Bioprospecting the solar panel microbiome
This week, one of our latest bioprospecting work, focused on the microbiota that inhabits the surfaces of solar panels, has been published in the international scientific journal Frontiers in Microbiology. This extreme environment is characterized by suffering high amounts of solar radiation, drying and temperature fluctuations, resulting in an adaptation of the microorganisms that inhabit it to these conditions. One of the ways to survive the effects of radiation is the accumulation of pigments, in particular, carotenoids, which are very interesting both for its high commercial value and its antioxidant capacity.
In this work we have isolated, from the surface of solar panels located at the University of Valencia, 68 microorganisms (the vast majority pigmented) belonging to 20 different microbial genera. A total of 14 isolates were selected from this collection (eliminating those pathogens or opportunistic pathogens) in order to perform oxidative stress tests in Caenorhabditis elegans, a nematode that is often used as a model organism and that presents a series of advantages over other model organisms, including its small size and simplicity, its short life cycle and low economic cost. In addition, it feeds on microorganisms, which means that it can be fed with our selected pigmented strains.
A total of 10 of the 14 isolates were shown to protect C. elegans from oxidative stress, being the best: Planomicrobium glaciei PS1, Rhodobacter maris PS21, and Bacillus megaterium PS75, which provided 57-78% survival compared to worms fed a control diet, whose average survival was 37%. These isolates also proved 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 that inhabit the surface of solar panels, as well as their biotechnological potential due to the production of carotenoids of high commercial value.