Soil salinity, which affects plant photosynthesis mechanisms, significantly limits plant productivity. Soil microorganisms, including cyanobacteria, can synthesize various exometabolites that contribute to plant growth and development in several ways. These microorganisms can increase plant tolerance to salt stress by secreting various phytoprotectants; therefore, it is highly relevant to study soil microorganisms adapted to high salinity and investigate their potential to increase plant resistance to salt stress. This study evaluated the antioxidant activity of four cyanobacterial strains: Spirulina platensis Calu-532, Nostoc sp. J-14, Trichormus variabilis K-31, and Oscillatoria brevis SH-12. Among these, Nostoc sp. J-14 presented the highest antioxidant activity. Their growth-stimulating effects under saline conditions were also assessed under laboratory conditions. These results indicate that Nostoc sp. J-14 and T. variabilis K-31 show significant promise in mitigating the harmful effects of salinity on plant size and weight. Both strains notably enhanced the growth of Oryza sativa plants under saline conditions, suggesting their potential as biostimulants to improve crop productivity in saline environments. This research underscores the importance of understanding the mechanisms by which cyanobacteria increase plant tolerance to salt stress, paving the way for sustainable agricultural practices in saline areas.

Pollution and freshwater scarcity, coupled with the energy sector’s continued dependence on fossil fuels, constitute a dual challenge to sustainable development. A promising response is biosystems that jointly address wastewater treatment and the production of renewable products. This review centers on a managed consortium of aquatic macrophytes and microalgae, in which the spatial architecture of plant communities, rhizosphere processes, and the photosynthetic activity of microalgae act in concert. This configuration simultaneously expands the spectrum of removable pollutants and yields biomass suitable for biorefinery, thereby linking remediation to the production of energy carriers and bioproducts within a circular bioeconomy. The scientific novelty lies in treating the integrated platform as a coherent technological unit, and in using the biomass “metabolic passport” to align cultivation conditions with optimal valorization trajectories. The work offers a practical framework for designing and scaling such consortia that can reduce the toxicological load on aquatic ecosystems, return macronutrients to circulation, and produce low-carbon energy carriers.

Microalgae offer a simple and sustainable way to capture carbon dioxide (CO2) from industrial emissions while producing valuable biomass for fuels, feed and other bioproducts. In this review, we summarize recent progress in designing and improving closed-loop microalgae systems that capture CO2 and recycle nutrients and energy. We compare several industrial pilot projects around the world to show which designs work best at scale and highlight remaining hurdles. To organize these challenges, we introduce a Barrier-Impact Matrix that maps technical, economic and regulatory obstacles alongside potential solutions. Finally, we discuss how to get more value from the harvested biomass and how life cycle assessments (LCAs) can guide future improvements.

Dark fermentation of organic waste offers a means of coupling molecular hydrogen (H₂) production with the bioconversion of wet organic feedstocks. However, its practical performance remains limited by unstable carbon and electron-flow distribution, substrate heterogeneity, and dynamic shifts in microbial community structure. This review critically evaluates microbial consortium engineering as a strategy to improve the selectivity, stability, and controllability of dark-fermentative H₂ production. Available experimental evidence indicates that H₂ productivity is determined not by a single high-performing strain but by the coordinated activity of microorganisms responsible for hydrolysis, fermentation of soluble compounds, and conversion through H₂-producing pathways. Disruption of this coordination redirects carbon and electrons toward lactate, alcohols, methane, and homoacetogenic pathways. Synthetic microbial consortia enable more targeted control over community composition and the allocation of metabolic functions; nevertheless, their operational performance and reproducibility may decline substantially when defined model substrates are replaced by chemically heterogeneous, non-sterile waste-derived substrates. The most reproducible performance is achieved when community composition is matched to feedstock chemistry and reactor operating conditions. Further progress will require a transition from empirical culture selection to substrate-specific engineering of microbial functions supported by metabolite profiling, molecular analyses, and mass- and electron-balance data.

Fusarium oxysporum-associated disease symptoms in rice (Oryza sativa L.) seedlings represent an experimentally tractable model for evaluating microbiome-mediated disease suppression under controlled conditions. Biological control of Fusarium-associated disease development in rice provides a promising ecological alternative to chemical fungicides. However, the mechanisms underlying the spatial reconfiguration of the host plant multicompartment microbiome in response to complex inoculants remain insufficiently understood. In this study, we investigated the ability of the monoculture Bacillus amyloliquefaciens Bn1 (B. amyloliquefaciens Bn) and phototrophic–heterotrophic consortia composed of Nostoc sp. J-1 and B. amyloliquefaciens Bn1 to suppress Fusarium oxysporum infection, with parallel profiling of bacterial and fungal communities in rhizosphere soil, the root endosphere, and the phyllosphere using 16S rRNA and ITS amplicon sequencing. Phenotypic screening showed that microbial inoculant application significantly reduced the disease index by up to 55% while maintaining plant dry weight. The protective phenotype was not primarily associated with shifts in alpha diversity, but rather with compartment-specific reorganization of microbial communities. These findings suggest that biological control efficacy was associated less with the overall taxonomic scale of microbiome disturbance than with the formation of a functionally balanced, compartment-specific holobiont architecture but by the formation of a functionally balanced, compartment-specific holobiont architecture, providing a conceptual basis for the targeted design of next-generation phototrophic–heterotrophic biopreparations.