Article
Multidisciplinary Sciences
Yvette Roske, Florian Lindemann, Anne Diehl, Nils Cremer, Victoria A. Higman, Brigitte Schlegel, Martina Leidert, Kristina Driller, Kursad Turgay, Peter Schmieder, Udo Heinemann, Hartmut Oschkinat
Summary: Studying bacterial biofilm generation is important for understanding cell-cell communication, cohabitation principles, and antibiotic resistance. Bacillus subtilis biofilms are a model system with potential applications, and their major matrix proteins are TasA and TapA. This study presents the structure of TapA and reveals its role in promoting the growth of nonamyloidic TasA filaments.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Review
Microbiology
Yuxuan Qin, Leticia Lima Angelini, Yunrong Chai
Summary: This minireview discusses cell differentiation in Bacillus subtilis, a soil-dwelling, spore-forming Gram-positive bacterium, and its role in biofilm formation and prevalence in the environment. It provides a comprehensive review of the classic model of endospore formation in B. subtilis, as well as recent investigations on cell fate determination and generation of multiple cell types during biofilm formation. Mechanistic details of how cell fate determination and mutually exclusive cell differentiation are regulated during biofilm formation are also presented.
Article
Microbiology
Yangfu Li, Nuo Chen, Qingping Wu, Xinmin Liang, Xiaoming Yuan, Zhenjun Zhu, Yin Zheng, Shubo Yu, Moutong Chen, Jumei Zhang, Juan Wang, Yu Ding
Summary: This study found that knocking out the flagellar hook encoding gene flgE in emetic Bacillus cereus strains resulted in the loss of flagellar structure and swimming ability, defects in both pellicle and ring formation, and a decrease in cereulide synthesis. This suggests that flagellar components play an important role in biofilm formation and cereulide production in emetic B. cereus.
FRONTIERS IN MICROBIOLOGY
(2022)
Review
Biochemistry & Molecular Biology
Christopher Blake, Mathilde Nordgaard Christensen, Akos T. Kovacs
Summary: Bacillus subtilis is a widely studied plant growth-promoting rhizobacteria, with the ability to promote plant growth and control plant pathogens through various mechanisms. Despite extensive recognition and study of its benefits in crop production under laboratory conditions, the success of its application in fields varies greatly due to the inability of the bacteria to persist in the rhizosphere. Successful root colonization is crucial for the interaction between microbe and plant, highlighting the importance of bacterial traits and signaling interplay with the plant for growth promotion and biocontrol effects.
MOLECULAR PLANT-MICROBE INTERACTIONS
(2021)
Article
Microbiology
Shanshan Xu, Qianqian Cao, Zengzhi Liu, Junpeng Chen, Peiguang Yan, Bingyu Li, Ying Xu
Summary: Bacillus strains are widely distributed in various environments and have biofilm-formation ability. This study focuses on the biofilm formation in Bacillus subtilis and its regulation by tmRNA. The researchers constructed a ssrA mutant in B. subtilis and found that biofilm formation was impaired. They also identified a biofilm-formation suppressor that restored biofilm formation even stronger than the wild type. By analyzing transcriptomic data, they predicted the functions of differentially expressed genes (DEGs) involved in tmRNA regulation of biofilm formation. Furthermore, they identified two immediate regulators, acoA and yhjR, that could restore biofilm formation in the ssrA mutant.
Article
Food Science & Technology
Vanessa Pereira Perez Alonso, Jessica de Oliveira Morais, Dirce Yorika Kabuki
Summary: The study investigated the diversity of spore-forming bacilli in UHT milk, finding that B. cereus s.s., B. sporothermodurans, and G. stearothermophilus were commonly present in UHT milk and capable of forming biofilms. The data highlights the need for the dairy industry to strengthen control over raw materials and cleaning procedures to prevent the formation of persistent microbial communities.
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
(2021)
Article
Food Science & Technology
Yeong Jin Park, Yeon Jin Kim, Hwan Hee Yu, Na-Kyoung Lee, Hyun-Dong Paik
Summary: This study evaluated the anti-biofilm effect of cell-free supernatants (CFS) of Bacillus species against L. monocytogenes and found that B. subtilis KU43 had the most potent anti-biofilm activity.
Article
Food Science & Technology
Angela Maria Catania, Tiziana Civera, Pierluigi Aldo Di Ciccio, Maria Ausilia Grassi, Patrizia Morra, Alessandra Dalmasso
Summary: Processed cheeses from an Italian dairy plant were found to contain Bacillus strains in the initial production hours. Genetic analysis revealed different sequence types for Bacillus cereus strains and identification of a new sequence type for Bacillus subtilis strains. All isolates showed biofilm-forming ability, suggesting the presence of a recurring Bacillus population.
Article
Microbiology
Shirmin Islam, Md Liton Mahmud, Waleed H. Almalki, Suvro Biswas, Md Ariful Islam, Md Golam Mortuza, Mohammad Akbar Hossain, Md Akhtar-E Ekram, Md Salah Uddin, Shahriar Zaman, Md Abu Saleh
Summary: This study investigates the inhibition of biofilm formation in Pseudomonas sp. by compounds from the cell-free supernatant of Bacillus subtilis. It demonstrates that these compounds exhibit strong anti-biofilm activity and provides insights into their mode of action through molecular docking and molecular dynamics simulations.
Article
Microbiology
Min Qiu, Lianjun Feng, Caijun Zhao, Siyuan Gao, Lijuan Bao, Yihong Zhao, Yunhe Fu, Xiaoyu Hu
Summary: In this study, it was found that commensal Bacillus subtilis inhibited Staphylococcus aureus colonization and alleviated S. aureus-induced mastitis by influencing biofilm formation. The antibiofilm effect of Bacillus subtilis H28 was the most significant, and its treatment showed relief in a mice model of S. aureus-induced mastitis.
FEMS MICROBIOLOGY ECOLOGY
(2022)
Article
Multidisciplinary Sciences
Vasco M. Worlitzer, Ajesh Jose, Ilana Grinberg, Markus Bar, Sebastian Heidenreich, Avigdor Eldar, Gil Ariel, Avraham Be'er
Summary: This study investigates the transition from swarming to biofilm formation in Bacillus subtilis and reveals the roles of both biological and physical processes in facilitating this transition. Individual cells initiate the formation of large aggregates, where cells continue swarming around the aggregates while trapped cells join the biofilm.
Article
Microbiology
Wei Yang, Haixia Yan, Guanghui Dong, Zhengpeng Li, Chunhao Jiang, Dalu Gu, Dongdong Niu, Danni Zhou, Yuming Luo
Summary: This study evaluated the impacts of cadmium on the components, morphology, and function of biofilms of Bacillus subtilis. The results showed that cadmium ion stress led to changes in the biofilm morphology and gene expression. The strain exhibited increased mobility and tolerance to cadmium stress, while also altering the composition of the biofilm and promoting the production of poly-gamma-glutamic acid.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Ryan J. Morris, David Stevenson, Tetyana Sukhodub, Nicola R. Stanley-Wall, Cait E. MacPhee
Summary: Microbial biofilms are characterized by the production of an extracellular matrix that protects the cells and influences the structure and dynamics of the biofilm. In this study, a highly active population of bacteria was found during early stages of biofilm formation in Bacillus subtilis, facilitated by fluid extraction from the agar substrate. The extraction was traced back to the production of poly-gamma-glutamic acid (PGA). The activity of bacteria developed behind a moving front of fluid and was controlled by extracellular polysaccharides (EPS). The production of PGA was also found to be positively correlated with higher temperatures, which resulted in distinct biofilm morphologies.
NPJ BIOFILMS AND MICROBIOMES
(2022)
Article
Microbiology
Yu-Chieh Lin, Chun-Yi Wu, Hung-Tse Huang, Mei-Kuang Lu, Wei-Shou Hu, Kung-Ta Lee
Summary: The study found that the culture fluid of Bacillus subtilis natto can effectively inhibit Enterococcus faecalis biofilm formation, improve biofilm structure, and reduce exopolysaccharide synthesis. Furthermore, the culture fluid of Bacillus subtilis natto also downregulates specific genes involved in E. faecalis cell envelope synthesis and biofilm formation through transcriptome sequencing.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Ecology
I. C. Engelhardt, D. Patko, Y. Liu, M. Mimault, G. de las Heras Martinez, T. S. George, M. MacDonald, M. Ptashnyk, T. Sukhodub, N. R. Stanley-Wall, N. Holden, T. J. Daniell, L. X. Dupuy
Summary: This study used live microscopy techniques to observe collective movement of B. subtilis bacteria in soil, resembling the behavior of bird flocks or fish schools. Genetic analysis suggests that this movement may be driven by diffusion of extracellular signaling molecules and influenced by physical obstacles and hydrodynamics in the soil environment.
Article
Environmental Sciences
Anirban Kundu, Orfeo Harrisson, Subhasis Ghoshal
Summary: This study examined hydrocarbon degradation and microbial activity in seven sub-Arctic soils contaminated with Arctic diesel. The results showed that nutrient amendment promoted hydrocarbon biodegradation and caused significant shifts in microbial diversity and abundance. In addition, the alkane degrading gene alkB was more abundant in systems with nutrient amendment. The extent of microbial community shifts or alkB copy number increases may not be closely correlated with hydrocarbon biodegradation and bioremediation performance across different treatments or soils.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Jun-Ray Macairan, Brian Nguyen, Frank Li, Nathalie Tufenkji
Summary: An effective methodology is required to detect unlabeled microplastics in environmental samples in order to understand the biological impacts of plastic pollution. Current methods rely on digestion protocols which can result in the loss of spatial information and smaller plastics. The use of fluorescence microscopy for visualization is limited by nonspecific labeling strategies. A new method of nonspecific labeling with tissue-clearing technique is developed, allowing clear visualization of internalized microplastics. The method is demonstrated in living aquatic organisms and a model vertebrate.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Olubukola S. Alimi, Dominique Claveau-Mallet, Mathieu Lapointe, Thinh Biu, Lan Liu, Laura M. Hernandez, Stephane Bayen, Nathalie Tufenkji
Summary: In this study, we investigated the changes in physicochemical properties of polystyrene microplastics generated from a disposable cup due to UV-weathering, and their impact on microplastic transport potential and contaminant sorption ability in simulated freshwaters. UV exposure led to a decrease in microplastic hydrophobicity, increase in density, carbonyl index, and microscale roughness. Settling velocity also increased, indicating enhanced deposition to sediments. Weathered microplastics showed reduced sorption capacity for a hydrophobic contaminant compared to unaged ones. These findings provide new insights into the risks and behavior of microplastics in aquatic environments.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Mathieu Lapointe, Rafael S. Kurusu, Laura M. Hernandez, Nathalie Tufenkji
Summary: New iron grafted cellulose fibers were developed for wastewater treatment to improve removal of contaminants. These fibers increased floc size and allowed for compact screening technology instead of settling tanks. When combined with a coagulant and flocculant, the fibers significantly increased nanoplastics removal and removed a high percentage of BTEX contaminants. Additionally, the fibers were washable and reusable, reducing operational costs and providing environmental benefits.
Article
Environmental Sciences
Laura M. Hernandez, Jeffrey M. Earner, Dominique Claveau-Mallet, Mira Okshevsky, Heidi Jahandideh, Sara Matthews, Ranjan Roy, Varoujan Yaylayan, Nathalie Tufenkji
Summary: This study presents an optimized procedure for using Nile red as a fluorescent staining agent to pre-screen microplastics in bottled water. The appropriate concentration of Nile red is crucial for obtaining accurate particle counts. The method was successfully used to screen microplastics in different brands of bottled water, and chemical characterization and qualitative analysis techniques were employed to identify the composition of the particles.
Article
Environmental Sciences
Ziruo Liu, Subhasis Ghoshal, Audrey Moores, Saji George
Summary: The effects of natural organic matters (NOMs) adsorbed on the surface of titanium dioxide (TiO2) nanoparticles on their band gap energy, reactive oxygen species (ROS) generation, surface chemistry and phototoxicity were investigated. The adsorption of NOM reduced the band-gap energy and ROS generation of TiO2 nanoparticles, while increasing their phototoxicity to Chlorella vulgaris.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2023)
Article
Engineering, Environmental
E. Roubeau Dumont, X. Gao, J. Zheng, J. Macairan, L. M. Hernandez, A. Baesu, S. Bayen, S. A. Robinson, S. Ghoshal, N. Tufenkji
Summary: Tire wear particle (TWP) contamination is a growing concern due to its ubiquity and toxicity in various environmental compartments. The complex mixture of chemicals in TWP and its ability to release micro- and nanoparticles in water makes it difficult to assess toxicity and predict impacts on ecosystems. Our study investigated the toxicity of dissolved chemicals and nanoparticle fractions of TWP leachate on three freshwater model species. We found acute toxicity in filter-feeder species and phytotoxicity in aquatic plants, highlighting the importance of considering the toxicity of nanoparticles.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Agriculture, Multidisciplinary
Peiying Wang, Valerie Gravel, Vinicius Bueno, Juliana A. Galhardi, Alexandra Roginski, Subhasis Ghoshal, Kevin J. Wilkinson, Stephane Bayen
Summary: This study compared the impact of two different types of nanocarriers (Allosperse and SiO2 nanoparticles) loaded with two active ingredients (azoxystrobin and bifenthrin) on the phenolic contents and metabolic profiles of strawberries. The results showed slight decreases in total phenolic content and pelargonidin 3-glucoside content, but increases in gallic acid, quercetin, and kaempferol levels in strawberries treated with the nanoencapsulated pesticides. Principal component analysis identified the effects of nanocarriers on metabolites and phenolic profiles. Overall, while the effects of nanopesticides on strawberry plants were not obvious, there were significant molecular-level changes in plant health and fruit quality. Further research is needed to assess the impact of diverse nanopesticides on other plant metabolites.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
(2023)
Article
Biochemical Research Methods
Fazel Abdolahpur Monikh, Anders Baun, Nanna B. Hartmann, Raine Kortet, Jarkko Akkanen, Jae-Seong Lee, Huahong Shi, Elma Lahive, Emilia Uurasjarvi, Nathalie Tufenkji, Korinna Altmann, Yosri Wiesner, Hans-Peter Grossart, Willie Peijnenburg, Jussi V. K. Kukkonen
Summary: This study proposes an exposure protocol that takes into account the particle-specific properties and dynamic behavior of micro- and nanoplastics (MNPs). It describes the production and characterization of more realistic MNPs as well as the development of toxicity tests in soil and aquatic environments. The protocol can be applied by students, academics, environmental risk assessors, and industries.
Article
Nanoscience & Nanotechnology
Nicholas Lin, Geoffrey Mckay, Dao Nguyen, Christopher Moraes, Nathalie Tufenkji
Summary: Mechano-bactericidal nanopillars, with specific width and spacing, were found to exhibit antibacterial properties that are dependent on bacterial concentration. Bioluminescence monitoring was shown to be a promising tool for evaluating the efficacy of such nanopillars as antibacterial coatings.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Oluwadamilola Pikuda, Laura M. Hernandez, Dahyun Kyung, Qiqing Chen, Jun-Ray Macairan, Lan Liu, Xiaoyu Gao, Stephane Bayen, Subhasis Ghoshal, Dimitrios Berk, Nathalie Tufenkji
Summary: The use of single-use face masks during the COVID-19 pandemic has resulted in indiscriminate disposal of face masks, some of which end up in the aquatic environment. These masks release microplastics and plastic-associated chemicals when exposed to environmental conditions. Limited knowledge exists about the impact of these masks on aquatic organisms. This study found that the microplastics and chemicals released from face masks had different toxic impacts on Daphnia magna, with younger daphnids being more affected.
ENVIRONMENTAL SCIENCE-NANO
(2023)
Article
Engineering, Environmental
R. S. Cheong, E. Roubeau Dumont, P. E. Thomson, D. C. Castaneda-Cortes, L. M. Hernandez, X. Gao, J. Zheng, A. Baesu, J. R. Macairan, A. J. Smith, H. N. N. Bui, H. C. E. Larsson, S. Ghoshal, S. Bayen, V. S. Langlois, S. A. Robinson, N. Tufenkji
Summary: Tire wear particles (TWP) are a potentially toxic form of plastic in the environment, but their mechanisms of toxicity are poorly understood. This study exposed the amphibian Silurana tropicalis to different fractions of TWP leachate and found that the nanoparticle fraction caused a significant decrease in survival, while the fraction containing leached chemicals caused more malformations. These results highlight the particle-specific and chemical-specific effects of TWP leachate.
JOURNAL OF HAZARDOUS MATERIALS ADVANCES
(2023)
Article
Agriculture, Multidisciplinary
Peiying Wang, Valerie Gravel, Vinicius Bueno, Juliana A. Galhardi, Subhasis Ghoshal, Kevin J. Wilkinson, Stephane Bayen
Summary: This study assessed the thermal degradation of nanoencapsulated pesticides during food processing and found that nanocarriers provide protection to the active ingredients against degradation but have no impact on the degradation product types. The degradation rate of the pesticide active ingredients was slightly affected by the nanocarriers.
ACS AGRICULTURAL SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Juliana A. Galhardi, Peiying Wang, Vinicius Bueno, Subhasis Ghoshal, Valerie Gravel, Kevin J. Wilkinson, Stephane Bayen
Summary: Polymeric and SiO2 nanoparticles can enhance the efficacy of pesticide delivery in agriculture, but have minimal impact on soil and plant health, as well as soil microbial composition and function.
ENVIRONMENTAL SCIENCE-NANO
(2022)
Article
Chemistry, Multidisciplinary
Vinicius Bueno, Peiying Wang, Orfeo Harrisson, Stephane Bayen, Subhasis Ghoshal
Summary: Porous silica nanocarriers encapsulating pesticides have minimal impacts on soil microbial community and plant development, while non-encapsulated pesticides inhibit plant growth and increase toxicity to plants. The slow release of pesticides from nanocarriers prevents phytotoxicity and promotes healthy plant growth.
ENVIRONMENTAL SCIENCE-NANO
(2022)
Article
Engineering, Environmental
Rong-Gui Zhu, Chang-Gui Pan, Feng-Jiao Peng, Chao-Yang Zhou, Jun-Jie Hu, Kefu Yu
Summary: This comprehensive survey investigated the occurrence, bioaccumulation, and trophic magnification of parabens and their metabolite 4-HB in a marine food web. Results showed that parabens were the predominant pollutants in marine organisms, with significant bioaccumulation from sediments. The estimated trophic magnification factor indicated biomagnification for MeP and trophic dilution for 4-HB. Overall, the risks for humans consuming marine organisms were found to be low.
Article
Engineering, Environmental
Andres F. Torres-Franco, Deborah Leroy-Freitas, Cristina Martinez-Fraile, Elisa Rodriguez, Pedro A. Garcia-Encina, Raul Munoz
Summary: Anaerobic and microalgae-based technologies have emerged as sustainable alternatives for municipal wastewater treatment. However, the presence of viruses in the treated wastewater is a major concern for reuse applications. This study assessed the ability of these technologies to reduce viruses during secondary wastewater treatment. The results showed that all technologies were effective in reducing the concentration of viruses, with microalgae-based treatment exhibiting the highest potential for reducing the disinfection requirements of treated wastewater.
Article
Engineering, Environmental
Young Gwang Kim, Sae Yun Kwon, Spencer J. Washburn, Scott C. Brooks, Ji Won Yoon, Lucien Besnard
Summary: The study uses Hg isotope ratios to identify the sources and exposure pathways of mercury in bivalves, finding that dissolved Hg phases in the water column are the primary source and exposure pathway to bivalves. This provides new insights into using bivalves as bioindicators for sediment quality monitoring.
Article
Engineering, Environmental
Hui Geng, Ying Xu, Rui Liu, Dianhai Yang, Xiaohu Dai
Summary: This study investigates the effect of cation exchange resin (CER) on the sequential recovery of hydrogen and methane from anaerobic digestion (AD) and the corresponding mechanisms. The results show that CER can simultaneously enhance the production of hydrogen and methane by promoting the solubilisation, hydrolysis, and acidification of organic matter. Additionally, CER facilitates effective contact between bacteria and organic particulates and reduces the energy barrier for mass transfer during methane production. The study also reveals changes in the microbial community structure and metagenomics during the AD process.
Article
Engineering, Environmental
Xiaojing Lin, Zhan Jin, Shunfeng Jiang, Zhiquan Wang, Suqing Wu, Ke Bei, Min Zhao, Xiangyong Zheng
Summary: Dehumidification combined with addition of absorbent resin supplement (ARS) was used to achieve rapid evaporation of non-pretreated urine, resulting in high water evaporation efficiency and nutrient recovery.
Article
Engineering, Environmental
Yangli Che, Chaoran Lin, Shen Li, Jiao Liu, Longhai Zhu, Shilei Yu, Nan Wang, Haoshuai Li, Mutai Bao, Yang Zhou, Tonghao Si, Rui Bao
Summary: Hydrodynamic processes play a crucial role in the transmission of sediments, microbial assembly, and organic carbon redistribution in the ocean. Through experiments and analysis, we found that hydrodynamics shape the assembly of microbial communities and control the redistribution of different sourced organic carbon, thereby influencing microbial-mediated biogeochemical transformation.
Article
Engineering, Environmental
Chao Chen, Yu Yang, Nigel J. D. Graham, Zhenyu Li, Xingtao Yang, Zhining Wang, Nadia Farhat, Johannes S. Vrouwenvelder, Li -an Hou
Summary: The fouling of seawater reverse osmosis membranes is a persistent challenge in desalination. This study monitored the operational performance of a desalination plant for 7 years and the fouling development in different areas of membrane modules. The findings showed that operational performance declined over time and fouling mainly occurred at the feed side of the modules, with the highest microbial diversity. Keystone species like Chloroflexi and Planctomycetes played an important role in maintaining community structure and biofilm maturation. Polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic substances contributed to fouling. Overall, biofouling had a significant impact on membrane fouling after 7 years of operation.
Article
Engineering, Environmental
Dan Li, Jieyi Sun, Yibo Fu, Wentao Hong, Heli Wang, Qian Yang, Junhong Wu, Sen Yang, Jianhui Xu, Yunfei Zhang, Yirong Deng, Yin Zhong, Ping'an Peng
Summary: Sulfidation-oxidation treatment of magnetite (Fe3O4) enhances the production of dark center dot OH, which can efficiently degrade dissolved organic matter (DOM) and accelerate carbon cycling.
Article
Engineering, Environmental
Cheng Yu, Kaijun Wang, Kaiyuan Zhang, Ruiyang Liu, Pingping Zheng
Summary: This study implemented a microaerobic-aerobic configuration in a full-scale municipal wastewater treatment facility and investigated the effects on sludge characteristics, pollutant removal, microbial community, and granulation mechanisms. The results showed successful transition from flocculent-activated sludge to well-defined AGS after two months of operation. The primary pathways for pollutant removal were simultaneous nitrification, denitrification, and phosphorus removal. Moreover, the incorporation of internal separators induced shifts in the flow pattern, which promoted granulation.
Article
Engineering, Environmental
Zhe Zhang, Shaoyang Hu, Guangrong Sun, Wei Wang
Summary: Halogenated aromatic disinfection byproducts (DBPs), such as halogenated phenols, have garnered widespread attention due to their high toxicity and prevalence. This study reports on the analysis, occurrence, and cytotoxicity of a group of emerging halogenated aromatic DBPs, known as halogenated polyhydroxyphenols (HPPs), in drinking water.
Article
Engineering, Environmental
Shengyue Chen, Jinliang Huang, Peng Wang, Xi Tang, Zhenyu Zhang
Summary: Accurate prediction of river water quality is crucial for sustainable water management. This study introduces wavelet analysis and transfer learning techniques to assist LSTM modeling, proposing a newly coupled modeling approach that improves short-term prediction of river water quality.
Article
Engineering, Environmental
Bang Du, Xinmin Zhan, Piet N. L. Lens, Yifeng Zhang, Guangxue Wu
Summary: Efficient anaerobic digestion relies on the cooperation of different microorganisms with different metabolic pathways. This study investigated the effects of different operational modes and the addition of powdered activated carbon (PAC) on ethanol metabolic pathways. The results showed that the SBR mode and the presence of CO2 facilitated ethanol metabolism towards propionate production, while the CFR mode with extended solids retention time enriched Geobacter. Adjusting operational modes and PAC addition can modulate anaerobic ethanol metabolism and enrich Geobacter.
Article
Engineering, Environmental
Wanfa Wang, Si-Liang Li, Jun Zhong, Yuanbi Yi, Fujun Yue, Zenglei Han, Qixin Wu, Ding He, Cong-Qiang Liu
Summary: This study compares the carbon biogeochemical processes in karst and non-karst regions within large thermal stratified river-reservoir systems. The results demonstrate that karst reservoirs have a reduced potential for carbon emissions and highlight the importance of considering geologic settings to improve accuracy in regional and global CO2 emission estimates.
Article
Engineering, Environmental
Chunxia Jiang, Zelong Zhao, Dong Zhu, Xiong Pan, Yuyi Yang
Summary: This study analyzed the occurrence and distribution of antibiotic resistance genes (ARGs) in different environmental media of the Yangtze River using metagenomics. Core resistome dominated by multidrug resistance genes was found in all samples, while rare resistome dominated by various resistance genes was more prevalent in plasmids. Specific bacteria were identified as hosts for both core and rare resistomes, with high clinical concern ARGs found in the rare resistome. Particle-associated environment provided the most ideal conditions for resistome hosts. This study provided insights into the genetic locations of ARGs and the community assembly mechanisms of ARG hosts in freshwater environments.
Article
Engineering, Environmental
Yu Zhang, Yongtao He, Linchun Jia, Lei Xu, Zheng Wang, Yueling He, Ling Xiong, Xumeng Lin, Hong Chen, Gang Xue
Summary: By synergizing organic carbon source, thiosulfate, and zero-valent iron, efficient mixotrophic denitrification of oligotrophic secondary effluent can be achieved. Thiosulfate plays a vital role in promoting TN removal efficiency, while corrosion of Fe0 releases OH- to neutralize H+ from thiosulfate-driven denitrification, creating a suitable environment for denitrification. The coordination of thiosulfate and Fe0 maintains the dominance of Thiobacillus for denitrification.