Project description:Increasing salinization in wetland systems is a major threat to ecosystem services carried out by microbial communities. Thus, it is paramount to understand how salinity drives both microbial community structures and their diversity. Here we evaluated the structure and diversity of the prokaryotic communities from a range of highly saline soils (EC1:5 from 5.96 to 61.02 dS/m) from the Odiel Saltmarshes and determined their association with salinity and other soil physicochemical features by analyzing 16S rRNA gene amplicon data through minimum entropy decomposition (MED). We found that these soils harbored unique communities mainly composed of halophilic and halotolerant taxa from the phyla Euryarchaeota, Proteobacteria, Balneolaeota, Bacteroidetes and Rhodothermaeota. In the studied soils, several site-specific properties were correlated with community structure and individual abundances of particular sequence variants. Salinity had a secondary role in shaping prokaryotic communities in these highly saline samples since the dominant organisms residing in them were already well-adapted to a wide range of salinities. We also compared ESV-based results with OTU-clustering derived ones, showing that, in this dataset, no major differences in ecological outcomes were obtained by the employment of one or the other method.
Project description:The fermented and distilled Chinese alcoholic beverage strong flavor baijiu (SFB) gets its characteristic flavor during fermentation in cellars lined with pit mud. Microbes in the pit mud produce many key precursors of flavor esters. The over 20 year maturation time of natural pit mud have promoted attempts to produce artificial pit mud (APM) with shorter maturation time. However, knowledge on the molecular basis of APM microbial dynamics and associated functional variation during SFB brewing is limited, and the role of this variability in high quality SFB production remains poorly understood. We studied APM maturation in new cellars till the fourth brewing batch using 16S rRNA gene amplicon sequencing, real-time quantitative PCR and function prediction based on the sequencing results, and metaproteomics and metabolomics techniques. The results provide insight into global APM prokaryotic dynamics and their role in SFB production, which will be helpful for further optimization of APM culture technique and improvement of SFB quality.
Project description:Desert microbial communities live in a pulsed ecosystem shaped by isolated and rare precipitation events. The Namib desert is one of the oldest continuously hyperarid ecosystems on Earth. In this study, surface microbial communities of open soils (without sheltering features like rocks, vegetation or biological soil crusts) are analysed. We designed an artificial rainfall experiment where a 7x7 (3.5 x 3.5 m) plot remained dry while an adjacent one received a 30 mm simulated rain. Samples were taken randomly in parallel from both plots at 10 min, 1 h, 3 h, 7 h, 24 h and 7 days after the watering moment. Duplicate libraries were generated from total (rRNA depleted) RNA and sequenced 2x150 bp in an Illumina Hiseq 4000 instrument.
Project description:Conventional prokaryotic RNA labeling method usually requires large amounts of starting materials and tends to generate high background signals. Recently, two novel methods based on amplification systems were introduced. Here, we compared three alternative strategies: direct labeling method, ployadenylation-involved oligo-dT priming amplification method and random priming amplification method (hereafter referred to as DL, PAOD and RPA method in this article) for prokaryotic RNA labeling employing the expression profiling investigation in Escherichia coli (E. coli) heat shock model.
Project description:We present Prokaryotic Expression-profiling by Tagging RNA In Situ and sequencing (PETRI-seq), a high-throughput prokaryotic scRNA-seq pipeline. We demonstrated that PETRI-seq effectively barcoded single bacterial cells in a species-mixing experiment with E. coli (MG1655) and S. aureus (USA300). Within the S. aureus population, we found rare prophage induction in 0.04% of cells. We further demonstrated that PETRI-seq was able to distinguish between E. coli growth phases based on mRNA expression patterns by combining stationary E. coli with exponential E. coli in multiple experiments.