Patterns of Change in Metabolic Capabilities of Sediment Microbial Communities in River and Lake Ecosystems

Abstract

Information on the biodegradation potential of lake and river microbial communities is essential for watershed management. The water draining into the lake ecosystems often carries a significant amount of suspended sediments, which are transported by rivers and streams from the local drainage basin. The organic carbon processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and apprehend some of these variabilities in the sediments, we sampled six sites: three from the Saint Clair River (SC1, SC2, and SC3) and three from Lake Saint Clair in the spring, summer, fall, and winter of 2016. Here, we investigated the shifts in metabolic profiles of sediment microbial communities, along Saint Clair River and Lake Saint Clair using Biolog EcoPlates, which test for the oxidation of 31 carbon sources. The number of utilized substrates was generally higher in the river sediments (upstream) than in the lake sediments (downstream), suggesting a shift in metabolic activities among microbial assemblages. Seasonal and site-specific differences were also found in the numbers of utilized substrates, which were similar in the summer and fall, and spring and winter. The sediment microbial communities in the summer and fall showed more versatile substrate utilization patterns than spring and winter communities. The functional fingerprint analyses clearly distinguish the sediment microbial communities from the lake sites (downstream more polluted sites), which showed a potential capacity to use more complex carbon substrates such as polymers. This study establishes a close linkage between physical and chemical properties (temperature and organic matter content) of lake and river sediments and associated microbial functional activities.

Spatio-temporal Variations in the Physiological Profiles of Streambed Bacterial Communities: Implication of Wastewater Treatment Plant Effluents

“…PCA revealed the seasonal pattern in BWC microbial community structure, and variations in the drivers of ecosystem change such as percent moisture content, temperature, and C/N ratios supported the PCA ndings. Our study extends other reported shorter-term and annual cycle studies of seasonal variations in microbial communities (Smoot and Findlay 2001;Brummer et al 2002;Sekiguchi et al 2002;Feris et al 2003;Oest et al 2018).…”

Physiological Profiling and Functional Diversity of Groundwater Microbial Communities in a Municipal Solid Waste Landfill Area

“…These substrates are naturally occurring as products of the bacterial degradation and photochemical degradation of the organic matter in surface waters [64,65]. The prompt ability (24 h) in the utilization of complex polymers (tween 80) might indicate the presence of organic pollutants in altered groundwater, being this functional trait linked to polluted environment [55,63]. In this study, organic pollutants were detected at low concentration in some of the altered groundwater sites [25].…”

“…The delay in utilizing tween 80 may reflect the metabolic plasticity [54] that modulates the microbial community functions, suggesting a higher sensitivity of pristine communities to contingent events of contamination by anthropogenic organic pollutants. The shift toward the utilization of amines in the pristine condition might indicate the presence of opportunistic classes of bacteria and a condition of nitrogen deprivation [37,55]. Unlike C-enriched substrates (i.e., carbohydrates and polymers), amines are enriched in nitrogen and utilized by bacteria to synthetize organic molecules such as amino acids and proteins [56].…”

Microbiome divergence across four major Indian riverine water ecosystems impacted by anthropogenic contamination: A comparative metagenomic analysis

“…We have observed a different carbon utilization pattern for each water samples. This may be due to the difference in the water quality, which nurtures diverse structure, the composition of microbial communities based on the nutrients [50,51] and other physic-chemical characteristics. The microbial communities based on carbon substrate utilization showed interesting results for instance, in Ganga, the samples from Alaknanda to Haridwar (G2 to G5) clustered together demonstrating that river Ganga gets most of its attributes from the source stream Alaknanda.…”