Copper stress response of aspergillus niger spores and the implications for antifungal surface functionalization

Abstract

Microbial life has been an enduring presence in various environments, prompting research into understanding the interactions between microorganisms and antimicrobial agents. Not only in terrestrial settings but even in human spaceflight related environments, Aspergillus niger has been identified alongside Penicillium ssp. as predominant species in HEPA filters and dust within the international space station. As especially fungal contaminations could have detrimental effects on built materials and negatively affect not only the structural integrity of a confined built environment, but cause negative effects on human health, it underscores the need to understand especially fungal responses to stress. Within this study we particularly researched the fungal stress response from novel functionalized copper surfaces. This study delves into the interaction between A. niger and innovative antimicrobial surfaces, combining actively antimicrobial copper and copper-alloys with microtopographies through Ultrashort pulses Direct Laser Interference Patterning (USP-DLIP). The preliminary findings of contact – killing assays using spores from a wildtype and melanin deficient mutant strain, reveal an unexpected heterogeneity in A. niger spore germination responses to copper stress, shedding light on the sophisticated regulation of copper homeostasis by this fungus. The results of those assays were further investigated using varied microscopy methods (Fluorescence and SEM) and will undergo detailed RNA profile analyses to discern the molecular mechanisms underlying any observed damage, providing valuable insights into the intricacies of A. niger's response to copperinduced stress. Understanding how A. niger reacts to copper stress is crucial for developing effective antimicrobial strategies with broader applications, addressing fungal contamination challenges across diverse settings.