Heavy metal (HM) contamination poses an escalating threat to human health and global terrestrial ecosystems. Inexpensive, eco-friendly technologies that reduce HM concentrations in soil are needed. Utilizing the synergy between hyperaccumulating plants and their rhizosphere microbes offers a promising approach to the bioremediation of HM-contaminated sites; however, the mechanisms underlying this plant-microbe relationship remain unclear. In the present study, high-resolution in situ imaging revealed that inoculation of the plant growth-promoting bacterium (PGPB) Bacillus megaterium altered the rhizosphere microenvironment of the Cd and Mn-hyperaccumulator Celosia argentea grown in HM-contaminated field soil. Decreased pH, increased O₂ fluxes, and stimulated microbial activity and enzyme-mediated C and P cycling were observed. Multi-omics analyses suggested that PGPB-modulated rhizosphere microbial succession selectively enriched beneficial taxa and functional genes associated with nutrient cycling and metal resistance. Transcriptomic and metabolomic profiling analysis revealed that the PGPB induced transcriptional reprogramming in C. argentea, leading to the activation of antioxidant defenses, metal transporter expression, and root exudate metabolism, with a focus on lipid- and sphingolipid-related pathways. These processes collectively enhanced the mobilization and uptake of Cd, Pb, and Zn at the root-soil interface, suggesting that the mutualistic plant-microbe system facilitated HM phytoextraction efficiency. Our findings offer novel insights into how microbial inoculants can rewire the rhizosphere microecology to regulate metal dynamics and enhance the remediation of multi-metal-contaminated soils.

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The H₂-based membrane biofilm reactor (H₂−MBfR) is an emerging technology for removal of nitrate (NO₃⁻) in water supplies. In this research, a lab-scale H₂−MBfR equipped with a separated CO₂ providing system and a microsensor measuring unit was developed for NO₃⁻ removal from synthetic groundwater. Experimental results show that efficient NO₃⁻ reduction with a flux of 1.46 g/(m²⋅d) was achieved at the optimal operating conditions of hydraulic retention time (HRT) 80 min, influent NO₃⁻ concentration 20 mg N/L, H₂ pressure 5 psig and CO₂ addition 50 mg/L. Given the complex counter-diffusion of substrates in the H₂−MBfR, mathematical modeling is a key tool to both understand its behavior and optimize its performance. A sophisticated model was successfully established, calibrated and validated via comparing the measured and simulated system performance and/or substrate gradients within biofilm. Model results indicate that i) even under the optimal operating conditions, denitrifying bacteria (DNB) in the interior and exterior of biofilm suffered low growth rate, attributed to CO₂ and H₂ limitation, respectively; ii) appropriate operating parameters are essential to maintaining high activity of DNB in the biofilm; iii) CO₂ concentration was the decisive factor which matters its dominant role in mediating hydrogenotrophic denitrification process; iv) the predicted optimum biofilm thickness was 650 µm that can maximize the denitrification flux and prevent loss of H₂.

With the transition towards a smart grid, the power system has become strongly intertwined with the information and communication technology (ICT) infrastructure. The interdependency of both domains requires a combined analysis of physical and ICT processes, but simulating these together is a major challenge due to the fundamentally different modeling and simulation concepts. After outlining these challenges, such as time synchronization and event handling, this manuscript presents an overview of state-of-the-art solutions to interface power system and ICT simulators. Due to their prominence in recent research, a special focus is set on co-simulation approaches and their challenges and potentials. Further, two case studies analyzing the impact of ICT on applications in power system operation illustrate the necessity of a holistic approach and show the capabilities of state-of-the-art co-simulation platforms.