scholarly journals Time Course-Dependent Methanogenic Crude Oil Biodegradation: Dynamics of Fumarate Addition Metabolites, Biodegradative Genes, and Microbial Community Composition

2018 ◽  
Vol 8 ◽  
Author(s):  
Courtney R. A. Toth ◽  
Lisa M. Gieg
2020 ◽  
Author(s):  
Christina Nikolova ◽  
Umer Zeeshan Ijaz ◽  
Clayton Magill ◽  
Sara Kleindienst ◽  
Samantha B. Joye ◽  
...  

AbstractBackgroundAlthough synthetic dispersants are effective in dispersing crude oil, they can alter the natural microbial response to oil and potentially hinder its biodegradation. Biosurfactants, however, are naturally derived products that play a similar role to synthetic dispersants in oil spill response but are easily biodegradable and less toxic. This study investigated the microbial community dynamics, ecological drivers, functional diversity, and oil biodegradation potential of a northeast Atlantic marine microbial community to crude oil when exposed to rhamnolipid or synthetic dispersant Finasol OSR52.ResultsWe found the microbial community composition and diversity were markedly different in the rhamnolipid-amended treatment compared to that with Finasol, with key aromatic hydrocarbon-degrading bacteria like Cycloclasticus being suppressed in the Finasol treatment but not in oil-only and rhamnolipid-amended treatments. Psychrophilic Colwellia and Oleispira dominated the community in both the rhamnolipid and Finasol OSR52 treatments initially but later community structure across treatments diverged significantly: Rhodobacteraceae and Vibrio dominated the Finasol-amended treatment and Colwellia, Oleispira, and later Cycloclasticus and Alcanivorax, dominated the rhamnolipid-amended treatment. Vibrio abundance increased substantially in treatments receiving Finasol, suggesting a potentially important role for these organisms in degrading dispersant components. In fact, Finasol was linked with a negative impact on alpha diversity. Deterministic environmental filtering played a dominant role in regulating the community assembly in all treatments but was strongest in the dispersant-amended treatments. Rhamnolipid-amended and oil-only treatments had the highest functional diversity, however, the overall oil biodegradation was greater in the Finasol treatment, but aromatic biodegradation was highest in the rhamnolipid treatment.ConclusionOverall, the natural marine microbial community in the northeast Atlantic responded differently to crude oil dispersed with either synthetic or biogenic surfactants over time, but oil degradation was more enhanced by the synthetic dispersant. Collectively, our results advance the understanding of how rhamnolipid biosurfactants affect the natural marine microbial community, supporting their potential application in oil spills.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252086
Author(s):  
Kerry L. McNally ◽  
Charles J. Innis ◽  
Adam Kennedy ◽  
Jennifer L. Bowen

Microbial communities of animals play a role in health and disease, including immunocompromised conditions. In the northeastern United States, cold-stunning events often cause endangered Kemp’s ridley turtles (Lepidochelys kempii) to become stranded on beaches in autumn. These sea turtles are admitted to rehabilitation facilities when rescued alive and are presumed immunocompromised secondary to hypothermia. To better understand the role that microbes play in the health of cold-stunned sea turtles, we characterized the oral and cloacal microbiome from Kemp’s ridley turtles at multiple timepoints during rehabilitation, from admission to pre-release, by using Illumina sequencing to analyze the 16S rRNA gene. Microbial communities were distinct between body sites and among turtles that survived and those that died. We found that clinical parameters such as presence of pneumonia or values for various blood analytes did not correlate with oral or cloacal microbial community composition. We also investigated the effect of antibiotics on the microbiome during rehabilitation and prior to release and found that the type of antibiotic altered the microbial community composition, yet overall taxonomic diversity remained the same. The microbiome of cold-stunned Kemp’s ridley turtles gradually changed through the course of rehabilitation with environment, antibiotics, and disease status all playing a role in those changes and ultimately the release status of the turtles.


LWT ◽  
2021 ◽  
pp. 111694
Author(s):  
Xiaoxi Chen ◽  
Qin Chen ◽  
Yaxin Liu ◽  
Bin Liu ◽  
Xubo Zhao ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raiza Hasrat ◽  
Jolanda Kool ◽  
Wouter A. A. de Steenhuijsen Piters ◽  
Mei Ling J. N. Chu ◽  
Sjoerd Kuiling ◽  
...  

AbstractThe low biomass of respiratory samples makes it difficult to accurately characterise the microbial community composition. PCR conditions and contaminating microbial DNA can alter the biological profile. The objective of this study was to benchmark the currently available laboratory protocols to accurately analyse the microbial community of low biomass samples. To study the effect of PCR conditions on the microbial community profile, we amplified the 16S rRNA gene of respiratory samples using various bacterial loads and different number of PCR cycles. Libraries were purified by gel electrophoresis or AMPure XP and sequenced by V2 or V3 MiSeq reagent kits by Illumina sequencing. The positive control was diluted in different solvents. PCR conditions had no significant influence on the microbial community profile of low biomass samples. Purification methods and MiSeq reagent kits provided nearly similar microbiota profiles (paired Bray–Curtis dissimilarity median: 0.03 and 0.05, respectively). While profiles of positive controls were significantly influenced by the type of dilution solvent, the theoretical profile of the Zymo mock was most accurately analysed when the Zymo mock was diluted in elution buffer (difference compared to the theoretical Zymo mock: 21.6% for elution buffer, 29.2% for Milli-Q, and 79.6% for DNA/RNA shield). Microbiota profiles of DNA blanks formed a distinct cluster compared to low biomass samples, demonstrating that low biomass samples can accurately be distinguished from DNA blanks. In summary, to accurately characterise the microbial community composition we recommend 1. amplification of the obtained microbial DNA with 30 PCR cycles, 2. purifying amplicon pools by two consecutive AMPure XP steps and 3. sequence the pooled amplicons by V3 MiSeq reagent kit. The benchmarked standardized laboratory workflow presented here ensures comparability of results within and between low biomass microbiome studies.


Sign in / Sign up

Export Citation Format

Share Document