Project description:Genome-wide expression assay of S. alterniflora individuals from populations (4 from Louisiana, 2 from Mississippi) either exposed or unexposed to the Deepwater Horizon oil spill
Project description:The experiment was designed to test the interactions of Spartina alterniflora, its microbiome, and the interaction of the plant-microbe relationship with oil from the Deepwater Horizon oil spill (DWH). Total RNA was extracted from leaf and root microbiome of S. alterniflora in soils that were oiled in DWH oil spill with or without added oil, as well as those grown in unoiled soil with or without added oil. The work in its entirety characterizes the transport, fate and catabolic activities of bacterial communities in petroleum-polluted soils and within plant tissues.
Project description:The application of chemical dispersants during marine oil spills can affect the community composition and activity of native marine microorganisms. Several studies have indicated that certain marine hydrocarbon-degrading bacteria, such as Marinobacter spp., can be inhibited by chemical dispersants, resulting in lower abundances and/or reduced hydrocarbon-biodegradation rates. In this respect, a major knowledge gap exists in understanding the mechanisms underlying these observed physiological effects. Here, we performed comparative proteomics of the Deepwater Horizon isolate Marinobacter sp. TT1 grown under different conditions that varied regarding the supplied carbon sources (pyruvate vs. n-hexadecane) and whether or not dispersant (Corexit EC9500A) was added, or that contained crude oil in the form of a water-accommodated fraction (WAF) or chemically-enhanced WAF (CEWAF). We characterized the proteins associated with alkane metabolism and alginate biosynthesis in strain TT1, report on its potential for aromatic hydrocarbon biodegradation and present a proposed metabolism of Corexit components as carbon substrates for the strain. Our findings implicate Corexit in affecting hydrocarbon metabolism, chemotactic motility, biofilm formation, and inducing solvent tolerance mechanisms like efflux pumps in strain TT1. This study provides novel insights into dispersant impacts on microbial hydrocarbon degraders that should be taken into consideration for future oil spill response actions.
Project description:Purpose:To help identify molecular mechanisms and pathways potentially involved in the developmental toxicity for fish exposed to Deepwater Horizon (DWH) oil, transcriptomic profiles in mahi-mahi (Coryphaena hippurus) embryos exposed to different DWH oils (source and artificially weathered oil) were evaluated at different critical windows of development using High Throughput Sequencing (HTS). Methods:Total mRNA profiles of 24, 48, 96 hpf mahi-mahi larvae after slick and source oil exposure were generated by deep sequencing, in triplicate, using Illumina HiSeq2500. qRTâPCR validation was performed using SYBR Green assays. Results: Exposure to slick oil induced more pronounced changes in gene expression over time than did exposure to source oil. Predominant transcriptomic responses included alteration of E1F2 signaling, steroid biosynthesis, ribosome biogenesis, perturbation in eye development and peripheral nervous, and activation of P450 pathway. Comparisons of changes of cardiac / Ca2+-associated genes with phenotypic responses revealed reduced heart rate and increased pericardial edema in larvae exposed to slick oil but not source oil. Total mRNA profiles of 24, 48, 96 hpf mahi-mahi larvae after slick and source (mass) oil exposure were generated by deep sequencing, in triplicate, using Illumina HiSeq2500.
