Increased groundwater recharge under climate change will enhance nitrogen fixation in groundwater-dependent ecosystems.

Pseudogymnoascus destructans (Pd), the causative agent of bat white-nose syndrome, persists in cave soils and acts as a chronic source of infection, yet the environmental processes governing this reservoir remain unclear. We performed seasonal sampling of bat cave soils in Northeast China and combined metagenomic, untargeted metabolomic and physicochemical analyses to identify drivers of Pd loads. Pd abundance tracked strong seasonal gradients in temperature, soil water content, electrical conductivity and nitrogen availability. The microbial community structure exhibited pronounced seasonal variation, primarily associated with pH, and was governed predominantly by stochastic ecological processes. Nitrogen-cycling genes showed a switch from nitrogen fixation and nitrification in summer to denitrification and nitrate reduction in winter. Antibiotic resistance genes and mobile genetic elements covaried with core bacterial taxa, while antifungal metabolites such as tetracycline, glycitin and chrysin were positively associated with putatively antagonistic genera (e.g., Rhodanobacter, Pseudomonas, Streptomyces, and Bacillus), indicating a microbe-metabolite defence network. Structural equation modelling revealed a temperature-driven cascade linking nutrient cycling, microbial communities, metabolite profiles and Pd loads. Our results show that seasonal dynamics of Pd in cave soils emerge from interactions between climate-regulated soil processes and microbe-metabolite feedbacks, with implications for environmental control of pathogenic fungi.

Characterising complex metabolic responses in an engineered, cross-feeding microbial co-culture using quantitative proteomics.

Root nodules host nitrogen-fixing bacteria and likely evolved through modifications of the lateral root program. Members of the NOOT-BOP-COCH-LIKE transcriptional coregulator family suppress root identity in nodules and plant hormones play key roles in nodule organogenesis, but the interaction between these pathways is unclear. In this study, we investigate how COCH regulates nodule identity through crosstalk with plant hormones, using the Pisum sativum cochleata (Pscoch) mutant - which forms root-nodule hybrids - in combination with hormone biosensors, double mutants, hormone quantification, and RNA-seq analysis. We found that COCH suppresses cytokinin levels and response during nodule formation. By contrast, PsCOCH promotes auxin accumulation and precise auxin response patterning in nodules. Mutant coch developing nodules have gene expression profiles more similar to that of root primordia, with increased expression of defence and auxin response genes and reduced expression of cytokinin biosynthesis genes compared to wild-type. We found gibberellin is unlikely to act downstream of PsCOCH. Constitutive expression of PsCOCH also produces root-nodule hybrids and we found intriguing links between the autoregulation of nodulation pathway and PsCOCH. We show that PsCOCH is required for spatial tight regulation of auxin and cytokinin during nodule organogenesis and identify key hormone and signalling genes that act downstream of COCH.

Soil microbial communities play a pivotal ecological role in contaminated environments. However, conventional metagenomic approaches struggle to distinguish between "potential function holders" and "in situ metabolically active executors". Here, we employed a method combining fluorescent d-amino acid labeling, fluorescence-activated cell sorting, and metagenomics (FDAA-FACS-Metagenomics) to capture and profile active microbes in complex soils. The secondary addition of As(V) and Sb(V) enhanced the community's reductive activity toward these metalloids, reshaping the active assemblages. Clostridium was markedly enriched, and several low-abundance members were activated as true executors of the reduction process. MAGs recovered via FDAA-FACS revealed an active core community with functional partitioning: some taxa participated directly in As(V)/Sb(V) reduction, while others contributed to community stability through tolerance and metabolic support. Notably, a Desulfitobacteriaceae genome (MAG29) harbored both arrAB and anrAB gene clusters, a complete Wood-Ljungdahl carbon fixation pathway, and nitrogen fixation genes. These genomic features suggest the potential for a multifunctional metabolic lifestyle involving metalloid reduction, carbon fixation, and nitrogen transformation. Such metabolic versatility may enable MAG29 to contribute to coupled carbon-nitrogen cycling and metalloid transformation under contaminated environmental conditions. These findings emphasize the important ecological roles of rare, metabolically active microbes in metalloid transformation and soil ecosystem functioning.

Emerging trends in photocatalytic nitrogen fixation and nitrate reduction using MOF & COF-based catalysts: Recent progress and future perspectives

Deconvoluting electrostatic, noncovalent, and magnetic effects of iron-sulfur cofactors inside synthetic cage frameworks.

Regulating nitrogen activation and proton supply to boost photocatalytic nitrogen fixation via Co-ZnO/ MIL-125(SH)2 S-scheme heterojunction

Towards global estimates of reservoir nitrogen fixation: insights from machine learning.

Enhancing nitrogen conservation in aerobic composting through microbial and material interventions: Implications for carbon neutrality.

We report the complete genome sequence of Enterobacter vonholyi strain IBGEEm25P6, an endophyte isolated from wheat seeds. The 4.7-Mb genome is predicted to encode diverse biosynthetic genes putatively associated with nutrient metabolism and antifungal activity, including genes predicted to be involved in nitrogen fixation.

Nitrogen pollution represents a critical challenge in the 21st century, highlighting the urgent need for sustainable alternatives to industrial nitrogen fixation. Diazotrophic bacteria, which uniquely convert dinitrogen (N2) into bioavailable forms, offer a promising solution through biological nitrogen fixation (BNF). These bacteria typically perform nitrogen fixation under nitrogen-limited conditions. Over the past 50 years, extensive research has elucidated the molecular mechanisms and regulatory pathways governing BNF. Recent microbiome studies have revealed that wild rice accessions harbor a greater abundance of diazotrophic bacteria, whereas a substantial proportion of these beneficial microbes have been lost in modern cultivated varieties. Advancements in synthetic biology have enabled the engineering of nitrogen‑exporting diazotrophs, potentially reducing dependence on industrial nitrogen fertilizers. This review emphasizes the importance of targeted research to develop customized diazotrophic microbes in conjunction with synthetic microbial community that can serve as nitrogen exporters for rice. Furthermore, it highlights the necessity of identifying rice cultivars that are particularly responsive to these microbial interventions. Finally, it provides a comprehensive roadmap addressing key challenges and opportunities in deploying BNF to supplement plant nitrogen nutrition and advance sustainable agriculture.

Biodegradable polylactic acid microplastics affect nutrient cycling during the entire crop growth cycle: Implications for soil ecosystem multifunctionality.

Despite more than eighty years of study, the selective agents driving local adaptation largely remain unknown, in part because populations exist in complex environments where they experience both abiotic and biotic conditions that can exert strong selection. We used a replicated reciprocal transplant experiment combined with a greenhouse inoculation experiment to investigate plant adaptation to soil moisture and the role of nitrogen-fixing rhizobium mutualists in plant local adaptation. We find that the annual legume hog peanut (Amphicarpaea bracteata) is locally adapted to soil moisture conditions and that interactions with nitrogen-fixing rhizobia likely contribute to the observed local adaptation. Specifically, plant populations from wet sites transplanted into wet habitats were more likely than those from dry sites to associate with rhizobium mutualists and formed more nodules and had higher nitrogen fixation rates when inoculated with rhizobium strains isolated from wet compared to dry habitats. As a result, local adaptation to wet environments was most apparent when plants successfully associated with rhizobia in the field. In sum, our results suggest that: 1) soil moisture is a strong cause of local adaptation in this system and 2) divergence in how plant populations interact with rhizobia likely contributes to plant local adaptation to soil moisture. These findings illustrate how biotic interactions can influence plant adaptation to a strong abiotic gradient and highlight the need to consider microbial mutualists in studies of plant local adaptation.

This work pioneers in photohydrogenotrophic cultivation of Rhodobacter capsulatus in an open, non-axenic bubble column reactor to maximize biomass productivity and selectivity for purple non-sulphur bacteria. Using full-spectrum light and non-limiting ammonium levels, biomass productivity reached up to 0.98 gTSS L-1 d-1. To enhance microbial selectivity, two operational strategies were tested: (i) alternating of full light spectrum exposure and infrared light which increased pigment production (15 ± 1 mg bacteriochlorophyll gVSS-1 and 4.7 ± 0.5 mg carotenoids gVSS-1) and protein content (0.78 ± 0.22 g protein gVSS-1) while minimizing microalgae content and (ii) ammonium limitation that stimulated the biological nitrogen fixation capability of purple non-sulphur bacteria, resulting in the highest purple non-sulfur bacteria abundance, representing up to 96% of the prokaryotic community, without compromising on productivity. These results demonstrate the feasibility of open culture photohydrogenotrophic cultivation, offering a stepstone to scalable and ecologically aligned alternative for microbial protein production for food and biobased applications.

Although alfalfa is capable of nitrogen fixation, the optimal nitrogen (N) application rate for jujube-alfalfa intercropping systems in arid oasis regions remains unclear. This study evaluated four N application rates (0, 80, 160, and 240kg/ha) to determine their effects on alfalfa photosynthesis, yield, and quality. Measurements of gas exchange and chlorophyll fluorescence revealed that the 160kg/ha treatment (N2) significantly enhanced photosynthetic performance, particularly at the early flowering stage-a critical period when peak photosynthetic activity directly governs biomass accumulation and final yield. At this stage, the net photosynthetic rate (Pn) in the first and second harvests increased by 31.1% and 42.8%, respectively, while the photosynthetic performance index (PIabs) improved by 37.7%-102.2%. Compared with the unfertilized control, the N2 treatment significantly increased fresh forage yield by 23.8%-45.8% and dry matter yield by 18.4%-29.7%; crude protein content rose by up to 9.6% in the second harvest. Yield was significantly positively correlated with Pn, transpiration rate (Tr), the maximum photochemical efficiency of PSII (Fv/Fm), and PIabs. In conclusion, a nitrogen application rate of 160kg/ha is recommended to maximize alfalfa yield and quality in this intercropping system.

Photoelectrochemical nitrogen (N) fixation to ammonia (NH3) is a sustainable route for hydrogen storage yet limited by the stubborn N≡N bond and competitive interfacial reaction kinetics. Inspired by nitrogenase, we design single-atom iron (Fe)-doped tungsten oxide (WO3) subnanowires as a bioinspired, dynamically integrated catalytic platform to systematically overcome these challenges: (i) The distorted lattice and asymmetric sites create a dynamically responsive catalytic center, where photoinduced valence-lattice oscillation drives electron delocalization, shifting the conventional N2 adsorption mode and reaction pathway; (ii) the unique self-adhesive and film-forming properties enable robust, binder-free electrodes with maximized active-site exposure; and (iii) surface ligand engineering establishes a bioinspired microenvironment that selectively enriches N2 and regulates proton access. This system achieves an NH3 yield of 286 micrograms per milligram of catalyst per hour, a 24-fold improvement over conventional Fe-WO3 nanowires, with stable performance over 30 cycles. This work demonstrates functionally integrated, bioinspired catalysis at the subnanoscale, offering a paradigm for efficient molecular conversion.

Variations in the root-soil system influence the grapevine holobiont by shaping plant physiology and root microbiome.

Research progress in light-driven chemical synthesis based on whole-cell bio-composite systems

Soybean primarily acquires nitrogen through symbiosis with nitrogen-fixing bacteria. Water deficit (WD) is a major stress limiting crop yield. Nodulation may enhance drought tolerance in legumes by modulating nitrogen and hormone metabolism, osmotic adjustment, and antioxidant defenses; however, the molecular basis underlying the differential WD responses between N-fix and N-fed plants remain unclear. Translational control of gene expression is a key regulatory mechanism during stress. We compared the transcriptome and translatome of soybean roots from N-fix and N-fed plants exposed to WD across four combined treatments. N-fix plants under WD exhibited more complex responses in terms of total differentially expressed genes (DEGs) compared to N-fed plants. This increased complexity was also evident among translationally regulated DEGs and differentially expressed transcription factors, whose involvement in WD responses of N-fix plants is novel. Co-expression network analysis identified modules associated with core biological processes encompassing nodulation, WD, and notably, their interplay was particularly prominent in Module 1, which was enriched in genes related to ribosomal protein synthesis and oxidative phosphorylation (OXPHOS). Guilt-by-Association analysis enabled the prediction of novel functions for differentially expressed, uncharacterized hub genes related to stress and/or nodulation responses. Translational regulation of genes involved in OXPHOS and translation initiation emerged as a central response in N-fix plants under WD. These findings reveal distinct molecular adaptations in N-fix soybean roots facing WD and highlight translational control as a key regulatory layer. We also identified promising candidate genes-including transcription factors and uncharacterized hub genes under translational regulation-that represent potential targets for improving drought tolerance in legumes once validated functionally.