CHEMOSPHERE
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2021
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IF 7.086
Meiling Yi,Lilan Zhang,Cunli Qin,Peili Lu,Hongcheng Bai,Xinkuan Han,Shupei Yuan
Phenanthrene (PHE) is frequently detected in worldwide soils. But it is still not clear that how the microbial community succession happens and the nitrogen-cycling processes alter during PHE degradation. In this study, the temporal changes of soil microbial community composition and nitrogen-cycling processes during the biodegradation of PHE (12 μg g −1 ) were explored. The results showed that the biodegradation of PHE followed the second-order kinetics with a half-life of 7 days. QPCR results demonstrated that the bacteria numbers increased by 67.1%–194.7% with PHE degradation, whereas, no significant change was observed in fungi numbers. Thus, high-throughput sequencing based on 16 S rRNA was conducted and showed that the abundances of Methylotenera , Comamonadaceae , and Nocardioides involved in PHE degradation and denitrification were significantly increased, while those of nitrogen-metabolism-related genera such as Nitrososphaeraceae , Nitrospira , Gemmatimonadacea were decreased in PHE-treated soil. Co-occurrence network analysis suggested that more complex interrelations were constructed, and Proteobacteria instead of Acidobacteriota formed intimate associations with other microbes in responding to PHE exposure. Additionally, the abundances of nif H and nar G were significantly up-regulated in PHE-treated soil, while that of amo A especially AOA amo A was down-regulated. Finally, correlation analysis found several potential microbes ( Methylotenera , Comamonadaceae , and Agromyces ) that could couple PHE degradation and nitrogen transformation. This study confirmed that PHE could alter microbial community structure, change the native bacterial network, and disturb nitrogen-cycling processes.
研究领域:
环境微生物学
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土壤科学
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生物修复
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微生物生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SOIL ECOLOGY
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2024
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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
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微生物学
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农业
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土壤学
✓ 已验证
产品关联
DOI
高影响因子
ISME Journal
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2023
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IF 11
Liu Xiaohan,Li Ping,Wang Helin,Han Li-Li,Yang Kai,Wang Yanhong,Jiang Zhou,Cui Li,Kao Shuh-Ji
Biological nitrogen fixation (BNF), the conversion of N 2 into bioavailable nitrogen (N), is the main process for replenishing N loss in the biosphere. However, BNF in groundwater systems remains poorly understood. In this study, we examined the activity, abundance, and community composition of diazotrophs in groundwater in the Hetao Plain of Inner Mongolia using 15 N tracing methods, reverse transcription qPCR (RT-qPCR), and metagenomic/metatranscriptomic analyses. 15 N 2 tracing incubation of near in situ groundwater (9.5–585.4 nmol N L −1 h −1 ) and N 2 -fixer enrichment and isolates (13.2–1728.4 nmol N g −1 h −1 , as directly verified by single-cell resonance Raman spectroscopy), suggested that BNF is a non-negligible source of N in groundwater in this region. The expression of nifH genes ranged from 3.4 × 10 3 to 1.2 × 10 6 copies L −1 and was tightly correlated with dissolved oxygen (DO), Fe(II), and NH 4 + . Diazotrophs in groundwater were chiefly aerobes or facultative anaerobes, dominated by Stutzerimonas , Pseudomonas , Paraburkholderia , Klebsiella , Rhodopseudomonas , Azoarcus , and additional uncultured populations. Active diazotrophs, which prefer reducing conditions, were more metabolically diverse and potentially associated with nitrification, sulfur/arsenic mobilization, Fe(II) transport, and CH 4 oxidation. Our results highlight the importance of diazotrophs in subsurface geochemical cycles.
研究领域:
环境微生物学
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地球化学
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水文地质学
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微生物生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）