[Objective] To study the population diversity, spatial distribution characteristics, and correlations with physicochemical factors of yeasts in the Napahai plateau wetland. [Methods] Yeast strains were isolated from the water samples of the Napahai plateau wetland by membrane filtration and plate culture. The strains were identified based on the D1/D2 sequences of the 26S rRNA gene and morphological characteristics. R 4.2.2 and Canoco 5 were used to analyze the yeast diversity and its correlations with physicochemical factors. [Results] A total of 565 yeast strains were isolated from the water bodies in the Napahai plateau wetland and identified as 36 species of 21 genera. The dominant species wereRhodotorula mucilaginosa,Meyerozyma guilliermondii, andRhodotorula graminis. Total nitrogen was the main physicochemical factor affecting the yeast count, which presented a negative correlation. [Conclusion] The water bodies of Napahai plateau wetland harbor abundant yeast resources which present significant spatial heterogeneity. Human activities and total nitrogen have significant impacts on the yeast count. The yeast community composition in the water bodies of the Napahai plateau wetland is significantly different from that in other plateau freshwater lakes and has unique yeast resources that require further research.

[Objective] Loess-paleosol sequence (LPS) is a good carrier recording the changes of Quaternary climate and environment, and the characteristics of soil microorganisms in it indicates important information about the changes of soil environment. Due to the climate difference between loess and paleosoil, the soil microbial community may have different responses in the structural characteristics. The research on this problem, however, is limited. [Methods] In this paper, the loess (RL and JL)-paleosol (RS and JS) sequences in Renjiapo (R) and Jiuzhoutai (J) were selected, and high-throughput sequencing and linear discriminant analysis effect size (LEfSe) were employed to gain insights into the community structure and group differences of soil prokaryotes. Furthermore, functional annotation of prokaryotic taxa (FAPROTAX) was used to predict the community function, and the Mantel test was carried out to identify the environmental factors affecting the community stability of soil prokaryotes. [Results] The carbon and nitrogen in soil showed changes consistent with the magnetic susceptibility and Rb/Sr ratio, the alternative indicators of climate change. The content of carbon and nitrogen was high in the paleosol (RS and JS, especially in RS) and low in the corresponding loess (RL and JL). In the same climate era, Jiuzhoutai was drier and colder than Renjiapo. The paleosol deposition stage in Jiuzhoutai was affected by strong winter monsoon, which ultimately led to the gradual change from the dry-cold to wet-warm climate. In the prokaryotic community, thermophilic or mesophilic bacteria and archaea, such asAcidobacteria,Crenarchaeota, andChloroflexi, were abundant in RL and RS, while those with tolerance to drought and extreme environments, such asGemmatimonadetes,Actinobacteria,Firmicutes,Euryarchaeota, andDeinococcus-Thermus, had high abundance in JL and JS. The functional genes related to energy source and nitrogen, manganese, iron, and chlorine cycling had the highest expression levels in RS, while those involved in carbon, hydrogen, and sulfur cycling showed the highest expression levels in RL. The prokaryotic community in Jiuzhoutai had higher species diversity and fewer functional species than that in Renjiapo. Mantel test results indicated that soil organic carbon (SOC), soil water content (SWC), total nitrogen (TN), and nitrate nitrogen (NO₃⁻-N) were the key environmental factors influencing the stability and functions of the prokaryotic community in Renjiapo, while the influencing factors in Jiuzhoutai were TN, SOC, pH, and ammonium nitrogen (NH₄⁺-N). [Conclusion] During the warm-humid period, the microbial community differentiated into more functional categories and exhibited more vigorous life activities. When the climate was dry and cold, the microbial community completed the main life activities by improving species diversity and jointly maintaining the community survival and stability to adapt to environmental stress. The findings are of great significance for understanding the impacts of climate change on the diversity and functions of soil microorganisms.

Soil viruses are the most abundant biological entities on Earth. They play important roles in the regulation of host dynamics and soil ecosystem, including microbial diversity, community composition, and element cycling. However, due to the tremendous complexity of the soil ecosystem, the incredible functions of soil viruses and the underlying functioning mechanisms remain largely unexplored and represent a hot topic and frontier in soil biology, microbial ecology, and environmental science. The recent advances in molecular biotechnology and the widespread application of ecological theories have significantly boosted the research on soil viruses. To provide a comprehensive overview of the state-of-the-art knowledge of soil virology, we conducted a literature review using bibliometric methods. This paper offers an overview of the current status and hotspots in soil virus research, shedding light on the development in this field. Taking into account the characteristics of soil environments, the study presents the future prospects for soil virus research, including the diversity, biological characteristics, environmental factors, mechanisms, and applications of soil viruses. With the interdisciplinary integration and advancements in research technologies, soil virus research is experiencing rapid growth. The noteworthy achievements in nutrient cycling, ecosystem services, and biological regulation through soil virus research can contribute to soil health and carbon neutrality initiatives.

[Objective] Hydrothermal plumes exchange matter and energy with background seawater during the processes of buoyant rising and non-buoyant lateral migration. Due to the dynamic variability of both hydrothermal activity and ocean currents, the pattern, physico-chemical parameters, and microbial communities of hydrothermal plumes experience spatio-temporal variations. However, due to the lack of long-term monitoring and time-series sampling of hydrothermal plumes, the diversity and spatio-temporal variations of microbial communities, especially archaea, remain unclear. [Methods] From July 2018 to June 2019, a mooring system with two sediment traps (one for collection of hydrothermal plume samples 300 m above seafloor and the other for collection of near-bottom water 40 m above seafloor) and a turbidity sensor (150 m above seafloor) was deployed at 300 m southeast of the active Wocan-1 hydrothermal field for 18 months. We employed 16S rRNA gene high-throughput sequencing to study the diversity and spatio-temporal variations of archaeal communities in the samples on the monthly scale. [Results] The abundance of hydrothermal plume-associated archaea includingThermoplasmata,Methanosarcinia, andMethanobacteria increased when turbidity anomalies were higher. Spatially, the archaeal community structures in the hydrothermal plume and near-bottom water were similar at the phylum and class levels but showed differences at the order level. The relative abundance ofThermoplasmata was generally higher in the plume, whereas ammonia-oxidizing archaea andMethanosarcinia were more abundant in the near-bottom water. [Conclusion] Both the hydrothermal plume and the near-bottom water from 300 m southeast of the Wocan-1 hydrothermal field were affected by hydrothermal fluids, with the plume layer being more significantly affected. The near-bottom layer was affected by re-suspended sediments in addition to hydrothermal fluids. Dynamic changes of hydrothermal contributions and re-suspension of sediments were probably the main factors responsible for the spatial and temporal heterogeneity of archaeal communities. This study gives insights into the structure and spatio-temporal evolution of the archaeal community in the hydrothermal-influenced zone on a monthly scale.

[Objective] Currently, there are few studies on microorganisms in Antarctic ice cores, and the available studies mostly employ the pure culture and high-throughput sequencing methods, with limited knowledge about the microbial diversity. We studied the microbial community composition of the meltwater at −183 m depth of the Dalk Glacier in eastern Antarctica, aiming to provide a reference for the development of extremophiles in Antarctica. [Methods] We employed the culture, single-cell sorting, and high-throughput sequencing methods to study the microbial community composition in the meltwater at −183 m depth of the Dalk Glacier. [Results] We obtained bacterial isolates belonging to 94 genera, 19 orders of 10 phyla, in whichProteobacteria,Alphaproteobacteria, andSphingomonas were the dominant phylum, order, and genus, respectively. This result indicated high microbial diversity in the meltwater. The culture, single-cell sorting, and high-throughput sequencing yielded 25 bacterial strains, 24 bacterial strains, and 55 183 sequences (116 operational taxonomic units), respectively. The dominant taxa were different among the three methods. By the culture and single-cell sorting methods, we identified 7 bacterial strains with the 16S rRNA gene identity less than 98.65% compared with their closest relatives in GenBank, of which two strains had the identity less than 95.00% identity. Accordingly, we inferred that there may be two potential new genera and five potential new species. [Conclusion] We studied the microbial diversity in the meltwater of the Dalk Glacier in eastern Antarctica by using the culture, single-cell sorting, and high-throughput sequencing method and discovered rich bacterial species in the meltwater. Each method has its own advantages and limitations. This means that when studying microbial diversity, more comprehensive information about the composition of the microbial community can be obtained by combining different methods. The results of this study can serve as a reference for further research on the genetic resources in Antarctica.

[Objective] To isolate efficient phosphorus-solubilizing strains from soils in the permafrost region of the Qinghai-Xizang Plateau and provide strain resources for the activation of unavailable phosphorus in the soil of the Plateau. [Methods] The selective media with organic and inorganic phosphorus were used to isolate phosphorus-solubilizing strains from the soil samples collected in the permafrost region around the Tanggula Pass of the Qinghai-Xizang Plateau by the plate streaking method. The phylogenetic tree was built based on the 16S rRNA gene sequences to identify the strains, and then the phosphorus-solubilizing abilities and stress tolerance of the strains were determined. [Results] Five strains belonging toPseudomonas were isolated, including three inorganic phosphorus-solubilizing strains (i5, i6, and i9L) and two organic phosphorus-solubilizing strains (Qb and Qo). After 7 days of incubation in shake flasks at 30 ℃, the content of available phosphorus in the supernatants of Qb and Qo was 534.8 mg/L and 723.7 mg/L, respectively, which was significantly higher than that (166.9–210.5 mg/L) in the supernatants of i5, i6, and i9L. The available phosphorus content in the supernatant of Qo was the highest (519.7–683.0 mg/L) among the five isolates under different concentrations of PEG6000. The phosphorus-solubilizing abilities of Qb and Qo were stronger than those of the other strains at 5 ℃ and 10 ℃. [Conclusion] Qo outperformed the other strains in terms of tolerance to low temperature and drought stress, serving the development of microbial fertilizers and vegetation restoration in alpine regions such as the Qinghai-Xizang Plateau.

Yuncheng Salt Lake, located in the southwest of Shanxi Province, has a long history and unique climatic and geographical features, harboring rich microbial resources. The soil ecosystem is of great significance for understanding the diversity and functions of bacteria in the saline-alkali soil. [Objective] To explore the diversity of bacteria in the soil and sediment of Yuncheng Salt Lake, analyze its influencing factors, and provide a scientific basis and reference for the sustainable management of saline-alkali soil ecosystems and the mining of pure cultures. [Methods] Eighteen soil samples were collected from six sampling sites of Yuncheng Salt Lake. We measured the soil physicochemical properties and carried out high-throughput sequencing of the 16S rRNA gene to analyze the impact of environmental factors on bacterial diversity. [Results] Pseudomonadota,Bacteroidota, andBacillota were the dominant bacteria in the soil of Yuncheng Salt Lake. The bacterial diversity and community composition showed significant differences among different sampling sites. The results of canonical correlation analysis indicated that total dissolved solids (TDS), total nitrogen (TN), total carbon (TC), and SO₄²⁻ had the greatest impacts on soil microbial diversity, followed by Na⁺, Ca²⁺, Cl⁻, available phosphorous (A-P), and pH. HCO₃⁻, nitrate nitrogen (NO₃⁻-N), ammonia nitrogen (NH₄⁺-N), K⁺, and Mg²⁺ had mild impacts on the diversity. [Conclusion] The soil microorganisms of Yuncheng Salt Lake had high diversity which was closely related to environmental factors. This study provides comprehensive biological information on the bacterial resources in the soil of Yuncheng Salt Lake, offering a theoretical basis for the exploration and research of bacterial resources in this lake.

[Background] Yuncheng Salt Lake is a high-salt environment with intensive human activities. The community structure and ecological diversity of bacteria in Yuncheng Salt Lake are similar to those in other salt lakes while having their particularities. [Objective] Yuncheng Salt Lake is rich in color and harbors abundant halophilic and salt-tolerant microorganisms. To understand the distribution of bacterial resources in Yuncheng Salt Lake, we measured the bacterial diversity and community structures in different areas of this lake. [Methods] We employed 16S rRNA gene amplicon sequencing to study the community structures of halophiles in different areas of Yuncheng Salt Lake and predicted the potential metabolic functions of the bacteria. [Results] The dominant bacteria varied in different areas of Yuncheng Salt Lake. Specifically,Pseudomonadota,Actinobacteriota, andBacteroidota were dominant in the central lake,Bacillota in the eastern lake, andPatescibacteria in the western lake. The bacterial diversity in the central lake area with light yellow water was significantly higher than that in the eastern and western lake. However, the bacterial diversity was low in the central lake area with red water. This result indicated that the bacterial distribution was different in the central lake areas with different water colors the metabolic pathway activity of bacteria in the salt lake and strong regional distribution. The microbial metabolism in the east and west lake was more active than that in the lake. [Conclusion] Bacteria show high diversity in Yuncheng Salt Lake. The environment in different of lake influence the community structure of bacteria. This study provides a theoretical basis for the diversity conservation, development, and utilization of the bacterial resources in Yuncheng Salt Lake.

As an interdisciplinary subject combined with deep space exploration, astrobiology studies the habitability of extraterrestrial planets by the analogical study of the extreme environments on Earth, the exploration of carrier information of ancient life, and simulation. Notably, suitable environmental conditions are crucial for evaluating the habitability of planets. Recently, a large number of lava landforms suspected of lava tubes have been found on the Moon and planets such as Mars. These giant tube-shaped underground spaces may provide shelters for life to survive in consideration of the relative stable temperature inside and the function of radiation protection. Therefore, the analogical studies based on lava tubes on Earth can provide fundamental clues for exploring the traces of extraterrestrial life. Here, we review the microbial studies about the lava tubes on Earth, the implications of microbial metabolism of trace gas for astrobiology, and the recent progress in astrobiology, aiming to provide ideas for astrobiological research on lava tubes on Earth and other planets.

The oily sludge produced in petroleum exploitation and processing is the main pollution source in the petrochemical industry, causing continuous harm to the surrounding eco-environment. Bioremediation as an effective and sustainable technology has attracted much attention. However, the current studies focus on the microbial degradation of petroleum in oily sludge and rarely report enzymatic degradation. [Objective] This study aims to screen petroleum-degradation enzymes by computer simulation and experimental techniques and improve the degradation effect by adding surfactants and enzyme immobilization. [Methods] Molecular docking was employed to analyze the possibility and mode of binding of target enzymes to common substrates in petroleum and the strongest degrading enzyme was screened out by enzymatic degradation experiments. Furthermore, the degradation conditions of the enzyme screened out were optimized, and the degradation effect on petroleum was further improved by immobilization and addition of surfactants. [Results] A total of five petroleum-degrading enzymes were obtained by molecular docking simulation and experimental verification. Among them,Bacillussubtilis laccase (BsLac) exhibited the highest degradation rate of petroleum, which reached 34.1% at the time point of 72 h. Surfactants improved the degradation of BsLac on petroleum, and sophorolipid showcased the strongest promoting effect, with the highest degradation rate of 46.3% at the sophorolipid concentration of 1 000 mg/L. However, 2,2′-azinoo-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) did not present promoting effect on BsLac for petroleum degradation. The BsLac immobilized by peanut shell as the adsorption carrier exhibited the highest petroleum degradation rate (56.3%). [Conclusion] We screened out the strongest petroleum-degrading enzyme by molecular docking and experimental verification. Furthermore, the immobilization of BsLac can improve the degradation performance on petroleum. The findings lay an experimental and theoretical foundation for further exploring the enzymatic degradation of petroleum.