BIOLOGY AND FERTILITY OF SOILS
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2022
·Vol. 58
·期 5
·527-539
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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
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微生物学
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DOI
高影响因子
IEEE Geoscience and Remote Sensing Letters
·
2021
·
IF 3.966
Keren Dai,Ningling Wen,Xuanmei Fan,Jin Deng,Lele Zhang,Rubing Liang,Jie Liu,Qiang Xu
In the context of global warming, monitoring glacial lakes is of great significance for revealing climate change and mitigating glacier lake outburst floods (GLOFs). Multitemporal mapping of glacier lakes through optical satellite remote-sensing imageries can only provide us comparative analysis of glacier lake changes during long time intervals. In recent years, the rapid development of synthetic aperture radar (SAR) has made it possible to observe seasonal changes of glacial lakes. This letter proposed a polarization enhancement-based maximum interclass variance (PE-MIV) method to accurately and automatically mapping the seasonal cycles of glacial lakes based on multipolarization SAR data. Taking the Gongcuo and Langcuo glacial lakes in Laigu village, Tibetan Plateau, as examples, based on 113 Sentinel-1 SAR imageries covering 2017 to 2020 with a 12-day revisiting time, the seasonal boundary changes of both lakes were extracted automatically with a relative accuracy of 93.59%. The seasonal variations of glacial lake area are closely related to temperature and precipitation. This letter demonstrated that the satellite SAR (short revisiting time, multipolarization, etc.) is an effective tool to monitor areal changes of glacier lakes, which can be widely applied in detecting glacier lakes, GLOFs, and their response to climate change.
研究领域:
遥感监测
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冰川学
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气候学
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环境变化
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DOI
高影响因子
ENVIRONMENTAL MICROBIOLOGY
·
2023
·Vol. 25
·期 12
·2822-2833
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IF 5.1
Xiaoyan Qi,Mukan Ji,Chao-Fan Yin,Ning-Yi Zhou,Yongqin Liu
Polyethylene terephthalate (PET) is a major component of microplastic contamination globally, which is now detected in pristine environments including Polar and mountain glaciers. As a carbon-rich molecule, PET could be a carbon source for microorganisms dwelling in glacier habitats. Thus, glacial microorganisms may be potential PET degraders with novel PET hydrolases. Here, we obtained 414 putative PET hydrolase sequences by searching a global glacier metagenome dataset. Metagenomes from the Alps and Tibetan glaciers exhibited a higher relative abundance of putative PET hydrolases than those from the Arctic and Antarctic. Twelve putative PET hydrolase sequences were cloned and expressed, with one sequence (designated as GlacPETase) proven to degrade amorphous PET film with a similar performance as Is PETase, but with a higher thermostability. GlacPETase exhibited only 30% sequence identity to known active PET hydrolases with a novel disulphide bridge location and, therefore may represent a novel PET hydrolases class. The present work suggests that extreme carbon-poor environments may harbour a diverse range of known and novel PET hydrolases for carbon acquisition as an environmental adaptation mechanism.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
ISME Journal
·
2021
·Vol. 15
·期 6
·1844-1857
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IF 10.302
Liu Qing,Li Wei,Liu Di,Li Lingyan,Li Jie,Lv Na,Liu Fei,Zhu Baoli,Zhou Yuguang,Xin Yuhua,Dong Xiuzhu
Bacteria that inhabit glaciers usually produce carotenoids. Here, we report that a group of zeaxanthin-producing glacial Flavobacterium exhibited light-promoted growth. Of the tested 47 strains, 45 showed increased growths but two died under illumination at 50 μmol photon m −2 s −1 . Light stimulation occurred mainly in either anoxic or nutrient-poor cultures, while the same levels of light promotion were found for that grown at 14 and 7 °C. Pigment assays identified overrepresentative zeaxanthin but trace retinal in the light promoted 45 strains, while flexirubin was exclusively in the light-lethal two. Genomic analysis revealed the gene cluster for zeaxanthin synthesis in the 45 strains, in which 37 strains also harbored the proteorhodopsin gene prd . Transcriptomic analysis found that light-induced expressions of both the zeaxanthin synthesis and proteorhodopsin genes. Whereas, deletion of the prd gene in one strain did not diminish light promotion, inhibition of zeaxanthin synthesis did. In comparison, no light promotion was determined in a glacier Cryobacterium luteum that produced a non-zeaxanthin-type carotenoid. Therefore, light stimulation on the glacial Flavobacterium is mostly likely related to zeaxanthin, which could provide better photoprotection and sustain membrane integrity for the organisms living in cold environments.
研究领域:
微生物学
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环境科学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
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