Search Results (1,088)

With the continuous expansion of Pleurotus ostreatus cultivation, substantial quantities of post-harvest spent mushroom substrate (SMS) are generated. Improper disposal of this organic waste poses potential threats to soil health, including contamination and ecological imbalance. Consequently, a rigorous safety assessment is indispensable to support the sustainable and agronomically viable utilization of SMS as a soil amendment. In this study, P. ostreatus SMS was subjected to sterilized and non-sterilized treatments, and a controlled co-culture system integrating P. ostreatus mycelium with wheat was established. This system facilitated a comprehensive evaluation of residual mycelium impacts on wheat growth and development at phenotypic, cytological, and non-targeted metabolomics (LC-MS) levels. Results demonstrated that direct field application of non-sterilized SMS severely compromised wheat performance, inducing root necrosis and significantly reducing grain set. Comparative experiments confirmed that non-sterilized SMS—not its sterilized counterpart—exerted pronounced phytotoxic effects, markedly inhibiting seedling growth and triggering wilting symptoms. To elucidate the temporal dynamics of mycelial interaction, wheat seedlings were inoculated with viable P. ostreatus mycelium and co-cultured for seven days. Under these conditions, the mean root length of the control group (10.82 cm) was approximately threefold that of the treatment group. Histopathological analysis revealed a progressive infection pattern initiating at the root apex and extending basipetally; prolonged exposure ultimately caused complete root system collapse. Scanning electron microscopy further showed extensive mycelial colonization on infected root surfaces, accompanied by characteristic cellular damage—including severe cell wall wrinkling and widespread cell death. LC-MS profiling identified 1867 annotated compounds. Comparative analysis revealed significant dysregulation of secondary metabolism, with 495 metabolites upregulated and 419 metabolites downregulated in the treatment group. Collectively, these findings provide robust evidence that unprocessed P. ostreatus SMS poses tangible agronomic risks upon direct soil application. This study establishes a critical scientific foundation for developing safe, evidence-based protocols for the valorization and integrated management of SMS. Full article

Background/Objectives: Proso millet (Panicum miliaceum L.), a drought-tolerant cereal vital to semi-arid agriculture, faces severe yield losses from head smut disease caused by the pathogen Sporisorium destruens. Although partial resistance exists, the dynamic molecular mechanisms governing its defense response across developmental stages remain poorly understood. Methods: Here, we performed untargeted metabolomics on leaf samples from Inoculated Asymptomatic (IA) and Inoculated Symptomatic (IS) plants of the partially resistant cultivar ‘Chishu 13’ at four key growth stages following pathogen inoculation, with group classification validated by qPCR. Using weighted metabolite co-expression network analysis (WGCNA) combined with differential metabolite screening, we identified 18 metabolites markedly enriched in the tricarboxylic acid (TCA) cycle, metabolite transport-related processes, and phenylpropanoid biosynthesis pathways. Results: Notably, L-phenylalanine accumulated substantially in IA plants relative to IS plants and correlated closely with biosynthesis of key defensive phenylpropanoids, including cinnamic acid and p-coumaric acid. Our results reveal distinct temporal patterns in metabolic reprogramming that correlate with resistance outcomes in Inoculated Asymptomatic plants: early stages are characterized by differential regulation of energy metabolism, while later stages show enhanced phenylpropanoid biosynthesis. These stage-specific metabolic adaptations are strongly associated with successful defense outcomes. Conclusions: These findings elucidate stage-specific metabolic adaptations that distinguish successful defense in IA plants from susceptibility in IS plants, providing robust biomarkers and stage-targeted strategies for breeding smut-resistant millet varieties. Full article

Increasing domestic sewage production associated with urban population growth poses environmental challenges. Biosolids from wastewater treatment can recycle nutrients in agriculture, while plant growth-promoting rhizobacteria (PGPR) enhance nutrient availability and plant performance. This study evaluated the effects of the combined application of sewage sludge–derived biosolid and Bacillus aryabhattai on sunflower growth, biomass production, physiological traits, and nutrient status during the early growth stage under greenhouse conditions. We hypothesized that this combined treatment would enhance plant performance compared with biosolid application alone. Four treatments were established: control (T1), 5 g of biosolid alone (T2), 5 g biosolid + 3.2 mL B. aryabhattai (T3), and 5 g biosolid + 6.4 mL B. aryabhattai (T4). The formulation contains B. aryabhattai strain CMAA 1363 (1 × 10${}^8$ CFU mL${}^{-1}$) as the active microbial component, together with humic substances and other formulation agents (thickener, preservative, and water). The Plants were grown for 44 days. The data were analyzed using one-way ANOVA followed by mean comparison among treatments. Shoot dry mass was significantly higher in T4 compared with the T1 and T2 (p < 0.001), while no significant difference was observed between T3 and T4 (p > 0.05). Biosolid application increased the photosynthetic rate, and its combination with B. aryabhattai further enhanced photosynthetic performance, with significant difference detected between bacterial doses only at the end of growth period. Substomatal CO${}_2$ concentration was lower in inoculated treatments, indicating greater CO${}_2$ assimilation efficiency. Total chlorophyll increased with the addition of sludge and further increased by inoculation with 6.4 mL. Leaf N, Mn, and Zn contents were highest in T4. Overall, the combined application of biosolid and B. aryabhattai improved photosynthetic efficiency and biomass accumulation, highlighting the potential of integrating biosolids and beneficial rhizobacteria as a sustainable approach for nutrient recycling and improved crop productivity in agricultural systems. Full article

The pathways governing the transformation of crop residues into humic acid (HA) remain incompletely understood because multiple biochemical routes may operate simultaneously during composting-like humification. In this study, a 30-day solid-state humification experiment was conducted by integrating physicochemical pretreatments, including steam explosion (SE) and ammonification coupled with steam explosion (SE-N), with a multi-fungal inoculation strategy involving Aspergillus niger, Candida spp., and Phanerochaete chrysosporium. Across three representative substrate–pretreatment systems and 81 experimental groups, the contents of lignocellulosic fractions, reducing sugars (RS), a UV-280-based soluble nitrogen-containing precursor index (operationally denoted as SNP), fulvic acid (FA), and HA were compared. The results showed that neither physicochemical pretreatment alone nor single-strain inoculation was sufficient to achieve substantial HA formation. SE mainly improved substrate accessibility and promoted carbon release, whereas ammonification provided essential nitrogen preloading for subsequent precursor coupling. In the saccharification-dominant treatment, RS reached 27.5%, but HA remained negligible. In the Candida-only treatment, the soluble nitrogen-containing precursor index increased markedly, yet HA formation was still minimal. By contrast, the highest HA yield (13.7%) was obtained under multi-fungal co-inoculation, particularly when nitrogen preloading by ammonification was combined with concurrent accumulation of carbon and aromatic precursors. The data suggest that lignin-targeting activity by P. chrysosporium was associated with the likely generation of phenolic and quinone-like intermediates that bridged the condensation of sugar- and nitrogen-derived compounds. Overall, the findings support a synergistic humification framework in which polysaccharide depolymerization, microbial nitrogen transformation, and lignin-derived aromatic precursor formation jointly contribute to HA accumulation, rather than a single linear pathway dominating the process. Full article

Using non-Saccharomyces yeasts is a promising way to modulate wine composition, particularly in warm regions where high sugar levels result in wines with high alcohol content and low acidity. This study examined the impact of various inoculation methods involving Lachancea thermotolerans and Metschnikowia pulcherrima on the chemical and aromatic profiles of Tempranillo wines. Five treatments were tested: a control with Saccharomyces cerevisiae; two sequential inoculations, with each non-Saccharomyces species followed by S. cerevisiae; and two co-inoculations of both species at different ratios, followed by S. cerevisiae. L. thermotolerans was found to significantly increase lactic acid levels, resulting in higher acidity and lower pH, particularly at higher doses. Wines inoculated with M. pulcherrima exhibited the highest levels of fruity esters, whereas L. thermotolerans increased higher alcohols, acetaldehyde and ethyl lactate, but reduced ester content. Co-inoculations produced intermediate or synergistic effects, depending on the proportions of the yeast species. Aromatic analysis indicated that treatments involving M. pulcherrima were associated with higher contributions to the fruity, floral and waxy aromatic series, while L. thermotolerans increases creamy series. Multivariate analysis clearly differentiated wines according to the dominant species. Overall, the co-inoculation of both yeasts is an effective method of modulating volatile composition and aroma-related parameters in warm-climate red wines. Full article

Basidiomycetes can colonize sweet chestnut (Castanea sativa Mill) xylem, causing white or brown rot and losses in wood quality. The aim of this study was to assess the degradative potential of five Basidiomycota strains (Armillaria mellea (Vahl) P. Kumm. (Am), Fistulina hepatica (Shaeff.) With. (Fh), and Laetiporus sulphureus (Bull.) Murrill (Ls), and two strains of Ganoderma resinaceum Boud.) on three chestnut woods differing in chemistry. The woods differed in nitrogen content (0.3%–1.0%), carbon/nitrogen (C/N) ratio (43–150), and phenolic-related traits. In a 39-day laboratory assay, the five fungal strains were inoculated on three chestnut woods and compared for colonization time, extracellular enzymatic activity, and C mineralization. Fungal colonization strongly depended on fungus × wood interaction: L. sulphureus colonized all woods within 6 days, whereas the two G. resinaceum strains required 9–33 days depending on wood type; A. mellea and F. hepatica colonized only selected woods (up to 39 days). Enzymatic screening indicated laccase activity mainly in G. resinaceum (and to a lesser extent A. mellea), while L. sulphureus expressed cellulolytic activity but no laccase. Over 39 days, total C mineralization peaked under G. resinaceum on the two Sicilian woods (up to 270–300 mg CO₂–C g⁻¹ dry wood), whereas the Tuscan wood (highest C/N and phenolic content) markedly inhibited most strains; only L. sulphureus increased mineralization in this wood (85 mg CO₂–C g⁻¹ dry wood). These findings indicate that wood chemistry, especially C/N ratio and phenolic traits, strongly modulates strain-specific decay patterns. Overall, these results highlight the need for an integrated biological–biochemical approach to evaluate fungal decay potential and to inform both the selection of more durable chestnut woods for wood products and the identification of efficient strains to accelerate lignocellulosic biomass composting. Full article

Lactiplantibacillus plantarum EL2, isolated from traditional fermented yak milk in the high-altitude Gannan Tibetan Autonomous Prefecture, produces the class IIb bacteriocin PlnJK. This study established three distinct cultivation models that critically influenced bacteriocin yield. Microbial co-culture was found to enhance the stress tolerance of EL2, significantly boosting PlnJK production. The optimal inducing strain, Enterococcus faecalis MH2, increased the bacteriocin inhibition zone diameter from 15.38 mm to 25.58 mm. Following optimization of key parameters—initial inoculum concentration (10⁷ CFU/mL), inoculation ratio (3:1, EL2:MH2), and initial pH (6.0)—the inhibition zone diameter reached 30.32 mm, representing a 1.97-fold increase over pure culture. Co-culture not only advanced the onset but also extended the duration of bacteriocin synthesis. Throughout the 24 h incubation, cell density, AI-2 autoinducer concentration, and the expression of key regulatory genes were significantly elevated in co-culture compared to monoculture, aligning with a cell-density-dependent, quorum-sensing (QS) regulatory paradigm. Bacteriocin production was co-regulated by two QS pathways: the AI-2/luxS system and the plnA-mediated autoinducing peptide (AIP). Gene expression analysis revealed differential temporal regulation: luxS expression was higher during the exponential phase (2.29 vs. 1.42 in stationary phase), while plnA exhibited the opposite pattern (1.42 in exponential vs. 2.21 in stationary phase). This indicates that the AI-2/luxS pathway drives strong induction during active growth, whereas plnA/AIP-mediated promotion becomes predominant later. The stationary-phase effect is likely triggered by the accumulation of specific MH2 metabolites, which impose an environmental stress on EL2, stimulating the pln-encoded regulatory system and further enhancing bacteriocin yield. This work provides an economically viable strategy and a novel theoretical framework for optimizing microbial cultivation, enhancing bacteriocin production, and elucidating the complex QS-mediated regulatory mechanisms involved. Full article

Bacterial wilt caused by Ralstonia solanacearum is a major constraint on tomato (Solanum lycopersicum L.) production, yet the molecular basis of quantitative resistance remains poorly understood. In this study, comparative transcriptome profiling was performed on resistant (‘ZM3’) and susceptible (‘ZM86’) tomato inbred lines following pathogen inoculation in roots, stems, and leaves. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were conducted to identify resistance-associated regulatory modules and hub genes. The results revealed distinct gene expression patterns between the two genotypes after infection. Several co-expression modules were significantly associated with resistance or susceptibility traits. Functional enrichment analysis showed that differentially expressed genes were mainly involved in plant hormone signal transduction, plant–pathogen interaction, phenylpropanoid biosynthesis, and cell wall modification. Genes related to ethylene and salicylic acid signaling were strongly induced following infection, whereas brassinosteroid-associated genes showed genotype-dependent expression patterns. Network analysis further identified several hub genes within defense-related modules, including ACO (Solyc04g007980), ERF1 (Solyc09g091950), MAPK9, receptor-like kinase RLK (Solyc07g006770), and a dirigent family gene (Solyc10g008900). Taken together, our results suggest that tomato resistance to Ralstonia solanacearum involves a coordinated defense network integrating hormone-mediated transcriptional regulation and structural reinforcement, and provides candidate genes for breeding bacterial wilt-resistant cultivars. Full article

Hydrogen-mediated microbial electrosynthesis (MES) of chemicals from CO₂ relies on effective gas–liquid transfer at the cathode interface, yet the extent to which cathode surface area regulates acetate productivity remains insufficiently quantified. In this study, three identical MES reactors equipped with stainless-steel cathodes of different geometric areas (8 × 1, 8 × 4, and 8 × 16 cm²) were operated at a constant electric current of 0.3 A. The largest cathode significantly accelerated hydrogen mass transfer (k_La = 0.592 h⁻¹), reaching dissolution equilibrium within 3 min, which was nearly twice as fast as the smallest electrode. Upon inoculation with enriched acetate-producing microbial consortia, the 8 × 16 cm²_cathode reactor fed with CO₂ achieved the highest steady-state acetate concentration of 32 g·L⁻¹ produced at a rate of 2.12 g·L⁻¹·d⁻¹, with 94% hydrogen utilization, and 59% coulombic efficiency. In contrast, smaller electrodes exhibited rapid bubble detachment and reduced residence time, thereby limiting microbial gas uptake, and resulting in low acetate productivity. These findings demonstrate that cathode surface area is a key engineering lever controlling both hydrogen availability and electron recovery efficiency in H₂-driven MES. The results provide practical guidance for electrode design and scale-up of CO₂-to-acetate bioconversion via the MES process. Full article

Tomato fruit rot severely impacts yield and quality, causing economic losses. This study aimed to identify the pathogenic fungi associated with post-harvest tomato fruit rot and characterize the transcriptomic responses of tomatoes. Pathogens were isolated from diseased tomato fruit tissues and identified using morphology, phylogenetic analysis, and in vitro pathogenicity tests. The genome of Cladosporium oxysporum Co-1 was assembled and annotated. RNA-seq analysis was used to profile transcriptional changes in tomatoes infected with C. oxysporum Co-1, with RT-qPCR validating the RNA-seq data and spectrophotometric assays analyzing the host physiological responses. Three pathogenic fungi were isolated. Colonies of C. oxysporum exhibited a near-circular shape, with colonies transitioning from an olive-green center to gray-green at the edges, and based on ITS, β-tubulin, and EF-1α gene sequences, this isolate exhibited 99% identity with C. oxysporum. The other two fungal isolates were identified as Alternaria alternata and Fusarium incarnatum, respectively, based on morphological and multi-locus sequence analysis. All three strains induced fruit rot and browning in tomatoes, confirming their pathogenicity. The genome size of C. oxysporum Co-1 was 34,515,558 bp, comprising 52 scaffolds with a GC content of 52.82%, and encoding 10,081 protein-coding genes. RNA-seq analysis showed dynamic gene expression changes in tomatoes infected with strain A, with differentially expressed genes enriched in pathogenicity-related pathways. Spectrophotometric assays revealed that peroxidase and superoxide dismutase activities decreased initially followed by an increase post-inoculation with C. oxysporum, indicating that tomatoes defend against pathogen infection through the antioxidant enzyme system. These findings revealed the pathogenic fungi were associated with post-harvest tomato rot disease, provided genomic resources for C. oxysporum, and provided insight into the host’s response to this strain. Full article

The common bean (Phaseolus vulgaris L.) cultivar Jalo Vermelho carries the Co-12 gene, which confers resistance to both Andean and Mesoamerican races of Colletotrichum lindemuthianum. Despite its importance for breeding programs, the genomic location and candidate genes underlying this resistance remain poorly defined. The Co-12 locus was fine-mapped using a biparental population derived from the cross Jalo Vermelho × Crioulo 159. A total of 172 F₂ plants were used to generate 172 F_2:3 families, which were phenotyped after inoculation with race 1545 of C. lindemuthianum. Segregation analysis confirmed a 1:2:1 Mendelian ratio, consistent with a single dominant resistance gene. Genotyping of resistant and susceptible plants using the BARBean6K_3 Illumina BeadChip (5398 SNP markers) mapped Co-12 to chromosome Pv04, between 1695 bp (ss715649768) and 9,651,954 bp (ss715646644). Subsequent fine mapping with simple sequence repeat (SSR) markers delimited the locus to a 41 kb genomic interval flanked by BARCPVSSR04557 and BARCPVSSR04570. Within this region, three candidate genes were identified, including one encoding a gamma-glutamyl-GABA enzyme and two encoding lipid transfer proteins (LTP2). Lipid transfer proteins are widely recognized components of plant defense; however, their association with anthracnose resistance in the common bean has not been previously reported. The identification of LTP2 genes within the Co-12 interval suggests a previously unrecognized resistance mechanism and expands the current understanding of host defense pathways in Phaseolus vulgaris. The markers identified here provide valuable tools for marker-assisted selection and will facilitate efficient introgression of Co-12 into common bean cultivars. Full article

The study evaluated the effects of replacing soybean meal (SBM) with marula oilcake (MOC) at equal inclusion (10% fresh weight) levels in whole-crop maize silage treated with or without lactic acid bacteria inoculants on fermentation characteristics, nutritive value, aerobic stability, and in vitro nutrient degradability. Maize was ensiled with SBM or MOC in a non-iso-nitrogenous 2 × 3 factorial design and either inoculated or uninoculated with Lalsil Fresh or Sil-All 4×4 for 90 days. Protein sources differed significantly (p < 0.05). The MOC showed high DM, EE, GE, and ADL, whereas SBM had high CP, ash, and IVOMD. Fibre fractions (aNDF and ADF) were similar (p > 0.05). The SBM control showed significantly high (p < 0.05) LA, NH₃-N, CP, IVOMD, propionic acid, and early gas production, indicating efficient fermentation. The SBM + Lalsil maintained low pH, and early OM, CP, and GE degradability. The SBM + Sil-All achieved the highest (p < 0.05) OM, NDF, and ADF degradability and acetic acid production than other treatments. The MOC control showed low (p < 0.05) pH, high fibre and GE, reduced butyric acid, and low 48 h gas production, indicating slower fermentation but improved stability. The MOC + Lalsil had high (p < 0.05) DM, low CO₂ and yeasts and moulds, and the highest (p < 0.05) CP degradability, propionic acid, and peak gas production at 12 h. The MOC + Sil-All showed high (p < 0.05) GE and WSC with peak GE degradation at 12 h, but low NDF degradability and reduced gas production. Overall, SBM improved degradability and fermentation efficiency, particularly with Sil-All, whereas MOC enhanced energy density and aerobic stability, with Lalsil optimising protein utilisation. Matching inoculant type to protein source is essential to optimise silage quality and rumen fermentation. Further research should assess different inoculant inclusion rates and include a maize-only control, and evaluate protein source inclusion under iso-nitrogenous conditions to allow more accurate comparisons. Full article

The response of five Passiflora species as rootstocks for yellow passion fruit was evaluated against the Meloidogyne incognita complex and Fusarium oxysporum f. sp. passiflorae. Individual, sequential, and simultaneous inoculations were applied, quantifying disease severity, nematode reproduction (RF), biomass, and plant vigour. In addition, integrated analysis was performed using the Combined Tolerance Index (CTI) to confirm the simultaneous interaction of the inoculation condition. The graft compatibility index (GCI) of the materials under study was also determined. The results showed critical functional differences; P. maliformis showed tolerance in terms of compensatory vigour but presented high susceptibility to the nematode and low graft affinity (GCI = 1.39). In contrast, P. platyloba emerged as the superior genotype, combining effective resistance to Meloidogyne (zero incidence at critical stages), excellent anatomical compatibility (deviation from the ideal of 0.04), and physiological stability superior to the control. Although P. nitida showed resilience in biomass under severe stress conditions, it is concluded that P. platyloba is the most promising alternative for use as rootstock. This is because its morphological affinity and health resistance ensure crop sustainability in field conditions and promote more sustainable agricultural practices. Full article

Human hair waste represents a dense nitrogen reservoir (~15% N); however, its agricultural valorization is hindered by two concurrent barriers: the extreme recalcitrance of alpha-keratin and the high salinity derived from cosmetic treatments. While chemical hydrolysis generates secondary pollutants, biological composting often fails due to osmotic inhibition of non-adapted inoculants. Here, we report a biological strategy to circumvent this osmotic bottleneck using unwashed human hair collected from professional salons. We compared the degradation efficiency of a syntrophic Effective Microorganisms (EM) consortium with traditional single-strain inoculants (Trichoderma spp. and Bacillus spp.) in a 16-week co-composting system. Data revealed that the EM consortium displayed superior resilience, sustaining thermophilic sanitation (>45 °C) compliant with US EPA PFRP standards and achieving a Nitrogen Mineralization Rate of 883 mg N kg⁻¹ week⁻¹ (nearly triple the control), resulting in a final N content of 1.41% (14,133 mg kg⁻¹). Crucially, the EM treatment reduced electrical conductivity from a phytotoxic 7.23 mS cm⁻¹ to a tolerable level of 3.82 mS cm⁻¹, a mitigation effect likely mediated by humification-driven ion chelation. This performance suggests a “syntrophic succession” mechanism where initial acidification facilitates subsequent proteolytic attack. The final product presented a high sulfur-to-nitrogen ratio indicative of extensive disulfide bond cleavage. Preliminary economic estimates (~$60 USD ton⁻¹) confirm the process’s viability for decentralized scalability, though future molecular validation is recommended. We conclude that bio-augmentation with metabolically diverse consortia is essential to process chemically treated hair waste, converting a hazardous salon residue into a high-value proteinaceous biofertilizer. Full article

Microbial biofertilizers offer a sustainable alternative to reduce inorganic fertilizer inputs in intensive vegetable production. While rhizobia are traditionally associated with legumes, their co-inoculation with native rhizobacteria for non-leguminous crops like tomatoes remains under-explored. This study aimed to isolate native rhizobacteria compatible with Bradyrhizobium diazoefficiens NE1-65 and evaluate their combined effect on the tomato plant (var. max F1) under reduced inorganic fertilizer rates. From the initial eighteen isolates screened on nitrogen-free media, and solubilization assays of phosphorus and potassium, three isolates (RM-8, RM-17, RM-18) were found compatible with B. diazoefficiens NE1-65. Isolate RM-17 (tentatively identified as Aureimonas sp. based on 16S rRNA gene sequence) was selected for its high K-solubilizing capacity (KSI = 8.60). Then, a 90-day growth trial compared various fertilizer application rates (0, 25, 50, 75, and 100%) with and without the bacterial consortia. The 75% fertilizer rate plus the consortia significantly outperformed the 100% fertilizer rate alone. Specifically, it increased plant height (11.57%), fruit diameter (9.23%), fruit number (53.90%), and fruit weight (16.15%). These findings demonstrate that the RM-17 and B. diazoefficiens NE1-65 consortia can partially substitute inorganic fertilizers while significantly enhancing tomato growth and yield, highlighting its potential application for sustainable tomato production systems. Full article