The characterization of microbial communities and associations in karst tiankeng

Abstract

The karst tiankeng is a special and grand negative terrain on the surface, that maintains a unique ecosystem. However, knowledge about bacterial and fungal communities in karst tiankengs is still limited. Therefore, soil samples from five karst tiankengs were collected and subjected to high-throughput sequencing of 16S rRNA and ITS genes, and multivariate statistical analysis. The results showed abundant and diversified bacterial and fungal communities in karst tiankeng. The bacterial communities were dominated by Proteobacteria and Acidobacteria, and the fungal communities were dominated by Ascomycota and Basidiomycota. Statistical analysis revealed significant differences in bacterial and fungal communities among the five karst tiankengs, which may indicate that the distribution of bacterial and fungal communities was driven by separate karst tiankengs. The co-occurrence network structure was characterized by highly modularized assembly patterns and more positive interactions. The keystone taxa were mainly involved in nutrient cycling and energy metabolism. The null model analysis results showed that the stochastic process, especially dispersal limitation, tended to be more important in controlling the development of bacterial and fungal communities in karst tiankeng. The bacterial community structure was significantly associated with soil properties (SWC, TN, AN, and BD), while the fungal community structure was significantly associated with soil properties (SWC and TP) and plant diversity. These results can expand our knowledge of the karst tiankeng microbiome.

The bacterial succession and its role in flavor compounds formation during the fermentation of cigar tobacco leaves

“…6 A, B). These networks demonstrated a prevalence of strong positive correlations among bacterial nodes, indicating that microorganisms cooperate to adapt to the phyllosphere environment and maintain the bacterial community structure (Jiang et al 2022 ). The modularity index values for the Hainan and Sichuan networks were 0.468 and 0.639 (> 0.4), respectively, suggesting a typical modular structure with nonrandom patterns of microbial interactions in tobacco leaves (Newman 2006 ; Olesen et al 2007 ).…”

Moso bamboo (Phyllostachys edulis (Carrière) J. Houzeau) invasion affects soil microbial communities in adjacent planted forests in the Lijiang River basin, China

“…Pearson’s correlation coefficient and Spearman’s rank correlations were used to determine the correlation between two normally and non-normally distributed variables, respectively. The Mantel test was performed to discern correlations of soil properties with microbial community composition, abundance, and diversity using the R (version 4.2.1) package “vegan” ( Jiang et al, 2022b ). Significant difference in all tests was considered at p < 0.05.…”

“…We used Observed, Chao1, and Shannon indexes to represent composition, abundance, and diversity of microorganism, respectively. The SEM test was used to discern correlations among soil properties with microbial Observed, Chao1, and Shannon indexes using the R (version 4.2.1) package “Vegan” ( Jiang et al, 2022b ).…”