First characterization of cultivable extremophile Chroococcidiopsis isolates from a solar panel

Sara Baldanta; Raquel Arnal; Amaya Blanco-Rivero; Govinda Guevara; Juana María Navarro Llorens

doi:10.3389/fmicb.2023.982422

First characterization of cultivable extremophile Chroococcidiopsis isolates from a solar panel

Front Microbiol. 2023 Feb 17:14:982422. doi: 10.3389/fmicb.2023.982422. eCollection 2023.

Authors

Sara Baldanta¹, Raquel Arnal¹, Amaya Blanco-Rivero¹, Govinda Guevara¹, Juana María Navarro Llorens¹

Affiliation

¹ Metabolic Engineering Group, Department of Biochemistry and Molecular Biology, Universidad Complutense de Madrid, Madrid, Spain.

Abstract

Introduction: Microorganisms colonize a wide range of natural and artificial environments. Even though most of them are unculturable in laboratory conditions, some ecosystems are ideal niches for bioprospecting extremophiles with unique properties. Up today, there are few reports concerning microbial communities found on solar panels, a widespread, artificial, extreme habitat. Microorganisms found in this habitat belong to drought-, heat- and radiation-adapted genera, including fungi, bacteria, and cyanobacteria.

Methods: Here we isolated and identified several cyanobacteria from a solar panel. Then, some strains isolated were characterizated for their resistance to desiccation, UV-C exposition, and their growth on a range of temperature, pH, NaCl concentration or diverse carbon and nitrogen sources. Finally, gene transfer to these isolates was evaluated using several SEVA plasmids with different replicons to assess their potential in biotechnological applications.

Results and discussion: This study presents the first identification and characterization of cultivable extremophile cyanobacteria from a solar panel in Valencia, Spain. The isolates are members of the genera Chroococcidiopsis, Leptolyngbya, Myxacorys, and Oculatella all genera with species commonly isolated from deserts and arid regions. Four of the isolates were selected, all of them Chroococcidiopsis, and characterized. Our results showed that all Chroococcidiopsis isolates chosen were resistant up to a year of desiccation, viable after exposition to high doses of UV-C, and capable of being transformed. Our findings revealed that a solar panel is a useful ecological niche in searching for extremophilic cyanobacteria to further study the desiccation and UV-tolerance mechanisms. We conclude that these cyanobacteria can be modified and exploited as candidates for biotechnological purposes, including astrobiology applications.

Keywords: Chroococcidiopsis; SEVA vectors; UV-C; desiccation; extremophile cyanobacteria; solar panel.