scholarly journals Metagenomic Sequencing Identifies Highly Diverse Assemblages of Dinoflagellate Cysts in Sediments from Ships’ Ballast Tanks

2019 ◽  
Vol 7 (8) ◽  
pp. 250 ◽  
Author(s):  
Shang ◽  
Hu ◽  
Deng ◽  
Liu ◽  
Zhai ◽  
...  
Keyword(s):  
Single Cell ◽  
Harmful Algal Bloom ◽  
Freshwater Species ◽  
Metagenomic Sequencing ◽  
Ballast Tank ◽  
Operational Taxonomic Units ◽  
Single Cell Pcr ◽  
Great Heterogeneity ◽  
Ballast Tanks ◽  
Metagenomic Approach

Ships’ ballast tanks have long been known as vectors for the introduction of organisms. We applied next-generation sequencing to detect dinoflagellates (mainly as cysts) in 32 ballast tank sediments collected during 2001–2003 from ships entering the Great Lakes or Chesapeake Bay and subsequently archived. Seventy-three dinoflagellates were fully identified to species level by this metagenomic approach and single-cell polymerase chain reaction (PCR)-based sequencing, including 19 toxic species, 36 harmful algal bloom (HAB) forming species, 22 previously unreported as producing cysts, and 55 reported from ballast tank sediments for the first time (including 13 freshwater species), plus 545 operational taxonomic units (OTUs) not fully identified due to a lack of reference sequences, indicating tank sediments are repositories of many previously undocumented taxa. Analyses indicated great heterogeneity of species composition among samples from different sources. Light and scanning electron microscopy and single-cell PCR sequencing supported and confirmed results of the metagenomic approach. This study increases the number of fully identified dinoflagellate species from ballast tank sediments to 142 (> 50% increase). From the perspective of ballast water management, the high diversity and spatiotemporal heterogeneity of dinoflagellates in ballast tanks argues for continuing research and stringent adherence to procedures intended to prevent unintended introduction of non-indigenous toxic and HAB-forming species.

A Study into the Coating Thickness of Ship Ballast Tanks

2020 ◽  
Vol 162 (A3) ◽  
Author(s):  
B Khan ◽  
F Khan ◽  
B Veitch
Keyword(s):  
Coating Thickness ◽  
Performance Standard ◽  
Coating System ◽  
Ballast Tank ◽  
Coating Performance ◽  
Coating Application ◽  
Flat Surfaces ◽  
Ballast Tanks ◽  
Dry Film Thickness

Ballast tanks are expected to be coated according to the IMO Performance Standard for Protective Coating regulations (PSPC15), in addition to the paint application requirements of the paint producer. In general, a coating system should consist of minimum two spray coats of light-colored epoxy coating on flat surfaces with a Nominal total Dry Film Thickness (NDFT) of 320 μm and 90% of all thickness measurements greater than, or equal to the NDFT and none of the remaining measurements below 0.9 x NDFT (the “90/10 rule”). Allegedly, the value of 320 μm in this PSPC15 rule may be misconstrued as a benchmark for coating application on flat surfaces, eventually leading to a non-PSPC15 compliance due to the resulting variation in coating thickness violating this 90/10 rule. This study indicates that over the years, the arithmetic mean in-situ DFT appears to be 498±18 μm and that too high and low thicknesses, below 288 μm and above 800 μm, were noted in the field. Analysis of a survey of ballast tank coating performance of ships indicates that too low thicknesses appear to be negatively impacting the average theoretical ballast tank performance. However, when an application mean DFT benchmark of 525 μm is used, the coating will almost surely comply to the 90/10 rule and the risk of falling below the 288 μm threshold is small, less than 2% in most cases. Consequently, using 320 μm as a mean DFT benchmark could result in a non-PSPC15 compliance with the in-situ ascertained coating thickness variation as this does not exclude coating thicknesses below 288 μm, which may then result in a significantly less than average theoretical coating performance. If the coating application is performed very evenly, the benchmark may be reduced to 429 μm with a probability of falling below 288 μm reduced to 0.1%. It should therefore be emphasized that the PSPC15 requirement is a coating system framework description, and that the requirement should be broadened to include a mean DFT as a coating applicator benchmark together with a clearly specified minimum and maximum DFT, in order to avoid any misinterpretations.

scholarly journals Tick-Borne Pathogens Shape the Native Microbiome Within Tick Vectors

2020 ◽  
Vol 8 (9) ◽  
pp. 1299
Author(s):  
Abdulsalam Adegoke ◽  
Deepak Kumar ◽  
Cailyn Bobo ◽  
Muhammad Imran Rashid ◽  
Aneela Zameer Durrani ◽  
...  
Keyword(s):  
Vector Competence ◽  
Bacterial Pathogen ◽  
Blood Feeding ◽  
Metagenomic Sequencing ◽  
Microbial Composition ◽  
Alpha And Beta Diversity ◽  
Operational Taxonomic Units ◽  
Diverse Community ◽  
Tick Vectors ◽  
Validation Experiments

Ticks are blood-feeding arthropods and transmit a variety of medically important viral, bacterial, protozoan pathogens to animals and humans. Ticks also harbor a diverse community of microbes linked to their biological processes, such as hematophagy, and hence affect vector competence. The interactions between bacterial and/or protozoan pathogens and the tick microbiome is a black-box, and therefore we tested the hypothesis that the presence of a protozoan or bacterial pathogen will alter the microbial composition within a tick. Hence, this study was designed to define the microbial composition of two tick species, Hyalomma (H.) anatolicum and Rhipicephalus (R.) microplus. We used a combination of PCR based pathogen (Anaplasma marginale and Theileria species) and symbiont (Wolbachia species) identification followed by metagenomic sequencing and comparison of the microbial communities in PCR positive and negative ticks. A total of 1786 operational taxonomic units was identified representing 25 phyla, 50 classes, and 342 genera. The phylum Proteobacteria, Firmicutes, Actinobacteriota, and Bacteroidota were the most represented bacteria group. Alpha and beta diversity were not significantly affected in the presence or absence of Theileria sp. and A. marginale as see with H. anatolicum ticks. Interestingly, bacterial communities were significantly reduced in Theileria sp. infected R. microplus ticks, while also exhibiting a significant reduction in microbial richness and evenness. Putting these observations together, we referred to the effect the presence of Theileria sp. has on R. microplus a “pathogen-induced dysbiosis”. We also identify the presence of Plasmodium falciparum, the causative agent of human malaria from the microbiome of both H. anatolicum and R. microplus ticks. These findings support the presence of a “pathogen-induced dysbiosis” within the tick and further validation experiments are required to investigate how they are important in the vector competence of ticks. Understanding the mechanism of “pathogen-induced dysbiosis” on tick microbial composition may aid the discovery of intervention strategies for the control of emerging tick-borne infections.

scholarly journals Comparison of gut microbiome from Sulawesi carrion and burying beetles (Coleoptera: Silphidae) through metagenomic analysis of 16S rRNA gene

2020 ◽  
Vol 19 ◽  
pp. 00015
Author(s):  
Ruby Setiawan ◽  
I Nyoman Sumerta ◽  
Syahfitri Anita ◽  
Raden Pramesa Narakusumo ◽  
Anang Setiawan Achmadi
Keyword(s):  
Lower Number ◽  
Rrna Gene ◽  
Microbial Structure ◽  
Specific Level ◽  
Operational Taxonomic Units ◽  
Nutrient Processing ◽  
Microbial Symbionts ◽  
Gut Microbial Community ◽  
Central Sulawesi ◽  
Metagenomic Approach

Carrion beetle (Coleoptera: Silphidae) is one of the scavengers which obtain nutrition from carcass decomposition which supported by the microbial symbionts through the mutual symbiosis. In this study, we characterized and compared the gut microbial community from the species of Nicrophorinae (Nicrophorus distinctus Grouvelle, 1885) and Silphinae (Necrophila renatae Portevin, 1920) from Dako Mountain, Central Sulawesi using 16S metagenomic approach. A total of 661 bacterial Operational Taxonomic Units (OTUs) at the species level were obtained from the guts of Ni. distinctus and Ne. renatae. Those numbers were predominated by Firmicutes and Proteobacteria, followed by Bacteriodetes in both species. Interestingly, a high number of Lactobacillales was observed in Ni. distinctus and lower number in Clostridiales and Cardiobacteriales compared to Ne. renatae, which showed higher abundance of those classes. Both of these insect species have nearly the same microbial diversity values, even though there some lower taxa levels were found different abundance. These results suggest that the patterns of the gut microbial structure depicted their roles in certain behavior and habitat on decomposing carcasses and could be correlated to the specific level of taxa roles in nutrient processing.

Numerical Simulation of Sloshing of Water in Ship Tanks During Sequential Ballast Water Exchange in Seaways

2002 ◽  
Author(s):  
Makoto Arai ◽  
Humberto S. Makiyama ◽  
Liang-Yee Cheng
Keyword(s):  
Ballast Water ◽  
Water Exchange ◽  
Sea Water ◽  
Marine Pollution ◽  
Aquatic Organisms ◽  
Exchange Method ◽  
Ballast Tank ◽  
Open Sea ◽  
Merchant Ship ◽  
Ballast Tanks

In recent years, ballast water has been blamed for a variety of marine pollution problems, particularly for transporting harmful aquatic organisms from one part of the world to another and damaging the ecosystem of the new areas. A relatively simple mechanism to control this problem is to exchange ballast water on the high seas between ports in order to remove invasive species before the ship reaches its destination. However, some issues regarding ballast exchange on the open sea need to be addressed before this operation is introduced. One of them is the sloshing of the sea water in the ballast tank. In this paper, ballast water exchange on the open sea by means of the Sequential exchange method is simulated. Irregular seaways are generated from the ISSC spectrum, and the sloshing response of the water in the ballast tanks of a large merchant ship is numerically computed by using a finite difference code developed by the authors. The results showed that there is little possibility that severe sloshing presents a serious problem in regard to the ballast tank’s strength, especially in the case of a bulk carrier whose tanks are generally short in length, with sloshing anticipated only at the low water level.

Analysis of granulosa cells by single cell PCR

2012 ◽  
Vol 94 (1) ◽  
pp. 117-118
Author(s):  
J. Pastuschek ◽  
S. Hoelters ◽  
M. Weber ◽  
J. Fitzgerald ◽  
E. Schleussner ◽  
...  
Keyword(s):  
Single Cell ◽  
Granulosa Cells ◽  
Single Cell Pcr
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