Evaluation of the Human Interference on the Microbial Diversity of Poyang Lake Using High-Throughput Sequencing Analyses

A novel method for quantifying human disturbances: A case study of Huaihe River Basin, China

Human disturbances have become the main factors affecting the ecological environment. Therefore, evaluating the intensity of human disturbances is of great significance for ensuring effective regional conservation and ecosystem management. In this study, we constructed a novel method to quantify human disturbances based on three components of human disturbances into three types, namely naturalness transformation, natural resource consumption, and pollutant emissions. These components were quantified using the land use naturalness index (LNI), resource consumption index (RCI), and pollution emission index (PEI). Based on these three indicators, the human disturbances index (HDI) was calculated to reflect the intensity of human disturbances. In addition, remote sensing (RS), geographic information system (GIS), and multisource data were combined in the HDI method, taking into account the temporal variability of input parameters to achieve more convenient and comprehensive dynamic monitoring and evaluation of human disturbances. The applicability and effectiveness of the HDI method were assessed in the Huaihe River Basin, China. The obtained results revealed an increase and decrease in the intensities of human disturbances in the Huaihe River Basin from 1990 to 2005 and from 2010 to 2018, respectively. In addition, areas with a high level of human disturbances in the 1990-2005 period were mainly concentrated in the agricultural and industrial areas, while those in the 2010-2018 period were mainly observed in urban areas. This change was mainly due to a decrease in the pollutant emission amounts from agricultural and industrial lands and a marked increase in resource consumption in urban areas. This study provides theoretical guidance for regional conservation in the Huaihe River Basin and a new method for quantifying human disturbances.

Bacterial and archaeal communities within the alkaline soda Langaco Lake in the Qinghai-Tibet Plateau

Purpose

Langaco Lake (LGL) is a soda lake located at an altitude of 4548 m in the Qinghai-Tibet Plateau in China. LGL exhibits unique hydrochemical characteristics among soda lakes, but little is known about the microbial diversity of LGL and the microbial interactions with environmental factors.

Methods

The water samples were filtered using chemical-grade cellulose acetate membrane (pore size of 0.45 μm), and the hydrochemical characteristics were analyzed. Community DNA was extracted, and then high-throughput sequencing of 16S rRNA genes was conducted to evaluate the composition of the microbial community.

Results

The high-throughput sequencing of 16S rRNA genes revealed that the bacterial diversity in LGL consisted of 327 genera in 24 phyla (4871 operational taxonomic units (OTUs); Shannon index values of 5.20–6.07), with a significantly higher diversity than that of the Archaea (eight phyla and 29 genera comprising 1008 OTUs; Shannon index values of 2.98–3.30). The bacterial communities were dominated by Proteobacteria (relative abundances of 42.79–53.70%), followed by Bacteroidetes (11.13–15.18%), Planctomycetes (4.20–12.82%), Acidobacteria (5.91–9.50%), Actinobacteria (2.60–5.80%), and Verrucomicrobia (2.11–4.08%). Furthermore, the archaeal communities were dominated by Crenarchaeota (35.97–58.29%), Euryarchaeota (33.02–39.89%), and Woesearchaeota (6.50–21.57%). The dominant bacterial genus was Thiobacillus (8.92–16.78%), and its abundances were most strongly correlated with the total phosphorus (TP) content, pH value, CO32− concentration, and temperature. The most abundant archaeal genus was Methanoregula (21.40–28.29%), and its abundances were the most highly correlated with the total organic carbon (TOC) content, total salinity (TS), and K+ and Na+ concentrations.

Conclusions

The results of this study provide valuable insights for developing a more comprehensive understanding of microbial diversity in these unique carbonate alkaline environments, as well as a better understanding of the microbial resources on the Qinghai-Tibet Plateau.

Next generation sequencing approaches to evaluate water and wastewater quality

The emergence of next generation sequencing (NGS) is revolutionizing the potential to address complex microbiological challenges in the water industry. NGS technologies can provide holistic insight into microbial communities and their functional capacities in water and wastewater systems, thus eliminating the need to develop a new assay for each target organism or gene. However, several barriers have hampered wide-scale adoption of NGS by the water industry, including cost, need for specialized expertise and equipment, challenges with data analysis and interpretation, lack of standardized methods, and the rapid pace of development of new technologies. In this critical review, we provide an overview of the current state of the science of NGS technologies as they apply to water, wastewater, and recycled water. In addition, a systematic literature review was conducted in which we identified over 600 peer-reviewed journal articles on this topic and summarized their contributions to six key areas relevant to the water and wastewater fields: taxonomic classification and pathogen detection, functional and catabolic gene characterization, antimicrobial resistance (AMR) profiling, bacterial toxicity characterization, Cyanobacteria and harmful algal bloom identification, and virus characterization. For each application, we have presented key trends, noteworthy advancements, and proposed future directions. Finally, key needs to advance NGS technologies for broader application in water and wastewater fields are assessed.