Effects of combined 4-chlorophenol and Cu2+ on functional genes for nitrogen and phosphorus removal and heavy metal resistance genes in sequencing batch bioreactors

2022 ◽  
pp. 126666
Author(s):  
Yahe Li ◽  
Jianguo Zhao ◽  
Yu Li ◽  
Baodan Jin ◽  
Lan Wang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Phosphorus Removal ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Functional Genes ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Batch Bioreactors

scholarly journals Revealing taxon-specific heavy metal-resistance mechanisms in denitrifying phosphorus removal sludge using genome-centric metaproteomics

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuan Lin ◽  
Liye Wang ◽  
Ke Xu ◽  
Kan Li ◽  
Hongqiang Ren
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Phosphorus Removal ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Energy Utilization ◽  
Nitrogen And Phosphorus ◽  
Denitrifying Phosphorus Removal ◽  
Metabolic Versatility

Abstract Background Denitrifying phosphorus removal sludge (DPRS) is widely adopted for nitrogen and phosphorus removal in wastewater treatment but faces threats from heavy metals. However, a lack of understanding of the taxon-specific heavy metal-resistance mechanisms hinders the targeted optimization of DPRS’s robustness in nutrient removal. Results We obtained 403 high- or medium-quality metagenome-assembled genomes from DPRS treated by elevating cadmium, nickel, and chromium pressure. Then, the proteomic responses of individual taxa under heavy metal pressures were characterized, with an emphasis on functions involving heavy metal resistance and maintenance of nutrient metabolism. When oxygen availability was constrained by high-concentration heavy metals, comammox Nitrospira overproduced highly oxygen-affinitive hemoglobin and electron-transporting cytochrome c-like proteins, underpinning its ability to enhance oxygen acquisition and utilization. In contrast, Nitrosomonas overexpressed ammonia monooxygenase and nitrite reductase to facilitate the partial nitrification and denitrification process for maintaining nitrogen removal. Comparisons between phosphorus-accumulating organisms (PAOs) demonstrated different heavy metal-resistance mechanisms adopted by Dechloromonas and Candidatus Accumulibacter, despite their high genomic similarities. In particular, Dechloromonas outcompeted the canonical PAO Candidatus Accumulibacter in synthesizing polyphosphate, a potential public good for heavy metal detoxification. The superiority of Dechloromonas in energy utilization, radical elimination, and damaged cell component repair also contributed to its dominance under heavy metal pressures. Moreover, the enrichment analysis revealed that functions involved in extracellular polymeric substance formation, siderophore activity, and heavy metal efflux were significantly overexpressed due to the related activities of specific taxa. Conclusions Our study demonstrates that heavy metal-resistance mechanisms within a multipartite community are highly heterogeneous between different taxa. These findings provide a fundamental understanding of how the heterogeneity of individual microorganisms contributes to the metabolic versatility and robustness of microbiomes inhabiting dynamic environments, which is vital for manipulating the adaptation of microbial assemblages under adverse environmental stimuli.

scholarly journals Retromobilization of heavy metal resistance genes in unpolluted and heavy metal polluted soil

1995 ◽  
Vol 18 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Eva M. Top ◽  
Helene Rore ◽  
Jean-Marc Collard ◽  
Veerle Gellens ◽  
Galina Slobodkina ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Polluted Soil

scholarly journals Isolation and Molecular Identification of Virulence, Antimicrobial and Heavy Metal Resistance Genes in Livestock-Associated Methicillin-Resistant Staphylococcus aureus

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 79 ◽  
Author(s):  
Chumisa C. Dweba ◽  
Oliver T. Zishiri ◽  
Mohamed E. El Zowalaty
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Staphylococcus Aureus ◽  
South African ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Livestock Production ◽  
Metal Resistance ◽  
Diffusion Method ◽  
Methicillin Resistant

Staphylococcus aureus is one of the most important pathogens of humans and animals. Livestock production contributes a significant proportion to the South African Gross Domestic Product. Consequently, the aim of this study was to determine for the first time the prevalence, virulence, antibiotic and heavy metal resistance in livestock-associated S. aureus isolated from South African livestock production systems. Microbial phenotypic methods were used to detect the presence of antibiotic and heavy metal resistance. Furthermore, molecular DNA based methods were used to genetically determine virulence as well as antibiotic and heavy metal resistance determinants. Polymerase chain reaction (PCR) confirmed 217 out of 403 (53.8%) isolates to be S. aureus. Kirby-Bauer disc diffusion method was conducted to evaluate antibiotic resistance and 90.8% of S. aureus isolates were found to be resistant to at least three antibiotics, and therefore, classified as multidrug resistant. Of the antibiotics tested, 98% of the isolates demonstrated resistance towards penicillin G. High resistance was shown against different heavy metals, with 90% (196/217), 88% (192/217), 86% (188/217) and 84% (183/217) of the isolates resistant to 1500 µg/mL concentration of Cadmium (Cd), Zinc (Zn), Lead (Pb) and Copper (Cu) respectively. A total of 10 antimicrobial resistance and virulence genetic determinants were screened for all livestock associated S. aureus isolates. Methicillin-resistant S. aureus (MRSA) isolates were identified, by the presence of mecC, in 27% of the isolates with a significant relationship (p < 0.001)) with the host animal. This is the first report of mecC positive LA-MRSA in South Africa and the African continent. The gene for tetracycline resistance (tetK) was the most frequently detected of the screened genes with an overall prevalence of 35% and the highest prevalence percentage was observed for goats (56.76%) followed by avian species (chicken, duck and wild birds) (42.5%). Virulence-associated genes were observed across all animal host species. The study reports the presence of luks/pv, a gene encoding the PVL toxin previously described to be a marker for community acquired-MRSA, suggesting the crossing of species between human and livestock. The high prevalence of S. aureus from the livestock indicates a major food security and healthcare threat. This threat is further compounded by the virulence of the pathogen, which causes numerous clinical manifestations. The phenomenon of co-selection is observed in this study as isolates exhibited resistance to both antibiotics and heavy metals. Further, all the screened antibiotic and heavy metal resistance genes did not correspond with the phenotypic resistance.

Detection of Heavy Metal Resistance Genes in an Environmental Pseudomonas aeruginosa Isolate

2016 ◽  
Vol 17 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Alaa Mihdir ◽  
Abdulrahman Assaeedi ◽  
Hussein Abulreesh ◽  
Gamal Osman
Keyword(s):  
Heavy Metal ◽  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Metal Resistance

scholarly journals Co-selection of antibiotic and heavy metal resistance in freshwater bacteria

2016 ◽  
Vol 75 (s2) ◽  
Author(s):  
Andrea Di Cesare ◽  
Ester Eckert ◽  
Gianluca Corno
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Resistant Bacteria ◽  
Human Pathogens ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Selection Of

<p class="p1">Antibiotic resistant bacteria are found in most environments, especially in highly anthropized waters. A direct correlation between human activities (<em><span class="s1">e.g., </span></em>pollution) and spread and persistence of antibiotic resistant bacteria (ARB) and resistance genes (ARGs) within the resident bacterial communities appears more and more obvious. Furthermore, the threat posed for human health by the presence of ARB and ARGs in these environments is enhanced by the risk of horizontal gene transfer of resistance genes to human pathogens. Although the knowledge on the spread of antibiotic resistances in waters is increasing, the understanding of the driving factors determining the selection for antibiotic resistance in the environment is still scarce. Antibiotic pollution is generally coupled with contamination by heavy metals (HMs) and other chemicals, which can also promote the development of resistance mechanisms, often through co-selecting for multiple resistances. The co-selection of heavy metal resistance genes and ARGs in waters, sediments, and soils, increases the complexity of the ecological role of ARGs, and reduces the effectiveness of control actions. In this mini-review we present the state-of-the-art of the research on antibiotic- and HM-resistance and their connection in the environment, with a focus on HM pollution and aquatic environments. We review the spread and the persistence of HMs and/or ARB, and how it influences their respective gene co-selection. In the last chapter, we propose Lake Orta, a system characterized by an intensive HM pollution followed by a successful restoration of the chemistry of the water column, as a study-site to evaluate the spread and selection of HMs and antibiotic resistances in heavily disturbed environments.</p>

Structure analysis of bacterial community and their heavy-metal resistance determinants in the heavy-metal-contaminated soil sample

Biologia ◽  
2012 ◽  
Vol 67 (6) ◽  
Author(s):  
Jana Harichová ◽  
Edita Karelová ◽  
Domenico Pangallo ◽  
Peter Ferianc
Keyword(s):  
Heavy Metal ◽  
Soil Sample ◽  
16S Rdna ◽  
Resistance Genes ◽  
Contaminated Soil ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Resistance Determinants ◽  
Cultivable Bacteria ◽  
Rdna Sequences

AbstractIn this study we performed the phylogenetic analysis of non-cultivable bacteria from anthropogenically disturbed soil using partial sequences of the 16S rRNA (16S rDNA) and the heavy-metal resistance genes. This soil sample contained high concentrations of nickel (2,109 mg/kg), cobalt (355 mg/kg) and zinc (177 mg/kg), smaller concentrations of iron (35.75 mg/kg) and copper (32.2 mg/kg), and also a trace amount of cadmium (<0.25 mg/kg). The 16S rDNA sequences from a total of 74 bacterial clones were distributed into four broad taxonomic groups, Acidobacteria, Actinobacteria, Bacteroidetes and Gemmatimonadetes, and some of them were unidentified. Comparing our clone sequences with those from the GenBank database, only 9 clones displayed high similarity to known bacteria belongig to actinomycetes; others were identified as uncultured ones. Among clones evidently Actinobacteria predominated. Sixteen clones from soil sample carried only the nccA-like heavy-metal-resistance genes and all sequences showed too low similarity to known proteins encoded by these genes. However, our results suggested that the heavy-metal-contaminated soil is able to present very important reservoir of the new and until now unknown partly bacteria, partly heavy-metal-resistance determinants and their products. Bacteria and nccA-like genes identified in this study could represent the objects of interest as bioremediation agents because they can be potentially used in different transformation and immobilization processes.

scholarly journals Bacterial Heavy Metal Resistance Genes and Bioremediation Potential

2019 ◽  
Vol 09 (01) ◽  
pp. 1-12 ◽  
Author(s):  
Hannah Johnson ◽  
Hyuk Cho ◽  
Madhusudan Choudhary
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Metal Resistance
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