Explore the vast range of titles available.

Microorganisms in the soil that have been contaminated with heavy metals for a long-time exhibited resistance to heavy metals. In recent years, the use of resistant microbes and heavy metal-tolerant plants to repair heavy metal-contaminated soil has become an increasingly hot subject. In this study, heavy metal-tolerant bacteria ZG7 was isolated from the mining soils and injected into Bidens pilosa L. and Medicago sativa L.. The results revealed that: (1) Compared to the non-inoculated group, inoculation with ZG7 notably increased the dry weight and chlorophyll content in plants under heavy metal stress, as well as promoted the content of several types of antioxidant chemicals; (2) Combined remediation improved soil enzyme activities, with soil catalase, sucrase, and phosphatase activities remarkably increased by 136.06%, 124.17% and 180.14% in the ZG7- Bidens pilosa L.; And soil catalase, urease, and sucrase activities promoted by 68.07%, 130.08% and 239.79% in the ZG7- Medicago sativa L.; (3) The content of Pb and Zn in the ZG7- Medicago sativa L. combination soil were considerably lower (9.28% and 6.2%, respectively) than no strain group, but there was no substantial change in soil heavy metal content when combined with the Bidens pilosa L. remediation when compared to no strain group. In summary, the combination of strain ZG7 and plants had a good effect on the remediation of heavy metal contaminated soils, and ZG7- Medicago sativa L. had the best effect, which is a reliable technique for effective control of heavy metal pollution. This study provided theoretical support for microbial-phytoremediation joint remediation.

Chromium, being among the most toxic heavy metals, continues to demand immediate attention in the remediation of Cr-contaminated environments. In this study, a strain of LBA36 ( Bacillus toyonensis ) was isolated from heavy metal contaminated soil in Luanchuan County, Luoyang City, China. The reduction and adsorption rates of LBA36 in 30 mg·L −1 Cr-containing medium were 97.95% and 8.8%, respectively. The reduction mechanism was confirmed by Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). Cr(VI) reduction by this strain predominantly occurred outside the cell, with hydroxyl, amide, carboxyl, C-N group, carbonyl, and sulfur carbonyl as the main reaction sites. XPS analysis revealed the presence of Cr 2p1/2 and Cr 2p3/2 . Furthermore, the hydroponic experiment showed that the fresh weight and plant height of radish seedlings increased by 87.87% and 37.07%, respectively, after inoculation with LBA36 strain under 7 mg·L −1 Cr(VI) stress. The levels of chlorophyll, total protein, malondialdehyde, superoxide dismutase and catalase were also affected to different degrees. In conclusion, this study demonstrated the potential of microbial and phytoremediation in the treatment of heavy metal toxicity, and laid the foundation for the development of effective bioremediation methods for Cr(VI) pollution.

To address yttrium (Y) contamination from ion adsorption mining, this study developed a combined microbial phytoremediation strategy for dual objectives: ensuring crop safety in and enhancing Y recovery by . Two specific microbial consortia were constructed from rare earth tailings isolates: inoculant I (bacterial: sp., sp., sp.) applied to , and inoculant II (fungal: sp., sp., sp.) applied to . Inoculant I increased biomass by 26% while reducing Y content in roots and rhizosphere soil solution by 47% and 56%, respectively, potentially through down-regulation of amino acid metabolites. Inoculant II increased Y content in the rhizosphere soil solution by 89%, linked to up-regulation of organic acids and coumarin derivatives. Both consortia reduced plant stress markers and enhanced soil enzyme activities. These findings demonstrate that specialized microbial consortia can differentially regulate Y behavior in the rhizosphere-immobilizing it in a crop for food safety, while enhancing its bioavailability for a hyperaccumulator-offering a targeted strategy for managing rare earth element-contaminated agricultural soils.

Manipulation of bio-technological processes in treatment of dyestuffs has attracted considerable attention, because a large proportion of these synthetic dyes enter into natural environment during synthesis and dyeing operations that contaminates different ecosystems. Moreover, these dyestuffs are toxic and difficult to degrade because of their synthetic origin, durability, and complex aromatic molecular structures. Hence, bio-assisted phytoremediation has recently emerged as an innovative cleanup approach in which microorganisms and plants work together to transform xenobiotic dyestuffs into nontoxic or less harmful products. This manuscript will focus on competence and potential of plant-microbe synergistic systems for treatment of dyestuffs, their mixtures and real textile effluents, and effects of symbiotic relationship on plant performances during remediation process and will highlight their metabolic activities during bio-assisted phytodegradation and detoxification.

Environmental pollution from hazardous waste materials, organic pollutants and heavy metals, has adversely affected the natural ecosystem to the detriment of man. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals could accumulate in agricultural soils and get into the food chain, thereby becoming a major threat to food security. Conventional and physical methods are expensive and not effective in areas with low metal toxicity. Bioremediation is therefore an eco-friendly and efficient method of reclaiming environments contaminated with heavy metals by making use of the inherent biological mechanisms of microorganisms and plants to eradicate hazardous contaminants. This review discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for environmental remediation. It also emphasized the importance of modern biotechnological techniques and approaches in improving the ability of microbial enzymes to effectively degrade heavy metals at a faster rate, highlighting recent advances in microbial bioremediation and phytoremediation for the removal of heavy metals from the environment as well as future prospects and limitations. However, strict adherence to biosafety regulations must be followed in the use of biotechnological methods to ensure safety of the environment.

The petroleum industry’s development has been supported by the demand for petroleum and its by-products. During extraction and transportation, however, oil will leak into the soil, destroying the structure and quality of the soil and even harming the health of plants and humans. Scientists are researching and developing remediation techniques to repair and re-control the afflicted environment due to the health risks and social implications of petroleum hydrocarbon contamination. Remediation of soil contamination produced by petroleum hydrocarbons, on the other hand, is a difficult and time-consuming job. Microbial remediation is a focus for soil remediation because of its convenience of use, lack of secondary contamination, and low cost. This review lists the types and capacities of microorganisms that have been investigated to degrade petroleum hydrocarbons. However, investigations have revealed that a single microbial remediation faces difficulties, such as inconsistent remediation effects and substantial environmental consequences. It is necessary to understand the composition and source of pollutants, the metabolic genes and pathways of microbial degradation of petroleum pollutants, and the internal and external aspects that influence remediation in order to select the optimal remediation treatment strategy. This review compares the degradation abilities of microbial–physical, chemical, and other combination remediation methods, and highlights the degradation capabilities and processes of the greatest microbe-biochar, microbe–nutrition, and microbe–plant technologies. This helps in evaluating and forecasting the chemical behavior of contaminants with both short- and long-term consequences. Although there are integrated remediation strategies for the removal of petroleum hydrocarbons, practical remediation remains difficult. The sources and quantities of petroleum pollutants, as well as their impacts on soil, plants, and humans, are discussed in this article. Following that, the focus shifted to the microbiological technique of degrading petroleum pollutants and the mechanism of the combined microbial method. Finally, the limitations of existing integrated microbiological techniques are highlighted.

Aims Nitrogen is correlated with plant biomass and Cd concentration, collectively influencing phytoextraction of Cd-polluted soil. The Cd phytoextraction by hyperaccumulating plants and high biomass plants as affected by nitrogen remains elusive. Methods Sweet sorghum ( Sorghum bicolor (L.) Moench), a high biomass energy plant, and Solanum nigrum L., a Cd hyperaccumulator were investigated. Plant growth, Cd accumulation and soil properties as affected by different forms and dosages of nitrogen supply in Cd-polluted soil were studied. Additionally, rhizosphere soil bacterial and fungal community changes of the two species and their relationships with plant Cd accumulation were determined. Results A high level of nitrate resulted in the highest and equal Cd accumulation in shoots of the two plants. Sweet sorghum exhibited high photosynthesis rates with capacity for bioethanol production, enabling the re-utilization of post-harvested Cd materials. Consequently, sweet sorghum demonstrated a greater potential for Cd phytoextraction than S. nigrum . Regarding microbial community, clay was the driving factor influencing rhizosphere soil bacterial community in sweet sorghum as affected by nitrogen under Cd stress, while soil available Cd played a vital role in S. nigrum . Moreover, Pseudomonas and AKYG1722 bacteria showed a positive correlation with shoot Cd accumulation in sweet sorghum. AKYG1722, Sphingobium herbicidovorans , Sphingobium chlorophenolicum , Streptomyces scabiei , Devosia sp. I507, Bacillus simplex and Ensifer meliloti were positively correlated with shoot Cd accumulation in S. nigrum . Conclusions Nitrate performs better than ammonium and urea for improving phytoremediation of Cd-polluted soil using sweet sorghum and S. nigrum , but their rhizosphere soil microbial communities were species-dependent. Graphical abstract

Globally, substantial research into endophytic microbes is being conducted to increase agricultural and environmental sustainability. Endophytic microbes such as bacteria, actinomycetes, and fungi inhabit ubiquitously within the tissues of all plant species without causing any harm or disease. Endophytes form symbiotic relationships with diverse plant species and can regulate numerous host functions, including resistance to abiotic and biotic stresses, growth and development, and stimulating immune systems. Moreover, plant endophytes play a dominant role in nutrient cycling, biodegradation, and bioremediation, and are widely used in many industries. Endophytes have a stronger predisposition for enhancing mineral and metal solubility by cells through the secretion of organic acids with low molecular weight and metal-specific ligands (such as siderophores) that alter soil pH and boost binding activity. Finally, endophytes synthesize various bioactive compounds with high competence that are promising candidates for new drugs, antibiotics, and medicines. Bioprospecting of endophytic novel secondary metabolites has given momentum to sustainable agriculture for combating environmental stresses. Biotechnological interventions with the aid of endophytes played a pivotal role in crop improvement to mitigate biotic and abiotic stress conditions like drought, salinity, xenobiotic compounds, and heavy metals. Identification of putative genes from endophytes conferring resistance and tolerance to crop diseases, apart from those involved in the accumulation and degradation of contaminants, could open new avenues in agricultural research and development. Furthermore, a detailed molecular and biochemical understanding of endophyte entry and colonization strategy in the host would better help in manipulating crop productivity under changing climatic conditions. Therefore, the present review highlights current research trends based on the SCOPUS database, potential biotechnological interventions of endophytic microorganisms in combating environmental stresses influencing crop productivity, future opportunities of endophytes in improving plant stress tolerance, and their contribution to sustainable remediation of hazardous environmental contaminants. Graphical Abstract

The picture emerging from the rapidly growing literature on host-associated microbiota is that host traits and fitness often depend on interactive effects of host genotype, microbiota, and abiotic environment. However, testing interactive effects typically requires large, multi-factorial experiments and thus remains challenging in many systems. Furthermore, most studies of plant microbiomes focus on terrestrial hosts and microbes. Aquatic habitats may confer unique properties to microbiomes. We grew different populations of duckweed (Lemna minor), a floating aquatic plant, in three microbial treatments (adding no, “home”, or “away” microbes) at two levels of zinc, a common water contaminant in urban areas, and measured both plant and microbial performance. Thus, we simultaneously manipulated plant source population, microbial community, and abiotic environment. We found strong effects of plant source, microbial treatment, and zinc on duckweed and microbial growth, with significant variation among duckweed genotypes and microbial communities. However, we found little evidence of interactive effects: zinc did not alter effects of host genotype or microbial community, and host genotype did not alter effects of microbial communities. Despite strong positive correlations between duckweed and microbe growth, zinc consistently decreased plant growth, but increased microbial growth. Furthermore, as in recent studies of terrestrial plants, microbial interactions altered a duckweed phenotype (frond aggregation). Our results suggest that duckweed source population, associated microbiome, and contaminant environment should all be considered for duckweed applications, such as phytoremediation. Lastly, we propose that duckweed microbes offer a robust experimental system for study of host–microbiota interactions under a range of environmental stresses.

Phytoremediation is a sustainable technique that employs plants to reinforce polluted environments such as agroecosystems. In recent years, new strategies involving the plant microbiome as an adjuvant in remediation processes have been reported. By leveraging this microbial assistance to remediate soils contaminated with heavy metals such As, Pb, Cd, Hg, and Cr, plants can sequester, degrade, or stabilize contaminants more efficiently. Remarkably, some plant species are known for their hyper-accumulative traits in synergy with their microbial partners and can successfully mitigate heavy metal pollutants. This sustainable biotechnology based on plant–microbe associations not only aids in environmental cleanup but also enhances biodiversity, improves soil structure, and promotes plant growth and health, making it a promising solution for addressing agro-pollution challenges worldwide. The current review article emphasizes the potential of synergistic plant–microbe interactions in developing practical and sustainable solutions for heavy metal remediation in agricultural systems, which are essential for food security.