Planktonic algal bloom significantly alters sediment bacterial community structure

2017 ◽  
Vol 17 (10) ◽  
pp. 2547-2556 ◽  
Author(s):  
Xian Xiao ◽  
Meng Pei ◽  
Xiang Liu ◽  
Yuan Zhao ◽  
Yuting Liang
2020 ◽  
Vol 9 (1) ◽  
pp. 259-263

To better understand long-term combined effects of crude oil and dispersant on bacterial community, sediments microcosms were set up in triplicates and treated with dispersant (Corexit 9500A), crude oil, and Corexit 9500A plus crude oil. After 60 days exposure, there was a significant change in the bacterial community structure in all treatments. The shift in the bacterial community structure in Corexit 9500A plus crude oil treatment was considerably different from those by either Corexit 9500A or crude oil. DNA sequence analysis showed that Hydrocarboniphaga effuse, Parvibaculum lavamentivorans,and Alicyclobacillus ferrooxydans were the major bacterial species in crude oil treatment. Pandoraea thiooxydans, Janthinobacterium sp. and Hyphomicrobium nitrativorans were the most dominant species in Corexit 9500A treatment. The species Janthinobacterium sp., Parvibaculum lavamentivorans, and Dyella sp. were enriched in Corexit 9500A plus crude oil treatment. The majority of the detected species were hydrocarbons degraders. The study showed that Corexit 9500A addition enhanced the biodegradation rate by increasing the diversity and richness of hydrocarbons degrading species. Corexit A9500 application should be considered during crude oil spills to evaluate environmental impacts.


2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephanie E. Hereira-Pacheco ◽  
Yendi E. Navarro-Noya ◽  
Luc Dendooven

AbstractRhizosphere and root endophytic bacteria are crucial for plant development, but the question remains if their composition is similar and how environmental conditions, such as water content, affect their resemblance. Ricinus communis L., a highly drought resistant plant, was used to study how varying soil water content affected the bacterial community in uncultivated, non-rhizosphere and rhizosphere soil, and in its roots. Additionally, the bacterial community structure was determined in the seeds of R. communis at the onset of the experiment. Plants were cultivated in soil at three different watering regimes, i.e. 50% water holding capacity (WHC) or adjusted to 50% WHC every two weeks or every month. Reducing the soil water content strongly reduced plant and root dry biomass and plant development, but had little effect on the bacterial community structure. The bacterial community structure was affected significantly by cultivation of R. communis and showed large variations over time. After 6 months, the root endophytic bacterial community resembled that in the seeds more than in the rhizosphere. It was found that water content had only a limited effect on the bacterial community structure and the different bacterial groups, but R. communis affected the bacterial community profoundly.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mark Loftus ◽  
Sayf Al-Deen Hassouneh ◽  
Shibu Yooseph

Abstract Background Colorectal cancer is a leading cause of cancer-related deaths worldwide. The human gut microbiome has become an active area of research for understanding the initiation, progression, and treatment of colorectal cancer. Despite multiple studies having found significant alterations in the carriage of specific bacteria within the gut microbiome of colorectal cancer patients, no single bacterium has been unequivocally connected to all cases. Whether alterations in species carriages are the cause or outcome of cancer formation is still unclear, but what is clear is that focus should be placed on understanding changes to the bacterial community structure within the cancer-associated gut microbiome. Results By applying a novel set of analyses on 252 previously published whole-genome shotgun sequenced fecal samples from healthy and late-stage colorectal cancer subjects, we identify taxonomic, functional, and structural changes within the cancer-associated human gut microbiome. Bacterial association networks constructed from these data exhibited widespread differences in the underlying bacterial community structure between healthy and colorectal cancer associated gut microbiomes. Within the cancer-associated ecosystem, bacterial species were found to form associations with other species that are taxonomically and functionally dissimilar to themselves, as well as form modules functionally geared towards potential changes in the tumor-associated ecosystem. Bacterial community profiling of these samples revealed a significant increase in species diversity within the cancer-associated gut microbiome, and an elevated relative abundance of species classified as originating from the oral microbiome including, but not limited to, Fusobacterium nucleatum, Peptostreptococcus stomatis, Gemella morbillorum, and Parvimonas micra. Differential abundance analyses of community functional capabilities revealed an elevation in functions linked to virulence factors and peptide degradation, and a reduction in functions involved in amino-acid biosynthesis within the colorectal cancer gut microbiome. Conclusions We utilize whole-genome shotgun sequenced fecal samples provided from a large cohort of late-stage colorectal cancer and healthy subjects to identify a number of potentially important taxonomic, functional, and structural alterations occurring within the colorectal cancer associated gut microbiome. Our analyses indicate that the cancer-associated ecosystem influences bacterial partner selection in the native microbiota, and we highlight specific oral bacteria and their associations as potentially relevant towards aiding tumor progression.


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