Warming effects on pelagic carbon metabolism is related to substrate composition and bacterioplankton community history.

Investigating the critical role of carbon cycling feedback to warming is essential for understanding future biosphere development. One of the current challenges is that the warming effect on carbon cycling is inconsistent across various aquatic ecosystems. It was postulated that the composition of dissolved organic matter (DOM) and the microbial community influenced the response of carbon metabolism to warming.

Methylparaben changes the community composition, structure, and assembly processes of free-living bacteria, phytoplankton, and zooplankton.

Parabens are common contaminants in river and lake environments. However, few studies have been conducted to determine the effects of parabens on bacteria, phytoplankton, and zooplankton communities in aquatic environments. In this study, the effect of methylparaben (MP) on the diversity and community structure of the aquatic plankton microbiome was investigated by incubating a microcosm with MP at 0.

Metabolic versatility of aerobic methane-oxidizing bacteria under anoxia in aquatic ecosystems.

The potential positive feedback between global aquatic deoxygenation and methane (CH) emission emphasizes the importance of understanding CH cycling under O-limited conditions. Increasing observations for aerobic CH-oxidizing bacteria (MOB) under anoxia have updated the prevailing paradigm that MOB are O-dependent; thus, clarification on the metabolic mechanisms of MOB under anoxia is critical and timely. Here, we mapped the global distribution of MOB under anoxic aquatic zones and summarized four underlying metabolic strategies for MOB under anoxia: (a) forming a consortium with oxygenic microorganisms; (b) self-generation/storage of O by MOB; (c) forming a consortium with non-oxygenic heterotrophic bacteria that use other electron acceptors; and (d) utilizing alternative electron acceptors other than O.

Methane ebullition fluxes and temperature sensitivity in a shallow lake.

Inland waters are important sources of atmospheric methane (CH), with a major contribution from the CH ebullition pathway. However, there is still a lack of CH ebullition flux (eFCH) and their temperature sensitivity (Q) in shallow lakes, which might lead to large uncertainties in CH emission response from aquatic to climate and environmental change. Herein, the magnitude and regulatory of two CH pathways (ebullition and diffusion) were studied in subtropical Lake Chaohu, China, using the real-time portable greenhouse gas (GHG) analyzer-floating chamber method at 18 sites over four seasons.

Hydrogenotrophic pathway dominates methanogenesis along the river-estuary continuum of the Yangtze River.

Rivers are considered as an important source of methane (CH) to the atmosphere, but our understanding for the methanogenic pathway in rivers and its linkage with CH emission is very limited. Here, we investigated the diffusive flux of CH and its stable carbon isotope signature (δC-CH) along the river-estuary continuum of the Yangtze River. The diffusive CH flux was estimated to 27.

The selection of copiotrophs may complicate biodiversity-ecosystem functioning relationships in microbial dilution-to-extinction experiments.

The relationships between biodiversity-ecosystem functioning (BEF) for microbial communities are poorly understood despite the important roles of microbes acting in natural ecosystems. Dilution-to-extinction (DTE), a method to manipulate microbial diversity, helps to fill the knowledge gap of microbial BEF relationships and has recently become more popular with the development of high-throughput sequencing techniques. However, the pattern of community assembly processes in DTE experiments is less explored and blocks our further understanding of BEF relationships in DTE studies.

Iron oxides act as an alternative electron acceptor for aerobic methanotrophs in anoxic lake sediments.

Conventional aerobic CH-oxidizing bacteria (MOB) are frequently detected in anoxic environments, but their survival strategy and ecological contribution are still enigmatic. Here we explore the role of MOB in enrichment cultures under O gradients and an iron-rich lake sediment in situ by combining microbiological and geochemical techniques. We found that enriched MOB consortium used ferric oxides as alternative electron acceptors for oxidizing CH with the help of riboflavin when O was unavailable.

Unexpected enrichment of antibiotic resistance genes and organic remediation genes in high-altitude lakes at Eastern Tibetan Plateau.

Elevation has a strong effect on aquatic microbiome. However, we know little about the effects of elevation on functional genes, especially antibiotic resistance genes (ARGs) and organic remediation genes (ORGs) in freshwater ecosystems. In this study, we analyzed five classes of functional genes including ARGs, metal resistance genes (MRGs), ORGs, bacteriophages, and virulence genes between two high-altitude lakes (HALs) and two low-altitude lakes (LALs) in Mountain Siguniang at Eastern Tibetan Plateau by means of GeoChip 5.

Improved Assembly of Metagenome-Assembled Genomes and Viruses in Tibetan Saline Lake Sediment by HiFi Metagenomic Sequencing.

With the development and reduced costs of high-throughput sequencing technology, environmental dark matter, such as novel metagenome-assembled genomes (MAGs) and viruses, is now being discovered easily. However, due to read length limitations, MAGs and viromes often suffer from genome discontinuity and deficiencies in key functional elements. Here, by applying long-read sequencing technology to sediment samples from a Tibetan saline lake, we comprehensively analyzed the performance of high-fidelity (HiFi) reads and the possibility of integration with short-read next-generation sequencing (NGS) data.

Intrahabitat Differences in Bacterial Communities Associated with in the Large Shallow Eutrophic Lake Taihu.

The Asian clam Corbicula fluminea is a keystone zoobenthos in freshwater ecosystems. However, its associated microbiome is not well understood. We investigated the bacterial communities of this clam and its surrounding environment, including sediment and water simultaneously, in a large lake by means of 16S rRNA gene sequencing.