Article
Ecology
Swamini Khurana, Falk Hesse, Anke Hildebrandt, Martin Thullner
Summary: The subsurface is a vital component of the Earth's critical zone, where biogeochemical transformations are crucial for nutrient cycling. Spatial heterogeneity influences groundwater microbial biomass distribution and nutrient cycling, neglecting its effects can lead to overestimation of nutrient removal.
Article
Geochemistry & Geophysics
D. M. Nisson, T. L. Kieft, H. Drake, O. Warr, B. Sherwood Lollar, H. Ogasawara, S. M. Perl, B. M. Friefeld, J. Castillo, M. J. Whitehouse, E. Kooijman, T. C. Onstott
Summary: Geochemical and isotopic analyses were performed on hypersaline brines from the Moab Khotsong gold and uranium mine in the Witwatersrand Basin of South Africa to investigate brine evolution over time and evaluate habitability conditions. The results showed that the brines were highly saline and exhibited low dissolved inorganic carbon and high dissolved organic carbon pools. Radiolysis and water-rock interactions were identified as significant contributors to the brine chemistry, with radiolytic production of H2 and oxidant species supporting a potentially low biomass microbial community. The findings also revealed distinct fluid events during the cooling of the basin, as evidenced by stable isotopic signatures.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Environmental Sciences
Sinchan Banerjee, Anna Bedics, Peter Harkai, Balazs Kriszt, Nagaraju Alpula, Andras Tancsics
Summary: This study investigated the microbial community diversity and degradation abilities of xylene isomers in a legacy BTEX-contaminated site. The results showed that different bacterial groups were involved in the degradation of different xylene isomers, and the composition of the bacterial community was distinct for each isomer. Two Hydrogenophaga strains were identified as effective degraders of p-xylene, and comparative whole-genome analysis revealed the genomic adaptations that contribute to their different xylene isomer-degrading abilities.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Huanjun Zhang, Yin Lu, Yi Li, Lei Wang, Wenlong Zhang, Longfei Wang, Lihua Niu, Zhongjun Jia
Summary: This study identified bacteria involved in estrogen metabolism in sediments from different bays of Taihu Lake using DNA-SIP technology, revealing their distinct roles in the biodegradation process of E2. The results showed a significant and positive correlation between the increase in relative abundance of these bacteria and E2 mineralization rate.
ENVIRONMENTAL POLLUTION
(2021)
Article
Environmental Sciences
Weimin Sun, Xiaoxu Sun
Summary: This study found that methane can be produced through anaerobic degradation of toluene over a long-term enrichment experiment. The DNA-SIP technique identified bacteria in the phylum Proteobacteria as the dominant toluene-degrading bacteria under anaerobic conditions.
WATER AIR AND SOIL POLLUTION
(2021)
Article
Biotechnology & Applied Microbiology
Nagwa I. Elarabi, Abdelhadi A. Abdelhadi, Amr A. Nassrallah, Mahmoud S. M. Mohamed, Heba A. R. Abdelhaleem
Summary: This study aimed to examine the soil microbial diversity and find bacterial isolates capable of efficiently degrading the persistent phenylurea herbicide isoproturon. The best isolates were identified as Pseudomonas putida and Acinetobacter johnsonii, and their ability to degrade isoproturon was compared. The catA gene responsible for degradation was cloned and expressed in E. coli, which showed higher degradation efficiency than P. putida. The study also identified intermediate metabolites and demonstrated the potential of these bacteria for bioremediation and biodegradation technology development.
Article
Engineering, Civil
Lucheng Zhan, Pei Xin, Jiansheng Chen
Summary: This study investigates the distribution and evolution rules of underground salinity in a coastal reclamation zone of eastern China using methods such as electrical resistivity tomography (ERT), water stable isotope, and hydrochemical analyses. The results reveal that the phreatic aquifer is dominated by highly saline water due to seawater flooding before reclamation. After being isolated from marine conditions, the near-surface zone experiences highly variable water salinity caused by dilution effect of rainwater and salt accumulation effect driven by evaporation. Long-term reclamation for agricultural use accelerates the desalination of the upper phreatic aquifer, leading to a downward migration of saline groundwater. Findings of this study provide important insights into the distribution and evolution characteristics of salinity in coastal agricultural lands.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Jianfei Chen, Yuyin Yang, Yanchu Ke, Xiuli Chen, Xinshu Jiang, Chao Chen, Shuguang Xie
Summary: This study utilized DNA-stable isotope probing and metagenomics to investigate the active microorganisms and mechanisms of sulfonamide (SA) biodegradation in antibiotic-contaminated wetland sediments. The results revealed that SA-assimilating bacteria, particularly members of Proteobacteria, played a dominant role in SA degradation. It was found that ipso-hydroxylation was the main process by which both sulfadiazine and sulfamethoxazole were dissipated, and this process was driven by similar microbes. Additionally, some genes encoding dioxygenases were proposed to be involved in SA metabolism. This study provides important insights into the ecological roles of uncultured microorganisms and the in-situ biodegradation mechanisms of SA.
ENVIRONMENT INTERNATIONAL
(2022)
Article
Engineering, Environmental
Jinha Kim, Myung Hwangbo, Chih-Hsuan Shih, Kung-Hui Chu
Summary: Stable isotope probing (SIP) is a powerful tool for studying microbial community structure and function. It has provided substantial information to understand complex microbial ecosystems. This review provides an overview of the advances and applications of SIP-based technologies and discusses important factors to be considered in experimental designs and data interpretation.
Article
Plant Sciences
Zeeshan Niaz, Zhenghong Sui, Sadaf Riaz, Sohrab Khan, Qingwei Du, Wei Zhou, Jinguo Wang
Summary: This study examined the ubiquitin gene in Alexandrium catenella and found significant changes in gene expression under different nutritional conditions. Upregulation of the gene in high nitrogen and nitrogen-phosphorous conditions was associated with rapid algae growth, while under low nitrogen and phosphorous conditions, oxidative stress led to gene upregulation and activation of the ubiquitin-proteasome system.
PAKISTAN JOURNAL OF BOTANY
(2021)
Article
Engineering, Environmental
Benjamin Heckel, Martin Elsner
Summary: This study investigates the mechanisms of natural reductive dechlorination by microorganisms of chlorinated alkanes using cobamide as a cofactor. The findings demonstrate the involvement of chloroalkyl-cobalamin complexes and a nucleophilic substitution reaction. Isotope analysis of different enzymes (RDases) shows a diversity of biochemical reaction mechanisms. This study provides important information for understanding bacterial reductive dehalogenation and bioremediation.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Jordi Palau, Alba Trueba-Santiso, Rong Yu, Siti Hatijah Mortan, Orfan Shouakar-Stash, David L. Freedman, Kenneth Wasmund, Daniel Hunkeler, Ernest Marco-Urrea, Monica Rosell
Summary: This study investigates the dual C-Br isotope fractionation during in vivo biodegradation of 1,2-dibromoethane by two anaerobic enrichment cultures. Different reaction mechanisms were observed, providing valuable information for future biodegradation studies of 1,2-dibromoethane in contaminated sites.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Xuexia Chen, Shuai Zhang, Lijin Yi, Zhengwei Liu, Xiangyu Ye, Bo Yu, Shuai Shi, Xiaoxia Lu
Summary: The contamination of BTEX in the soil and groundwater of petrochemical sites near the Yangtze River poses a threat to ecosystems and human health. This study evaluated the biodegradation of BTEX in the subsurface environment, providing scientific basis for bioremediation. Molecular analysis of field samples and laboratory microcosm studies were conducted. The results showed that certain bacteria were dominant in highly or slightly contaminated areas, and the relative abundances of predicted functions were higher in the highly contaminated samples. The biodegradation of BTEX occurred in microcosms with different electron acceptors, and the rate constants varied.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Engineering, Environmental
Yiran Tong, Matthew J. Berens, Bridget A. Ulrich, Jakov Bolotin, Jennifer H. Strehlau, Thomas B. Hofstetter, William A. Arnold
Summary: The study evaluated the isotope fractionation of RDX under the influence of Fe minerals and natural sediments with Fe(II), finding that RDX can be reduced to nitroso compounds with N isotope enrichment. Analysis of groundwater samples in the ammunition plant showed an 85% extent of reductive transformation of RDX. However, limited accessibility to reactive Fe(II) in laboratory flow-through systems resulted in masking of N isotope fractionation after RDX reduction.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Alexander P. Schwarz, Anna A. Kovalenko, Maria V. Zakharova, Aleksey V. Zaitsev
Summary: Adenosine deaminase-dependent RNA editing is a widespread mechanism of gene function modulation, with changes in RNA editing potentially impacting various physiological and pathological processes. In the GluA2 subunit of AMPA receptor, editing at the Q607R site alters receptor function, making it calcium-impermeable. The development of RT-qPCR assays for quantifying edited/unedited mRNA shows promise for studying RNA editing levels efficiently.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2021)