Search Results (316)

Soil phosphorus (P) availability is an important determinant of productivity in Pinus massoniana (Masson pine) forests. The mechanistic bases governing the physiological and growth responses of Masson pine to varying soil P conditions remain insufficiently characterized. This study aims to decipher the adaptive strategies of Masson pine to different soil P levels, focusing on root morphological–architectural plasticity and the allocation dynamics of nutrient elements and photosynthetic assimilates. One-year-old potted Masson pine seedlings were exposed to four P addition treatments for one year: P0 (0 mg kg⁻¹), P1 (25 mg kg⁻¹), P2 (50 mg·kg⁻¹), and P3 (100 mg kg⁻¹). In July and December, measurements were conducted on seedling organ biomass, root morphological indices [root length (RL), root surface area (RSA), root diameter (RD), specific root length (SRL), and root length ratio (RLR) for each diameter grade], root architectural indices [number of root tips (RTs), fractal dimension (FD), root branching angle (RBA), and root topological index (TI)], as well as the content of nitrogen (N), phosphorus (P), carbon (C), and non-structural carbohydrates (NSCs) in roots, stems, and leaves. Compared with the P0 treatment, P2 and P3 significantly increased root biomass, root–shoot ratio, RL, RSA, RTs, RLR of finer roots (diameter ≤ 0.4 mm), nutrient accumulation ratio in roots, and starch (ST) content in roots, stems and leaves. Meanwhile, they decreased soluble sugar (SS) content, SS/ST ratio, C and N content, and N/P and C/P ratios in stems and leaves, as well as nutrient accumulation ratio in leaves. The P3 treatment significantly reduced RBA and increased FD and SRL. Our results indicated that Masson pine adapts to low P by developing shallower roots with a reduced branching intensity and promoting the conversion of ST to SS. P’s addition effectively alleviates growth limitations imposed by low P, stimulating root growth, branching, and gravitropism. Although a sole P addition promotes short-term growth and P uptake, it triggers a substantial consumption of N, C, and SS, leading to significant decreases in N/P and C/P ratios and exacerbating N’s limitation, which is detrimental to long-term growth. Under high-P conditions, Masson pine strategically prioritizes allocating limited N and SS to roots, facilitating the formation of thinner roots with low C costs. Full article

This study evaluates the agronomic potential of two types of vermicompost—one produced solely from wine industry residues (WIR) and one incorporating sewage sludge (WIR + SS)—under rainfed and deficit irrigation conditions in Mediterranean vineyards. The vermicompost was obtained through a two-phase process involving initial thermophilic pre-composting, followed by vermicomposting using Eisenia fetida for 90 days. The conditions were optimized to ensure aerobic decomposition and maintain proper moisture levels (70–85%) and temperature control. This resulted in end products that met the legal standards required for agricultural use. However, population dynamics revealed significantly higher worm reproduction and biomass in the WIR treatment, suggesting superior substrate quality. When applied to grapevines, WIR vermicompost increased soil organic matter, nitrogen availability, and overall fertility. Under rainfed conditions, it improved vegetative growth, yield, and must quality, with increases in yeast assimilable nitrogen (YAN), sugar content, and amino acid levels comparable to those achieved using chemical fertilizers, as opposed to the no-fertilizer trial. Foliar analyses at veraison revealed stronger nutrient uptake, particularly of nitrogen and potassium, which was correlated with improved oenological parameters compared to the no-fertilizer trial. In contrast, WIR + SS compost was less favorable due to lower worm activity and elevated trace elements, despite remaining within legal limits. These results support the use of vermicompost derived solely from wine residues as a sustainable alternative to chemical fertilizers, in line with the goals of the circular economy in viticulture. Full article

The rising cost of mineral fertilizers and the decreasing availability of manure in vegetable farming highlight the need for alternative fertilization strategies. To examine the possibility of applying byproducts from the food processing industry, sugar beet molasses, and compost from brewery sewage sludge in celery production, the field experiment was conducted over two years, using a randomized complete block design with three replications. The examined variants were T0—control (without fertilizer); T1—mineral fertilizer; T2—cattle manure; T3—sheep manure; T4—poultry manure; T5—supercompost; and T6—molasses. In the first year, there was no significant difference between T1 and T5 in thickened root yield, while these two variants achieved significantly higher yield compared with other variants. In both years, the highest leaf yield was achieved with T1, while no significant difference was found between T5, T6, and conventional organic fertilizers of animal origin. The highest amount of N was absorbed by roots in T1 (42.0 kg/ha and 51.2 kg/ha, respectively), while the lowest amount was absorbed in T0 (25.5 kg/ha and 26.7 kg/ha, respectively). A significantly higher amount of P₂O₅ was absorbed by roots in all organic fertilizer variants compared to T0 and T1. In both years, of all the nutrients, K₂O was the most absorbed nutrient by the celery root, while CaO was absorbed in greater quantities than N. Based on two years of research, it can be concluded that compost from brewery sludge and sugar beet molasses can be used as an alternative source of nutrients for plants. Full article

Arbuscular mycorrhizal fungi (AMF) symbiosis has great potential in improving grapevine performance and reducing external input dependency in viticulture. However, the precise, strain-specific impacts of different AMF species on ‘Summer Black’ grapevine cuttings across multiple physiological and morphological dimensions remain underexplored. To address this, we conducted a controlled greenhouse pot experiment, systematically evaluating four different AMF species (Diversispora versiformis, Diversispora spurca, Funneliformis mosseae, and Paraglomus occultum) on ‘Summer Black’ grapevine cuttings. All AMF treatments successfully established root colonization, with F. mosseae achieving the highest infection rate. In detail, F. mosseae notably enhanced total root length, root surface area, and volume, while D. versiformis specifically improved primary adventitious and 2nd-order lateral root numbers. Phosphorus (P) uptake in both leaves and roots was significantly elevated across all AMF treatments, with F. mosseae leading to a 42% increase in leaf P content. Furthermore, AMF inoculation generally enhanced the activities of catalase, superoxide dismutase, and peroxidase, along with soluble protein and soluble sugar contents in leaves and roots. Photosynthetic parameters, including net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr), were dramatically increased in AMF-colonized cutting seedlings. Whereas, P. occultum exhibited inhibitory effects on several growth metrics, such as shoot length, leaf and root biomass, and adventitious lateral root numbers, and decreased the contents of Nitrogen (N), potassium (K), magnesium (Mg), and iron (Fe) in both leaves and roots. These findings conclusively demonstrate that AMF symbiosis optimizes root morphology, enhances nutrient acquisition, and boosts photosynthetic efficiency and stress resilience, thus providing valuable insights for developing targeted bio-fertilization strategies in sustainable viticulture. Full article

A substrate–product switch model was proposed to describe ethanol fermentation from longan solid waste using Candida tropicalis at an initial glucose and xylose ratio of 2 to 1. The model incorporated multiple rate equations for cell growth, sugar uptake, and ethanol production along with ethanol consumption. It elucidated the following three-step mechanism: (I) sugar uptake, (II) sugar conversion, and (III) ethanol consumption concerning the effects of concentration factor (CF) and associated growth function. Optimal kinetic parameters were estimated and validated against experimental data. The identification of two critical xylose concentrations showed that ethanol consumption either preceded or coincided with xylose consumption cessation. The phenolics inhibitory effect of gallic acid, ellagic acid, pyrogallol, and catechol on cell growth and ethanol production was elucidated with relatively minimal effect. The highest ethanol concentration of 25.5 g/L was reached with corresponding ethanol mass yield and productivity of 0.30 g/g and 1.063 g/L/h, respectively. The proposed model and kinetics provide valuable insights for designing and optimizing ethanol fermentation, contributing to more sustainable and cost-effective ethanol production. Full article

Efficient co-utilization of glucose and xylose from lignocellulosic biomass remains a critical bottleneck limiting the viability of sustainable biorefineries. While Corynebacterium glutamicum has emerged as a promising industrial host due to its robustness, further improvements in mixed-sugar co-utilization are needed. Here, we demonstrate how a single amino acid substitution can dramatically transform cellular sugar transport capacity. By combining rational strain engineering with continuous adaptive laboratory evolution, we evolved a ptsG-deficient C. glutamicum strain in glucose–xylose mixtures for 600 h under consistent selection pressure. Whole-genome sequencing revealed a remarkable finding: a single point mutation; exchanging proline for alanine in the myo-inositol/proton symporter IolT1 was sufficient to boost glucose uptake by 83% and xylose uptake by 20%, while increasing the overall growth rate by 35%. This mutation, located in a highly conserved domain, likely disrupts an alpha helical structure, thus enhancing transport function. Reverse engineering confirmed that this single change alone reproduces the evolved phenotype, representing the first report of an engineered IolT1 variant in PTS-independent C. glutamicum that features significantly enhanced substrate uptake. These results both provide an immediately applicable engineering target for biorefinery applications and demonstrate the power of evolutionary approaches to identify non-intuitive solutions to complex metabolic engineering challenges. Full article

The critical nitrogen (N) dilution curve is widely used to diagnose crop N status, but no such model has been developed for sugar beet. This study evaluated the effects of irrigation amount and N rate on sugar yield, N use efficiency, and soil nitrate-N (NO₃-N) residue of drip-fertigated sugar beet in the arid southern Xinjiang of China. A reliable N nutrition index (NNI) for sugar yield was also established based on a critical N dilution curve derived from the dry matter of sugar beet. A three-year field experiment was established with six N rates (25–480 kg N ha⁻¹) and three irrigation levels based on crop evapotranspiration (ET_c) (0.6, 0.8, and 1.0 ET_c in 2019 and 2020, and 0.4, 0.6, and 0.8 ET_c in 2021). Results showed that sugar yield and N uptake increased and then generally stabilized with increasing N rate, while N use efficiency decreased. Most soil NO₃-N was mainly distributed in the 0–60 cm soil layer, but increasing irrigation amount reduced residual NO₃-N in the 0–80 cm soil layer. Additionally, the established critical N dilution curve of sugar beet was considered stable (Normalized RMSE = 16.6%), and can be used to calculate plant N requirements and further N rates during sugar beet growth. The results indicated that the optimal NNI was 0.97 under 0.6 ET_c for sugar yield production of sugar beet in this study. This study provides a basis for efficient water and N management in sugar beet production in arid and semi-arid regions globally. Full article

Microalgae-based bioremediation is increasingly recognized as a sustainable, efficient, and straightforward technology. Despite this growing interest, the potential of Parachlorella hussii for metal biosorption remains underexplored. This study is the first report evaluating the metal biosorption activity in Parachlorella hussii ACOI 1508 (N9), highlighting the impact of the culture age on the monosaccharide composition and its correlation to the metal binding capacity. The capsular strain (N9) was isolated from the hypersaline ecosystem—Lake Chott Aïn El-Beida—in southeastern Algeria. Cultivated in Bold’s Basal medium, the strain produced 0.807 ± 0.059 g L⁻¹ of RPSs and 1.975 ± 0.120 g L⁻¹ of CPSs. Biochemical analysis of the extracts revealed a high total sugar content (% w/w) that ranged from 62.98 ± 4.87% to 95.60 ± 87% and a low protein content (% w/w) that ranged from 0.49 ± 0.08% to 1.35 ± 0.69%, with RPS-D7 and RPS-D14 having high molecular weight (≥2 MDa). HPLC-based monosaccharide characterization demonstrated compositional differences between the exponential and stationary phases, with rhamnose dominating (~55%) in RPS-D14 and with the presence of uronic acids comprising 7–11.3%. Metal removal efficiency was evaluated using the whole biomass in two growth phases. Copper uptake exhibited the highest capacity, reaching 18.55 ± 0.61 mg Cu g⁻¹ DW at D14, followed by zinc removal with 6.52 ± 0.61 mg Zn g⁻¹ DW. Interestingly, removal efficiencies increased to about twofold during the stationary phase, reaching 51.15 ± 1.14% for Cu, 51.08 ± 3.35% for Zn, and 36.55 ± 3.09% for Ni. The positive results obtained for copper/zinc removal highlight the biosorption potential of P. hussii, and notably, we found that the metal removal capacity significantly improved with culture age—a parameter that has been poorly investigated in prior studies. Furthermore, we observed a growth phase-dependent modulation in monosaccharide composition, which correlated with enhanced functional properties of the excreted biomolecules involved in biosorption. This metabolic adjustment suggests an adaptive response that may contribute to the species’ effectiveness in heavy metal uptake, underscoring its novelty and biotechnological relevance. Full article

Background: Iminosugars are natural or synthetic sugar analogues with a very broad spectrum of activities, including those against the most prominent bacterial pathogens, like P. aeruginosa or S. aureus. In a series of studies, we have demonstrated that one of the synthetic iminosugars, PDIA (beta-1-C-propyl-1,4-dideoxy-1,4-imino-L-arabinitol), possesses the ability to suppress biofilm production by different pathogenic bacteria without inhibiting their growth. Thereby, PDIA is able to influence experimental skin infection caused by S. aureus. Methods: To elucidate molecular mechanisms by which PDIA impedes biofilm formation by S. aureus, a transcriptomic study was performed in which a biofilm-producing S. aureus strain was grown in the presence of PDIA for 24 and 48 h in comparison to a control without the iminosugar. The RNA was then isolated, converted into cDNA, sequenced, and data analysis was performed. Results: It appeared that PDIA caused the down-regulation of many bacteriophage genes responsible for the processes of bacterial cell lysis, and some genes responsible for cell wall degradation were also down-regulated. Among the 25 most upregulated genes were those representing the phosphotransferase system (PTS), which is required for carbohydrate uptake and control of carbon metabolism. The ranking of the most significant down-regulated genes after 24 h exposure to PDIA shows that they predominantly coded for both the synthesis and lysis of the peptidoglycan. Conclusions: We have shown here that the influence of PDIA on the expression of S. aureus genes is broad and affects many genes encoding metabolism and ribosomes. Full article

This study investigated the effects of Trichoderma harzianum inoculation on the growth, physiological responses, and soil nutrient uptake of three turfgrass species cultivated on eco-concrete—Axonopus compressus (Sw.) Beauv., Cynodon dactylon (L.) Pers., and Zoysia sinica Hance. A 2 × 2 factorial design was used to evaluate plant growth, physiological responses, and soil metrics under cement stress, incorporating T. harzianum inoculation (inoculated vs. control) and substrate composition (eco-concrete vs. pastoral soil). Our results indicate that inoculation with Trichoderma harzianum significantly enhanced the growth potential of the three turfgrass species compared to uninoculated controls. Furthermore, under cement stress conditions in vegetated concrete, inoculation with T. harzianum significantly alleviated the inhibition of growth and development. More specifically, in the vegetated concrete habitat, inoculated plants exhibited significantly increased root length and surface area. This enhancement promoted the uptake of available nitrogen (AN), available phosphorus (AP), and available potassium (AK) from the soil. Concurrently, inoculated plants showed higher leaf epidermal cell density, stomatal width, soluble sugar content, and antioxidant enzyme activity (SOD, POD, CAT, and APX). Additionally, significant reductions were observed in root activity, relative conductivity, and malondialdehyde (MDA) and proline contents. In conclusion, T. harzianum inoculation promotes the growth of the three turfgrass species under cement stress, likely by enhancing root development, increasing osmoregulatory substance accumulation, and elevating antioxidant enzyme activities. Full article

Maltose and maltotriose are the most abundant sugars in brewing wort, and their transport represent a critical bottleneck in the fermentation process. This transport relies on specific transmembrane proteins; however, many yeast strains exhibit inefficient uptake of these sugars, particularly maltotriose. Addressing this limitation requires a comprehensive understanding of the factors influencing the transport of maltose and maltotriose. This review provides a detailed synthesis of the key characteristics and functions of the maltose and maltotriose transmembrane transporters identified in brewer’s Saccharomyces yeasts. Critical amino acid residues involved in transporter activity are also highlighted, and the impact of specific polymorphisms and sequence variations on sugar preference and uptake efficiency is examined. Furthermore, a thorough discussion of the most important reported residues is presented, underscoring the need to closely examine their amino acid composition to better understand transporter mechanisms, optimize their performance, and enhance fermentation outcomes. Full article

The effects of soy protein and whey protein supplementation on glycemic control show inconsistency, and the mechanisms underlying the impact of a high-protein diet on blood glucose regulation remain unclear. This study aimed to explore the impact of a dual-protein (DP) blend comprising soy protein isolate (SPI) and whey protein concentrate (WPC), processed through high-pressure homogenization, on mice with Type 2 diabetes mellitus (T2DM) and its potential mechanisms. In the in vitro experiments, an insulin-resistant (IR) HepG2 cell model was treated with DP, resulting in a significant enhancement of glucose uptake and upregulation of IRS1 and GLUT4 expression. For the in vivo experiments, male C57BL/6J mice were randomly assigned into four groups (n = 6) based on body weight: normal control, T2DM model group, Metformin-treated group, and DP-treated group. Following a 5-week feeding period, Metformin and DP significantly reduced levels of blood sugar, AUC, TC, TG, and LDL-C in T2DM mice. Additionally, TP and ALB levels in the DP group were notably higher in the model group. In the liver and pancreas, DP alleviated histopathological changes and promoted liver glycogen synthesis in T2DM mice. Moreover, the levels of IRS1 and PI3K in the livers of mice in the DP group were significantly higher than those in the model group. Compared with the model groups, DP significantly reduced the expression of CD45 and increased the expression of CD206 in the pancreas of mice. Furthermore, 16S rRNA analysis revealed that DP altered the composition of the gut microbiota in diabetic mice, increasing the relative abundance of Lactobacillus, Parvibacter, and Lactobacillaceae. This suggested that DP could alleviate functional metabolic disorders in the gut and potentially reverse the risk of related complications. In conclusion, soy whey dual-protein may have an effective nutritional therapeutic effect on T2DM mice by regulating lipid metabolism, the INS/IRS1/PI3K signaling pathway, and gut microbiota. Full article

This study investigates the impact of dynamically adjusting the potassium-to-calcium ratio (molar ratio) in nutrient solutions used on cherry tomatoes at different growth stages (seedling, flowering and fruit setting, and maturity) to enhance fruit appearance, nutritional quality, and mineral content. By focusing on the ‘Saopolo’ variety, 17 treatments were implemented, each involving a specific potassium-to-calcium ratio in the nutrient solutions applied during the seedling, flowering and fruit setting, and fruiting stages. The aim was to optimize the nutrient solution formula and enhance fruit quality. Fruit quality parameters were assessed at the initial maturity stage across various treatments, encompassing commodity quality (fruit stalk length, fruit shape index, and fruit hardness), taste quality (total soluble sugar, titratable acid content, and sugar-acid ratio), nutritional quality (vitamin C (Vc), soluble protein, and lycopene content), antioxidant quality (total phenol and flavonoid content), as well as comprehensive quality (soluble solids content). Principal component analysis was conducted on these parameters. Additionally, mineral element levels in fruits were analyzed at different developmental stages (white ripe, color transition, and mature stages). When tomato plants were treated with nutrient solutions containing varying potassium-to-calcium ratios at different growth stages, observations revealed distinct outcomes in the first fruit cluster. T15 (seedling stage (A): 0.5 times standard nutrient solution; flowering and fruit-setting stage (B): potassium-to-calcium = 1.6:1; fruiting stage (C): potassium-to-calcium = 2.1:1) exhibited the highest fruit firmness (1.54 kg·cm⁻²), while T14 (A; B (K:Ca = 1.6:1); C (K:Ca = 2.0:1)) elevated levels of total soluble sugars (6.59%), titratable acidity (0.74%), soluble proteins (2.79 mg·g⁻¹), and total phenolics (2.56 mg·g⁻¹). T13 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.9:1)) demonstrated superior soluble solids (5.9%), lycopene (32.09 µg·g⁻¹), and flavonoid contents (0.77 mg·g⁻¹), whereas T12 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.8:1)) showcased the highest sugar–acid ratio (12.63) and soluble solids content (5.9%). Notably, T8 (A; B (K:Ca = 1.5: 1); C (K:Ca = 1.9:1)) exhibited the highest Vc content (10.03 mg·100 g⁻¹). Mineral element analysis indicated that an increased potassium-to-calcium ratio in the nutrient solution during various growth stages enhanced phosphorus and potassium uptake by the fruits but hindered the absorption of nitrogen, calcium, magnesium, and iron. In summary, employing half the standard nutrient solution dosage during the seedling stage, utilizing a potassium-to-calcium ratio of 1.6:1 in the nutrient solution at the flowering and fruit setting stage, and applying nutrient solution T13 with a potassium-to-calcium ratio of 1.9:1 during the fruit-bearing phase, optimally coordinates fruit nutrient accrual and enhances flavor quality. These findings support the use of stage-specific nutrient modulation to improve cherry tomato quality in controlled-environment agriculture. Full article

To unravel the mechanisms underpinning salt tolerance, different studies have attempted to determine the physiological and genetic variations behind the difference in salt tolerance between Arabidopsis thaliana and the salt-tolerant Thellungiella salsuginea (halophila). Most of these studies were limited to a specific duration of salt treatment and neglected the time response as a possible contributing factor to the higher salt tolerance exhibited by T. salsuginea. In this work, a comprehensive and detailed comparison of the response of the two species to high salinity was conducted at different times for up to ten days of salt treatment. T. salsuginea responded more rapidly and to a higher extent to adjust its metabolism and showed constitutive levels of anticipatory metabolism to salinity. T. salsuginea responded more rapidly in terms of maintaining light use efficiency, limiting the uptake of Na⁺, and increasing the accumulation of sugars and proline when exposed to salinity. T. salsuginea had much higher constitutive levels of metabolites, including malate, proline, and inositol, in comparison to A. thaliana. Interestingly, T. salsuginea showed a reduction in malate levels under salt treatment in contrast to A. thaliana. These results suggest that constitutive levels and the rapidity of the deployment of resistance mechanisms, together with metabolic plasticity, in response to salt stress are important adaptive traits for salt tolerance in plants. Full article

In the present study, the effects of varying ultrasound treatment durations (5, 15, 30, and 45 min) applied prior to osmotic dehydration in xylitol solutions on apple tissues were investigated. The efficiency of the osmotic dehydration process was assessed by analyzing its kinetic parameters. In selected samples of osmotically dehydrated fruits, physicochemical properties were evaluated, including dry matter content, total acidity, pH, sugar profile, color attributes, total phenolic content, antioxidant activity (measured by DPPH and ABTS assays), and vitamin C content. Additionally, principal component analysis (PCA) was conducted to explore the relationships among the measured variables and to identify underlying patterns within the dataset. Osmotic dehydration in xylitol significantly modified the physicochemical and antioxidant properties of apples, promoting substantial water loss and partial replacement of natural sugars with xylitol. The results showed that ultrasound pretreatment markedly influenced these effects, with treatment duration playing a critical role. Shorter ultrasound applications (15–30 min) enhanced xylitol uptake while better preserving antioxidant activity and color, whereas longer ultrasound treatments (45 min) achieved greater mass transfer but led to higher losses of bioactive compounds compared to untreated samples. Full article