Reviews in Environmental Science and Bio/Technology最新文献

B vitamins are essential cofactors in cellular metabolism, influencing host physiology and microbial community dynamics. Current supplies rely on dietary intake, supplementation, or chemical synthesis, but high production cost, environmental burden, and reliance on non-renewable feedstocks underscore the need for sustainable alternatives. Microbial fermentation offers bioavailable B vitamins, offering potential gut-targeted benefits, particularly when integrated with agro-food waste valorization. This review summarizes advances in microbial production systems, including commensal and industrial strains, metabolic engineering, and co-culture approaches, alongside vitamin-specific biosynthetic pathways. Agro-food residues as low-cost renewable substrates are discussed in the context of circular bioeconomy and zero-waste principles. Special emphasis is placed on the gut microbiota, where B vitamins modulate microbial diversity, host immunity, and metabolism, and act as regulators of microbial communication, affecting quorum sensing, biofilm formation, virulence, and resistance. By interlinking agro-waste valorization, microbial biosynthesis, gut microbiota modulation, and microbial communication, this review highlights sustainable B vitamin production, identifies knowledge gaps, and outlines future directions for microbiome-targeted innovations.

Wastewater treatment stands as a cornerstone in preserving public health and environmental integrity by effectively eliminating contaminants and pathogens from wastewater before discharge or reuse. Despite its crucial role, conventional wastewater treatment faces formidable challenges, mostly due to the quick metabolic adaptation strategies bacteria employ, which, among others, contribute to the dissemination of antibiotic-resistant bacteria. In response, recent attention has turned to bacteriophages, viruses with a predilection for infecting bacteria, as potential antimicrobial agents within wastewater treatment facilities. This review critically examines the rise of bacteriophages as an integrated biological tool in wastewater treatment plants, specifically targeting putative opportunistic pathogens that may harbor and propagate drug resistance. The exploitation of bacteriophage applications offers a promising pathway toward robust pathogen control within these facilities, although we still lack demonstrations and pilot-scale experiments. Furthermore, our review delves into a wide range of considerations arising and examines prospective methodologies for future wastewater treatment approaches.

CaCO₃ is a well-known mineral that has been used extensively as an additive to improve the processability and as a reinforcement material for industrial-based applications. Recently, emphasis has been laid on the fabrication of CaCO₃-based nanoplatforms for enhanced drug and vectors for gene delivery, biosensing, and bioimaging, combinatorial effects of photothermal and photodynamic therapies to treat tumors and cancers. For instance, Fe₃O₄@CaCO₃ nanocomposites not only exhibit excellent biocompatibility in cancer chemotherapy but also provide magnetic separability for reuse in pollutant remediation. Similarly, the association of C dots with CaCO₃ has huge potential in the fabrication of novel and advanced biomaterials that can serve as platforms for various biological and biotechnological-based applications. On the environmental aspect, CaCO₃ nanohybrids have shown efficacy in adsorbing heavy metals, degrading dyes, and even acting as slow-release fertilizers, aligning with sustainable agriculture and circular economy models. Thus, there is a lot of scope for the fabrication of novel CaCO₃-based nanohybrids in the future, and this review highlights the recent advances and developments in this direction. Despite these advances, key gaps and challenges still remain that need to be addressed. Current studies are mostly confined to laboratory settings, with limited translation into clinical or field-scale applications. The challenges include optimizing particle size, morphology, and stability under physiological and environmental conditions, with more emphasis on issues pertaining to biosafety and long-term ecological impacts. Future research must focus on interdisciplinary strategies integrating green synthesis, advanced functionalization, and rigorous in vivo/field trials to fully harness CaCO₃ nanohybrids as multifunctional platforms that aid in biomedical innovation with environmental sustainability.

Graphical abstract

The increasing discharge of azo dyes is of ecological concern due to its toxicity and resistance to conventional treatment methods. Microbial fuel cell (MFC) technology has long been identified as a potential solution for treating recalcitrant waste, such as azo dye effluents, providing a dual advantage of dye degradation and energy recovery. This review elucidates azo dye structure, chemistry and its influence on the degradation in MFC with emphasis on redox transformations at the electrodes. At the anode, azo bond reduction with the help of microbial catalysts produces aromatic amines. At the cathode, azo dye can be the terminal electron acceptor, leading to dye decolorization, or it can be degraded to smaller intermediates in an advanced oxidation process. The anodic dye degradation, electrode materials, microbial catalyst, co-substrate, degradation at biotic/abiotic cathode and various membranes used in MFCs have been summarized. The integration of nanomaterials into MFC components for improving electron transfer rates, reducing electrode overpotentials, facilitating electrode-microbes interaction and enhancing membrane cation transfer has been discussed. The recent advancement in scaling up of MFC for dye treatment by integrating with other treatment systems and stacking individual MFCs has been outlined. The review concludes with a future perspective on advancing scalable MFC by consolidating research insights on MFC materials, microbial interactions, reactor design and operational parameters to realize real-world applications.

Graphical abstract

Photovoltaic power generation is playing an increasingly prominent role in the global energy transition, and the rapid expansion of photovoltaic power plants (PVPPs) has raised growing concerns regarding their ecological impacts. This research presents a comprehensive review of the ecological effects of PVPPs from atmosphere, soil, hydrology, and biodiversity. In the atmosphere, PVPPs contribute to the regulation of microclimates, increasing surface albedo from 0.22 to 0.24, reducing the annual mean temperature by 0.32 °C/TWh of generated electricity. In the soil environment, PVPPs increase available soil phosphorus and pH levels, and indirectly promote carbon fixation through vegetation restoration and optimized land utilization. Concurrently, PVPP deployment significantly increased the soil organic carbon concentration to 1.20 g kg^–1. In hydrology, PVPPs alter local hydrological cycles by reducing wind speed, intercepting rainfall, and increasing surface runoff. At the biodiversity level, PVPPs enhance avian diversity while simultaneously increasing plant species richness and improving microbial resilience. Notably, PVPP implementation at a coverage of 27.00–33.00% modifies habitats, resulting in a 116.70% increase in plant species richness and a 68.70% increase in aboveground biomass. This research offers valuable insights for ecosystem protection, land management, and the advancement of policy-making strategies, thereby promoting sustainable development and ecological conservation.

Transitioning towards a low-carbon society can be accelerated by producing clean hydrogen fuels from sustainable resources, such as biomass and water, thereby offering a sustainable energy source that effectively reduces greenhouse gas emissions. This review provides a comprehensive analysis of hydrogen production technologies, including fossil fuel-based processes (e.g., thermochemical conversions and steam methane reforming), electrolysis-based routes (alkaline, polymer electrolyte membrane, and solid oxide water), and biological methods (dark fermentation, photofermentation, and biophotolysis), along with emerging photocatalytic and photochemical systems. For each pathway, we critically assess its technological maturity, deployment status, and potential to enhance the share of clean energy in the global renewable energy supply chain. The manuscript also highlights research gaps, prospects, and challenges for numerous upstream hydrogen generation from both biological and non-biological sources, with a specific focus on enhancing efficiency, reducing costs, and improving environmental performance. Photochemical, electrochemical, and photocatalytic hydrogen generation systems utilizing biomass and water as feedstocks have garnered significant attention.

Technological advances in the downstream enrichment and storage of hydrogen gas are critically evaluated, including opportunities, current challenges, and barriers associated with commercial applications. Metal–organic framework-based pressure swing adsorption, electrochemical hydrogen pumps, and metal hydrides are analyzed for their capacity to achieve high hydrogen purification (~ 99.99%) and enable a scalable storage solution. However, the economic and commercial feasibility of hydrogen production from biomass remains a substantial challenge due to the high production cost ($4.11–$7.45/kg H₂). This can be alleviated by appropriate biomass selection, the development of highly selective catalysts, the integration of different processes, and the application of artificial intelligence-/machine learning-driven models to predict the outcomes for better industrial automation. This study offers insightful information for the selection of highly effective and advanced hydrogen generation, purification, and storage techniques. We conclude with strategic recommendations for technology development, scale-up efficiency, and policy frameworks that can expedite the transition to a sustainable hydrogen economy.

Graphical abstract

Sugarcane vinasse biodigestion presents challenges due to its sulfate-rich nature (2–3 g-SO₄^2– L^–1), causing microbial competition, inhibition, and H₂S-rich biogas production. The high H₂S content (up to 45,000 ppm) is considered a significant economic drawback for energy recovery purposes, mainly for the upgrading routes toward biomethane. Despite the potential benefits, the adoption of two-stage biodigestion faces obstacles because of high alkalinization costs. However, the fermentative-sulfidogenic process is promising by producing bicarbonate alkalinity as a by-product of the organic matter oxidation and consuming H⁺ ions through ionized sulfide generation. This pathway mitigates the need for expensive alkalinizing inputs and enhances the biogas energetic value (CH₄ > 80%, H₂S-free), providing favorable conditions for cost-effective and environmentally sustainable upgrading strategies. Moreover, the H₂S- and CO₂-rich biogas produced during the fermentative-sulfidogenic stage must be addressed from an environmental perspective as an “off-gas”, enabling promising biotechnological routes for sulfur and biogenic CO₂ recovery. Although significant progress has been made at laboratory scale, further understanding is needed regarding the role of the fermentative-sulfidogenic step as a biological alkalinity source for methanogenesis. In parallel, developing low-cost and environmentally advantageous strategies to support sulfidogenic activity remains critical. This review elucidates the fermentative-sulfidogenic pathway’s central role in vinasse biodigestion, highlighting its dual potential for biogas upgrading and recovery of valuable by-products such as elemental sulfur and biogenic CO₂.

Graphical abstract

Per- and polyfluoroalkyl substances (PFAS) are persistent eco-pollutants that pose significant risks to human health and ecosystems. The US EPA and EU databases catalog over 14,900 PFAS, labeling stable C-F bonds as ‘forever’ chemicals. This review critically examines advancements in photocatalytic degradation strategies for PFAS using multi-modal ternary functional materials. An overview of the occurrence, toxicity, and ecological impact highlights the concurrent need for effective remediation techniques. The article focuses on the design, synthesis, and performance of ternary photocatalysts, emphasizing their enhanced charge separation, broad spectral absorption, tailored band gap, and synergistic effects. Key aspects of material engineering strategies, degradation mechanisms, efficiency amplification strategies, and scalability prospects have been highlighted. The discussion elucidates emerging Z-scheme, S-scheme, and C-scheme heterojunctions for tailored and efficient photodegradation strategies, addressing the limitations of PFAS photodegradation. Prospects include developing highly paramagnetic, non-corrosive catalysts and integrating advanced analytical techniques for mechanistic insights. Analyzing the obstacles to incorporating these strategies into real-time, efficient, sustainable, and scalable degradation units paves the way for a brighter future in PFAS remediation.

Bacteria have developed specific mechanisms to survive under various terrestrial and aquatic habitats, through combating the challenges posed on account of numerous physical forces and stresses principally occurred due to the circulation of fluid flow and surrounding pressure as well as surface contact. To overcome the fluid shear, bacteria often live as assemblages within the matrix, termed biofilms, which is a significant mode of microbial life. One of the established purpose is to decipher how the evolution of multi-cellularity conferred fitness advantage. Investigation into the formation of biofilm have uncovered their remarkable complexity comprising diversity in both composition of resident species and phenotypic traits. In the biofilm development process, several environmental factors, such as nutrients, pH, and oxygen, play a significant role in bacterial phenotypes. Cellular components of bacteria allow them to sense and react to different mechanical stimuli to optimize their function, eventually enhancing bacterial overall fitness. Bacterial cytoskeleton proteins such as FtsZ, MreB, RodZ, MinC, MinD, and MinE present in several bacteria, such as Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa have been shown to be responsible for changing and maintaining the phenotypic form of these bacteria as a response to different environmental factors or stressors. The differential expression of these cytoskeletal proteins help to alter the cell shape and size, leading to pleomorphism. This review entails how the pleomorphism of bacteria within a community influences the cooperative as well as competitive inter-cellular and intra-cellular interactions that regulate the biofilm formation and function. Furthermore, the review highlights the role of local environmental niches in phenotypic switching, to develop stabilized biofilm for environmental and biomedical applications.