Storm Events Restructured Bacterial Community and Their Biogeochemical Potentials

Abstract

Large rainstorms deliver significant amounts of upland materials to headwater streams, thereby introducing the particle-associated microorganisms from complex soil environments into stream networks. "Seeding and mixing" from terrestrial sources may generate "new" in-stream microbial consortia and facilitate nutrient transformations and export to receiving waters. In order to investigate how large storm events influence the microbial community, bacterial community structure from White Clay Creek (Chester Co., PA, USA) was characterized following the Hurricane Irene and the Tropical Storm Lee. High-throughput sequencing of the 16S rRNA genes was used to track changes of bacterial community before, during, and after the events. Detailed bacterial community structures based on analyses of 3,004,072 sequences indicated an increase of bacterial diversity during peak discharge of the storm. Significant successional changes of bacterial community structure during the events were observed: Betaproteobacteria decreased in relative abundance, while members of Deltaproteobacteria, Acidobacteria, Chloroflexi, Nitrospirae, Planctomycetes, and Verrucomicrobia increased with the discharge suggesting potential impacts from terrestrial inputs and re-suspended sediments. Cyanobacteria bloomed after the storm events, indicating that photosynthesis was one of the primary recovering processes. Real-time polymerase chain reaction (quantitative polymerase chain reaction) analyses on functional genes (amoA for nitrification and nirS/nirK for denitrification) suggested that storm events also changed the functional perspectives of the microbial communities, with the potential for alteration of subsequent biogeochemical transformations. Thus, large storm events inoculate microbes from terrestrial and streambeds to headwaters, and downslope dispersal ("mass-effect") and "species-sorting" likely restructure the microbial community as well as potential nutrient cycling.

Hurricane Disturbance Stimulated Nitrification and Altered Ammonia Oxidizer Community Structure in Lake Okeechobee and St. Lucie Estuary (Florida)

“…Few studies have documented changes in ammonia oxidizer community structure following disturbances in aquatic systems. Responses of ammonia oxidizers to various perturbations differ and include increased AOB diversity or abundance (wastewater, Aalto et al, 2018 ; flow restriction, Bernhard et al, 2015 ; flooding, Bouskill et al, 2011 ; storms, Kan, 2018 ), decreased AOA diversity or abundance (storms, Happel et al, 2018 ; hurricanes, Newell et al, 2014 ), or little to no effect (oil spill, Bernhard et al, 2019 ; oil spill, Marton et al, 2015 ). Here, we observed substantial hurricane impacts on the abundance, community composition, and diversity of ammonia oxidizers.…”

Biogeographical distribution of microbial communities along the Rajang River–South China Sea continuum

“…The majority of bacterial taxa were restricted to a relatively small number of assemblages. Dominant phyla typically found in Malaysian peat swamps such as Proteobacteria (Kanokratana et al, 2011;Too et al, 2018; Tripathi et al, 2016) are found throughout the Rajang River, whereas Acidobacteria is not a major phylum in the Rajang River. However, due to the heterogeneity of the Rajang River, substantial shifts in OTU diversity were shown, while exhibiting successional changes in community composition downstream.…”

“…Metagenomics studies substantiated the dominance of Proteobacteria and Actinobacteria while Bacteroidetes, Cyanobacteria and Verrucomicrobia were also found to be abundant in rivers (Cottrell et al, 2005;Kolmakova et al, 2014;Lemke et al, 2009;Newton et al, 2011;Read et al, 2015;Staley et al, 2013). While there are studies related to the freshwater-marine gradients of rivers such as studies by Crump and Hobbie (2005) and Fortunato et al (2013) and tropical peatlands (Kanokratana et al, 2011;Mishra et al, 2014;Yule et al, 2016;Too et al, 2018), to the authors' knowledge, this is the first study which links both freshwater-marine gradients as well as tropical peatlands as a cohesive component (i.e. tropical peat-draining river to coastal ecosystem).…”

“…community composition and diversity in freshwater habitats, especially in lotic environments, are much less studied compared to marine and soil communities (Kan, 2018).…”

Biogeographical distribution of Microbial Communities along the Rajang River-South China Sea Continuum

“…Biogeochemical transformations are primarily governed by microbial communities (Konopka, 2009), and it is crucial to understand their dynamics in order to predict biosphere modulations in response to a changing climate. Despite the importance of freshwater to society and despite hosting the highest microbial diversity (Besemer et al, 2013), microbial community composition and diversity in freshwater habitats, especially in lotic environments, are much less studied compared to marine and soil communities (Kan, 2018).…”