Bioprospecting of the solar panel microbiome

This week, one of our latest bioprospecting studies focused on the microbiota inhabiting the surfaces of solar panels was published in the international scientific journal Frontiers in Microbiology. This extreme environment is characterized by high levels of solar radiation, desiccation, and temperature fluctuations, resulting in the adaptation of microorganisms that inhabit it. One way to survive the effects of radiation is the accumulation of pigments, particularly carotenoids, which are of great interest both for their high commercial value and their antioxidant capacity.

 

In this study, we isolated 68 microorganisms (the vast majority pigmented) from the surface of solar panels located at the University of Valencia, belonging to 20 different microbial genera. From this collection, a total of 14 isolates were selected (excluding pathogens or opportunistic pathogens) to perform oxidative stress tests on Caenorhabditis elegans, a nematode often used as a model organism that has several advantages over other model organisms, including its small size and simplicity, short life cycle, and low economic cost. Additionally, it feeds on microorganisms, meaning we can feed it our selected pigmented strains.

 

A total of 10 out of the 14 isolates demonstrated the ability to protect C. elegans against oxidative stress, with the best being Planomicrobium glaciei PS1, Rhodobacter maris PS21, and Bacillus megaterium PS75, which provided between 57-78% survival compared to worms fed a control diet, which had an average survival rate of 37%. These isolates also demonstrated the ability to protect *C. elegans* against ultraviolet radiation, and an analysis of the carotenoids contained in these microorganisms revealed the presence of colorless carotenoids such as phytoene and phytofluene, as well as colored carotenoids such as β-cryptoxanthin, adonirubin, canthaxanthin, astaxanthin, and β-carotene.

 

These results reveal the great antioxidant capacity of the microorganisms inhabiting the surface of solar panels, as well as their biotechnological potential due to the production of high-value commercial carotenoids.