Reviews in Environmental Science and Bio/Technology最新文献

Photoelectrotrophic metabolism (photoelectrotrophy) is an emerging energy-conversion mode in which non-photosynthetic microorganisms harvest light-derived electrons from photosensitizers (e.g., semiconductor minerals and natural organic matter) to fuel intracellular redox reactions and support growth. This concept broadens microbial energy acquisition beyond classical phototrophy and chemotrophy. However, it is still not fully understood how environmental conditions, metabolic pathways, and environmental geochemical factors affect photoelectrotrophic metabolism in microorganisms. This review synthesizes evidence for three prerequisites—sunlight, photosensitizers, and suitable microorganisms—and evaluates the likelihood that photoelectrotrophy occurs in natural environments based on insights from model systems. Proposed mechanisms of photoelectron uptake and transfer, including mediator-assisted and direct interfacial pathways, are then summarized and linked to major biogeochemical cycles of carbon, nitrogen, and other elements. Finally, environmental implications such as redox cycling and reactive oxygen species production are discussed, and opportunities and challenges for harnessing photoelectrotrophy in energy and environmental applications are outlined.

Manganese (Mn) oxides, which originate from oxidative precipitation of soluble Mn(II), are a range of phases with different structural arrangements of MnO₆ octahedra. These phases are widely distributed across diverse environmental contexts, often with relatively low abundance. Nonetheless, owing to variable oxidation states of Mn and the potent oxidative and adsorptive capacities of Mn oxides, the influences of Mn oxides on the cycling of contaminants and nutrients considerably exceed its own abundance. This review aims to synthesize current knowledge on the origin, structure, and reactivity of Mn oxides. First, the biotic and abiotic origins as well as the structures of common layered and tunnel Mn oxide phases are described. Subsequently, the reactivity of Mn oxides towards redox-insensitive and redox-sensitive metals and metalloids is discussed. In particular, the intricacies of the redox interactions between Mn oxides and metal(loid)s are illustrated with two main examples: (1) arsenic, a pervasive global groundwater problem, and (2) chromium, a serious pollutant due to wide industrialization. The influences from the structural nature of Mn oxides and from typical environmental variables on the interactions between Mn oxides and metal(loid)s are also summarized. Finally, some future research directions in this field are outlined.

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Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are growing organic and inorganic pollutants in blue ecosystems due to increasing maritime traffic, industrial effluents, and other anthropogenic activities. Over the last two decades, microbial remediation has emerged as a sustainable strategy for mitigating PAHs and HMs. However, the co-occurrence of PAHs and HMs presents considerable challenges to microbial degradation, as HMs can interfere with PAH-degrading enzymatic pathways. Interestingly, sub-inhibitory concentrations of certain HMs may induce adaptive microbial responses, including enhanced biofilm formation, extracellular polymeric substance production, and activation of stress-response mechanisms. This review highlights recent advances in microbial bioremediation strategies targeting PAH–HM co-contamination. Advanced kinetic models and molecular insights reveal complex interactions, highlighting the need to optimize microbial strategies for co-contaminated site remediation. Innovative approaches such as CRISPR-Cas-based gene editing are being employed to enhance microbial resistance and catabolic efficiency. In addition, algae–microbe consortia and biofilm-based systems offer synergistic potential in marine environments. Emerging tools including electro-bioremediation, metagenomics, and artificial intelligence (AI)-driven monitoring systems are contributing to a deeper understanding of in situ microbial functions and enabling real-time optimization of remediation processes. These integrative strategies not only improve pollutant removal efficiency but also align with sustainable and scalable aquatic pollution management practices. The convergence of environmental microbiology, synthetic biology, and digital technologies offers a transformative framework to tackle complex pollutant mixtures and supports global sustainable development goals (SDG 6-clean water and sanitation).

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The toxic characteristics and environmental persistence of per- and polyfluoroalkyl substances (PFAS) have made the removal of such substances from water a critical concern. PFAS have a hydrophobic and oleophobic tendency due to their unique molecular structure, their chemical inertness and structural stability make the traditional methods of degradation and removal almost ineffective in the water environment. This review examines the existing technologies of PFAS removal in water with their advantages and drawbacks, and particularly focus on membrane distillation (MD) as an emerging separation-based approach. In contrast to pressure-driven processes such as nanofiltration and reverse osmosis, MD operates at lower hydraulic pressures and exhibits reduced fouling susceptibility under certain operating conditions, while maintaining high PFAS rejections. Reported studies indicate that direct contact membrane distillation (DCMD) can achieve PFAS rejection rates up to 96%. Current literature suggests that the hydrophobic properties of PFAS molecules promotes the effectiveness of MD, in which hydrophobic membranes are also employed, to achieve notable rejection rates of PFAS. Furthermore, the review covers promising developments that may be made in MD systems which include the use of new membrane materials and optimization of the operating conditions. However, key challenges including membrane fouling, wetting risk, and relatively high thermal energy demand are also critically assessed. Although there have been comprehensive reviews on the PFAS treatment technologies and MD as individual subjects, there has been no dedicated review on PFAS removal using MD. This review identifies current knowledge gaps and outlines future research directions required to enhance performance, scalability, and economic feasibility.

The bacterial extracellular polymeric substances (EPS) based flocculants significantly receive interest as a green and sustainable alternative for the wastewater treatment over polyacrylamides. However, despite of their initial progress, currently these materials are stagnated without significant advancements. It is due to the poor understanding of their chemical structure, synthesis pathways, molecular regulation and surface chemistry of flocculation. The polysaccharides are serving as the major backbones for the EPS flocculants. Particularly, amino sugars, neutral sugars, uronic acids, and amino acids are found to be their building blocks. However, many bioflocculants have unprecedented proportions of unrevealed “dark matters”. Advanced molecular techniques and polymer purification systems are paving the way to uncover such materials. The wastewater treatment efficacy of EPS flocculants has been established in various types of wastewaters. Their ability of enhancing various wastewater parameters namely turbidity, COD, suspended solids, heavy metals and dyes promote them as a potential alternative for synthetic flocculants. Among several theories, the electrostatic patching theory best explains their flocculation mechanism especially for cation dependent EPS flocculants. Compared with polyacrylamides, the substrate-to-product conversion level is several folds lower for EPS. The largescale operations have to face various challenges including lower yield, failure of runs and critical purification practices. However, these drawbacks can be overcome by advanced techniques such as genetic engineering. Moreover, several studies have indicated that the EPS flocculants can be produced from cheap waste substrates that paves a way for sustainable productivity.

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Land degradation caused by industrial activity, pollution, and unsustainable land use poses a significant threat to global ecosystem functions. Miscanthus × giganteus (M × g), a sterile C4 perennial grass known for its high biomass productivity and tolerance to abiotic stress, has gained increasing attention as a phytomanagement crop for restoring degraded lands. A growing body of evidence suggests that the effectiveness of M × g in these environments is strongly mediated by its interactions with rhizospheric, endophytic, and mycorrhizal microorganisms. This review synthesizes current knowledge on the structure, function, and ecological roles of microbial communities associated with M × g, with a focus on their contributions to plant growth, nutrient acquisition, stress tolerance, and contaminant degradation. Particular emphasis is placed on plant growth-promoting rhizobacteria (PGPR), endophytes, and arbuscular mycorrhizal fungi (AMF), as well as their roles in enhancing soil microbial activity, carbon sequestration, and phytoremediation of heavy metals and petroleum-based pollutants. While numerous studies have demonstrated positive microbial effects on M × g performance under controlled conditions, field-based evidence remains limited. Future research should prioritize long-term, multi-scale investigations and the development of tailored microbial inoculants for use in phytomanagement systems. By integrating plant–microbe interactions, M × g cultivation can be optimized not only for biomass production but also for ecological restoration of degraded environments.

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The production of biogas through anaerobic digestion (AD) of organic-renewable feedstocks is recognized as a viable solution within the renewable energy sector. Biogas typically contains a methane concentration ranging from 60 to 70%, presenting a significant opportunity for energy generation. However, the co-generated carbon dioxide (CO₂), which constitutes approximately 30–40% of biogas, poses challenges to overall energy efficiency, thus necessitating the implementation of purification methods to enhance methane concentrations. It is noteworthy that the production of one ton of biomethane results in the generation of approximately two tons of biogenic CO₂. This reality opens avenues for carbon capture, storage, and valorization strategies. The biogas industry is beginning to recognize CO₂ not merely as a byproduct to be discarded, but as a valuable resource for the synthesis of biomethane, chemicals, fuels, and even building materials. There is a growing interest in utilizing biogenic CO₂ as a climate-friendly feedstock, with “bio-Carbon Capture and Utilization” (bio-CCU) practices facilitating the development of sustainable fuels, chemicals, and materials. The article extends to various methods of valorization for biogenic CO₂, providing an analysis of techniques for separating and upgrading CO₂ derived from biogas. This assessment encompasses both physical and biological methodologies within the carbon capture, utilization, and storage (CCUS) framework. The article further demonstrates both in-situ and ex-situ processes, including biological methodologies that employ microorganisms for CO₂ conversion, as well as thermo-physicochemical processes that transform CO₂ into biobased products. Additionally, the article demonstrates the economic and environmental advantages associated with the strategic utilization of biogenic CO₂. Repurposing this resource is vital for achieving sustainability goals, particularly in renewable energy sectors, where it can significantly enhance energy efficiency and reduce waste. Finally, the article emphasizes the importance of these practices in climate change mitigation, advocating for a circular economy that prioritizes carbon reuse over atmospheric emissions, thus contributing to the advancement of a sustainable future.

Zearalenone (ZEN) is a thermostable, lipophilic, non-steroidal estrogenic mycotoxin produced by Fusarium spp. that persistently contaminates cereals and feed, posing major risks to food safety, human and animal health, and environmental sustainability. Conventional physical and chemical detoxification methods often compromise nutritional quality and leave toxic residues. This review critically evaluates recent advances in ZEN degradation, integrating physical, chemical, biological, and emerging hybrid approaches, and compares their mechanistic efficiency and applicability. Biological systems employing microorganisms and recombinant enzymes such as peroxidases, laccases, and lactonases exhibit high substrate specificity and eco-compatibility, yet remain limited by enzyme stability and cofactor dependence. Innovative methods including cold atmospheric plasma, polyphenol-mediated redox systems, and nanobiotechnology enhance degradation via reactive species generation, electron transfer, or catalytic surface interactions. Conceptually, this review synthesizes cross-disciplinary progress linking enzymatic catalysis with nanomaterial-assisted detoxification, highlighting hybrid enzyme-nanoparticle systems and synthetic-biology-driven enzyme engineering as promising solutions. Persistent gaps include industrial scalability and regulatory acceptance. Future research should emphasize integrated multi-modal frameworks that couple enzymatic precision with nanomaterial reactivity to achieve efficient, residue-free, and sustainable ZEN detoxification.

Nitrogen (N) plays a critical role in crop growth, development, and yield. In global agriculture, however, about 40 to 60 percent of nitrogen applied to soil is lost through nitrous oxide (N₂O) emissions, nitrate (NO₃⁻) leaching, and ammonia (NH₃) volatilization, resulting in significantly reduced crop yields and environmental issues, such as water body eutrophication, soil degradation, and increased greenhouse gas emissions. While a range of mitigation strategies have been explored, effective and scalable solutions that simultaneously enhance N retention in soil and promote crop uptake remain limited. In this context, integrated approaches that combine microbial aggregates with functional materials represent a promising yet underexplored pathway. This review examines the structural functions of microbial aggregates and the properties of common functional materials, emphasizing their mechanisms of action in reducing soil nitrogen loss and their potential contributions to mitigating environmental pollution. Additionally, the physical, chemical, and biological interactions during the synergistic application of these technologies were investigated, resulting in a 14–26% increase in soil nitrogen retention and a 15–35% increase in crop yields through improved inter-root nitrogen supply. This review aims to provide practical strategies for reducing agricultural nitrogen loss and its associated environmental hazards while promoting sustainable agricultural practices.

The viable but non-culturable (VBNC) state represents a unique survival strategy adopted by many aquatic bacterial pathogens under environmental stress. In aquaculture environments, factors such as low temperatures, nutrient imbalances, oxidative stress, and disinfection treatments (e.g., UV or chlorine) can induce bacteria to enter the VBNC state, wherein they remain metabolically active yet undetectable using traditional culturing methods. This dormant state allows pathogens such as Vibrio spp., Edwardsiella spp., and Aeromonas spp. to evade standard monitoring systems, persist in aquaculture systems, and later resuscitate under favorable conditions, regaining pathogenicity and contributing to disease outbreaks. VBNC cells also exhibit increased antibiotic resistance and may serve as reservoirs for resistance genes, amplifying concerns about treatment failure and the spread of antimicrobial resistance. Recent advancements in molecular diagnostics, including PMA-qPCR, FISH, and omics-integrated AI detection, have improved the identification of VBNC populations. Furthermore, resuscitation mechanisms involving quorum sensing, oxidative stress regulators (e.g., RpoS, OxyR), and resuscitation-promoting factors (Rpfs) are being actively investigated. This review provides a comprehensive overview of the VBNC state in aquatic pathogens, with a focus on its environmental triggers, physiological and molecular characteristics, implications for disease transmission, and recent advances in detection and control strategies. A deeper understanding of VBNC dynamics is essential for improving aquatic animal health, enhancing biosecurity, and establishing sustainable aquaculture practices.