Microbial Mat Compositional and Functional Sensitivity to Environmental Disturbance

Abstract

The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. While studies have indicated that rare microbial taxa may provide a biological reservoir that supports long-term ecosystem stability, how this dynamic population is influenced by environmental parameters remains unclear. In this study, a microbial mat ecosystem located on San Salvador Island, The Bahamas was used as a model to examine how environmental disturbance affects the protein synthesis potential (PSP) of rare and abundant archaeal and bacterial communities and how these changes impact potential biogeochemical processes. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1) during 2011–2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of 16S rRNA and rRNA genes from samples before and after the pulse disturbance showed significant changes in the diversity and PSP of abundant and rare taxa, suggesting overall compositional and functional sensitivity to environmental change. In both archaeal and bacterial communities, while the majority of taxa showed low PSP across conditions, the overall community PSP increased post-disturbance, with significant shifts occurring among abundant and rare taxa across and within phyla. Broadly, following the post-disturbance reduction in salinity, taxa within Halobacteria decreased while those within Crenarchaeota, Thaumarchaeota, Thermoplasmata, Cyanobacteria, and Proteobacteria, increased in abundance and PSP. Quantitative PCR of genes and transcripts involved in nitrogen and sulfur cycling showed concomitant shifts in biogeochemical cycling potential. Post-disturbance conditions increased the expression of genes involved in N-fixation, nitrification, denitrification, and sulfate reduction. Together, our findings show complex community adaptation to environmental change and help elucidate factors connecting disturbance, biodiversity, and ecosystem function that may enhance ecosystem models.

Understanding the Mechanisms Behind the Response to Environmental Perturbation in Microbial Mats: A Metagenomic-Network Based Approach

“…Due to their capacity to perform most of the biogeochemical cycles in a physically and chemically reduced environment, microbial mats are excellent models of study. Microbial mats are successful ecological communities which have adapted continuously to environmental changes since the Archean Eon ( van Gemerden, 1993 ; Guerrero et al, 2002 ; Bolhuis et al, 2014 ; Preisner et al, 2016 ). Here, we seek to identify the general patterns caused by environmental perturbation.…”

How environment selects: Resilience and survival of microbial mat community within intermittent karst spring Krčić (Croatia)

“…In these situations, the ability of ecosystems to adapt to the exerted changes depends on the duration and the intensity of the change, as well as on its biological diversity. In the study conducted by Preisner, Fichot, and Norman (2016), significant changes in diversity and shifts in biogeochemical cycling potential were recorded within microbial mats as a consequence of changes exerted to the ecosystem.…”

Bacterial Diversity of a Microbial Mat from Hot Spring at Wartawan Beach, Lampung and Its Potential as a Source of Hydrogenases

“…In addition, Cyanobacteria was the most abundant group with more than 40% followed by Proteobacteria (16%). Cyanobacteria and Proteobacteria in many mat microbial community types were considered as major components (Guerrero et al, 2002;Lau et al, 2009;Moyer, Dobbs, & Karl, 1995;Preisner, Fichot, & Norman, 2016). The presence of Cyanobacteria as a phototrophic plays role for primary producers to support the mat communities (Lau et al, 2009).…”