ABSTRACT: Microbial and metabolic characterization of organic artisanal sauerkraut fermentation and study of gut health promoting properties of sauerkraut brine
Project description:The aim of the study was to decipher metabolisms responsible (i) for the peculiar adaptation of L. plantarum during soy juice fermentation and (ii) for the release of aroma compounds, amino and short-chain fatty acid, and metabolites with health-promoting properties in soy yogurt. The strategy was the sequencing and annotation of a strain (L. plantarum CIRM-BIA777, PRJEB77707) able to degrade galacto- oligosaccharides, the sampling of soy yogurt, RNA-seq to identify differentially expressed genes of L. plantarum and corresponding metabolisms throughout the kinetics of fermentation. Acids and volatile compounds were also quantified.
Project description:Silver nanoparticles (NPs) are extensively used due to their antimicrobial activity and, therefore, their input into the ecosystem will increase. Silver can be bioaccumulated by low trophic level organisms and, then, incorporated into the food chain, reaching high level predators. The objectives of this study were to test the acute toxicity of N-vynil-2-pirrolidone/polyethylenimine (PVP-PEI) coated Ag NPs of 5 nm to brine shrimp (Artemia sp) larvae and to assess bioaccumulation and effects of silver transferred by the diet. For the later, brine shrimps were exposed to two different concentrations of Ag NPs, 100 ng/L as an environmentally relevant concentration and 100 µg/L as a likely effective concentration, in parallel with an unexposed control group and, then, used to feed zebrafish during 21 days in order to simulate two trophic levels of a simplified food web. For brine shrimp larvae, EC50 values ranged from 7.39 mg Ag/L (48 h post hatch larvae (hph) exposed for 48 h) to 19.63 mg Ag/L (24 hph larvae exposed for 24 h. Silver accumulation was measured in brine shrimps exposed to 0.1 and 1 mg/L of Ag NPs for 24 h. In zebrafish fed with brine shrimps exposed to Ag NPs, intestine showed higher metal accumulation than liver, although both organs presented the same pattern of dose and time-dependent metal accumulation as revealed by autometallography. Feeding of zebrafish for 3 days with brine shrimps exposed to 100 ng/L of Ag NPs was enough to impair fish health as reflected by the significant reduction of the lysosomal membrane stability and the presence of several histopathological conditions in the liver. Overall, results showed that Ag NPs were able to exert toxic effects on zebrafish through dietary exposure, even at an environmentally relevant concentration, which should act as concern of the need of studies in further detail about real impact of nanomaterials in the environment.
Project description:Halophilic microorganisms have long been known to survive within the brine inclusions of salt crystals, as evidenced by their pigmentation. However, the molecular mechanisms allowing this survival has remained an open question for decades. While protocols for the surface sterilization of halite (NaCl) have enabled isolation of cells and DNA from within halite brine inclusions, “-omics” based approaches have faced two main technical challenges: (1) removal of all contaminating organic biomolecules (including proteins) from halite surfaces, and (2) performing selective biomolecule extractions directly from cells contained within halite brine inclusions with sufficient speed to avoid modifications in gene expression during extraction. In this study, we present methods to resolve these two technical challenges. In addition, we apply these methods to perform the first examination of the early acclimation of a model haloarchaeon (Halobacterium salinarum NRC-1) to halite brine inclusions. Examinations of the proteome of Halobacterium cells two months post-evaporation revealed a high degree of similarity with stationary phase liquid cultures, but with a sharp down-regulation of ribosomal proteins. Low quantities of RNA from halite brine inclusions corroborate the hypothesis of low transcriptional and translational activities. While proteins for central metabolism were part of the shared proteome between liquid cultures and halite brine inclusions, proteins involved in cell mobility (archaellum, gas vesicles) were either absent or less abundant in halite samples. Proteins unique to cells within brine inclusions included transporters, suggesting modified interactions between cells and the surrounding brine inclusions microenvironment. The methods and hypotheses presented here enable future studies of the survival of halophiles in both culture model and natural halite systems.
Project description:To investigate the function of organic nitrogen on clavulanic acid biosynthesis in Streptomyces clavuligerus, we established F613-1 strain cells cultured in MH fermentation medium and ML fermentation medium. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different medium at three time points.
2022-08-25 | GSE211765 | GEO
Project description:Microbial community dynamics during spontaneous fermentation of northeast sauerkraut
Project description:RNA-Seq analysis was conducted at different growth phases of the cell cycle as well as various fermentation conditions. The genes encoding RNA polymerase were down-regulated in SH0012 compared to its mother strain, suggesting reprogramming of cells for survival in new environments. The micro-aerobic fermentation caused down-regulation of transporter proteins and 3-HP non-producing fermentation caused up-regulation of phage shock proteins and lipoproteins. Additionally, the clustering analyses revealed that there is a mode of temporal regulation of biological pathways during organic acid production.
Project description:Engineering microbes with novel metabolic properties is a critical step for production of biofuels and biochemicals. Synthetic biology enables identification and engineering of metabolic pathways into microbes; however, knowledge of how to reroute cellular regulatory signals and metabolic flux remains lacking. Here we used network analysis of multi-omic data to dissect the mechanism of anaerobic xylose fermentation, a trait important for biochemical production from plant lignocellulose. We compared transcriptomic, proteomic, and phosphoproteomic differences across a series of strains evolved to ferment xylose under various conditions.