134 | Living with mold: a growing problem for urban biodiversity

Andrea Furlan¹, Paolo Bonivento² | ¹Nanocoatings Research, Trieste, Italy; ²Istituto di Studi Europei “A. De Gasperi”, Roma, Italy.

The aim of our research is to explore the multifaceted and escalating impact of mold proliferation within urban environments, critically examining its implications for both microbial and macroscopic biodiversity, ecosystem function, and human well-being. As urbanization intensifies, the complex interplay between anthropogenically altered landscapes and indoor environments has precipitated a significant shift in fungal communities. This analysis moves beyond the traditional focus on merely identifying pathogenic mold to understanding its broader ecological ramifications. Specifically, we discuss how the documented increase in indoor fungal biomass and richness correlates directly with elevated water availability—a condition exacerbated by common urban infrastructure issues such as aging plumbing, poor ventilation, and the increasing frequency of extreme weather events. We investigate the hypothesis that this shift in urban mycobiomes is characterized by a proliferation of larger-spored, potentially pathogenic taxa that significantly contribute to adverse human health outcomes, including respiratory ailments and allergies. However, the scope of this research extends to the broader ecological impact on urban biodiversity. We analyze how these altered fungal communities disrupt delicate urban ecosystem services by influencing the diversity and function of other microbial and macro-organisms. Recent findings indicate a substantial reduction in both aerial and soil fungal diversity within urban areas compared to natural habitats, suggesting a profound ecological imbalance. This involves a nearly twofold reduction in species richness and a fivefold decrease in fungal DNA abundance even at small scales, underscoring a critical loss of ecological functionality necessary for urban regeneration. The prevailing indoor microbiome often comprises airborne species of outdoor origin that passively collect on surfaces rather than arising from endogenous growth. This challenges traditional views of indoor microbial sources and highlights the limitations of relying solely on mechanical systems such as heating, ventilation, and air conditioning (HVAC) to manage indoor air quality. Instead, we advocate for a holistic approach that incorporates sustainable building materials and responsive architectural design to foster resilient, diverse microbial communities. A major limitation in elucidating these complex interactions is the current reliance on 18S rRNA gene sequencing, which often lacks the taxonomic resolution required for genus-level identification. We propose that future research should employ shotgun metagenomic sequencing and RNA-based methods to distinguish viable organisms from dead cells, thereby providing a more comprehensive view of microbial diversity and metabolic pathways. Furthermore, integrating advanced "omic" approaches, ecological modeling, and machine learning will allow for the development of predictive frameworks. These frameworks are essential for understanding how urban development influences fungal successions and for informing interventions that promote beneficial microbial communities. Finally, this presentation addresses the potential of fungal bioremediation, or mycoremediation, as a sustainable solution for environmental contaminants. While current limitations in scaling exist due to knowledge gaps regarding fungal potential, biotechnological innovations offer promising avenues. We explore how genetic engineering can enhance fungal capabilities by constructing novel fungi with improved metabolic pathways for utilizing emerging contaminants. Additionally, the integration of nanotechnology with mycoremediation could significantly enhance the specificity and efficiency of contaminant degradation. By combining fungal biology with nanotechnological advancements, we can develop potent strategies for addressing persistent organic pollutants. Ultimately, this research aims to move beyond simplistic pathogen identification to embrace a functional ecological perspective, crucial for designing healthier, more resilient urban environments that balance human health needs with long-term ecosystem stability.