An “overlooked” habitat for thermophilic bacteria: the phyllosphere

By

Godon, Jean Jacques
Galès, Amandine
Latrille, Eric
Ouichanpagdee, Pornpimol
Seyer, Jean-Philippe

Type

Article

Date of Publication

2020-3-30

Original Publication

Biodiscovery

Volume

23

Pages

1--14

Subjects

airborn , Bacteria , Biotope , phyllosphere , thermophile

Contributed by

Pensoft Publishers

Language

English

Published by

Newport on Tay Scottish Science Press

Identifiers

DOI: https://doi.org/10.3897/biodiscovery.23.e47033

 

Abstract

Thermophilic microbes are present everywhere around us and their only known natural biotope is far away and most usually associated with geothermal energy. To answer this paradox, we explore the hypothesis that the phyllosphere (surface of leaves), due to its exposition to the sun, could well be a thermophilic habitat for microbes and thus a source of thermophilic microbes growing around 50°C – 60°C. To support this hypothesis, we reviewed the heat sources on earth and associated microbial habitats, as well as the difficult identification of thermophilic microbes. We further present an experiment to show the presence and activity of thermophilic bacteria in the phyllosphere. Leaves were collected from eleven tree species from five locations on three continents belonging to three different biomes. On fresh leaves, 16S rDNA sequencing reveals the presence of 0.2 to 7% of clearly identified thermophilic bacteria. Moreover, after incubation at 55°C under aerobic and anaerobic conditions, 16S rDNA sequencing reveals the presence of 4 to 99% of clearly identified thermophilic bacteria. The accumulation of observations provides coherence to our hypothesis and allows the emergence of a new vision of leaves as a thermophilic biotope. We then propose a life cycle of microbes belonging to the thermophilic biotope associated with leaf surfaces.