RECALCITRANT - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
788700.9921Double-edged sword effects of sulfate reduction process in sulfur autotrophic denitrification system: Accelerating nitrogen removal and promoting antibiotic resistance genes spread. This study proposed the double-edged sword effects of sulfate reduction process on nitrogen removal and antibiotic resistance genes (ARGs) transmission in sulfur autotrophic denitrification system. Excitation-emission matrix-parallel factor analysis identified the protein-like fraction in soluble microbial products as main endogenous organic matter driving the sulfate reduction process. The resultant sulfide tended to serve as bacterial modulators, augmenting electron transfer processes and mitigating oxidative stress, thereby enhancing sulfur oxidizing bacteria (SOB) activity, rather than extra electron donors. The cooperation between SOB and heterotroph (sulfate reducing bacteria (SRB) and heterotrophic denitrification bacteria (HDB)) were responsible for advanced nitrogen removal, facilitated by multiple metabolic pathways including denitrification, sulfur oxidation, and sulfate reduction. However, SRB and HDB were potential ARGs hosts and assimilatory sulfate reduction pathway positively contributed to ARGs spread. Overall, the sulfate reduction process in sulfur autotrophic denitrification system boosted nitrogen removal process, but also increased the risk of ARGs transmission.202439122125
855210.9921Sustainable material platforms for multi-log removal of antibiotic-resistant bacteria and genes from wastewater: A review. Antibiotic-resistant bacteria (ARB) and the associated resistance genes (ARGs) are now recognized as emerging contaminants that can disseminate via wastewater streams, posing significant risks to both human and ecosystem health. Conventional physicochemical treatment approaches (e.g., chlorination, ozonation, advanced oxidation processes) typically suppress these contaminants but may also result in the formation of hazardous by-products. This critical review comprehensibly evaluates bio-based and other sustainable materials designed for the removal of ARB and ARGs from aqueous environments. The materials are systematically categorized into (i) biopolymers and their composites (chitosan, alginate, cellulose), (ii) carbon-rich adsorbents and (photo-)catalysts (biochar, activated carbon, graphene), (iii) metal- and semiconductor-based nanomaterials, and (iv) nature-based treatment solutions (constructed wetlands, soil-aquifer treatment, clay sorbents). Observed log-reduction value range from 2 to 7 for ARB with platforms such as zinc oxide/activated-carbon alginate beads, Fe/N-doped biochars, and graphene-supramolecular-porphyrin hybrids demonstrating high multifunctional efficacy. Mechanistic studies reveal that removal involves synergistic adsorption, photodynamic or Fenton-like oxidation, cell-membrane disruption, and inhibition of horizontal gene transfer. This review emphasizes the advancing potential of sustainable material solutions for mitigating antibiotic resistance and highlights the urgent need to develop scalable, environmentally sustainable treatment methods for protecting water resources and public health.202540763861
855320.9919Unveiling the power of nanotechnology: a novel approach to eliminating antibiotic-resistant bacteria and genes from municipal effluent. The increasing global population and declining freshwater resources have heightened the urgency of ensuring safe and accessible water supplies.Query The persistence of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) in municipal effluents poses a significant public health threat, exacerbated by the widespread use of antibiotics and the inadequate removal of contaminants in wastewater treatment facilities. Conventional treatment methods often fail to eliminate these emerging pollutants, facilitating their entry into agricultural systems and natural water bodies, thereby accelerating the spread of antimicrobial resistance. To address these challenges, interdisciplinary strategies in water treatment are essential. Nanotechnology has emerged as a promising approach due to its unique physicochemical properties, biocompatibility, and high efficiency in detecting and removing biological and chemical contaminants. Various nanomaterials, including graphene-based structures, Carbon nanotubes (CNTs), noble metal nanoparticles (gold (Au) and silver (Ag)), silicon and chitosan-based nanomaterials, as well as titanium and Zinc oxide (ZnO) nanomaterials, demonstrate potent antimicrobial effects. Moreover, nanosensors and photocatalysts utilizing these nanomaterials enable precise detection and effective degradation of ARB and ARGs in wastewater. This review examines the mechanisms by which nanotechnology-based materials can mitigate the risks associated with antibiotic resistance in urban effluents, focusing on their applications in pathogen detection, pollutant removal, and wastewater treatment. By integrating nanotechnology into existing treatment frameworks, we can significantly enhance the efficiency of water purification processes, ultimately contributing to global water security and the protection of public health.202540512401
861630.9918Mechanisms of inhibition and recovery under multi-antibiotic stress in anammox: A critical review. With the escalating global concern for emerging pollutants, particularly antibiotics, microplastics, and nanomaterials, the potential disruption they pose to critical environmental processes like anaerobic ammonia oxidation (anammox) has become a pressing issue. The anammox process, which plays a crucial role in nitrogen removal from wastewater, is particularly sensitive to external pollutants. This paper endeavors to address this knowledge gap by providing a comprehensive overview of the inhibition mechanisms of multi-antibiotic on anaerobic ammonia-oxidizing bacteria, along with insights into their recovery processes. The paper dives deeply into the various ways antibiotics interact with anammox bacteria, focusing specifically on their interference with the bacteria's extracellular polymers (EPS) - crucial components that maintain the structural integrity and functionality of the cells. Additionally, it explores how anammox bacteria utilize quorum sensing (QS) mechanisms to regulate their community structure and respond to antibiotic stress. Moreover, the paper summarizes effective removal methods for these antibiotics from wastewater systems, which is crucial for mitigating their inhibitory effects on anammox bacteria. Finally, the paper offers valuable insights into how anammox communities can recuperate from multi-antibiotic stress. This includes strategies for reintroducing healthy bacteria, optimizing operational conditions, and using bioaugmentation techniques to enhance the resilience of anammox communities. In summary, this paper not only enriches our understanding of the complex interactions between antibiotics and anammox bacteria but also provides theoretical and practical guidance for the treatment of antibiotic pollution in sewage, ensuring the sustainability and effectiveness of wastewater treatment processes.202439366232
860940.9917Nano-biochar regulates phage-host interactions, reducing antibiotic resistance genes in vermicomposting systems. Biochar amendment reshapes microbial community dynamics in vermicomposting, but the mechanism of how phages respond to this anthropogenic intervention and regulate the dissemination of antibiotic resistance genes (ARGs) remains unclear. In this study, we used metagenomics, viromics, and laboratory validation to explore how nano-biochar affects phage-host interactions and ARGs dissemination in vermicomposting. Our results revealed distinct niche-specific phage life strategies. In vermicompost, lytic phages dominated and used a "kill-the-winner" strategy to suppress antibiotic-resistant bacteria (ARB). In contrast, lysogenic phages prevailed in the earthworm gut, adopting a "piggyback-the-winner" strategy that promoted ARGs transduction through mutualistic host interactions. Nano-biochar induced the conversion of lysogenic to lytic phages in the earthworm gut, while concurrently reducing the abundance of lysogenic phages and their encoded auxiliary metabolic genes carried by ARB. This shift disrupted phage-host mutualism and inhibited ARGs transmission via a "phage shunting" mechanism. In vitro validation with batch culture experiments further confirmed that lysogenic phages increased transduction of ARGs in the earthworm gut, while nano-biochar reduced the spread of ARGs by enhancing lysis infectivity. Our study constructs a mechanistic framework linking nano-biochar induced shifts in phage lifestyles that suppress ARG spread, offering insights into phage-host coadaptation and resistance mitigation strategies in organic waste treatment ecosystems.202540838886
864450.9917Biotic and abiotic drivers of soil carbon, nitrogen and phosphorus and metal dynamic changes during spontaneous restoration of Pb-Zn mining wastelands. The biotic and abiotic mechanisms that drive important biogeochemical processes (carbon, nitrogen, phosphorus and metals dynamics) in metal mine revegetation remains elusive. Metagenomic sequencing was used to explored vegetation, soil properties, microbial communities, functional genes and their impacts on soil processes during vegetation restoration in a typical Pb-Zn mine. The results showed a clear niche differentiation between bacteria, fungi and archaea. Compared to bacteria and fungi, the archaea richness were more tightly coupled with natural restoration changes. The relative abundances of CAZyme-related, denitrification-related and metal resistance genes reduced, while nitrification, urease, inorganic phosphorus solubilisation, phosphorus transport, and phosphorus regulation -related genes increased. Redundancy analysis, hierarchical partitioning analysis, relative-importance analysis and partial least squares path modelling, indicated that archaea diversity, primarily influenced by available lead, directly impacts carbon dynamics. Functional genes, significantly affected by available cadmium, directly alter nitrogen dynamics. Additionally, pH affects phosphorus dynamics through changes in bacterial diversity, while metal dynamics are directly influenced by vegetation. These insights elucidate natural restoration mechanisms in mine and highlight the importance of archaea in soil processes.202540054196
787360.9916Wheat straw pyrochar more efficiently decreased enantioselective uptake of dinotefuran by lettuce and dissemination of antibiotic resistance genes than hydrochar in an agricultural soil. Remediation of soils pollution caused by dinotefuran, a chiral pesticide, is indispensable for ensuring human food security. In comparison with pyrochar, the effect of hydrochar on enantioselective fate of dinotefuran, and antibiotic resistance genes (ARGs) profiles in the contaminated soils remain poorly understood. Therefore, wheat straw hydrochar (SHC) and pyrochar (SPC) were prepared at 220 and 500 °C, respectively, to investigate their effects and underlying mechanisms on enantioselective fate of dinotefuran enantiomers and metabolites, and soil ARG abundance in soil-plant ecosystems using a 30-day pot experiment planted with lettuce. SPC showed a greater reduction effect on the accumulation of R- and S-dinotefuran and metabolites in lettuce shoots than SHC. This was mainly resulted from the lowered soil bioavailability of R- and S-dinotefuran due to adsorption/immobilization by chars, together with the char-enhanced pesticide-degrading bacteria resulted from increased soil pH and organic matter content. Both SPC and SHC efficiently reduced ARG levels in soils, owing to lowered abundance of ARG-carrying bacteria and declined horizontal gene transfer induced by decreased dinotefuran bioavailability. The above results provide new insights for optimizing char-based sustainable technologies to mitigate pollution of dinotefuran and spread of ARGs in agroecosystems.202336996986
855470.9916Nanomaterial-Enhanced Hybrid Disinfection: A Solution to Combat Multidrug-Resistant Bacteria and Antibiotic Resistance Genes in Wastewater. This review explores the potential of nanomaterial-enhanced hybrid disinfection methods as effective strategies for addressing the growing challenge of multidrug-resistant (MDR) bacteria and antibiotic resistance genes (ARGs) in wastewater treatment. By integrating hybrid nanocomposites and nanomaterials, natural biocides such as terpenes, and ultrasonication, this approach significantly enhances disinfection efficiency compared to conventional methods. The review highlights the mechanisms through which hybrid nanocomposites and nanomaterials generate reactive oxygen species (ROS) under blue LED irradiation, effectively disrupting MDR bacteria while improving the efficacy of natural biocides through synergistic interactions. Additionally, the review examines critical operational parameters-such as light intensity, catalyst dosage, and ultrasonication power-that optimize treatment outcomes and ensure the reusability of hybrid nanocomposites and other nanomaterials without significant loss of photocatalytic activity. Furthermore, this hybrid method shows promise in degrading ARGs, thereby addressing both microbial and genetic pollution. Overall, this review underscores the need for innovative wastewater treatment solutions that are efficient, sustainable, and scalable, contributing to the global fight against antimicrobial resistance.202439591087
854880.9916Persulfate salts to combat bacterial resistance in the environment through antibiotic degradation and biofilm disruption. Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) have become a critical topic among researchers because of the excessive use of antibiotics in human and animal health care. Globally, it poses a serious threat to human health and the environment. Antibiotics are often poorly metabolized, with 30-90 % excreted into the environment, contaminating aquatic and ground ecosystems, and fostering resistance. Advanced oxidation processes (AOPs), particularly sulfate radical-based AOPs (SR-AOPs), offer promising solutions for degrading antibiotics and resistant biofilms. Persulfate (PS) and Peroxymonosulfate (PMS) are key oxidants in these processes, generating sulfate and hydroxyl radicals when activated by heat, UV light, or transition metals. PS with a redox potential of E°=2.01 V is an affordable and effective oxidant. However, PS requires activation for the degradation of contaminants. PMS is stable across a broad pH range and produces both sulfate and hydroxyl radicals, allowing it to function independently without activation. Thus, PMS serving as a versatile agent for environmental treatment. This review broadly describes the degradation mechanisms of different classes of antibiotics and biofilms. Despite these promising developments, SR-AOPs still face challenges in managing complex wastewater systems, which often contain multiple pollutants. Moreover, gaps remain in understanding of the toxicity of reaction intermediates and in optimizing the large-scale application of these processes. Future research should focus on the in-situ generation of sulfate radicals, combining different activation methods to enhance degradation efficiency, and developing sustainable and cost-effective approaches for large-scale wastewater treatment.202540532556
877290.9916The role of drought response genes and plant growth promoting bacteria on plant growth promotion under sustainable agriculture: A review. Drought is a major stressor that poses significant challenges for agricultural practices. It becomes difficult to meet the global demand for food crops and fodder. Plant physiology, physico-chemistry and morphology changes in plants like decreased photosynthesis and transpiration rate, overproduction of reactive oxygen species, repressed shoot and root shoot growth and modified stress signalling pathways by drought, lead to detrimental impacts on plant development and output. Coping with drought stress requires a variety of adaptations and mitigation techniques. Crop yields could be effectively increased by employing plant growth-promoting rhizobacteria (PGPR), which operate through many mechanisms. These vital microbes colonise the rhizosphere of crops and promote drought resistance by producing exopolysaccharides (EPS), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phytohormones including volatile compounds. The upregulation or downregulation of stress-responsive genes causes changes in root architecture due to acquiring drought resistance. Further, PGPR induces osmolyte and antioxidant accumulation. Another key feature of microbial communities associated with crops includes induced systemic tolerance and the production of free radical-scavenging enzymes. This review is focused on detailing the role of PGPR in assisting plants to adapt to drought stress.202439002396
7926100.9916Microplastics Exacerbated Conjugative Transfer of Antibiotic Resistance Genes during Ultraviolet Disinfection: Highlighting Difference between Conventional and Biodegradable Ones. Microplastics (MPs) have been confirmed as a hotspot for antibiotic resistance genes (ARGs) in wastewater. However, the impact of MPs on the transfer of ARGs in wastewater treatment remains unclear. This study investigated the roles and mechanisms of conventional (polystyrene, PS) and biodegradable (polylactic acid, PLA) MPs in the conjugative transfer of ARGs during ultraviolet disinfection. The results showed that MPs significantly facilitated the conjugative transfer of ARGs compared with individual ultraviolet disinfection, and PSMPs exhibited higher facilitation than PLAMPs. The facilitation effects were attributed to light shielding and the production of reactive oxygen species (ROS) and nanoplastics from ultraviolet irradiation of MPs. The light shielding of MPs protected the bacteria and ARGs from ultraviolet inactivation. More importantly, ROS and nanoplastics generated from irradiated MPs induced intracellular oxidative stress on bacteria and further increased the cell membrane permeability and intercellular contact, ultimately enhancing the ARG exchange. The greater fragmentation of PSMPs than PLAMPs resulted in a higher intracellular oxidative stress and a stronger enhancement. This study highlights the concerns of conventional and biodegradable MPs associated with the transfer of ARGs during wastewater treatment, which provides new insights into the combined risks of MPs and ARGs in the environment.202539723446
8163110.9915Green materials science and engineering reduces biofouling: approaches for medical and membrane-based technologies. Numerous engineered and natural environments suffer deleterious effects from biofouling and/or biofilm formation. For instance, bacterial contamination on biomedical devices pose serious health concerns. In membrane-based technologies, such as desalination and wastewater reuse, biofouling decreases membrane lifetime, and increases the energy required to produce clean water. Traditionally, approaches have combatted bacteria using bactericidal agents. However, due to globalization, a decline in antibiotic discovery, and the widespread resistance of microbes to many commercial antibiotics and metallic nanoparticles, new materials, and approaches to reduce biofilm formation are needed. In this mini-review, we cover the recent strategies that have been explored to combat microbial contamination without exerting evolutionary pressure on microorganisms. Renewable feedstocks, relying on structure-property relationships, bioinspired/nature-derived compounds, and green processing methods are discussed. Greener strategies that mitigate biofouling hold great potential to positively impact human health and safety.201525852659
8615120.9915How anammox responds to the emerging contaminants: Status and mechanisms. Numerous researches have been carried out to study the effects of emerging contaminants in wastewater, such as antibiotics, nanomaterials, heavy metals, and microplastics, on the anammox process. However, they are fragmented and difficult to provide a comprehensive understanding of their effects on reactor performance and the metabolic mechanisms in anammox bacteria. Therefore, this paper overviews the effects on anammox processes by the introduced emerging contaminants in the past years to fulfill such knowledge gaps that affect our perception of the inhibitory mechanisms and limit the optimization of the anammox process. In detail, their effects on anammox processes from the aspects of reactor performance, microbial community, antibiotic resistance genes (ARGs), and functional genes related to anammox and nitrogen transformation in anammox consortia are summarized. Furthermore, the metabolic mechanisms causing the cell death of anammox bacteria, such as induction of reactive oxygen species, limitation of substrates diffusion, and membrane binding are proposed. By offering this review, the remaining research gaps are identified, and the potential metabolic mechanisms in anammox consortia are highlighted.202134087646
8549130.9915Current perspectives on microalgae and extracellular polymers for reducing antibiotic resistance genes in livestock wastewater. Antibiotic resistance genes (ARGs) in livestock wastewater resulting from excessive antibiotics used in animal farming pose significant environmental and public health risks. Conventional treatment methods are often costly, inefficient, and may inadvertently promote ARG transmission. Microalgae, with their long genetic distance from bacteria and strong ability to utilize wastewater nutrients, offer a sustainable solution for ARG mitigation. This review studied the abundance and characterization of ARGs in livestock wastewater, highlighted microalgal-based removal mechanisms of ARGs, including phagocytosis, competition, and absorption by extracellular polymeric substances (EPS), and explored factors influencing their efficacy. Notably, the microalgae-EPS system reduced ARGs by 0.62-3.00 log, demonstrating significant potential in wastewater treatment. Key challenges, such as optimizing algal species, understanding EPS-ARG interactions, targeted reduction of host bacteria, and scaling technologies, were discussed. This work provides critical insights for advancing microalgal-based strategies for ARG removal, promoting environmentally friendly and efficient wastewater management.202540324729
8568140.9914Bioremediation potential of sulfadiazine-degrading bacteria: Impacts on ryegrass growth and soil functionality. The extensive use of antibiotics, particularly sulfadiazine (SDZ), has led to significant environmental contamination and the proliferation of antibiotic resistance genes (ARGs). This study investigates the bioremediation potential of two SDZ-degrading bacterial strains, Acinetobacter sp. M9 and Enterobacter sp. H1, and their impact on ryegrass (Lolium perenne) growth and the inter-root microenvironment in SDZ-contaminated soils. A pot experiment combined with amplicon and metagenomic sequencing revealed that inoculation with M9 and H1 significantly enhanced ryegrass growth by alleviating oxidative stress, increasing chlorophyll content, and improving soil nutrient availability. The strains also promoted SDZ degradation efficiency and improved carbon and nitrogen cycling through the upregulation of key functional genes. Furthermore, microbial community analysis demonstrated increased alpha diversity, shifts in dominant taxa, and functional enrichment in pollutant degradation pathways. The dynamics of ARGs revealed a decrease in aminoglycoside, rifamycin, and streptomycin resistance genes, while sulfonamide resistance genes increased due to the residual SDZ stress. These findings highlight the potential of M9 and H1 as sustainable bioremediation agents to mitigate antibiotic contamination, improve soil health, and support plant growth in polluted environments.202540122011
8569150.9914Indole-3-acetic acid-mediated root exudates as potential inhibitors of antibiotic resistance genes in the rhizosphere microbiome: Mechanistic insights into microbial community assembly and resistome dissemination. Although the threat of antibiotic resistance genes (ARGs) in agriculture to human health has raised concerns, there is still a lack of effective and environmentally friendly measures to mitigate antibiotic resistance. Indole-3-acetic acid (IAA) and root exudates are environmentally friendly natural substances. However, the development of technologies harnessing their potential to suppress agricultural ARGs remains unexplored. Here, IAA-mediated key root exudates, N-acetylserotonin and N-methyltryptamine, were found to effectively reduce ARGs in rhizosphere soil. They affected microbial community assembly and further shaped ARGs profiles. Additionally, they inhibited antibiotic-resistant bacteria, potentially suppressing the vertical transfer of ARGs. More importantly, N-acetylserotonin and N-methyltryptamine inhibited ARGs conjugative transfer through suppressing pili assembly and homologous recombination. Overall, IAA-mediated root exudates reduce ARGs in rhizosphere soil by influencing microbial community assembly and inhibiting ARGs transfer. This study provides inspiration for the development of technologies related to plant auxins and root exudates to reduce ARGs in agriculture.202540850579
8613160.9914Insights into the role of extracellular polymeric substances (EPS) in the spread of antibiotic resistance genes. Antibiotic resistance genes (ARG) are prevalent in aquatic environments. Discharge from wastewater treatment plants is an important point source of ARG release into the environment. It has been reported that biological treatment processes may enhance rather than remove ARG because of their presence in sludge. Attenuation of ARG in biotechnological processes has been studied in depth, showing that many microorganisms can secrete complex extracellular polymeric substances (EPS). These EPS can serve as multifunctional elements of microbial communities, involving aspects, such as protection, structure, recognition, adhesion, and physiology. These aspects can influence the interaction between microbial cells and extracellular ARG, as well as the uptake of extracellular ARG by microbial cells, thus changing the transformative capability of extracellular ARG. However, it remains unclear whether EPS can affect horizontal ARG transfer, which is one of the main processes of ARG dissemination. In light of this knowledge gap, this review provides insight into the role of EPS in the transmission of ARGs; furthermore, the mechanism of ARG spread is analyzed, and the molecular compositions and functional properties of EPS are summarized; also, how EPS influence ARG mitigation is addressed, and factors impacting how EPS facilitate ARG during wastewater treatment are summarized. This review provides comprehensive insights into the role of EPS in controlling the transport and fate of ARG during biodegradation processes at the mechanistic level.202438169168
8651170.9914Repercussions of Prolonged Pesticide Use on Natural Soil Microbiome Dynamics Using Metagenomics Approach. The residual pesticides in soil can affect the natural microbiome composition and genetic profile that drive nutrient cycling and soil fertility. In the present study, metagenomic approach was leveraged to determine modulations in nutrient cycling and microbial composition along with connected nexus of pesticide, antibiotic, and heavy metal resistance in selected crop and fallow soils having history of consistent pesticide applications. GC-MS analysis estimated residuals of chlorpyrifos, hexachlorbenzene, and dieldrin showing persistent nature of pesticides that pose selective pressure for microbial adaptation. Taxonomic profiling showed increased abundance of pesticide degrading Streptomyces, Xanthomonas, Cupriavidus, and Pseudomonas across the selected soils. Genes encoding for pesticide degrading cytochrome p450, organophosphorus hydrolase, aldehyde dehydrogenase, and oxidase were predominant and positively correlated with Bacillus, Sphingobium, and Burkholderia. Nitrogen-fixing genes (nifH, narB, and nir) were relatively less abundant in crop soils, correlating to the decrease in nitrogen-fixing bacteria (Anabaena, Pantoea, and Azotobacter). Microbial enzymes involved in carbon (pfkA, gap, pgi, and tpiA) and phosphorus cycle (gmbh and phnJ) were significantly higher in crop soils indicating extensive utilization of pesticide residuals as a nutrient source by the indigenous soil microbiota. Additionally, presence of antibiotic and heavy metal resistance genes suggested potential cross-resistance under pressure from pesticide residues. The results implied selective increase in pesticide degrading microbes with decrease in beneficial bacteria that resulted in reduced soil health and fertility. The assessment of agricultural soil microbial profile will provide a framework to develop sustainable agriculture practices to conserve soil health and fertility.202539096471
8638180.9914Enhancing phytoremediation through the use of transgenics and endophytes. In the last decade, there has been an increase in research on improving the ability of plants to remove environmental pollution. Genes from microbes, plants, and animals are being used successfully to enhance the ability of plants to tolerate, remove, and degrade pollutants. Through expression of specific bacterial genes in transgenic plants, the phytotoxic effects of nitroaromatic pollutants were overcome, resulting in increased removal of these chemicals. Overexpression of mammalian genes encoding cytochrome P450s led to increased metabolism and removal of a variety of organic pollutants and herbicides. Genes involved in the uptake or detoxification of metal pollutants were used to enhance phytoremediation of this important class of pollutants. Transgenic plants containing specific bacterial genes converted mercury and selenium to less toxic forms. In addition to these transgenic approaches, the use of microbes that live within plants, termed endophytes, also led to improved tolerance to normally phytotoxic chemicals and increased removal of the pollutants. Bacteria that degraded a herbicide imparted resistance to the herbicide when inoculated into plants. In another study, plants harboring bacteria capable of degrading toluene were more tolerant to normally phytotoxic concentrations of the chemical, and transpired less of it into the atmosphere. This review examines the recent advances in enhancing phytoremediation through transgenic plant research and through the use of symbiotic endophytic microorganisms within plant tissues.200819086174
8134190.9914Sweet scents from good bacteria: Case studies on bacterial volatile compounds for plant growth and immunity. Beneficial bacteria produce diverse chemical compounds that affect the behavior of other organisms including plants. Bacterial volatile compounds (BVCs) contribute to triggering plant immunity and promoting plant growth. Previous studies investigated changes in plant physiology caused by in vitro application of the identified volatile compounds or the BVC-emitting bacteria. This review collates new information on BVC-mediated plant-bacteria airborne interactions, addresses unresolved questions about the biological relevance of BVCs, and summarizes data on recently identified BVCs that improve plant growth or protection. Recent explorations of bacterial metabolic engineering to alter BVC production using heterologous or endogenous genes are introduced. Molecular genetic approaches can expand the BVC repertoire of beneficial bacteria to target additional beneficial effects, or simply boost the production level of naturally occurring BVCs. The effects of direct BVC application in soil are reviewed and evaluated for potential large-scale field and agricultural applications. Our review of recent BVC data indicates that BVCs have great potential to serve as effective biostimulants and bioprotectants even under open-field conditions.201626177913