A conventional surface that can be colonised by microbial community’s resistant to abrasive environmental conditions, such as high irradiation, temperature variations, and desiccation, solar panels are nearly everywhere in the world. These characteristics make them not only excellent sources of stress-resistant bacteria but also common tools for researching microbial communities and the process of colonisation in various parts of the planet. Here, we present a detailed account of the microbial communities connected to solar panels in Berkeley, California, in the United States. To examine the characteristics of cultivable bacteria, including their adhesion ability, UV and desiccation resistance, we isolated them. We have also been able to learn more about the taxonomic and functional characteristics of these communities by using parallel, culture-independent metagenomics and metabolomics approaches. Using the Illumina HiSeq2500 sequencing platform, a metagenomic analysis was conducted. The results showed that the bacterial community of the Berkeley solar panels is primarily made up of Actinobacteria, Bacteroidetes, and Proteobacteria, with smaller levels of DeinococcusThermus and Firmicutes. Additionally, a distinct Hymenobacter sp. preponderance was seen. A functional analysis showed that all metagenomes shared genes involved in carotenoid biosynthesis and processes involved in the persistence of bacteria on solar panels (such as stress response, capsule construction, and metabolite repair). However, genes implicated in general autotrophic subsystems and photosynthetic pathways were uncommon, indicating that these systems are not essential for survival on solar panels. Liquid chromatography tandem mass spectrometry was used to perform the metabolomics. Polar metabolite composition was found to be quite comparable across the solar panels from Berkeley and Valencia (Spain); however, some metabolites seemed to be differentially represented (for example, trigonelline, pantolactone, and 5-valerolactone were more abundant in the samples from Valencia than in the ones from Berkeley). Additionally, triglyceride metabolites were present in significant concentrations in all of the solar panel samples, and the profiles at the two sites were comparable. The striking similarities between the taxonomic profiles of the solar panels from California and those that had previously been described from Spain highlighted the importance of both selective pressures and the prevalence of microbial populations in the colonisation and establishment of microbial communities
