SOIL BIOLOGY & BIOCHEMISTRY
·
2023
·
IF 9.7
Jipeng Wang,Qian Zhao,Yiqiu Zhong,Shuhao Ji,Guanrui Chen,Qingqing He,Yanhong Wu,Haijian Bing
Free-living nitrogen fixation (FLNF) is a vital source of nitrogen for the initiation and development of ecosystems on bare lands. This process is catalyzed by the enzyme nitrogenase and is energy intensive. Of the three nitrogenase isoforms, molybdenum nitrogenase (Mo-Nase) is more efficient than its vanadium (V) and iron (Fe) counterparts at room temperature. However, the acquisition of Mo, one of the scarcest biometals in soils, represents a major resource investment for soil diazotrophs. In a vegetation restoration chronosequence developed on barren (low carbon and nitrogen) soils of a high-V region, we tested the following two hypotheses. First, the FLNF rate would be limited by the supply of energy. Second, high V availability would cut the cost of V acquisition, and it would be beneficial for diazotrophs to use V-Nase as a complement of Mo-Nase. For the soils collected along the chronosequence, the addition of a carbon cocktail remarkably stimulated the FLNF rate by relieving the energy constraint and by enriching the diazotrophic genus Paenibacillus . Despite the high V content in the soils, we failed to detect the vnf genes of V-Nase by metagenomic sequencing. Meanwhile, we observed a limited contribution of V-Nase activity to FLNF by checking the R ratio (ratio of FLNF rates measured by acetylene reduction and 15 N 2 incorporation) and the production of ethane during acetylene reduction. The reason might be that the Mo availability and temperature in our study area did not reach the thresholds for the onset of V-Nase activity. Overall, our results highlight the importance of carbon supply for FLNF in barren soils, indicating that plants may effectively regulate rhizosphere diazotrophs by secreting root exudates. This may be an important mechanism by which nonnitrogen-fixing plants survive on nitrogen-poor soils at the beginning of primary succession.
研究领域:
生态学
·
微生物学
·
土壤学
✓ 已验证
DOI
高影响因子
APPLIED SOIL ECOLOGY
·
2024
·
IF 4.8
Qian Zhao,Jipeng Wang,Qingqing He,Huajun Yin
Free-living nitrogen fixation (FLNF) is a ubiquitous and significant source of new nitrogen in ecosystems. This process requires a substantial amount of energy, and as a result, the input of labile carbon to soils may enhance FLNF. Here, we aim to explore the precise influence of different types and quantities of carbon on FLNF. We conducted experiments where sugars, carboxylic acids, and amino acids (common labile carbon inputs via root exudates) were added to cropland and forest soils. We monitored the changes in FLNF rate and diazotrophic community in response to these additions. Our findings revealed that sugars and carboxylic acids significantly stimulated FLNF rate, with an increase of up to three orders of magnitude, while amino acids either restricted FLNF or had no effect. When a mixture of sugars and carboxylic acids was added, the stimulation of FLNF was not observed until a threshold quantity of carbon was reached, indicating competition between diazotrophs and other microbes. Furthermore, the enhanced FLNF rate following carbon addition was attributable to shifts in diazotrophic community composition (e.g., increased abundance of Paenibacillus , a genus frequently used as biofertilizers), rather than to changes in the overall abundance of diazotrophs (reflected by nifH gene copy number). Our findings highlight the significant role of carbon type and quantity in regulating soil FLNF, partly through restructuring the diazotrophic community. The results have implications for predicting the response of rhizosphere FLNF to shifts in root exudation under environmental changes and can contribute to the application of diazotrophic biofertilizers in sustainable agriculture.
研究领域:
生态学
·
微生物学
·
农业
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
iScience
·
2022
·
IF 6.107
Fanyang Lv,Yuhua Zhan,Wei Lu,Xiubin Ke,Yahui Shao,Yiyuan Ma,Juan Zheng,Zhimin Yang,Shanshan Jiang,Liguo Shang,Yao Ma,Lei Cheng,Claudine Elmerich,Yongliang Yan,Min Lin
Summary Bacteria of the genus Pseudomonas consume preferred carbon substrates in nearly reverse order to that of enterobacteria, and this process is controlled by RNA-binding translational repressors and regulatory ncRNA antagonists. However, their roles in microbe-plant interactions and the underlying mechanisms remain uncertain. Here we show that root-associated diazotrophic Pseudomonas stutzeri A1501 preferentially catabolizes succinate, followed by the less favorable substrate citrate, and ultimately glucose. Furthermore, the Hfq/Crc/CrcZY regulatory system orchestrates this preference and contributes to optimal nitrogenase activity and efficient root colonization. Hfq has a central role in this regulatory network through different mechanisms of action, including repressing the translation of substrate-specific catabolic genes, activating the nitrogenase gene nifH posttranscriptionally, and exerting a positive effect on the transcription of an exopolysaccharide gene cluster. Our results illustrate an Hfq-mediated mechanism linking carbon metabolism to nitrogen fixation and root colonization, which may confer rhizobacteria competitive advantages in rhizosphere environments.
研究领域:
微生物学
·
植物科学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
Energy Storage Materials
·
2025
·
IF 20.2
Nengbiao Zhang,Luming Yin,Letian Chen,Bingbing Ma,Yuantonghe Li,Xinyi Zhang,Junqing Liu,Zhen Zhou
Abstact Lithium-nitrogen (Li-N 2 ) battery is not only an electrochemical energy storage platform, but also an environmentally friendly nitrogen fixation technology. However, a great challenge remains in regulating catalyst activity to accelerate cathode reaction kinetics. Herein, we proposed an oxygen vacancy-mediated modulation of Fe active sites in FeO x nano-particle catalysts and Fe single-atom catalysts to enhance nitrogen reduction reaction in Li-N 2 batteries. High-concentration oxygen vacancy is generated through a size- and crystallinity-dependent oxygen vacancy engineering based on the precise atomic layer deposition of reducible oxides. The oxygen vacancy on FeO x drives the electron redistribution of Fe 3+ d-orbitals to provide electron-donating Fe active sites for N 2 fixation. Meanwhile, oxygen vacancy-rich MoO y is used as a support to anchor Fe single atoms. Adjacent oxygen vacancy drives the stable coordination between Fe single atoms and O atoms to facilitate the directional electron transfer from MoO y to Fe to N 2 . Therefore, the Li-N 2 batteries exhibit large discharge capacity, excellent rate performance, and reliable cycle stability. In addition, the formation and decomposition of the discharge product Li 3 N indicate a reversible N 2 fixation. This work provides a precise regulation mechanism of catalytic active sites based on oxygen vacancy engineering, which is expected to promote the development of high-performance Li-N 2 batteries.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
BIOLOGY AND FERTILITY OF SOILS
·
2022
·Vol. 58
·期 5
·527-539
·
IF 6.605
Sun Shouqin,DeLuca Thomas H.,Zhang Jun,Wang Genxu,Sun Xiangyang,Hu Zhaoyong,Wang Wenzi,Zhang Wei
The ability of non-nodulating pioneer plants on newly exposed glacial till to obtain atmospheric N 2 was investigated using both acetylene reduction assay (ARA) and 15 N 2 gas incorporation methods. Plant tissues were also examined for the presence of endophytic diazotrophic bacteria using high-throughput nif H amplification sequencing. Both ARA and 15 N 2 gas incorporation demonstrated that non-nodulating pioneer plants can obtain atmospheric N 2 , but the amount was highly variable depending on the plant organ, with clearly higher values in leaves relative to twigs and roots. High-throughput amplification sequencing of nif H genes indicated that a great variety of diazotrophic communities developed in pioneer plant tissues under primary succession. The N 2 fixation rate (based on both 15 N 2 incorporation and ARA) was not directly linked to the abundance of any specific diazotrophs, but was correlated with the Chao1 index and the number of observed species, suggesting that different diazotrophs jointly accounted for N 2 fixation activity. Our results highlight that non-nodulating pioneer plants may acquire N through endophytic N 2 -fixing bacteria as a supplement for other potential N sources in oligotrophic environments in early stages of primary succession following glacier retreat.
研究领域:
生态学
·
微生物学
✓ 已验证
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Shixian Zhang,Xinshan Rong,Ting Sun,Ping Gao,Jun Liu,Xuchun Qiu,Xiangtong Zhou,Zhiren Wu
With the increasingly severe environmental problems the traditional high pollution and high energy consumption of nitrogen fixation industry is striving to develop new cleaner production technology. In this work, we designed and prepared the 3D porous g-C 3 N 4 with nitrogen vacancy (3DV N PCN) through a combination of alkali-assisted and supramolecular self-assembly methods. Subsequently, we synthesized, characterized and employed a Z -scheme 3DV N PCN/CoFe 2 O 4 photocatalyst with strong nitrogen adsorption and activation for nitrogen photofixation. The results show that the best photofixation nitrogen efficiency of the photocatalyst can reach 14.66 mmol/g/h within 120 min. This nitrogen fixation process carried out at room temperature, and only requires water and nitrogen as raw materials, which has the advantage of being energy efficient, environmental friendly and pollution-free.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Shizhen Liu,Shaobin Wang,Yao Jiang,Zhenqing Zhao,Guiyuan Jiang,Zhenyu Sun
Fe 2 O 3 loaded porous graphitic carbon nitride ( g -C 3 N 4 ) photocatalysts have been prepared simply by thermal treatment in a hypoxia environment and the photocatalytic activities were evaluated in photocatalytic nitrogen fixation under artificial solar irradiation. Efficient reduction of dinitrogen to ammonia by photocatalysis over the hybrid catalysts was achieved even when the content of iron in the sample was less than 1 wt%, with an ammonia yield rate reaching 47.9 mg/L/h, 6 times higher than that of bare g -C 3 N 4 . The photocatalytic performance also outperforms many currently reported g -C 3 N 4 -based photocatalysts. X-ray photoelectron spectroscopy and Mӧssbauer spectroscopy confirmed the formation of Fe 2 O 3 in the photocatalyst and BET analysis revealed an enlarged pore volume by adjusting treatment temperature, providing benefits for photogenerated carrier separation and N 2 adsorption over the catalyst surface. Such g -C 3 N 4 supported Fe 2 O 3 nanoparticles with low-cost holds promise as one of the family member of photocatalysts for efficient N 2 fixation.
研究领域:
材料化学
·
环境催化
·
能源化学
·
光催化
·
无机功能材料
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yuanfang Shen,Liangchen Chen,Luping Zhang,Weihang Han,Yurong Chang,Hui Zheng
Photocatalytic conversion of nitrogen to ammonium is a carbon neutralization reaction. Synthesizing suitably modified semiconductor substrate photocatalysts for nitrogen fixation is a challenge and hot topics in recent decades. This research aims to synthesize a photocatalyst with abundant oxygen vacancies and explore its nitrogen fixation performance. Herein, Cobalt oxide@Schiff was synthesized through organic synthesis and hydrothermal method. Its structure and nitrogen fixation properties were explored. It was found that Cobalt oxide@Schiff has an all-day nitrogen fixation performance from air directly, and the rate could reach 2880 μg/(L•h) under sunlight or day and night at normal temperature and pressure. The advantage of this photocatalyst is that the large π bond of the Schiff base ligand could significantly improve the light-trapping ability and the synergistic effect of nitrogen fixation, which provides a new pathway for nitrogen fixation day and night under room temperature and atmosphere pressure.
研究领域:
材料科学
·
环境科学
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
PLANT CELL AND ENVIRONMENT
·
2025
·
IF 6.3
Hongcheng Zhao,Jiarui Xu,Lin Huang,Yizhe Ding,Xianyong Lin,Chengliang Sun
Beneficial microbiomes significantly modulate root hair morphogenesis, yet the underlying signalling pathways remain unclear. Through comprehensive phenotypic analysis, we demonstrated that Azospirillum brasilense , a well-known plant-growth-promoting rhizobacteria (PGPR), promotes root hair development by prolonging the elongation period. The promotion of root hair growth by A. brasilense is attributed to increased auxin accumulation in root apices and enhanced shootward transport from the root tip, which is mediated by the accumulation of the auxin importer auxin transporter protein 1 (AUX1) in the lateral root cap and the overlying epidermis. Chemical or genetic disruption of auxin signalling abolished bacteria-induced root hair responses. Furthermore, A. brasilense upregulated several root hair-related basic helix-loop-helix family transcription factors, including root hair defective 6 (RHD6) and RHD6-LIKE 1 (RSL1), which control root hair development through RSL4. Morphological analysis revealed that while the rsl2rsl4 double mutant remained hairless after inoculation, A. brasilense successfully rescued root hair growth in rhd6rsl1 . These findings suggest that A. brasilense can bypass RHD6 to activate RSL4, which then drives root hair development dependent on ROS. Collectively, our study uncovers the core signalling components modulated by A. brasilense to fine-tune root hair responses.
研究领域:
植物生物学
·
微生物学
·
发育生物学
·
分子信号传导
·
根际细菌-植物互作
✓ 已验证
DOI
PubMed
高影响因子
AGRICULTURE ECOSYSTEMS & ENVIRONMENT
·
2017
·
IF 4.099
Congyan Wang,Jiawei Zhou,Jun Liu,Kun Jiang,Daolin Du
Soil N-fixing bacteria communities (SNB) can increase soil N availability, which can facilitate invasions of many kinds of invasive plant species. Meanwhile, variability in the forms of anthropogenic N deposition can mediate obvious shifts in both soil physicochemical properties and soil microbial communities (especially SNB). This can alter the soil micro-ecological mechanisms of plant invasions via changes in soil characteristics and soil microbial communities, especially SNB. This study uses next-generation high throughput sequencing technology to provide insight into the effects of invasion by Amaranthus retroflexus L. on the structure and diversity of SNB under different forms of simulated N deposition (SND). Soil pH under A. retroflexus invasion under various forms of SND was 8.08% lower than controls under a NH 4 -N treatment ( P < 0.05), 15.15% lower than controls under a NO 3 -N treatment ( P < 0.05), and 6.57% lower than controls under CO(NH 2 ) 2 -N and Mix-N treatments ( P < 0.05). Meanwhile, soil pH was one of the most important environmental variables explaining changes in the structure and diversity of SNB. The total number of species of SNB under A. retroflexus invasion was approximately 13.13% higher than controls for the NH 4 -N treatment ( P > 0.05), 11.00% higher than controls for the NO 3 -N treatment ( P > 0.05), 39.42% higher than controls for the CO(NH 2 ) 2 -N treatment ( P < 0.05), and 27.67 higher than controls for the Mix-N treatment ( P < 0.05). The positive effects mediated by the combined treatments of A. retroflexus invasion and SND may be ascribed to enhanced soil nutrient content (especially N), which can enhance the abundance of the nifH gene. The effects of A. retroflexus invasion on the total number of species of SNB under organic and mixed-N addition were greater than under inorganic N addition. This may be a consequence of a disturbance of the balance of inorganic to organic N for SND, as a result of the addition of a single form of inorganic N, which can diminish the stimulatory effects of soil nutrient content on SNB under inorganic N. Another potential cause of this pattern may be stronger acidification under inorganic N addition, which can exert more pronounced effects on SNB. LEfSe analysis showed that some species changed significantly under A. retroflexus invasion in the presence of SND (i.e., Rhodobacteraceae under NH 4 -N and Proteobacteria under CO(NH 2 ) 2 -N). Thus, A. retroflexus invasion in the presence of SND caused obvious shifts in certain species of SNB and increased the total number of species of SNB in particular, to facilitate its further invasion.
研究领域:
生态学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
·
2022
·Vol. 20
·期 1
·1-18
·
IF 9.429
Ma Jun,Zhou Yi,Li Jiaying,Song Zhiyong,Han Heyou
Background The study of symbiotic nitrogen fixation between (SNF) legumes and rhizobia has always been a hot frontier in scientific research. Nanotechnology provides a new strategy for biological nitrogen fixation research. However, how to construct abiotic nano-structure-biological system, using the special properties of nanomaterials, to realize the self-enhancement of biological nitrogen fixation capacity is important.Results In order to construct a more efficient SNF system, in this study, we applied manganese ferrite nanoparticles (MF-NPs) with sustainable diatomic catalysis to produce reactive oxygen species (ROS), thus regulating the nodulation pathway and increasing the number of nodules in soybean (Glycine max), eventually enhancing symbiotic nitrogen fixation. Symbiosis cultivation of MF-NPs and soybean plants resulted in 50.85% and 61.4% increase in nodule weight and number, respectively, thus inducing a 151.36% nitrogen fixation efficiency increase, finally leading to a 25.70% biomass accumulation increase despite no substantial effect on the nitrogenase activity per unit. Transcriptome sequencing analysis showed that of 36 differentially expressed genes (DEGs), 31 DEGs related to soybean nodulation were upregulated in late rhizobium inoculation stage (12 d), indicating that the increase of nodules was derived from nodule-related genes (Nod-R) continuous inductions by MF-NPs.Conclusion sOur results indicated that the nodule number could be effectively increased by extending the nodulation period without threatening the vegetative growth of plants or triggering the autoregulation of nodulation (AON) pathway. This study provides an effective strategy for induction of super-conventional nodulation.Graphical Abstract
研究领域:
植物科学
·
微生物学
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2021
·Vol. 87
·期 5
·
IF 4.792
Shanshan Chen,Xianyue Jing,Yongliang Yan,Shaofu Huang,Xing Liu,Piao Chen,Shungui Zhou
Diazotrophs can produce bioavailable nitrogen from inert N2 gas by bioelectrochemical nitrogen fixation (e-BNF), which is emerging as an energy-saving and highly selective strategy for agriculture and industry. However, current e-BNF technology is impeded by requirements for NH4+ assimilation inhibitors to facilitate intracellular ammonia secretion and precious metal catalysts to generate H2 as the energy-carrying intermediate. Here, we initially demonstrate inhibitor- and catalystless extracellular NH4+ production by the diazotroph Pseudomonas stutzeri A1501 using an electrode as the sole electron donor. Multiple lines of evidence revealed that P. stutzeri produced 2.32 ± 0.25 mg/liter extracellular NH4+ at a poised potential of −0.3 V (versus standard hydrogen electrode [SHE]) without the addition of inhibitors or expensive catalysts. The electron uptake mechanism was attributed to the endogenous electron shuttle phenazine-1-carboxylic acid, which was excreted by P. stutzeri and mediated electron transfer from electrodes into cells to directly drive N2 fixation. The faradaic efficiency was 20% ± 3%, which was 2 to 4 times that of previous e-BNF attempts using the H2-mediated pathway. This study reports a diazotroph capable of producing secretable NH4+ via extracellular electron uptake, which has important implications for optimizing the performance of e-BNF systems and exploring the novel nitrogen-fixing mode of syntrophic microbial communities in the natural environment.IMPORTANCE Ammonia greatly affects global ecology, agriculture, and the food industry. Diazotrophs with an enhanced capacity of extracellular NH4+ excretion have been proven to be more beneficial to the growth of microalgae and plants, whereas most previously reported diazotrophs produce intracellular organic nitrogen in the absence of chemical suppression and genetic manipulation. Here, we demonstrate that Pseudomonas stutzeri A1501 is capable of extracellular NH4+ production without chemical suppression or genetic manipulation when the extracellular electrode is used as the sole electron donor. We also reveal the electron uptake pathway from the extracellular electron-donating partner to P. stutzeri A1501 via redox electron shuttle phenazines. Since both P. stutzeri A1501 and potential electron-donating partners (such as electroactive microbes and natural semiconductor minerals) are abundant in diverse soils and sediments, P. stutzeri A1501 has broader implications on the improvement of nitrogen fertilization in the natural environment.
研究领域:
微生物学
·
环境科学
·
农业科学
✓ 已验证
DOI
PubMed
高影响因子
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