Soil and sediment microbial structure and function in intermittent stream corridors after a decade of catchment succession

Author(s):  
Jose Schreckinger ◽  
Aline Frossard ◽  
Linda Gerull ◽  
Mark O. Gessner ◽  
Michael Mutz

<p>Large-scale resource exploitation by open-cast mining severely alters landscapes and impairs key ecosystem properties such as soil and sediment structure and function. Understanding the ecological recovery processes starting from an initially bare landscape generated by destructive land-use is extremely limited. Here we took advantage of a 6-ha experimental catchment to assess microbial community structure and function in soils and stream sediments after 3 and 13 years of catchment succession. The catchment (Chicken Creek) was created in 2005 by depositing quaternary sands from a lignite mine forefield in northeastern Germany and has since been left to develop under undisturbed conditions. In the initial stage, 3 years after catchment construction, rills and small streams had formed and the sparse vegetation cover mainly consisted of forbs. Over the next 10 years, the geomorphology, hydrology, and vegetation structure underwent a major transformation. A nearly full vegetation cover established, including various tree, shrub and grass species. Increased evaporation lowered the shallow groundwater table and led to stream intermittency. These changes were accompanied by large modifications in the structure and function of the microbial communities in sediments and soils. Initially, microbial structure and function were strikingly disconnected, whereas linkages had established 10 years later, although some functions still remained disconnected. Potential enzymatic activities increased vastly over the course of 10 years and also became much less variable across seasons. Cyanobacteria, predominant in soils and sediments during the early successional stage, declined to become a minor component of the microbial community. Moreover, despite distinct flow intermittency of the streams, microbial structure and function distinctly differed between sediments and adjacent soils. These results demonstrate a rapid succession of microbial communities during a decade of ecosystem development, suggesting that undisturbed succession is a feasible catchment restoration strategy.</p>

2021 ◽  
Author(s):  
Jennifer D Rocca ◽  
Andrea Yammine ◽  
Marie Simonin ◽  
Jean Gibert

Temperature strongly influences microbial community structure and function, which in turn contributes to the global carbon cycle that can fuel further warming. Recent studies suggest that biotic interactions amongst microbes may play an important role in determining the temperature responses of these communities. However, how microbial predation regulates these communities under future climates is still poorly understood. Here we assess whether predation by one of the most important bacterial consumers globally, protists, influences the temperature response of a freshwater microbial community structure and function. To do so, we exposed these microbial communities to two cosmopolitan species of protists at two different temperatures, in a month-long microcosm experiment. While microbial biomass and respiration increased with temperature due to shifts in microbial community structure, these responses changed over time and in the presence of protist predators. Protists influenced microbial biomass and function through effects on community structure, and predation actually reduced microbial respiration rate at elevated temperature. Indicator species and threshold indicator taxa analyses showed that these predation effects were mostly determined by phylum-specific bacterial responses to protist density and cell size. Our study supports previous findings that temperature is an important driver of microbial communities, but also demonstrates that predation can mediate these responses to warming, with important consequences for the global carbon cycle and future warming.


Author(s):  
Samir Giri ◽  
Leonardo Oña ◽  
Silvio Waschina ◽  
Shraddha Shitut ◽  
Ghada Yousif ◽  
...  

AbstractThe exchange of metabolites among different bacterial genotypes is key for determining the structure and function of microbial communities. However, the factors that govern the establishment of these cross-feeding interactions remain poorly understood. While kin selection theory predicts that individuals should direct benefits preferentially to close relatives, the potential benefits resulting from a metabolic exchange may be larger for more distantly related species. Here we distinguish between these two possibilities by performing pairwise cocultivation experiments between auxotrophic recipients and 25 species of potential amino acid donors. Auxotrophic recipients were able to grow in the vast majority of pairs tested (78%), suggesting that metabolic cross-feeding interactions are readily established. Strikingly, both the phylogenetic distance between donor and recipient as well as the dissimilarity of their metabolic networks was positively associated with the growth of auxotrophic recipients. Finally, this result was corroborated in an in-silico analysis of a co-growth of species from a gut microbial community. Together, these findings suggest metabolic cross-feeding interactions are more likely to establish between strains that are metabolically more dissimilar. Thus, our work identifies a new rule of microbial community assembly, which can help predict, understand, and manipulate natural and synthetic microbial systems.SignificanceMetabolic cross-feeding is critical for determining the structure and function of natural microbial communities. However, the rules that determine the establishment of these interactions remain poorly understood. Here we systematically analyze the propensity of different bacterial species to engage in unidirectional cross-feeding interactions. Our results reveal that synergistic growth was prevalent in the vast majority of cases analyzed. Moreover, both phylogenetic and metabolic dissimilarity between donors and recipients favored a successful establishment of metabolite exchange interactions. This work identifies a new rule of microbial community assembly that can help predict, understand, and manipulate microbial communities for diverse applications.


2021 ◽  
Vol 12 ◽  
Author(s):  
Denise M. Akob ◽  
Adam C. Mumford ◽  
Andrea Fraser ◽  
Cassandra R. Harris ◽  
William H. Orem ◽  
...  

The widespread application of directional drilling and hydraulic fracturing technologies expanded oil and gas (OG) development to previously inaccessible resources. A single OG well can generate millions of liters of wastewater, which is a mixture of brine produced from the fractured formations and injected hydraulic fracturing fluids (HFFs). With thousands of wells completed each year, safe management of OG wastewaters has become a major challenge to the industry and regulators. OG wastewaters are commonly disposed of by underground injection, and previous research showed that surface activities at an Underground Injection Control (UIC) facility in West Virginia affected stream biogeochemistry and sediment microbial communities immediately downstream from the facility. Because microbially driven processes can control the fate and transport of organic and inorganic components of OG wastewater, we designed a series of aerobic microcosm experiments to assess the influence of high total dissolved solids (TDS) and two common HFF additives—the biocide 2,2-dibromo-3-nitrilopropionamide (DBNPA) and ethylene glycol (an anti-scaling additive)—on microbial community structure and function. Microcosms were constructed with sediment collected upstream (background) or downstream (impacted) from the UIC facility in West Virginia. Exposure to elevated TDS resulted in a significant decrease in aerobic respiration, and microbial community analysis following incubation indicated that elevated TDS could be linked to the majority of change in community structure. Over the course of the incubation, the sediment layer in the microcosms became anoxic, and addition of DBNPA was observed to inhibit iron reduction. In general, disruptions to microbial community structure and function were more pronounced in upstream and background sediment microcosms than in impacted sediment microcosms. These results suggest that the microbial community in impacted sediments had adapted following exposure to OG wastewater releases from the site. Our findings demonstrate the potential for releases from an OG wastewater disposal facility to alter microbial communities and biogeochemical processes. We anticipate that these studies will aid in the development of useful models for the potential impact of UIC disposal facilities on adjoining surface water and shallow groundwater.


2017 ◽  
Author(s):  
Pawel Sierocinski ◽  
Kim Milferstedt ◽  
Florian Bayer ◽  
Tobias Großkopf ◽  
Mark Alston ◽  
...  

ABSTRACTMicrobial communities commonly coalesce in nature, but the consequences for resultant community structure and function is unclear. Consistent with recent theory, we demonstrate using methanogenic communities that the most productive communities in isolation dominated when communities were mixed. As a corollary of this dynamic, total methane production increased with the number of inoculated communities. The cohesion and dominance of single communities was explained by more “niche-packed” communities being both more efficient at exploiting resources and resistant to invasion, rather than a function of the average performance of component species. These results are likely to be relevant to the ecological dynamics of natural microbial communities, as well as demonstrating a simple method to predictably enhance microbial community function in biotechnology, health and agriculture.


2017 ◽  
Author(s):  
Charley J. Hubbard ◽  
Marcus T. Brock ◽  
Linda T.A. van Diepen ◽  
Loïs Maignien ◽  
Brent E. Ewers ◽  
...  

AbstractPlants alter chemical and physical properties of soil, and thereby influence rhizosphere microbial community structure. The structure of microbial communities may in turn affect plant performance. Yet, outside of simple systems with pairwise interacting partners, the plant genetic pathways that influence microbial community structure remain largely unknown, as are the performance feedbacks of microbial communities selected by the host plant genotype. We investigated the role of the plant circadian clock in shaping rhizosphere community structure and function. We performed 16S rRNA gene sequencing to characterize rhizosphere bacterial communities of Arabidopsis thaliana between day and night time points, and tested for differences in community structure between wild-type (Ws) vs. clock mutant (toc1-21, ztl-30) genotypes. We then characterized microbial community function, by growing wild-type plants in soils with an overstory history of Ws, toc1-21 or ztl-30 and measuring plant performance. We observed that rhizosphere community structure varied between day and night time points, and clock misfunction significantly altered rhizosphere communities. Finally, wild-type plants germinated earlier and were larger when inoculated with soils having an overstory history of wild-type in comparison to clock mutant genotypes. Our findings suggest the circadian clock of the plant host influences rhizosphere community structure and function.


2012 ◽  
Vol 51 (16) ◽  
pp. 3862-3866 ◽  
Author(s):  
Bruno G. De Geest ◽  
Monique A. Willart ◽  
Bart N. Lambrecht ◽  
Charlotte Pollard ◽  
Chris Vervaet ◽  
...  

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