Microbial Communities Are Well Adapted to Disturbances in Energy Input

Abstract

Within the broader ecological context, biological communities are often viewed as stable and as only experiencing succession or replacement when subject to external perturbations, such as changes in food availability or the introduction of exotic species. Our findings indicate that microbial communities can exhibit strong internal dynamics that may be more important in shaping community succession than external drivers. Dynamic “unstable” communities may be important for ecosystem functional stability, with rare organisms playing an important role in community restructuring. Understanding the mechanisms responsible for internal community dynamics will certainly be required for understanding and manipulating microbiomes in both host-associated and natural ecosystems.

Using Maximum Entropy Production to Describe Microbial Biogeochemistry Over Time and Space in a Meromictic Pond

“…But is a 3 d optimization window sufficient? It seems the appropriate MEP time scales do not depend on just the characteristic time scales of organisms, because our study on periodically forced methanotroph communities showed that the communities were well adapted to 20 day cyclic inputs of energy, even though the characteristic turnover time of bacteria is closer to hours (Vallino et al, 2014;Fernandez-Gonzalez et al, 2016). We know that terrestrial systems function on long timescales, at least on the order of the four seasons, but their time scales are likely much Date Depth (m) 2 1 -J u n 2 2 -J u n 2 3 -J u n 2 4 -J u n 2 5 -J u n 2 6 -J u n 2 7 -J u n 0 longer given that individual trees can live hundreds of years, and forest succession takes longer than that (Odum, 1969;Finegan, 1984).…”

“…The advantage of the systems approach is that optimization can be used to determine how an ecosystem will organize and function without the knowledge of which organisms are present and how their population changes over time. Understanding and modeling of ecosystems can focus on function rather than on organisms, and there is growing support that stable function arises from dynamic communities (Fernandez et al, 1999;Fernandez-Gonzalez et al, 2016;Louca and Doebeli, 2016;Needham and Fuhrman, 2016;Coles et al, 2017). Here, we build upon the assumption that microbial systems organize to use all available energy sources.…”

Ultradeep Microbial Communities at 4.4 km within Crystalline Bedrock: Implications for Habitability in a Planetary Context

“…Microbes gain energy faster by partial oxidation of carbon compounds, producing intermediate metabolites that, with enough biodiversity, act as food and energy sources to other members of the community [109]. Substrates are recycled in a community so effectively that accumulation of end-products does not occur significantly [110], therefore complicating the observation of these possible biosignatures even further in the search for life in the Solar System.…”

Using maximum entropy production to describe microbial biogeochemistry over time and space in a meromictic pond

“…But is a 3 d optimization window sufficient? It 656 seems the appropriate MEP time scales do not depend on just the characteristic time scales of 657 organisms, because our study on periodically forced methanotroph communities showed that the 658 communities were well adapted to 20 day cyclic inputs of energy, even though the characteristic 659 turnover time of bacteria is closer to hours Fernandez-Gonzalez et al, 2016). 660 We know that terrestrial systems function on long timescales, at least on the order of the four 661 seasons, but their time scales are likely much longer given that individual trees can live hundreds 662 years, and forest succession takes longer than that (Odum, 1969;Finegan, 1984).…”

“…The advantage of the systems approach is that the variational 66 principle can be used to determine how an ecosystem will organize and function without the 67 knowledge of which organisms are present and how their population changes over time, provided 68 there is sufficient diversity. That is, understanding and modeling of ecosystems can focus on function 69 rather than on organisms, and there is growing support that stable function can arise from dynamic 70 communities (Fernandez et al, 1999;Fernandez-Gonzalez et al, 2016;Louca and Doebeli, 2016;71 Needham and Fuhrman, 2016; Coles et al, 2017). Here, we build upon the conjecture that microbial 72 systems organize to maximize entropy production.…”