Project description:In this study, microbial communities from triplicate leach-bed anaerobic bioreactors digesting grass were analysed. Each reactor comprised two microbial fractions, one immobilized on grass (biofilm) and the other in a planktonic state present in the leachate. Microbial communities from the two fractions were systematically investigated for community composition and function. This was carried out using DNA, RNA and protein co-extraction. The microbial structure of each fraction was examined using 16S rRNA deep sequencing, while the active members of the consortia were identified using the same approach on cDNA generated from co-extracted RNA samples. Microbial function was investigated using a metaproteomic workflow combining SDS-PAGE and LC-MS/MS analysis.
Project description:Healthy plants are vital for successful, long-duration missions in space, as they provide the crew with life support, food production, and psychological benefits. The microorganisms that associate with plant tissues play a critical role in improving plant growth, health, and production. To that end, it is necessary to develop methodologies that investigate the metabolic activities of the plant’s microbiome in orbit to enable rapid responses regarding the care of plants in space. In this study, we developed a protocol to characterize the endophytic and epiphytic microbial metatranscriptome of red romaine lettuce, a key salad crop that was grown under International Space Station (ISS)-like conditions. Microbial transcripts enriched from host-microbe total RNA were sequenced using the Oxford Nanopore MinION sequencing platform. Results showed that this enrichment approach was highly reproducible and effective for rapid on-site detection of microbial transcriptional activity. Taxonomic analysis based on 16S and 18S rRNA transcripts identified that the top five most abundant phyla in the lettuce microbiome were Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Ascomycota. The metatranscriptomic analysis identified the expression of genes involved in many metabolic pathways, including carbohydrate metabolism, energy metabolism, and signal transduction. Network analyses of the expression data show that, within the signal transduction pathway of the fungal community, the Mitogen-Activated Protein Kinase signaling pathway was tightly regulated across all samples and could be a potential driver for fungal proliferation. Our results demonstrated the feasibility of using MinION-based metatranscriptomics of enriched microbial RNA as a method for rapid, on-site monitoring of the transcriptional activity of crop microbiomes, thereby helping to facilitate and maintain plant health for on-orbit space food production.
2021-06-20 | GSE152914 | GEO
Project description:MinION sequencing of AnAOB enrichment bioreactor community
Project description:In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg NH3-N/L).
Project description:Transcriptional profiling of the Donna II mixed community containing Dehalococcoides mccartyi strain 195 comparing a batch starved control to the mixed community being fed 1,2,3,4-tetrachlorobenzene as an electron acceptor. The goal was to determine which transcripts are regulated in response to a shift in a different electron acceptor rather than the consistent tetrachloroethene (PCE) that the parent reactor was maintained on.
Project description:We developed a laboratory-scale model to improve our understanding and capacity to assess the biological risks of genetically engineered bacteria and their genetic elements in the natural environment. Our hypothetical scenario concerns an industrial bioreactor failure resulting in the introduction of genetically engineered bacteria to a downstream municipal wastewater treatment plant (MWWTP). As the first step towards developing a model for this scenario, we sampled microbial communities from the aeration basin of a MWWTP at three seasonal time points. Having established a baseline for community composition, we investigated how the community changed when propagated in the laboratory, including cell culture media conditions that could provide selective pressure in future studies. Specifically, using PhyloChip 16S rRNA gene-targeting microarrays, we compared the compositions of sampled communities to those of inoculates propagated in the laboratory in simulated wastewater conditionally amended with various carbon sources (glucose, chloroacetate, D-threonine) or the ionic liquid 1-ethyl-3-methylimidazolium chloride ([C2mim]Cl). Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in aeration basin and laboratory-cultured populations. Laboratory-cultured populations were enriched in Gammaproteobacteria. Enterobacteriaceae and Aeromonadaceae were enriched by glucose, Pseudomonadaceae by chloroacetate and D-threonine, and Burkholderiaceae by high (50 mM) concentrations of chloroacetate. Microbial populations cultured with chloroacetate and D-threonine were more similar to sampled populations than thoes cultured with glucose or [C2mim]Cl. Although observed relative richness in operational taxonomic units was lower for laboratory cultures than for sampled populations, both flask and reactor systems cultured phylogenetically diverse communities. These results importantly provide a foundation for laboratory models of industrial bioreactor failure scenarios. 46 samples, flask and reactor experiments were conducted in triplicate with two exceptions: [C2mim]Cl_flask and No-Carbon_flask treatments had only one sample (no replicates).