Ammonia-oxidizing archaea adapted better to the dark, alkaline oligotrophic karst cave than their bacterial counterparts.

Subsurface karst caves provide unique opportunities to study the deep biosphere, shedding light on microbial contribution to elemental cycling. Although ammonia oxidation driven by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) is well explored in soil and marine environments, our understanding in the subsurface biosphere still remained limited to date. To address this gap, weathered rock and sediment samples were collected from the Xincuntun Cave in Guilin City, an alkaline karst cave, and subjected to high-throughput sequencing and quantification of bacterial and archaeal , along with determination of the potential nitrification rates (PNR).

Deconstructing the Dimensions of Mycobiome Fingerprints in Luohandu Cave, Guilin, Southern China.

Subterranean karst caves are windows into the terrestrial subsurface to deconstruct the dimensions of mycobiome fingerprints. However, impeded by the constraints of remote locations, the inaccessibility of specimens and technical limitations, the mycobiome of subterranean karst caves has remained largely unknown. Weathered rock and sediment samples were collected from Luohandu cave (Guilin, Southern China) and subjected to Illumina Hiseq sequencing of ITS1 genes.

Niche differentiation of atmospheric methane-oxidizing bacteria and their community assembly in subsurface karst caves.

Karst caves are recently proposed as atmospheric methane sinks in terrestrial ecosystems. Despite of the detection of atmospheric methane-oxidizing bacteria (atmMOB) in caves, we still know little about their ecology and potential ability of methane oxidation in this ecosystem. To understand atmMOB ecology and their potential in methane consumption, we collected weathered rocks and sediments from three different caves in southwestern China.

USC Dominated Community Composition and Cooccurrence Network of Methanotrophs and Bacteria in Subterranean Karst Caves.

Karst caves have recently been demonstrated to act as a sink for atmospheric methane, due in part to consumption by microbes residing in caves that can oxidize methane at atmospheric levels. However, our knowledge about the responsible atmospheric methane-oxidizing bacteria (atmMOB) in this vast habitat remains limited to date. To address this issue, weathered rock samples from three karst caves were collected in Guilin City and subjected to high-throughput sequencing of and 16S rRNA genes.

Characteristics and influencing factors of hydrochemistry and dissolved organic matter in typical karst water system.

The unique hydrogeological conditions of karst area make the groundwater react rapidly to rainfall events, which makes the groundwater more susceptible to anthropogenic pollutions. The current study based on a combined excitation-emission matrix fluorescence spectroscopy and parallel factor analysis (EEM-PARAFAC) and geochemical-statistical investigation of water samples from the karst water system in Xintian County, Hunan Province, China, gives crucial information about the principal factors influencing karst water hydrochemistry and dissolved organic matter (DOM). The analyzed data revealed that both surface water and descending spring samples were within the Ca-Mg-HCO water type and dominated by humic-like fluorophore, and well water samples were within both the Ca-Mg-HCO and Na-HCO water types and controlled by protein-like fluorophore.

Impact of sulfuric and nitric acids on carbonate dissolution, and the associated deficit of CO uptake in the upper-middle reaches of the Wujiang River, China.

Carbonate weathering and the CO consumption in karstic area are extensive affected by anthropogenic activities, especially sulfuric and nitric acids usage in the upper-middle reaches of Wujiang River, China. The carbonic acid would be substituted by protons from sulfuric and nitric acids which can be reduce CO absorption. Therefore, The goal of this study was to highlight the impacts of sulfuric and nitric acids on carbonate dissolution and the associated deficit of CO uptaking during carbonate weathering.

[Major Ionic Features and Their Controlling Factors in the Upper-Middle Reaches of Wujiang River].

The Wujing River, the largest river in Guizhou Province, is one of the most important water resources for social and economical development. Recently, with the fast population proliferation and rapid economic growth, the drainage basin is intensively interfered by anthropogenic activities. The hydrochemistry of surface water was analyzed from the upper-middle reaches of Wujiang River for investigating the hydrochemical characteristics and their main influencing factors.

[Influence of Sulfuric Acid to Karst Hydrochemical and δ13CDIC in the Upper and Middle Reaches of the Wujiang River].

Groundwater and surface water from the Upper and Middle Reaches of the Wujiang River were sampled and analyzed for the hydrochemistry and Carbon isotope in DIC. Then hydrochemical characteristics and the main influencing factors were investigated, and the contributions of carbonate dissolution by sulphuric acid to total(Ca2+ + Mg2+) and HCO3 were calculated using the stoichiometry method. The results showed that the advantage cations of groundwater and surface water is Ca2+, which accounted for more than 50% and the advantage anions is HCO3- and SO(4)2-, which accounted for more than 85%.