Microbial communities on solar panels

Solar panel surfaces can be colonized by microorganisms adapted to desiccation, temperature fluctuations and solar radiation. Although the taxonomic and functional composition of these communities has been studied, the microbial colonization process remains unclear. In the present work, we have monitored this microbial colonization process during 24 months by performing weekly measurements of the photovoltaic efficiency, carrying out 16S rRNA gene high-throughput sequencing, and studying the effect of antimicrobial compounds on the composition of the microbial biocenosis. This is the first time a long-term study of the colonization process of solar panels has been performed, and our results reveal that species richness and biodiversity exhibit seasonal fluctuations and that there is a trend towards an increase or decrease of specialist (solar panel-adapted) and generalist taxa, respectively. On the former, extremophilic bacterial genera Deinococcus, Hymenobacter and Roseomonas and fungal Neocatenulostroma, Symmetrospora and Sporobolomyces tended to dominate the biocenosis; whereas Lactobacillus sp or Stemphyllium exhibited a decreasing trend. This profile was deeply altered by washing the panels with chemical agents (Virkon), but this did not lead to an increase of the solar panels efficiency. Our results show that solar panels are extreme environments that force the selection of a particular microbial community

太阳能板（solar panel）表面可被适应干旱、温度波动与太阳辐射的微生物定殖。尽管已有研究针对这些群落的分类学与功能组成展开分析，但微生物定殖的具体过程仍未明确。本研究中，我们通过每周监测光伏效率、开展16S rRNA基因高通量测序，以及探究抗菌化合物对微生物生物群落（biocenosis）组成的影响，对该微生物定殖过程进行了为期24个月的跟踪观测。本研究为首例针对太阳能板定殖过程的长期观测研究，结果显示物种丰富度与生物多样性呈现季节波动特征，特化（适配太阳能板）类群与泛化类群的分类单元（taxa）丰度分别呈现上升与下降趋势。其中，嗜极细菌属异常球菌属（Deinococcus）、汉氏菌属（Hymenobacter）与玫瑰单胞菌属（Roseomonas），以及真菌新链隔孢属（Neocatenulostroma）、对称孢属（Symmetrospora）和掷孢酵母属（Sporobolomyces）倾向于成为微生物生物群落的优势类群；而乳杆菌属（Lactobacillus sp.）与钉孢霉属（Stemphyllium）则呈现丰度下降趋势。使用化学药剂（Virkon）冲洗太阳能板会大幅改变该微生物群落结构，但并未提升太阳能板的光伏效率。本研究结果表明，太阳能板属于极端环境，会筛选出特定的微生物群落。