###### Abstract  
Global warming due to climate change has increased the frequency of sand and dust storms that affect air quality and ecosystems in general, contributing to air pollution. The Sahara Desert is the most potent emitter of atmospheric dust. The atmosphere is an extreme environment and microorganisms living in the troposphere are exposed to greater ultraviolet radiation, desiccation, low temperatures and nutrient deprivation than in other habitats. The Iberian Peninsula, and specifically the Canary Islands--due to its strategic location--is one of the regions that receive more Saharan dust particles annually, increasing year after year, although culturable microorganisms had previously never been described. In the present work, dust samples were collected from three calima events in the Canary Islands between 2021 and 2022. The sizes, mineralogical compositions and chemical compositions of dust particles were determined by laser diffraction, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. Particle morphology and biological features were also studied by scanning electron microscopy (SEM-EDX) and confocal laser scanning microscopy (CLSM). The mineral-bacteria interactions were described from microscopic observations, which revealed the presence of bierulites and small neoformed kaolinite crystals in association with bacteria. This article defines the term \"mineral atmospherogenesis\" and its variant, \"mineral bioatmospogenesis\", through microbial interaction. This is the first described case of kaolinite produced through mineral bioatmosprogenesis. The bacterial growth in atmospheric dust was illustrated in SEM images, constituting a novel finding. Twenty-three culturable microorganisms were isolated and identified by 165 rRNA sequencing. Members of the phyla _Pseudomonasota_, _Bacillota_ and _Actinomycetota_ have been found. Some of these microorganisms, such as _Periobacillus frigoritoleras_, have Plant Growth-Promoting Rhizobacteria (PGRP) properties. Potential human pathogenic bacteria such as _Actinebacter lwoffii_ were also found. The presence of desert dust and iberulites in the Canary Islands, together with transported biological components such as bacteria, could have a significant impact on the ecosystem and human health. extremophiles; Saharan dust; iberulite; atmospheregenesis; Canary Islands; calima; biofilm 2024 Biological material transported by dust storms deserves special attention. Extreme conditions such as high/low temperatures, high hydrostatic pressures, high salt concentration or high/low pH values define different types of extreme environments, suitable for extremophilic microorganisms [5]. The atmosphere, despite being the largest biome on Earth, remains one of the least understood environments in terms of microbial activity [6]. Due to radiation and temperature changes, it is one of the most extreme environments described so far. Some bacteria, fungi and viruses can survive in the atmosphere despite enduring different environmental stressors [7; 8]. Microbes attached to dust particles can be transported through the atmosphere and dispersed in exogenous environments [9; 10; 11; 12]. The long-range transport of viable bacteria along with mineral aerosols may represent a pathway for bacteria to colonize new environments and alter the existing diversity in remote terrestrial and aquatic habitats [7; 13]. Dust intrusions can be accompanied by a characteristic precipitation known as red rain, dust rain, bloody rain, coloured rain or muddy rain [14; 15]. Recently isolated culturable microorganisms and other microbial communities have been described in red rain episodes in the southeast of Spain [16]. A striking phenomenon is the occurrence of corpuscles with 50-200 \(\upmu\)m diameters and quasi-spherical morphology, known as iberulites [17]. Iberulites are typically observed during Saharan dust intrusions in the Iberian Peninsula and the Canary Islands.