Gradual Enhancement of the Assemblage Stability of the Reed Rhizosphere Microbiome with Recovery Time

Spartina alterniflora Ecosystem Stability: Insights Into the Interplay Between Soil Bacteria and Their Functional Traits

The relationship between soil microbiome stability and diversity remains a topic of debate. Our study aims to investigate the relationship between soil microbiome stability and diversity in different wetland types invaded by Spartina alterniflora and to reveal the mechanisms driving functional influences on this relationship during the later-stage development of the S. alterniflora invasion system. To investigated the structure, diversity, and functional traits of soil bacteria associated with S. alterniflora and their impact on bacteriome stability we conducted 16S rRNA sequencing of soils from two types of wetlands dominated by the invasive plant S. alterniflora at different growth stages, situated in temperate (salt marsh wetland) and subtropical (mangrove wetland) regions, and assessed bacteriome stability and its driving factors. Subsequently, we analyzed environmental and bacterial changes between the two sites and constructed co-occurrence networks among taxonomic groups and functional traits. The differences in the late-stage development of the two S. alterniflora-invaded wetland systems suggest that bacterial communities with higher diversity tend to exhibit greater stability. Keystone genera play both direct and indirect roles in regulating bacteriome stability, and all belong to dominant phyla. Furthermore, biological factors significantly outweigh nonbiological factors in driving stability. In contrast, core functions (broad functions) and specialized functions such as "nitrogen metabolism" and "sulfur metabolism" decrease bacteriome stability. Their enhancement of these metabolic processes correlates with reduced community stability, which is the key to the differences observed in the two invaded systems. This study advances our understanding of the relationship between soil microbial diversity and ecosystem stability, highlighting the importance of keystone taxa and functional traits for soil microbiome stability. It enhances our ability to predict microbial community transitions. It enhances a scientific basis for the management of S. alterniflora invasion.

Mechanistic Investigation of the Pyrolysis Temperature of Reed Wood Vinegar for Maximising the Antibacterial Activity of Escherichia coli and Its Inhibitory Activity

To solve the problem of large-scale growth of wetland reeds, wood vinegar, a by-product of pyrolysed reed wood vinegar, can be used as a natural antimicrobial agent. In this study, we compare the changes in growth and bacterial morphology of Escherichia coli (E. coli) treated with reed wood vinegar at different pyrolysis temperatures (300 °C, 500 °C and 700 °C) and reveal the bacterial inhibition mechanism of reed wood vinegar by RNA-Seq. The results of bacteria inhibitory activity showed that 1/2MIC 500 °C wood vinegar had the most prominent bacteria inhibitory activity. qPCR results showed that reed wood vinegar was able to significantly inhibit the expression of E. coli biofilm and genes related to the cell membrane transporter proteins. Electron microscopy observed that the wood vinegar disrupted the cellular morphology of E. coli, resulting in the crumpling of E. coli cell membranes. RNA-Seq showed the multifaceted antimicrobial effects of wood vinegar and demonstrated that the inhibitory effect of wood vinegar on E. coli was mainly realized through the inhibition of the expression of malE, which is an ATP-binding cassette (ABC) transporter complex of E. coli. In conclusion, our study provides an effective method and a theoretical basis for the mechanism of reed wood vinegar as a natural antimicrobial agent and its pathway of bacterial inhibition.

Progress of Ecological Restoration Research Based on Bibliometric Analysis

With the deterioration of the global/regional ecological environment, ecological restoration plays an important role in sustainable development. However, due to the differences in research methods, objectives, and perspectives, the research results are highly diverse. This makes it necessary to sort the publications related to ecological restoration, clarify the research status, grasp the research hotspots, and predict the future research trends. Here, 23,755 articles from the core database of Web of Science were retrieved, and bibliometric analysis was carried out to understand the global ecological restoration research progress from 1990 to 2022 from a macro perspective, with the aim to determine the future development direction. The results are as follows. (1) From 1990 to 2022, the number of publications in the field of ecological restoration constantly increased, and the fluctuation of the average annual citations increased. The most important articles were published in high-ranking journals. (2) Ecological restoration covers a wide range of research areas, including biodiversity, ecosystem services, climate change, land use, and ecological restoration theories and technologies. The four main hotspots in this field are heavy metal removal, soil microbial biomass carbon and nitrogen concentrations, grassland ecological restoration, and evaluation framework and modeling of ecological restoration's effects. Currently, studies focus on river basin remediation, heavy metal removal, and forest restoration. (3) Future ecological restoration research should strengthen the multi-object aspect and multi-scale ecological restoration research, improve the ecological restoration effect evaluation system, and incorporate social and economic issues. This study identified current research hotspots and predicted potential future research directions, providing a scientific reference for future studies in the field of ecological restoration.

Development of Microbial Indicators in Ecological Systems

Indicators can monitor ecological environment changes and help maintain ecological balance. Bioindicators are divided into animal, plant, and microbial indicators, of which animal and plant indicators have previously been the most researched, but microbial indicators have drawn attention recently owing to their high sensitivity to the environment and their potential for use in monitoring environmental changes. To date, reviews of studies of animals and plants as indicator species have frequently been conducted, but reviews of research on microorganisms as indicator species have been rare. In this review, we summarize and analyze studies using microorganisms as indicator species in a variety of ecosystems, such as forests, deserts, aquatic and plateau ecosystems, and artificial ecosystems, which are contained in wetlands, farmlands, and mining ecosystems. This review provides useful information for the further use of microorganisms as indicators to reflect the changes in different environmental ecosystems.