Primary microbial succession on lava fields

New freshly formed lava fields are unique environments as they are the only naturally sterile (life-free) places on Earth. As such the fresh lava fields are ideal research environments for studying microbial succession events – colonization of the rock and development of viable microbial communities – that eventually lead to soil formation and development of higher life (vegetation) in general. Volcanic environments can be used as model systems to understand more general patterns of distribution of microbes through time and space and to study how the geochemistry of different rocks can influence microbial diversity. Yet, it is not known which microorganisms drive the initial colonization or, more importantly, what specific traits allow the pioneering organisms to survive. In our project we are studying primary microbial succession on basaltic lava fields in order to identify the microbes responsible for the creation of a fertile ecosystem and pinpoint the key properties that enable these microbes to survive in a post-eruptive environment that holds little nutrients and is hostile to most organisms.

We are periodically sampling recently active volcanic sites and analysing the samples by using the tools of metagenomics to identify the taxa and metabolic properties of the pioneering organisms and to follow the community dynamics in time. Data gained from microbial succession studies improves our knowledge about development of biotopes now and in the past, possibilities of life to develop and evolve in different environments, and about the roles of microbes in geochemical cycles, soil formation and weathering.

Microbial weathering of terrestrial basalts

Recently it has been shown that, contrary to previous assumptions, igneous and metamorphic rocks are colonised by diverse microbial communities. In order to survive on and in oligotrophic rocks microbes have to interact with rock-forming minerals to gain nutrients. This interaction leads to weathering. Although rock weathering is an important factor in biogeochemical cycles providing the substrate and necessary compounds for life, still very little is known about the actual role microbes play in the process. In this project we study shallow igneous rocks (basalt flows) of well-defined age to reveal the progression of chemical alteration and the appearance and evolution of microbial communities in time and space. The combined data on the mode and intensity of weathering and on the depth and composition of microbial communities, and the knowledge on chemical reactions carried out by the microbes allow to understand the role of microbes in rock weathering.