The rhizosphere microbiome of burned holm-oak: Potential role of the genus Arthrobacter in the recovery of burned soils
After a forest wildfire, the microbial communities have a transient alteration in their composition. The role of the soil microbial community in the recovery of an ecosystem following such an event remains poorly understood. Thus, it is necessary to understand the plant-microbe interactions that occur in burned soils. By high-throughput sequencing, we identified the main bacterial taxa of burnt holm-oak rhizosphere, then we obtained an isolate collection of the most abundant genus and its growth promoting activities were characterised. 16S rRNA amplicon sequencing showed that the genus Arthrobacter comprised more than 21% of the total community. 55 Arthrobacter strains were isolated and characterized using RAPDs and sequencing of the almost complete 16S rRNA gene. Our results indicate that isolated Arthrobacter strains present a very high genetic diversity, and they could play an important ecological role in interaction with the host plant by enhancing aerial growth. Most of the selected strains exhibited a great ability to degrade organic polymers in vitro as well as possibly presenting a direct mechanism for plant growth promotion. All the above data suggests that Arthrobacter can be considered as an excellent PGP rhizobacterium that may play an important role in the recovery of burned holm-oak forests. ; This work was funded by the following grants: P08-CVI-03549 from The Department of Innovation, Science and Enterprise of the Autonomous Government of Andalusia; OAPN 021/2007 from The National Parks Autonomous Body (Ministry of the Environment) and 20134R069, RECUPERA 2020 from the Spanish Ministry of Economy and Competitiveness and CSIC, including ERDF (European Regional Development Fund). The work conducted by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. AJFG was awarded a pre-doctoral fellowship (FPU) from the Spanish Ministry of Education; JFCD was awarded a pre-doctoral fellowship from the Junta de Andalucía, and both with a postdoctoral contract from RECUPERA 2020. PMH was awarded a postdoctoral fellowship from Ramón Areces foundation ; Peer Reviewed