Project description:Populations of engineered metabolite-producing microorganisms are prone to evolutionary production declines during industrial-scale cultivations. In this study, we develop a synthetic product addiction system in E coli that addicts mevalonic acid production cells to mevalonic acid. Through experimentally simuluated long-term fermentation, we investigate how product-addicted organisms remain stable and avoid formation of genetic subpopulations of fit, non-producing cells.
Project description:Peatlands of the Lehstenbach catchment (Germany) house so far unidentified microorganisms with phylogenetically novel variants of the dissimilatory (bi)sulfite reductase genes dsrAB. These genes are characteristic for microorganisms that reduce sulfate, sulfite, or some organosulfonates for energy conservation, but can also be present in anaerobic syntrophs. However, nothing is currently known regarding the abundance, community dynamics, and biogeography of these dsrAB-carrying microorganisms in peatlands. To tackle these issues, soils from a Lehstenbach catchment site (Schlöppnerbrunnen II fen) from different depths were sampled at three time points over a six-year period to analyze the diversity and distribution of dsrAB-containing microorganisms by a newly developed functional gene microarray and quantitative PCR assays. Members of novel, uncultivated dsrAB lineages (approximately representing species-level groups) (i) dominated a temporally stable but spatially structured dsrAB community and (ii) represented ‘core’ members (up to 1-1.7% relative abundance) of the autochthonous microbial community in this fen. In addition, denaturing gradient gel electrophoresis (DGGE)- and clone library-based comparison of the dsrAB diversity in soils from a wet meadow, three bogs, and five fens of various geographic locations (distance ~1-400 km), identified one Syntrophobacter-related and nine novel dsrAB lineages to be widespread in low-sulfate peatlands. Signatures of biogeography in dsrB-DGGE data were not correlated with geographic distance but could largely be explained by soil pH and wetland type, implying that distribution of dsrAB-carrying microorganisms in wetlands on the scale of a few hundred kilometers is not limited by dispersal but determined by contemporary environmental conditions.
Project description:LGG exposure of C. elegans protects C. elegans against pathogen infection and prolongs lifespan. In particular, it prolongs lifespan by up-regulating specific genes to pathogenic microorganisms. We used microarrays to elucidate miRNA expression to determine how LGG exposure in C. elegans affected miRNAs and identified miRNAs that were significantly regulated in this process.
Project description:Peatlands of the Lehstenbach catchment (Germany) house so far unidentified microorganisms with phylogenetically novel variants of the dissimilatory (bi)sulfite reductase genes dsrAB. These genes are characteristic for microorganisms that reduce sulfate, sulfite, or some organosulfonates for energy conservation, but can also be present in anaerobic syntrophs. However, nothing is currently known regarding the abundance, community dynamics, and biogeography of these dsrAB-carrying microorganisms in peatlands. To tackle these issues, soils from a Lehstenbach catchment site (Schlöppnerbrunnen II fen) from different depths were sampled at three time points over a six-year period to analyze the diversity and distribution of dsrAB-containing microorganisms by a newly developed functional gene microarray and quantitative PCR assays. Members of novel, uncultivated dsrAB lineages (approximately representing species-level groups) (i) dominated a temporally stable but spatially structured dsrAB community and (ii) represented ‘core’ members (up to 1-1.7% relative abundance) of the autochthonous microbial community in this fen. In addition, denaturing gradient gel electrophoresis (DGGE)- and clone library-based comparison of the dsrAB diversity in soils from a wet meadow, three bogs, and five fens of various geographic locations (distance ~1-400 km), identified one Syntrophobacter-related and nine novel dsrAB lineages to be widespread in low-sulfate peatlands. Signatures of biogeography in dsrB-DGGE data were not correlated with geographic distance but could largely be explained by soil pH and wetland type, implying that distribution of dsrAB-carrying microorganisms in wetlands on the scale of a few hundred kilometers is not limited by dispersal but determined by contemporary environmental conditions. 36 dsrAB clones for chip evaluation, 33 hybridizations of labeled dsrAB RNA from environmental peatsoil samples
Project description:The conventional view is that high temperatures cause microorganisms to replicate slowly or die. In this view, microorganisms autonomously combat heat-induced damage. However, microorganisms co-exist with each other, which raises the underexplored and timely question of whether microorganisms can cooperatively combat heat-induced damages at high temperatures. Here, we use the budding yeast Saccharomyces cerevisiae to show that cells can help each other and their future generations to survive and replicate at high temperatures. As a consequence, even at the same temperature, a yeast population can exponentially grow, never grow or grow after unpredictable durations (hours to days) of stasis, depending on its population density. Through the same mechanism, yeasts collectively delay and can eventually stop their approach to extinction, with higher population densities stopping faster. These features arise from yeasts secreting and extracellularly accumulating glutathione—a ubiquitous heat-damage-preventing antioxidant. We show that the secretion of glutathione, which eliminates harmful extracellular chemicals, is both necessary and sufficient for yeasts to collectively survive at high temperatures. A mathematical model, which is generally applicable to any cells that cooperatively replicate by secreting molecules, recapitulates all of these features. Our study demonstrates how organisms can cooperatively define and extend the boundaries of life-permitting temperatures.
Project description:Background: Lung is the largest mucosal area of the human body and directly connected to the external environment, facing microbial exposure and environmental stimuli. Therefore, studying the internal microorganisms of the lung is crucial for a deeper understanding of the relationship between microorganisms and the occurrence and progression of lung cancer. Methods: Tumor and adjacent nontumor tissues were collected from 38 lung adenocarcinoma patients and used nanopore sequencing technology to sequence the 16s full-length sequence of bacteria, and combining bioinformatics methods to identify and quantitatively analyze microorganisms in tissues, as well as to enrich the metabolic pathways of microorganisms. Results: the microbial composition in lung adenocarcinoma tissues is highly similar to that in adjacent tissues, but the alpha diversity is significantly lower than that in adjacent tissues. The difference analysis results show that the bacterial communities of Streptococcaceae, Lactobacillaceae, and Neisseriales were significantly enriched in cancer tissues. The results of metabolic pathway analysis indicate that pathways related to cellular communication, transcription, and protein synthesis were significantly enriched in cancer tissue. In addition, clinical staging analysis of nicotine exposure and lung cancer found that Haemophilus, paralinfluenzae, Streptococcus gordonii were significantly enriched in the nicotine exposure group, while the microbiota of Cardiobactereae and Cardiobacterales were significantly enriched in stage II tumors. The microbiota significantly enriched in IA-II stages were Neisseriaeae, Enterobacteriales, and Cardiobacterales, respectively. Conclusion Nanopore sequencing technology was performed on the full length 16s sequence, which preliminarily depicted the microbial changes and enrichment of microbial metabolic pathways in tumor and adjacent nontumor tissues. The relationship between nicotine exposure, tumor progression, and microorganisms was explored, providing a theoretical basis for the treatment of lung cancer through microbial targets.