. 58 differential metabolites were screened from 964 non-volatile metabolites. KEGG pathway analysis revealed that the changes in volatile and non-volatile metabolites induced by different processing methods were due to the effect of blanching on glutathione and fatty acid metabolism. These findings provide a comprehensive understanding of how post-harvest processing affects the quality of dried roses.

Effects of processing conditions on change of amino acids, reducing sugar and total polyphenols of caramelized malt produced from IR50404 rice variety

Rice beer is a value-added product from rice since it consists of enough conditions for making beer. To produce the best caramelized malt from IR50404 rice variety, understanding the effects of processing conditions on change of amino acids, reducing sugar and total polyphenols is very important for developing such rice beer processing. Changes in chemical compositions and enzyme activities in caramelized malt processed from IR50404 rice variety were understood. Suitable germination conditions were indicated, including a soaking temperature of 30oC for 24 hrs, degree of steeping of 35- 36% and germination time of 4 days at 30oC. Green rice malt was incubated at 40-70oC for 30-120 mins. Then, rice malt was roasted at different temperatures of 125-200oC for 30-90 mins. The results showed that both tempering and roasting processes changed the concentration of polyphenols, reducing sugars and amino acids. When green malt was incubated at 50°C for 60 mins, reducing sugars, amino acids and polyphenol content (TPC) increased by 2 times (102.72 mg/g), 1.8 times (9.08 mg/g) and 1.5 times (4.26 mg GAE/g) respectively corresponding to the improvement of the amylase and protease activity. Moreover, there were maximum increases in phenolic compounds in roasted malt at 125 and 150°C for 45 and 75 mins for tempered malt and green malt, respectively. In contrast, higher heat treatment (roasted at 175-200°C) resulted in reducing the levels of all evaluated variables. Thus, malting with a moderate thermal treatment (125-150°C) could be considered an effective process to enrich (or enhance) antioxidants in rice grains for their further use as a functional ingredient in malt and beer production.

Assessment of aluminium toxicity on Dugesia tigrina: implications for reproduction, behaviour, and enzymatic metabolism

ABSTRACT Aluminium (Al) is the eighth most prevalent metallic contaminant in global aquatic environments. This study explores the toxicity of Al and the acidity generated in the aquatic environment, using Dugesia tigrina, elucidating its environmental repercussions. The research uniquely highlights reproductive, behaviours and enzymatic effects pertinent to Al toxicity. The paper evaluated median lethal concentration [LC50 (96 h)], planarian mobility (pLmV), reproductive effects, glycogen content, and enzymes activities. The LC50 (96 h) was 348.08 µM. The aqueous extract produced a 74.6% reduction in mobility after acute exposition, and a 34.3% decrease in glycogen content after 14 days at 100 µM Al. Fertility and fecundity decreased by 47.8% and 67.8%, respectively, after 30 days at 50 µM Al (pH 7.0), with a complete absence of cocoons at pH 5.9. Hatching time increased by 24.8% at 50 µM Al (pH 7.0). Exposure to 100 µM Al for 24 h increase enzyme activities: catalase (49%), superoxide dismutase (89.7%), and acetylcholinesterase (46%). The observed changes in enzyme activity underscore Al's adverse effects on reproduction, behaviour, and enzymatic metabolism in planarians, urging the implementation of effective environmental management strategies to mitigate potential implications for various species and ecosystems.

How plants respond to heavy metal contamination: a narrative review of proteomic studies and phytoremediation applications.

Heavy metal pollution caused by human activities is a serious threat to the environment and human health. Plants have evolved sophisticated defence systems to deal with heavy metal stress, with proteins and enzymes serving as critical intercepting agents for heavy metal toxicity reduction. Proteomics continues to be effective in identifying markers associated with stress response and metabolic processes. This review explores the complex interactions between heavy metal pollution and plant physiology, with an emphasis on proteomic and biotechnological perspectives. Over the last century, accelerated industrialization, agriculture activities, energy production, and urbanization have established a constant need for natural resources, resulting in environmental degradation. The widespread buildup of heavy metals in ecosystems as a result of human activity is especially concerning. Although some heavy metals are required by organisms in trace amounts, high concentrations pose serious risks to the ecosystem and human health. As immobile organisms, plants are directly exposed to heavy metal contamination, prompting the development of robust defence mechanisms. Proteomics has been used to understand how plants react to heavy metal stress. The development of proteomic techniques offers promising opportunities to improve plant tolerance to toxicity from heavy metals. Additionally, there is substantial scope for phytoremediation, a sustainable method that uses plants to extract, sequester, or eliminate contaminants in the context of changes in protein expression and total protein behaviour. Changes in proteins and enzymatic activities have been highlighted to illuminate the complex effects of heavy metal pollution on plant metabolism, and how proteomic research has revealed the plant's ability to mitigate heavy metal toxicity by intercepting vital nutrients, organic substances, and/or microorganisms.

Growth, antioxidant enzyme activity and transcriptome response to low-temperature induction of flowering in cultivated strawberry

This study is aimed to investigate the impact of low-temperature treatment on growth, antioxidant enzyme activity, flowering physiology and transcriptome change of the cultivated strawberry, cultivar 'Baiyu'. The runner plants were subjected to 16 ± 1 °C as low-temperature for 5, 10, and 15 days. By comparison with the plants just before treatment (at day 0), it was shown that during the 15-day low temperature treatment, plant height, leaf area, and dry weight significantly, amino acid and soluble sugar contents all decreased with concurrent calyx formation, while the levels of MDA, activities of SOD and CAT increased significantly. Flower bud differentiation began before day 5, as evidenced by significant upregulation in expression of several known flower -related genes including FaAP1, FaSVP, FaCO1, and FaLFY. Tissues from plants treated for 5d and 0d at 16 ± 1 °C were used for transcriptome analysis and the results showed that significant changes in more than 20,179 genes under low-temperature treatment, among which, the expression of genes in metabolic processes, catalytic activity and binding of the molecular function, signal transduction and encoding transcription factors were mostly affected.

Metagenomics unveils the differences in the functions of microbial community of medium-temperature Daqu before and after maturation

Daqu is the saccharifying, fermenting, and aroma-producing agent used in Baijiu brewing, and its maturation is crucial for obtaining high-quality Daqu. Previous studies have explored the microbial community composition and diversity before and after maturation. However, little is known about the changes in the functions of microbial community. In this study, based on the analyses of enzyme activities and volatile compounds of medium-temperature Daqu before and after maturation, metagenomics was used to analyze the differences in the composition of microbial community and the potential functions, with the aim to explore the microorganisms involved in changes in enzyme activities and important volatiles. The results showed that the moisture (P≤0.05), starch content, liquefying activity, saccharifying activity (P≤0.05), and fermentative activity decreased, while the acidity and esterifying activity (P≤0.05) increased after Daqu maturation. In the meantime, the composition of volatile compounds changed significantly (P=0.001), with significant decreases in the contents of aromatic alcohols and esters as well as significant increases in the contents of pyrazines, ketones, and higher fatty alcohols. The relative abundances of Mucorales (34.8%-23.0%) and Eurotiales (34.3%-20.1%) decreased in matured Daqu, and functional predictions showed these changes decreased the gene abundances of α-amylase, α-glucosidase, alcohol dehydrogenase, and alcohol dehydrogenase (NADP+) (P > 0.05), resulting in lower levels of liquefying activity (P > 0.05), saccharifying activity (P≤0.05), fermentative activity (P > 0.05), as well as aromatic alcohols such as phenylethyl alcohol (P≤0.05). In addition, higher relative abundances of Saccharomycetales (2.9%-16.6%), Lactobacillales (14.9%-23.6%), and Bacillales (0.8%-3.8%) were observed after maturation, and they were conducive to improving the gene abundances of alcohol O-acetyltransferase, carboxylesterase, acetolactate decarboxylase, (R)-acetoin dehydrogenase, and (S)-acetoin dehydrogenase (P≤0.05), resulting in significantly higher levels of esterifying activity and pyrazines (P≤0.05). The microorganisms involved in the changes in enzyme activities and important volatiles before and after Daqu maturation were studied at the gene level in this work, which may facilitate further rational regulation for Daqu production.

Ecological characteristics of sugar beet plant and rhizosphere soil in response to high boron stress: A study of the remediation potential

High boron (B) stress degrades the soil environment and reduces plant productivity. Sugar beet has a high B demand and potential for remediation of B-toxic soils. However, the mechanism regarding the response of sugar beet plants and rhizosphere soil microbiome to high B stress is not clear. In the potted soil experiment, we set different soil effective B environments (0.5, 5, 10, 30, 50, and 100 mg kg−1) to study the growth status of sugar beets under different B concentrations, as well as the characteristics of soil enzyme activity and microbial community changes. The results showed that sugar beet growth was optimal at 5 mg kg−1 of B. Exceeding this concentration the tolerance index decreased. The injury threshold EC20 was reached at an available B concentration of 35.8 mg kg−1. Under the treatment of 100 mg kg−1, the B accumulation of sugar beet reached 0.22 mg plant−1, and the tolerance index was still higher than 60%, which had not yet reached the lethal concentration of sugar beet. The abundance of Acidobacteriota, Chloroflexi and Patescibacteria increased, which was beneficial to the resistance of sugar beet to high B stress. In summary, under high B stress sugar beet had strong tolerance, enhanced capacity for B uptake and enrichment, and changes in soil microbial community structure. This study provides a theoretical basis for clarifying the mechanism of sugar beet resistance to high B stress and soil remediation.

Trichoderma harzianum prevents red kidney bean root rot by increasing plant antioxidant enzyme activity and regulating the rhizosphere microbial community.

Root rot is one of the main reasons for yield losses of red kidney bean (Phaseolus vulgaris) production. Pre-inoculation with Trichoderma harzianum can effectively lower the incidence of red kidney bean root rot. In this study, four treatments including CK (control), Fu13 (Fusarium oxysporum), T891 (T. harzianum) and T891 + Fu13 (T. harzianum + F. oxysporum) were arranged in a pot experiment to investigate how T891 affected the incidence and severity of root rot, plant growth, and changes of defense enzyme activity in red kidney bean plants. Community composition and diversity of the rhizosphere microbiota was evaluated through high-throughput sequencing, and co-occurrence network was analyzed. The results showed that when compared to the Fu13 treatment, pre-inoculation with T891 reduced the incidence and severity of red kidney bean root rot by 40.62 and 68.03% (p < 0.05), increased the root length, shoot length, total dry biomass by 48.63, 97.72, 122.17%. Upregulated activity of super-oxide dismutase (SOD), peroxidase (POD), catalase (CAT) by 7.32, 38.48, 98.31% (p < 0.05), and reduced malondialdehyde (MDA) by 23.70% (p < 0.05), respectively. Microbiological analyses also showed that F. oxysporum reduced alpha diversity resulting in alteration the composition of the rhizosphere microbial community in red kidney bean. T891 significantly reduced abundance of F. oxysporum, allowing the enrichment of potentially beneficial bacteria Porphyrobacter (ASV 46), Lysobacter (ASV 85), Microbacteriaceae (ASV 105), and Gemmatimonas (ASV 107), resulting in a more stable structure of the microbial network. The results of random forest analysis further revealed that ASV 46 (Porphyrobacter) was the primary influencing factor for the incidence of root rot after inoculation with T891, while ASV 85 (Lysobacter) was the primary influencing factor for the biomass of red kidney bean. In conclusion, T. harzianum promotes the growth of red kidney bean and inhibits root rot by improving plant antioxidant enzyme activity and regulating the rhizosphere microbial community.

Wild edible mushrooms as an alternative for the consumption of antioxidants and phenolic compounds: An overview

Fungi are a diverse group, and they are essential for health, the economy, and food. Interest in these organisms has increased because of the importance and effect of their chemical components viz., phenolic compounds, which are considered an alternative source of antioxidants. Antioxidants are compounds that prevent cell damage and can help prevent or counteract certain diseases (cardiovascular, neurodegen-erative, cancer, etc.) because they can improve cell function (changes in enzyme activity, enzyme patterns, membrane fluidity, and responses to stimuli), among others. To date, no adverse side effects have been reported. The difference in production is due to several factors, such as the growth environment, nutrition, cell age, the part from where the phenolic compounds are obtained (pileus, stipe, or mycelium), the extraction method, etc. This article aims to provide an overview of wild edible mushrooms, to promote the study of their antioxidant capacity, and to better understand the nutraceutical potential of edible mushrooms consumed in different parts of the world.