Microbial proteases represent critical biocatalysts for industrial applications, yet optimizing their production remains challenging. This study isolated and characterized a high-yield protease-producing bacterium from environmental sources and systematically optimized production parameters. Among 124 bacterial isolates screened from six environmental sources, poultry waste exhibited the highest microbial diversity, yielding 63 morphologically diverse isolates. The most potent proteolytic isolate, P15, was identified through 16S rRNA gene sequencing as Bacillus velezensis AZH3S (GenBank accession PX417380), sharing 99% sequence similarity with B. amyloliquefaciens. Initial screening of eight culture media identified glucose-casein-yeast extract medium as optimal, producing 442 U/mL protease activity. Time-course analysis revealed maximum enzyme production at 24h (420 U/mL), with yield coefficients increasing to 480 U/g biomass in late stationary phase. Carbon and nitrogen source optimization demonstrated that starch (470 U/mL) and peptone (480 U/mL) were superior substrates. Response surface methodology employing Box-Behnken design across five variables (starch, peptone, pH, temperature, agitation speed) generated a highly predictive model (R² = 0.99) identifying agitation speed as the most influential parameter. Optimized conditions (9.84g/L starch, 5.46g/L peptone, pH 7.5, 33.1°C, 244rpm) achieved 1160.3 ± 9.20U/mL protease activity, representing a 2.80-fold improvement over initial production. Three-step purification achieved 5.82-fold enrichment with 32.0% yield. The purified enzyme exhibited a molecular mass of approximately 20kDa with exceptional substrate affinity (Km = 0.207 mM, Vmax = 39.8 µmol/min), following classical Michaelis-Menten kinetics.These findings establish a robust bioprocess for industrial-scale protease production with significant biotechnological potential.

Defined microbial consortium with bioremediation potential: atrazine removal, phytotoxicity, and detection of genes involved in herbicide catabolism.

Effects of nutrient forms on the bloom dynamics and phytoplankton community associated with Prorocentrum cordatum.

The electrocatalytic upcycling of NOx species into valuable N-heterocycles presents an attractive route, but it is challenged by complex paths and low catalytic activity. This work reports a highly selective strategy for the electrochemical reduction of NOx to isoxazoles via coupling with 1,3-dicarbonyls, enabled by a Co-Zn dual-atom catalyst (Co-Zn-NC). Interestingly, the system achieves a remarkable Faraday efficiency of 92% for isoxazole and significantly inhibits hydrogen and ammonia production. The unique electronic structure significantly regulates the energy barrier of nitrate reduction reaction and the hydrogen adsorption energy revealed by density functional theory calculations, while obtaining moderate affinity towards hydroxylamine intermediate and isoxazole product illustrated from the adsorption measurements. This strategy demonstrates exceptional universality across various nitrogen sources (NO3 -, NO2 -, NO, NO2), carbon sources (1,3-dicarbonyls), and a series of M-Zn-NC catalysts, establishing a novel paradigm for synthesizing structurally complex N─O heterocycles directly from inorganic nitrogen wastes and creating a new platform for sustainable molecular manufacturing.

Ammonium and N₂O production pathways in quaternary hill-plain groundwater: Evidence from multi-isotope and isotopomer analysis.

Application of optical properties and photocatalytic degradation behavior of N, P-CQDs in organic dyes degradation.

Study on the optimization of enzyme-assisted cold isostatic pressure treatment of soybean meal for efficient fermentation.

Evaluation of ammonium chloride versus urea as nitrogen source for enriching comammox Nitrospira in continuous-flow biofilm reactors

Microwave-coupled molten potassium salt engineering structurally separates boron/nitrogen-biocarbon for signal-amplified multiplexed electrodetection of Cd2+, Pb2+ and Hg2+ micropollutants.

Machine learning-assisted unveiling of aroma modulation by inorganic nitrogen during cider fermentation by Pichia kluyveri.

Establishing genetically stable Escherichia coli for effective myo-inositol production.

Altitude, land use and precipitation regimes drive key factors of lake nitrous oxide emission on large geographic scales.

Aerobic rice systems require efficient nutrient and weed management to sustain productivity, yet complex nitrogen dynamics and severe weed competition often reduce growth and yield. Scientific evidence on the combined effects of integrated nitrogen sources and weed management strategies in aerobic rice remains limited. A two-year split-plot field experiment was conducted during Kharif 2023 and 2024 to investigate the effect of integrated nitrogen and weed management practices on crop growth, soil microbial attributes, and weed density in aerobic rice. The experiment comprised of four levels of nutrient management treatments in main plot, (N1 - 100% STBNR (Soil Test Based Nitrogen Recommendation), N2 - 75% STBNR + 25% nitrogen supplied through FYM (Farm Yard Manure), N3 - 75% STBNR + Soil application of Azotobacter and Azospirillum, and N4 - 75% STBNR + 25% nitrogen supplied through FYM + soil application of Azotobacter and Azospirillum) and four sub plot treatments comprised of Pendimethalin (1 kg/ha) applied one day after sowing followed by bispyribac-sodium at 25 DAS; a stale seedbed (15 DBS) followed by brown manuring plus bispyribac-sodium (25 g/ha) at 25 DAS; a stale seedbed (15 DBS) followed by one hand weeding at 25 DAS; and a weedy check replicated thrice. The results revealed significant interaction between nitrogen and weed management across the pooled years. The treatment, combining 75% STBNR + 25% N through FYM + Azotobacter and Azospirillum with SSB fb 1 HW at 25 DAS, recorded the tallest plants (74.2 cm) and the highest LAI (4.19), statistically at par with the same under SSB fb BM. This treatment also exhibited a notably higher bacterial population and microbial biomass, indicating improved soil biology and nutrient availability. The lowest weed density was observed in 75% STBNR +25% nitrogen through FYM with SSB fb BM (7.15 no./m²), which was at par with 75% STBNR +Azotobacter and Azospirillum with SSB fb BM. Plant height, and LAI showed significant positive correlations with bacterial population and microbial biomass carbon and negative correlations with total weed density and weed biomass, whereas weed indices strong positive relationships with weed density and biomass.

Achromobacter is commonly associated with the production of glycolipid biosurfactants, which are sought after for diverse applications in biomedical and environmental fields. Given the increasing demand for biosurfactants, this study focuses on optimizing culture conditions, characterizing the biosurfactant product, and examining its potential application for enhanced motor oil removal from contaminated sand. The study was conducted using minimal salt medium (MSM), and the one-factor-at-a-time approach was used to vary incubation time, carbon source, nitrogen source, and carbon-nitrogen ratio (C/N). The biosurfactant was acquired through chloroform: methanol: acetone extraction and subsequently characterized using TLC, FTIR, GC-MS, and LC-MS. Biosurfactants at various concentrations were used to examine motor oil removal ability at 24 h of incubation. The best conditions for biosurfactant production involve glucose as the carbon source and yeast extract as the nitrogen source at a C/N ratio of 6/1, pH 7, temperature 30°C, and 72 h of incubation. The biosurfactant product was identified as a rhamnolipid-like glycolipid with a carbon chain ranging from C8 to C16. To the best of our knowledge, this is the first report describing a C16-dominant rhamnolipid-like glycolipid from A. xylosoxidans BP (1)5. At critical micelle concentration (CMC), the biosurfactant showed potential for removing motor oil from contaminated sand, achieving a removal rate of 91.80%. This study provides a basis for designing large-scale fermentation processes for biosurfactant production and highlights its potential application.

Ammonia present in the environment is a major source of nitrogen, but it can be toxic to bacteria. While the biochemical mechanisms involved in the metabolic detoxification of cellular ammonia are well understood, little is known about how bacteria manage toxic external ammonia to survive, especially when ammonia is present as a waste product at high concentrations. Here, we demonstrate that a two-component system consisting of the sensor kinase GrtK and the response regulator GrtR is responsible for sensing and neutralizing toxic environmental ammonia produced as a waste product by the rice pathogen Burkholderia glumae. The growth of null mutants of grtK or grtR was inhibited in amino acid-rich media such as Luria-Bertani medium, but no growth inhibition was observed in amino acid-free media. The expression of obcAB, responsible for the biosynthesis of the previously known neutralizing agent oxalate, was dependent upon external ammonia concentration in a GrtR-dependent manner. Significant changes in fluorescence were observed when cells of B. glumae carrying a recombinant plasmid of the modified circular permutation GFP gene fused to grtK were incubated with compounds containing ammonium, suggesting that GrtK interacts selectively with external ammonia. Transcriptome analysis of grtK and grtR mutants also showed that GrtK and GrtR are involved in the metabolic detoxification of cellular ammonia as well. These results indicate that GrtK is an external ammonia sensor that is not a member of the ammonia transporter protein family and works together with the response regulator GrtR to counter the risk posed by its own metabolism.IMPORTANCEExcessive accumulation of external ammonia, resulting from the deamination of amino acids used as carbon sources, can be toxic to bacteria. However, there is a limited understanding of how bacteria sense toxic environmental ammonia and how this sensing is translated into outputs that regulate gene expression to avoid toxicity. We found a previously unknown bacterial two-component system composed of GrtK and GrtR responsible for sensing and neutralizing toxic environmental ammonia. Understanding how pathogenic bacteria modify their toxic environment for survival can aid in the development of appropriate treatments and provide drug targets to control pathogens. Our findings suggest that GrtK and GrtR could be potential targets for drug development to control rice panicle blight caused by B. glumae.

Fomes fomentarius is a medicinal mushroom from the Northern Hemisphere, recognized for its therapeutic and biotechnological applications. In contrast, tropical Fomes species remain poorly characterized, and information on their properties and cultivation is limited. We evaluated the biotechnological potential of the Neotropical species Fomes fasciatus. Four strains from Paraguay were isolated and assessed for growth on solid media, using both potato dextrose agar and oat seeds, and for indoor basidiomata production using a sawdust-based substrate. The strain showing the best performance on solid media was further evaluated for mycelial growth and exopolysaccharide production in liquid culture. Additionally, the nutritional and mineral composition of wild and cultivated basidiomata and mycelium was analyzed. Fomes fasciatus optimal growth on solid media was observed at approximately 32 °C, with no significant differences in basidiomata yield across strains under indoor cultivation. Successful domestication was achieved for three of the four strains studied. Exopolysaccharide production remained statistically unaffected by elicitor supplementation (i.e., CaCl2 or Tween 40) or variation in carbon and nitrogen sources of the liquid media. In contrast, mycelial biomass was significantly higher in the basal medium than in modified treatments. The wild and domesticated basidiomata and mycelium exhibited high protein content, a balanced amino acid profile, dietary fiber, and unsaturated fatty acids, along with essential macroelements such as zinc. These findings highlight that F. fasciatus is a promising medicinal mushroom species with potential for indoor cultivation, characterized by fast mycelial growth and valuable nutritional and bioactive properties. © 2026 Society of Chemical Industry.

Oxygen-dependent dynamics of metformin biodegradation at the sediment-water interface and non-additive effects on prokaryotic communities.

Nitrogen use efficiency is one of the sustainability criteria which get altered as a response to varied interventions like water conservation practices and source of nitrogen in rainfed agriculture. A two-year’ investigation was conducted to evaluate in-situ moisture conservation practices and different nitrogen sources for nitrogen uptake and NUE in rainfed sorghum on alfisols of the semi-arid region of India. The experiment was laid out in a split plot design replicated thrice. Main plot treatments were in-situ moisture conservation practices like conservation furrow (CF) and ridge and furrow (RF), while sub-plot treatments were different nitrogen sources like chemical fertilizers, farmyard manure (FYM), vermicompost (VC) and poultry manure(PM). Diverse agronomic indices viz., recovery efficiency, physiological efficiency, agronomic efficiency and partial factor productivity were derived to assess the NUE. The results demonstrated that CF and RF methods of in-situ moisture conservation exhibited equal response pertaining to N uptake, Soil N and nitrogen use efficiency. However, nitrogen uptake was higher through partial substitution of the recommended dose of nitrogen with PM (67.8 kg ha-1), FYM (63.8 kg ha-1) and VC (63.9 kg ha-1) along with synthetic fertilizers in integration. Soil fertility in the form of mineral N (NH4-N + NO3-N) was improved by combined use of chemical and organic sources of N. Higher crop recovery efficiency, physiological efficiency, agronomic efficiency and partial factor productivity were higher with inclusion of organic manures, especially in integrated manner. The experimental findings suggested that, in rainfed sorghum cultivation in semi-arid tropic of India, conjunctive use of 75% RDN through synthetic fertilizer and 25% RDN through PM or FYM or VC along with conservation furrow or ridge and furrow practice could be adopted for improved NUE.

Electrochemical urea (CO(NH2)2) synthesis using CO2 and available nitrogen sources is an alternative method featuring reactant sustainability and an overall energy efficiency. However, sluggish catalytic reaction kinetics for available electrocatalysts led to poor yield rates of urea production, seriously hindering its practical applications, because of the low density of reactant species and electric fields surrounding active sites. Herein, a new class of ordered multidimensional interfaces for electrocatalysts is discovered to enrich the local reaction fields surrounding active sites, thereby facilitating reaction kinetics for urea synthesis with ultrahigh yield rates. Using Cu-based electrocatalysts as a proof of concept, one-dimensional (1D) Cu2O nanowires were uniformly aligned along the 3-fold symmetry of two-dimensional (2D) Cu2Se (111) facets through in situ electrochemical epitaxial growth. This unique structure allows for accumulation of gas flows, electric fields, and species concentrations due to the interface confinement effect from multidimensions. Our Cu2O/Cu2Se interfaces yield a high current density, with a Faraday efficiency (FE) of 61.5% and a production rate of 0.96 mg h-1 in half cells, representing the highest reported values. Moreover, the designed membrane electrode assembly (MEA) coelectrolysis device demonstrates effective urea synthesis and plastic upcycling for practical applications. Enriching local reaction fields via ordered multidimensional interfaces can enable new strategies for designing efficient electrocatalysts and promoting reaction kinetics for practical applications.

Synthetically primed growth of Pseudomonas putida on 2,4-dinitrotoluene as sole carbon and nitrogen source.