Microorganisms as climate change proxies in tropical aquatic ecosystems: a molecular approach

Abstract

The effects of climate change at the scale of microbial communities and at different trophic levels have been little explored in the context of aquatic ecosystems. These limitations are mainly caused by the difficulty in (i) in situ experimentation in natural ecosystems, (ii) difficulties in obtaining data at a scale at which the effects of climate change could be observed (large geographic extent) and (iii) use of analytical and integrative methods in terms of processing genomic data on a Big Data scale and in the context of microbiome studies. Therefore, we will seek to analyze the effects of variations in climatic components, such as temperature, precipitation and heat waves, on the microbiome of tropical aquatic ecosystems, using bromeliads (natural microcosms) and water tanks (artificial mesocosms) in order to simulate small lakes or puddles temporary. We will also use natural space-for-time substitution experiments to predict the effects of climate change on the microbiomes of aquatic systems using spatial gradients (latitudinal, latitudinal, thermal, i.e., streams of geothermal origin) to simulate climate change projected over time. DNA extraction from the aquatic microbiome will be performed for subsequent analysis of changes in taxonomic profiles between treatments through large-scale sequencing of 16S rRNA genes (metagenomic) amplicons. Bioinformatics analyzes for processing the sequencing data, followed by analysis of alpha and beta diversity, will allow detecting the responses of microbial communities in the face of climatic variations. In a second step, the use of tools such as SIMPER or LEfSe will make it possible to identify the taxonomic groups responsible for the significant differences observed in the patterns of diversity and composition of the microbial community between treatments, in order to elect potential bioindicators of the effects of environmental changes on the aquatic system under study. It is expected, based on the integration of information on variations in the diversity patterns of microbiomes and organisms at other trophic levels (which will be obtained within the sub-projects of the Thematic Project), the creation of a community index to infer and monitor the health of tropical aquatic ecosystems (classification of environments). (AU)