Spatial Distribution Patterns and Assembly Processes of Abundant and Rare Fungal Communities in Pinus sylvestris var. mongolica Forests.

Revealing the biogeography and community assembly mechanisms of soil microorganisms is crucial in comprehending the diversity and maintenance of Pinus sylvestris var. mongolica forests. Here, we used high-throughput sequencing techniques and null model analysis to explore the distribution patterns and assembly processes of abundant, rare, and total fungal communities in P. sylvestris var. mongolica forests based on a large-scale soil survey across northern China. Compared to the abundant and total taxa, the diversity and composition of rare taxa were found to be more strongly influenced by regional changes and environmental factors. At the level of class, abundant and total taxa were dominated by Agaricomycetes and Leotiomycetes, while Agaricomycetes and Sordariomycetes were dominant in the rare taxa. In the functional guilds, symbiotrophic fungi were advantaged in the abundant and total taxa, and saprotrophic fungi were advantaged in the rare taxa. The null model revealed that the abundant, rare, and total taxa were mainly governed by stochastic processes. However, rare taxa were more influenced by deterministic processes. Precipitation and temperature were the key drivers in regulating the balance between stochastic and deterministic processes. This study provides new insights into both the biogeographical patterns and assembly processes of soil fungi in P. sylvestris var. mongolica forests.

Afforestation-Induced Shifts in Soil Bacterial Diversity and Community Structure in the Saihanba Region.

Afforestation plays a pivotal role in ecosystem restoration, exemplified by the Saihanba Mechanized Forest Farm, the world's largest planted forest; however, the assembly mechanisms and interactions of soil microbial communities in such forests remain inadequately understood. This study aimed to elucidate the impact of different afforestation tree species, namely Larix gmelinii var. principis-rupprechtii, Picea asperata, and Pinus sylvestris var. mongolica, on soil bacterial diversity and community structure in comparison to grassland. Sixty soil samples were collected at a 20 cm depth, and high-throughput sequencing was employed to identify bacterial communities and assess their interactions with environmental factors. A total of 6528 operational taxonomic units (OTUs) were identified, with Solirubrobacter, Conexibacter, Bacillus, Massilia, Gaiella, Acidibacter, and Vicinamibacter being the dominant genera. Afforestation significantly impacted soil bacterial alpha diversity, with notable influence from key soil chemical properties, including available phosphorus (AP), cation exchange capacity (CEC), and the carbon-to-nitrogen ratio of soil organic matter (SOM-C/N). The Mantel test highlighted pH, the Normalized Difference Vegetation Index (NDVI), and spatial variable (dbMEM) as primary environmental factors influencing dominant bacterial genera. The bacterial community structure demonstrated deterministic homogeneous selection, wherein SOM-C/N emerged as a significant factor influencing the dissimilarity of soil bacterial communities. Furthermore, plantation soils exhibited a more complex network structure than grassland soil, highlighting the crucial role of bacterial communities in vegetation changes and providing valuable insights into their response to environmental factors during the reforestation process.

Vishniacozyma pseudocarnescens sp. nov., a new anamorphic tremellomycetous yeast species.

Three strains belonging to the basidiomycetous yeast genus Vishniacozyma were isolated from marine water samples collected from intertidal zones in Liaoning province, northeast China. Phylogenetic analyses based on the sequences of the small subunit (SSU) ribosomal DNA (rDNA), the D1/D2 domain of the large subunit (LSU) ribosomal DNA (rDNA), the internal transcribed spacer region (ITS), the two subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1), and the mitochondrial gene cytochrome b (CYTB) showed that these strains together with 20 strains from various geographic and ecological origins from other regions of the world represent a novel species in the genus Vishniacozyma. We propose the name Vishniacozyma pseudocarnescens sp. nov. (holotype CGMCC 2.6457) for the new species, which differs phenotypically from its close relatives V. carnescens, V. tephrensis, and V. victoriae by its ability to grow at 30 °C and on 50 % (w/v) glucose-yeast extract agar.

Seasonal variation in the soil fungal community structure of Larix gmelinii forests in Northeast China.

Soil fungi play an indispensable role in forest ecosystems by participating in energy flow, material circulation, and assisting plant growth and development. Larix gmelinii is the dominant tree species in the greater Khingan Mountains, which is the only cold temperate coniferous forest in China. Understanding the variations in underground fungi will help us master the situation of L. gmelinii above ground. We collected soil samples from three seasons and analyzed the differences in soil fungal community structure using high-throughput sequencing technology to study the seasonal changes in soil fungal community structure in L. gmelinii forests. We found that the Shannon and Chao1 diversity in autumn was significantly lower than in spring and summer. The community composition and functional guild varied significantly between seasons. Furthermore, we showed that ectomycorrhizal fungi dominated the functional guilds. The relative abundance of ectomycorrhizal fungi increased dramatically from summer to autumn and was significantly negatively correlated with temperature and precipitation. Temperature and precipitation positively affect the alpha diversity of fungi significantly. In addition, pH was negatively correlated with the Chao1 diversity. Temperature and precipitation significantly affected several dominant genera and functional guilds. Among the soil physicochemical properties, several dominant genera were affected by pH, and the remaining individual genera and functional guilds were significantly correlated with total nitrogen, available phosphorus, soil organic carbon, or cation exchange capacity. For the composition of total fungal community, temperature and precipitation, as well as soil physicochemical properties except AP, significantly drove the variation in community composition.

Microbe-based management for colorectal cancer / 中华医学杂志(英文版)

Colorectal cancer (CRC) is one of the most prevalent, most lethal cancers in the world. Increasing evidence suggests that the intestinal microbiota is closely related to the pathogenesis and prognosis of CRC. The normal microbiota plays an essential role in maintaining gut barrier function and the immune microenvironment. Recent studies have identified carcinogenic bacteria such as enterotoxigenic Bacteroides fragilis (ETBF) and Streptococcus gallolyticus (S. gallolyticus), as well as protective bacterial such as Akkermansia muciniphila (A. muciniphila), as potential targets of CRC treatment. Gut microbiota modulation aims to restore gut dysbiosis, regulate the intestinal immune system and prevent from pathogen invasion, all of which are beneficial for CRC prevention and prognosis. The utility of probiotics, prebiotics, postbiotics, fecal microbiota transplantation and dietary inventions to treat CRC makes them novel microbe-based management tools. In this review, we describe the mechanisms involved in bacteria-derived colorectal carcinogenesis and summarized novel bacteria-related therapies for CRC. In summary, we hope to facilitate clinical applications of intestinal bacteria for preventing and treating CRC.

[Floral composition and ecological distribution of wood-decaying fungi in Laojunshan National Park, Southwest China]. / ä¸½æ±Ÿè€å›å±±å›½å®¶å ¬å›­æœ¨è çœŸèŒåŒºç³»ç»„æˆä¸Žåˆ†å¸ƒç‰¹å¾.

Wood-decaying fungi are important components of forest ecosystem, mainly growing on the dead wood and decomposing lignin, cellulose, and hemi-cellulose. Understanding the ecological distribution of wood-decaying fungi are necessary to reveal their ecological function. In this study, we investigated wood-decaying fungi at three sites with different altitudes in Laojunshan National Park. Fruit bodies of fungi were collected and identified based on morphological and molecular analy-sis. In total 68 species were recorded, belonging to 40 genera, 21 families and 8 orders. Polyporaceae, Fomitopsidaceae, and Hymenochaetaceae were dominant families. The floral composition showed a distinct north temperate character, which was the most important element among all the bio-geographical elements with the highest percentage of 38.2%. These wood-decaying fungi can be divided into two ecological types: saprophytic (63 species) and ectomycohizal (5 species). Among these saprophytic fungi, 51 species could cause white rot and 12 species cause brown rot. The amounts of fungal species in deciduous broad-leaf forest (DBF), coniferous broad-leaved mixed forest (CBMF) and dark coniferous forest (DCF) were 34, 26 and 22, respectively. Postia fragilis and Stereum hirsutum, distributed in all the three types of forests, were dominant species of Laojunshan National Park.

A comparison between "sandwich" and conventional methods of repairing spinal dura rupture.

OBJECTIVE: To study the therapeutic efficacy of the "sandwich" method (medical glue + gelatin sponge + medical glue) of spinal dural repair for preventing cerebrospinal fluid (CSF) leaks during treatment of subdural tumors. METHODS: Fifty-four patients with spinal subdural tumors treated between April 2007 and June 2011 were retrospectively investigated. The patients were divided into two groups: a conventional group (group A) and a "sandwich" group (group B). The group A patients included 16 males and 7 females with an average tumor course of 11 months (range, 2-34 months). Four of their 23 tumors were in the cervical spine, eight thoracic, and eleven lumbar. The group B patients included 19 males and 12 females with an average tumor course of 12 months (range, 3-36 months). Five of their 31 tumors were in the cervical spines, 10 thoracic, and 16 lumbar. In group A, the dural repairs were performed with interlocking sutures and a gelatin sponge covering the dura; whereas in group B, they were performed with interlocking sutures, painting of medical glue around the dural incision, covering this with a gelatin sponge, and finally covering of the gelatin sponge with medical glue. The total volume of drainage after operation, incidence of CSF leaks, healing of the incision, and recovery of clinical performance were recorded. RESULTS: Compared to group A patients, group B patients had a significantly smaller total volume of drainage (P < 0.05) on the day of surgery, and the first, second, and third postoperative days. The incidence of CSF leakage in group B was also significantly less than in group A (P < 0.05). Before discharge, three patients in group A developd hydrops, which was successfully treated by aspiration, continuous pressure from sandbags, and the prone position. During the first 3 months of follow-up, five patients developed deep hydrops under their incisions but required no treatment. There were no obvious abnormalities in group B. CONCLUSION: After removal of subdural spinal tumors by incising the dura mater, or in related spinal surgery, application of the "sandwich" complex to the damaged spinal dura reduces the volume of drainage postoperatively and reduces the incidence of CSF leakage.

[An association study between paranoid schizophrenia and four genes involved in dopamine metabolism].

Schizophrenia is a complex disease caused by interactions among multiple genes. Reports of one of its susceptibility genes, ethyltracatechol-O-mnsferase (COMT) have been conflicting. In the present study on paranoid schizophrenia, we have performed a multilocus association study to analyze the interactions among 4 genes that are involved in dopamine metabolism. Result supports the hypothesis that COMT-136-BclI regulates Val108/158Met. When the genotype of the former is CC, Met (A) is the genotype of susceptibility allele Val108/158Met; and when the genotype of the former is GG, Val (G) is the genotype of susceptibility allele Val108/158Met. This new hypothesis may explain the conflicting results about Val108/158Met (COMT) obtained by single-locus analyses. It also illustrates that multilocus analysis is necessary for the research of complex diseases.