Search Results (2,340)

Climate change has intensified the occurrence of biotic and abiotic stresses, representing a major threat to agricultural productivity. This climate variability, coupled with the excessive use of agrochemicals, not only compromises environmental sustainability but also exacerbates food insecurity, directly affecting food availability and quality. In this context, biotechnological strategies have proven essential for mitigating the effects of stress on plants, promoting practices focused on agricultural sustainability. Notable among these strategies is the use of plant growth-promoting microorganisms, which are emerging as promising alternatives capable of improving plant tolerance to stress conditions and simultaneously reducing dependence on agrochemicals. These microorganisms can act as nitrogen fixers and solubilizers of nutrients, such as phosphorus and potassium. Additionally, they can influence plant immune responses by inducing systemic resistance and promoting the synthesis of phytohormones, such as auxins, cytokinins, and abscisic acid, which support plant development during the stress response. The interaction between plants and microorganisms represents a sustainable agricultural management strategy capable of enhancing crop tolerance to environmental adversities. In this review, we discuss the microorganisms known to establish beneficial interactions with plants, leading to improved performance under biotic and abiotic stress. Overall, this work highlights the potential of plant–microbe partnerships as a cornerstone for advancing sustainable agriculture in the face of global challenges. Full article

Nucleation remains one of the least understood steps during protein crystallization, although it strongly impacts product quality attributes, including total crystal numbers, final crystal size distributions, and thus downstream processing. In this work, the nucleation behavior of Lactobacillus brevis alcohol dehydrogenase (LbADH) wild type (WT) and five mutants (Q207D, Q126H, K32A, D54F, and T102E) is investigated in a stirred 7 mL crystallizer monitored by in situ multi-angle dynamic light scattering (MADLS). Nucleation was studied with highly pure homotetrameric LbADHs by establishing a crystallization, lyophilization, and re-solubilization protocol combined with size exclusion chromatography (SEC) and size exclusion high-performance liquid chromatography (SE-HPLC), yielding tetramer purities above 94% and removing low molecular weight impurities. During stirred batch crystallizations initiated by the addition of polyethyleneglycol 550 monomethyl ether (PEG 550 MME), SEC and SE-HPLC revealed decreasing tetramer peak areas but essentially constant peak apex positions, indicating that no long-lasting oligomeric intermediates accumulate at detectable levels. Time-resolved MADLS measurements using a custom-made flow-through cuvette in a bypass to the stirred crystallizer uncovered transient cluster populations. All protein variants exhibited an initial tetramer peak, followed by the formation of larger aggregates and a rapid rise in signal above a hydrodynamic diameter of 1000 nm, coinciding with the onset of macroscopic turbidity. A simple mesoscale nucleation model was formulated, yielding end-of-nucleation times, crystallized fractions, critical soluble concentrations, and apparent nucleation rate constants. The crystal contact mutations modulate both the timing and magnitude of the nucleation burst (rapid build-up of nuclei/cluster populations). The mutant Q207D showed strongly attenuated nucleation compared to the WT, whereas the other mutants (K32A, D54F, and particularly T102E) display markedly accelerated nucleation at nearly invariant critical concentrations. The combined workflow demonstrates how in situ MADLS, together with a tailored kinetic description, can provide mechanistic insight into protein nucleation in stirred batch crystallizers. Full article

Strain 11B20 was isolated from a commercial field of maize (Zea mays L.) located in the Yaqui Valley, Mexico. The draft genome sequence revealed a genomic size of 3,759,824 bp, 41.6% G + C content, 973,288 bp N50, 2 L50, and 29 contigs. According to the 16S rRNA gene, strain 11B20 belongs to the genus Bacillus. Genome annotation revealed 3952 coding DNA sequences (CDSs) grouped into 319 subsystems. Among these, several CDSs were associated with traits related to plant growth promotion, including (i) virulence, disease, and defense (33 CDSs); (ii) iron acquisition and metabolism (28 CDSs); and (iii) secondary metabolism (6 CDSs), among others. In vitro, metabolic analysis (IAA, siderophore biosynthesis; phosphorus solubilization; and tolerance to thermal, hydric, and saline stress) confirmed the genomic background of this strain. Finally, in planta assays showed that the inoculation of Bacillus sp. 11B20 significantly (p ≤ 0.05) increased the root length (48.2%) and root dry weight (35.4%) versus non-inoculated maize plants. Thus, this is the first report of Bacillus sp. 11B20 as a promising beneficial strain for sustainable corn production, and further research is needed to ensure the success of the application of this strain in agriculture. Full article

Plants are sessile organisms and are constantly subjected to varying environmental stressors. However, they can mitigate the effects of these stresses by deploying plant growth-promoting (PGP) microbes for their protection. PGP microbes can boost plant growth and enhance plant protection from biotic and abiotic stresses through a wide variety of mechanisms. PGP mechanisms such as biological fixation of nitrogen in soil and plant roots, phosphate solubilization, siderophore production, ACC (1-aminocyclopropane-1-carboxylic acid) deaminase enzyme activity, and production of plant hormones to promote nutrient acquisition and mitigate stresses. Therefore, this review aims to document studies that reported on the role of PGP microbes in plant growth and development and how PGP traits mentioned above and a novel trait flavins (FLs) secretion help plants against biotic and abiotic stress. Several important PGP functions, and the bacterial strains involved in these functions, that can potentially improve plant growth, development, and plant health are reviewed. This review will help to identify gaps for future studies and guide the development of an alternative strategy to use PGP microbes as biofertilizers and biocontrol agents to support eco-friendly agriculture by reducing the indiscriminate use of synthetic agrochemicals. Full article

Phosphate-solubilizing bacteria (PSB) are pivotal in the cycling of phosphorus within terrestrial ecosystems and hold great promise for sustainable agriculture. In this study, we report the isolation of HRY1—a highly efficient phosphate-solubilizing strain—identified as Escherichia coli, a bacterium not traditionally recognized for plant-beneficial traits. Under optimized conditions (glucose as carbon source, (NH₄)₂SO₄ as nitrogen source, pH 7.0, 1% inoculum, and 5 g/L Ca₃(PO₄)₂), HRY1 consistently solubilized ~16% of inorganic phosphorus, with peak activity coinciding with its stationary growth phase (14 h). Whole-genome sequencing revealed a comprehensive genetic toolkit for phosphorus mobilization, including eight genes implicated in organic acid-mediated mineral dissolution, five high-affinity phosphate transporter genes (pit and pst gene cluster), and three two-component regulatory systems responsive to phosphate starvation (e.g., phoBR). The functional integration of these systems suggests a multifaceted strategy combining acidification, active uptake, and adaptive regulation to thrive under phosphorus limitation. Our findings redefine the ecological scope of E. coli and uncover an unconventional yet potent PSB candidate with significant potential for biofertilizer development and soil phosphorus activation. This discovery reveals E. coli’s untapped potential for phosphorus solubilization, with HRY1’s novelty residing in its high efficiency under optimized conditions and its practical promise as a biofertilizer. Full article

Quinoa (Chenopodium quinoa) is a promising source of plant proteins with the potential to produce bioactive peptides through enzymatic hydrolysis. This study aimed to extract quinoa protein and produce bioactive peptides using two microbial proteases: Alcalase (from Bacillus licheniformis) and Flavourzyme (from Aspergillus oryzae). The protein was extracted through alkaline solubilization and isoelectric precipitation, achieving a 72% yield. Hydrolysis was conducted for 4 h, and enzymatic activity was measured using the TNBS method to determine the degree of hydrolysis, while SDS-PAGE was used to analyze protein breakdown. The reaction was performed at controlled pH and temperature (Alcalase: 9.5 and 55 °C; Flavourzyme: 7 and 37 °C). Both enzymes achieved maximum hydrolysis at 60 min. Consequently, the separation and inhibitory capacity of angiotensin-converting enzyme (ACE-I) were tested at the first four time points (0, 20, 40, and 60 min). A wider variety and higher concentration of peptides smaller than 2 kDa were found in hydrolysates treated with Flavourzyme, which is associated with antihypertensive activity. The ACE-I assay showed greater activity at the end of hydrolysis. Inhibition percentages of 87.5 ± 2.11 were observed in hydrolysates with Flavourzyme, and 94.1 ± 1.11 in those with Alcalase. These findings indicate that quinoa protein, hydrolyzed with microbial proteases, is a feasible source of peptides with potential antihypertensive effects for use in functional foods and nutraceuticals. Full article

The sustainable conversion of agricultural waste biomass, particularly crop residues such as corn stover, into high-value products is vital for reducing their open-field burning and mitigating environmental hazards. The hydrothermal carbonization (HTC) process integrated with natural deep eutectic solvents (NADES) presents an alternative approach for valorizing biomass into lignin-rich solid fuels and fermentable sugars for bioethanol production. In this study, corn stover was subjected to HTC using deionized (DI) water, a xylose-based NADES (ChCl:Xy:W), and an oxalic acid-based NADES (ChCl:OA:W) in a 150–300 °C temperature range to optimize both solid fuel and sugar stream yields. Characterization, including fiber analysis, SEM, FTIR, EDS, and bomb calorimetry, was conducted to evaluate structural, compositional, and energetic transformations. The results explored the HTC process, restructuring the biomass, promoting extensive hemicellulose solubilization and cellulose depolymerization, as well as substantially enriching lignin and polymerized compounds with increasing temperature. In addition, the DI water at 300 °C generated a lignin-rich residue, the Xy-based NADES effectively removed ash and extractives, and the OA-based NADES produced the most carbon-dense hydrochar with the highest calorific value. Collectively, these findings demonstrate that solvent-assisted HTC may be employed as a possible strategy for the valorization of agricultural residues into high-energy solid fuels. Full article

Phytophthora blight, caused by Phytophthora capsici, an oomycete pathogen belonging to the phylum Oomycota, is a major soil-borne disease that limits the cultivation of pepper (Capsicum annuum). In this study, the bacterium Serratia plymuthica MM was evaluated for both its antagonistic ability and plant growth-promoting (PGP) potential. The sterile fermentation filtrate of S. plymuthica MM exhibited strong antifungal activity in vitro, inhibiting the mycelial growth of P. capsici by up to 88.32%. In pot experiments, Serratia plymuthica MM significantly reduced both disease incidence and disease severity of Phytophthora blight in pepper plants, achieving control efficacies of 88.33% (preventive application) and 55.56% (therapeutic application). Microscopic observations revealed severe hyphal abnormalities, including distortion, shrinkage, collapse, and fragmentation. Furthermore, propidium iodide (PI) and DAPI double staining provided cellular-level evidence of antifungal activity, demonstrating concentration-dependent disruption of membrane integrity and nuclear organization in P. capsici hyphae, which was supported by pronounced increases in ion leakage from pathogen cells. Further, S. plymuthica MM exhibited PGP traits, including nitrogen fixation, phosphate solubilization, siderophore production, and indole-3-acetic acid (IAA) synthesis. Pot experiments using the pepper cultivar ‘Longjiao’ (Capsicum annuum L. cv. Longjiao) confirmed significant growth promotion and enhanced activities of key defense-related enzymes (POD, PPO, PAL, and CAT). Stable colonization of pepper roots was verified by green fluorescent protein (GFP) labeling, demonstrating the strain’s persistence in the rhizosphere. Collectively, these results highlight the dual role of S. plymuthica MM in suppressing P. capsici and promoting pepper growth, supporting its potential as an eco-friendly biocontrol agent for sustainable pepper production. Full article

Ionic liquids (ILs) and deep eutectic solvents (DESs) have emerged as effective solvents for poorly soluble materials such as natural polysaccharides, including chitin. This review describes recently developed efficient chitin derivatization methods that harness the solubilizing power of ILs and DESs. It covers chitin acylation approaches, including acylation and mixed ester formation, as well as chitin etherification protocols. For example, the ILs 1-allyl-3-methylimidazolium bromide (AMIMBr) and 1-allyl-2,3-dimethylimidazolium bromide serve as effective media for chitin acylation and etherification, respectively, yielding single esters and benzyl derivatives with high degrees of substitution (DS). The use of DESs comprising AMIM chloride (AMIMCl) as a hydrogen bond acceptor and several hydrogen bond donors for chitin acylation are presented. In an optimized system, acylation using acyl chlorides proceeded smoothly without additives, such as a base/catalyst, in a DES comprising AMIMCl and 1,1,3,3-tetramethylguanidine, affording high-DS ester derivatives. The method was extended to the synthesis of mixed chitin esters bearing both long and bulky acyl substituents at appropriate substitution ratios, which exhibit thermoplasticity. Full article

Olive trees cultivated in the Viseu region (Portugal) were used in the present work. This study investigates the compositional characteristics and hydrothermal behavior of olive branches (OB) and olive leaves (OL) under autohydrolysis, aiming to assess their potential for biorefinery applications. Chemical analysis revealed that during autohydrolysis (140–180 °C, 15–30 min), OL exhibited greater solubilization than OB, consistent with their higher extractive content. Increasing the temperature promoted selective hemicellulose removal and partial cellulose degradation, leading to a relative enrichment of lignin in the solid residues. Nevertheless, the cellulose content of olive branches for 180 °C and 30 min hydrolysis increased. Fourier transform infrared spectroscopy confirmed progressive structural rearrangements, including enhanced hydroxyl exposure, carbonyl formation, and lignin condensation, indicating the transformation of the solid phase toward more aromatic and thermally stable structures. Autohydrolysis slightly increased the higher heating value of the solid residues while acid-catalyzed liquefaction markedly increased, exceeding those of both native and technical lignins. These results suggest extensive carbon enrichment and oxygen removal during liquefaction. Overall, autohydrolysis proved effective for hemicellulose solubilization and sugar recovery, while liquefaction favored energy densification and lignin condensation. The distinct behaviors of OB and OL highlight the importance of tailoring processing conditions to each feedstock type. Both materials show strong potential as renewable resources for bioenergy and value-added carbon-based products within an integrated olive biomass biorefinery framework. Full article

Buprenorphine (BUP) is widely used in the treatment of neonatal opioid withdrawal syndrome (NOWS). However, the most compounded formulation contains 30% ethanol, despite regulatory and clinical concerns regarding ethanol exposure in pediatric patients. Thus, this research aimed to develop an ethanol-free sublingual (SL) gel formulation of BUP that would be safe, stable, and suitable for NOWS. Multiple polymers were screened as gelling agents, with hydroxypropyl methylcellulose (HPMC) emerging as the ideal base polymer for the formulation due to its optimal pH, rheological characteristics, and stability. The formulated gels were stored at room temperature and refrigerated conditions for 30 days and evaluated for stability using pH, rheology, and liquid chromatography-mass spectrometry. BUP content was between 90–110% of the labeled amount of the dosage form (75 µg/mL) at all time-points, and the pH remained close to physiological values. Release studies demonstrated a drug release of 23–24% for SL gels without surfactants stored at room temperature and refrigerated conditions, respectively. Incorporation of non-ionic surfactants (Tween 20 and Tween 80) significantly increased drug release to 33% and 40%, respectively, reflecting enhanced solubilization and improved mucosal penetration. The ethanol-free formulation demonstrated physicochemical stability and favorable release characteristics suitable for neonatal administration. These findings represent a meaningful advance in the development of safer pediatric formulations for NOWS. Full article

The transformation pathways of organic carbon (OC) fractions and their interrelationship with microbial activity during natural composting (NC) and vermicomposting (VC) remain poorly understood across pig manure (PM)/straw pellets (SP) ratios. Therefore, the objective of this study was to elucidate the regulatory mechanisms of substrate mixing ratios on carbon fraction transformation and microbial functional networks during these processes. To achieve this, five PM/SP ratios [100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4), and 0:100 (T5)] were composted with or without earthworms, revealing the T2 (75:25) ratio had most efficient composting performance within 60 days due to the suitable initial C/N ratio (31.65 ± 0.99). Consequently, the T2 treatment reached the highest organic degradation, including TOC reduction (58.6%), TN accumulation (63.9%), and C/N decline (74.8%) in the VC. Vermicomposting markedly stimulated functional microbial groups—nitrogen-fixing, phosphate-solubilizing, and potassium-solubilizing bacteria—thereby enhancing nutrient (N, P, K) bioavailability. The prominence of the optimal C/N ratio across multiple hydrolytic and oxidative enzymes in the VC-T2 further proved that this ratio provided an optimal nutrient and structural balance for both earthworms and microbial consortia. Strong correlations between bacterial abundance and enzyme activities (r ≥ 0.98), lignin and dissolved OC (r ≈ −0.81), and particulate organic carbon and mineral-associated carbon (r > 0.9) highlighted microbially mediated carbon stabilization through enzymatic mineralization, aggregation, and redistribution of carbon from active pools toward mineral-associated OC. This work identifies the critical PM-SP ratio for waste valorization and mechanistically links earthworm–bacteria interactions to carbon sequestration pathways. Full article

This study presents the first characterization of the globulin fraction from a newly registered chickpea cultivar, which represents the first desi-type cultivar (GB Cappuccino) released in Brazil. Although desi chickpeas are widely consumed in other countries, they have not been part of the Brazilian dietary pattern, and this introduction may represent an opportunity for changing this scenario. Characterizing its proteins is essential, given that legumes are recognized as important protein sources. In this study, globulins were confirmed as the predominant protein fraction, with the legumin-like fraction accounting for more than 80% of the total globulins. Its electrophoretic and amino acid profiles were highly distinctive and strongly influenced by this major fraction. In addition to the expected solubilization in saline solution, under in vitro pepsin–pancreatin digestion conditions designed to assess maximum hydrolysis potential, the globulin fraction was partially hydrolyzed, indicating a degree of protein digestibility while simultaneously releasing peptides that exhibited antioxidant activity and angiotensin-converting enzyme (ACE) inhibitory potential. Overall, these results highlight the nutritional relevance of this new cultivar and, based on the preliminary bioactivity screening performed, suggest that its globulin-rich protein composition may represent a promising source of bioactive peptides. Full article

Oxalic acid is a key root exudate released by plants under phosphorus (P) deficiency and plays a direct role in solubilizing fixed soil P. However, its specific effects on soil microbial community assembly and ecological functions remain less clear. In this study, based on an ex planta soil microcosm incubation experiment, the impacts of oxalic acid input on soil bacterial and fungal community assemblage and functional profiles involved in P mobilization were explored. The results showed that oxalic acid input significantly changed soil bacterial and fungal community composition, decreased their diversity, and enriched bacterial taxa involved in P mobilization and fungal taxa associated with plants, showing the selective effects of oxalic acid on soil microorganisms. Further community assembly analyses (βNTI and NST) showed that oxalic acid input promoted a shift in bacterial community from a stochastic-process-dominated community to a deterministic-process-dominated community, while the fungal community exhibited a converse pattern. These findings reveal the important role of oxalic acid in shaping soil microbial community assembly and ecological functions under P deficiency, broadening our understanding of the role of oxalic acid in plant responses to low-P stress. Full article

Cyclodextrins (CDs) are cyclic oligosaccharides composed of α(1 → 4) linked glucose units, which are widely used as solubilizers and stabilizers in the food, pharmaceutical and cosmetic industries. Among the CDs, γ-CD has attracted much attention due to its larger hydrophobic cavity and higher solubility. However, the industrial production of γ-CD is limited by lack of suitable enzymes and production process shortcomings. In this study, various strategies of improving heterologous enzyme production and optimization of the starch conversion process were applied to increase the production of γ-CD. A γ-cyclodextrin glucanotransferase with good product specificity from Bacillus sp. FJAT-44876 (BFγ-CGTase) and a liquefying β-CGTase from Bacillus sp. 1011 (Bsβ-CGTase) were successfully secreted by Pichia pastoris. After codon optimization and using the one-factor-at-a-time (OFAT) principle to improve the fermentation, the yield of recombinant BFγ-CGTase was increased 13.3 times to 463 U/L. Next a process was established involving Bsβ-CGTase-assisted starch liquefaction and simultaneous pullulanase debranching and BFγ-CGTase production of γ-CD. The yield of γ-CD increased by 17.67% via optimizing the amounts of BFγ-CGTase and BtPul used for the reaction. Overall, combination of the various improvements provided a new process for efficient preparation of γ-CD. Full article