Project description:Two synthetic bacterial consortia (SC) composed by bacterial strains isolated from a natural phenanthrene-degrading consortium (CON), Sphingobium sp. AM, Klebsiella aerogenes B, Pseudomonas sp. Bc-h and T, Burkholderia sp. Bk and Inquilinus limosus Inq were grown in LMM supplemented with 200 mg/L of phenanthrene (PHN) during 72 hours in triplicate.
Project description:Bacterial consortia were enriched from original rubber wastewater sludge containing 2-MBT. These bacterial consortia were achieved by increasing 2-MBT in nitrogen-containing medium.
Project description:Phytoplankton and bacteria form the base of marine ecosystems and their interactions drive global biogeochemical cycles. The effect of bacteria and bacteria-produced compounds on diatoms range from synergistic to pathogenic and can affect the physiology and transcriptional patterns of the interacting diatom. Here, we investigate physiological and transcriptional changes in the marine diatom Thalassiosira pseudonana induced by extracellular metabolites of a known antagonistic bacterium Croceibacter atlanticus. Mono-cultures of C. atlanticus released compounds that inhibited diatom cell division and elicited a distinctive phenotype of enlarged cells with multiple plastids and nuclei, similar to what was observed when the diatom was co-cultured with the live bacteria. The extracellular C. atlanticus metabolites induced transcriptional changes in diatom pathways that include recognition and signaling pathways, cell cycle regulation, carbohydrate and amino acid production, as well as cell wall stability. Phenotypic analysis showed a disruption in the diatom cell cycle progression and an increase in both intra- and extracellular carbohydrates in diatom cultures after bacterial exudate treatment. The transcriptional changes and corresponding phenotypes suggest that extracellular bacterial metabolites, produced independently of direct bacterial-diatom interaction, may modulate diatom metabolism in ways that support bacterial growth.
Project description:Phytoplankton-derived metabolites fuel a large fraction of heterotrophic bacterial production in the global ocean, yet methodological challenges have limited our knowledge of organic molecules transferred between these two microbial groups. In an experimental bloom study in which the diatom Thalassiosira pseudonana was co-cultured with three heterotrophic marine bacteria, we concurrently measured diatom endometabolites (i.e., potential exometabolite supply) by nuclear magnetic resonance (NMR) spectroscopy and bacterial gene expression (i.e., potential exometabolite uptake) by metatranscriptomic sequencing.
Project description:Extensive gene methylation correlated strongly with transcriptional silencing and differential expression under specific conditions. DNA methylation and its role in gene regulation is conserved in stramenopile. Methylome of the whole genome of diatom phaeodactylum tricornutum.
Project description:The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) of Seminavis robusta in presence and absence of associated bacterial spent medium (Maribacter sp. and Roseovarius sp.) in order to highlight the effect of bacterial exudates on diatom gene expression and metabolic processes.