Diversity and distribution of sediment bacteria across an ecological and trophic gradient

Abstract

The microbial communities of lake sediments have the potential to serve as valuable bioindicators and integrators of watershed land-use and water quality; however, the relative sensitivity of these communities to physio-chemical and geographical parameters must be demonstrated at taxonomic resolutions that are feasible by current sequencing and bioinformatic approaches. The geologically diverse and lake-rich state of Minnesota (USA) is uniquely situated to address this potential because of its variability in ecological region, lake type, and watershed land-use. In this study, we selected twenty lakes with varying physio-chemical properties across four ecological regions of Minnesota. Our objectives were to (i) evaluate the diversity and composition of the bacterial community at the sediment-water interface and (ii) determine how lake location and watershed land-use impact aqueous chemistry and influence bacterial community structure. Our 16S rRNA amplicon data from lake sediment cores, at two depth intervals, data indicate that sediment communities are more likely to cluster by ecological region rather than any individual lake properties (e.g., trophic status, total phosphorous concentration, lake depth). However, composition is tied to a given lake, wherein samples from the same core were more alike than samples collected at similar depths across lakes. Our results illustrate the diversity within lake sediment microbial communities and provide insight into relationships between taxonomy, physicochemical, and geographic properties of north temperate lakes.

Sedimentary DNA and pigments show increasing abundance and toxicity of cyanoHABs during the Anthropocene

“…In contrast to Upper Red and Carlos lakes, this transition represents a clear switch from non‐diazotrophic to diazotrophic cyanobacteria as the dominant DNA preserved in the sediments. Although long‐term monitoring data are not available for South Center Lake, spot‐sampling has occurred and demonstrates that the lake does appear to be N‐limited for at least parts of the year (Summer N:P by mass = 10; Sauer et al, 2022).…”

“…F I G U R E 5 Latent Dirichlet Allocation (LDA) results showing the estimated prevalence of each community-type before and after major change points (black bar) in (a) Lake Carlos, (b) South Center Lake and (c) Upper Red Lake. South Center Lake, spot-sampling has occurred and demonstrates that the lake does appear to be N-limited for at least parts of the year (Summer N:P by mass = 10; Sauer et al, 2022).…”

Compositional Changes in Sediment Microbiota Are Associated with Seasonal Variation of the Water Column in High-Altitude Hyperarid Andean Lake Systems

“…Alternatively, as described in the case of the Salar de Llamara, this could be due to derived or accelerated changes in the geological conditions of the lagoons, the quality of the water, and the presence of microbiological structures ( 5 ). Authors such as Karaman ( 33 ) have also noted that these microbiological structures could influence and be influenced by the hydrological dynamics of lakes by generating structures that segregate or combine sub-bodies of water, thus altering the morphology and surface of the water mirror.…”

Alternative Media from Mangrove Fruit for the Growth of Shigella dysentery, Escherichia coli, and Salmonella typhi bacteria

“…Bacteria are thought to play a role in the weathering process of organic matter from plants in the forest in the form of wood or leaves. Generally, bacteria are taken from sediment, leaf litter, and weathered wood in the Mangrove environment (Prartono et al, 2022;Sauer et al, 2022). Bacteria need adequate space and nutrients to grow and develop (Gill, 2017).…”