scholarly journals Moderate Seasonal Dynamics Indicate an Important Role for Lysogeny in the Red Sea

2021 ◽  
Vol 9 (6) ◽  
pp. 1269
Author(s):  
Ruba Abdulrahman Ashy ◽  
Curtis A. Suttle ◽  
Susana Agustí
Keyword(s):  
Surface Water ◽  
Mitomycin C ◽  
Red Sea ◽  
Environmental Changes ◽  
Viral Infections ◽  
High Salinity ◽  
High Surface ◽  
Temperate Phage ◽  
Viral Dynamics ◽  
Second Year

Viruses are the most abundant microorganisms in marine environments and viral infections can be either lytic (virulent) or lysogenic (temperate phage) within the host cell. The aim of this study was to quantify viral dynamics (abundance and infection) in the coastal Red Sea, a narrow oligotrophic basin with high surface water temperatures (22–32 °C degrees), high salinity (37.5–41) and continuous high insolation, thus making it a stable and relatively unexplored environment. We quantified viral and environmental changes in the Red Sea (two years) and the occurrence of lysogenic bacteria (induced by mitomycin C) on the second year. Water temperatures ranged from 24.0 to 32.5 °C, and total viral and bacterial abundances ranged from 1.5 to 8.7 × 106 viruses mL−1 and 1.9 to 3.2 × 105 bacteria mL−1, respectively. On average, 12.24% ± 4.8 (SE) of the prophage bacteria could be induced by mitomycin C, with the highest percentage of 55.8% observed in January 2018 when bacterial abundances were low; whereas no induction was measurable in spring when bacterial abundances were highest. Thus, despite the fact that the Red Sea might be perceived as stable, warm and saline, relatively modest changes in seasonal conditions were associated with large swings in the prevalence of lysogeny.

scholarly journals Environmental Factors Causing Stress in Avicennia marina Mangrove in Rabigh Lagoon Along the Red Sea: Based on a Multi-Approach Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammed O. Aljahdali ◽  
Abdullahi B. Alhassan ◽  
Zhaohui Zhang
Keyword(s):  
Surface Water ◽  
Environmental Factors ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Red Sea ◽  
Nutrient Dynamics ◽  
High Salinity ◽  
Physiological Stress ◽  
High Surface ◽  
Nutrient Level

Lagoons along the Red Sea are socio-economically important but most vulnerable ecosystems. Strong evaporation, strengthened due to global warming, leads to high salinity and high temperature in surface water, which exacerbate physiological stress in mangroves. Rabigh Lagoon is characterized by unusually large spatial differences in nutrient dynamics and physicochemical parameters. We conducted a multi-approach study to demonstrate how environmental factors cause growth retardation and stress in mangroves. There were significant variations (P < 0.05) in water salinities and temperatures, nitrogen and phosphorus abundance in sediments, and antioxidants in mangroves among 8 sites across the lagoon. Salinity and water temperature rapidly increased from the northern where Red Sea seawater enters to the southern end, but dissolved oxygen declined. High salinity (44.9), high surface water temperature (28.8°C) and relatively high nutrients at the southern end of the lagoon (S8) corresponded to high concentrations of antioxidants. High δ13C (−12.4‰) and δ15N (4.9‰) in the sediments at S8 also reveal relatively high nutrient level due to stagnant water, camel grazing, and runoff bringing in fertilizer from agriculture activities in the catchments during seasonal flooding events. Principal component analyses showed that N and P limitation at the lagoon entrance is the leading cause for mangrove stress, while high salinity, temperature, and low dissolved oxygen are the predominant factors for high antioxidants concentrations at the southern end of the lagoon.

scholarly journals Airborne Microbes Contribute to N2Fixation in Surface Water of the Northern Red Sea

2018 ◽  
Author(s):  
Eyal Rahav ◽  
Adina Paytan ◽  
Esra Mescioglu ◽  
Yuri Galletti ◽  
Sahar Rosenfeld ◽  
...  
Keyword(s):  
Surface Water ◽  
Red Sea ◽  
Airborne Microbes ◽  
Northern Red Sea

High-resolution seismic imaging reveals infill history of a submerged Quaternary fjord system in the subantarctic Auckland Islands, New Zealand

2019 ◽  
Vol 93 ◽  
pp. 255-266 ◽  
Author(s):  
Edward J. Perkins ◽  
Andrew R. Gorman ◽  
Emily J. Tidey ◽  
Gary S. Wilson ◽  
Christian Ohneiser ◽  
...  
Keyword(s):  
High Resolution ◽  
Environmental Changes ◽  
High Surface ◽  
Leeward Side ◽  
Surface Erosion ◽  
Depositional History ◽  
Fluvial Erosion ◽  
Erosion Rates ◽  
Subantarctic Islands ◽  
History Of

AbstractQuaternary processes and environmental changes are often difficult to assess in remote subantarctic islands due to high surface erosion rates and overprinting of sedimentary products in locations that can be a challenge to access. We present a set of high-resolution, multichannel seismic lines and complementary multibeam bathymetry collected off the eastern (leeward) side of the subantarctic Auckland Islands, about 465 km south of New Zealand's South Island. These data constrain the erosive and depositional history of the island group, and they reveal an extensive system of sediment-filled valleys that extend offshore to depths that exceed glacial low-stand sea level. Although shallow, marine, U-shaped valleys and moraines are imaged, the rugged offshore geomorphology of the paleovalley floors and the stratigraphy of infill sediments suggests that the valley floors were shaped by submarine fluvial erosion, and subsequently filled by lacustrine, fjord, and fluvial sedimentary processes.

Port town and its harbors: sedimentary proxies for landscape and seascape reconstruction of the Greco-Roman site of Berenike Trogodytica on the Red Sea coast of Egypt

2018 ◽  
Vol 26 (2) ◽  
pp. 61-92 ◽  
Author(s):  
Anna M. Kotarba-Morley
Keyword(s):  
Indian Ocean ◽  
Red Sea ◽  
Environmental Changes ◽  
Greco Roman ◽  
The Indian Ocean ◽  
Geographical Position ◽  
Red Sea Coast ◽  
Trade And Exchange ◽  
Changing Role ◽  
Sea Coast

Berenike Trog<l>odytica was one of the key harbours on the Red Sea coast during the Ptolemaic and Roman periods and was a major trade and exchange hub connecting the Indian Ocean and the Mediterranean. Berenike’s geographical position was extraordinarily propitious owing partly to its natural harbours, protected against the prevailing northern winds, as well as its location in the vicinity of an ancient viewshed, the large peninsula of Ras Benas. This paper discusses how multifaceted geoarchaeological approaches to the study of ancient ports can contribute to a better understanding of the mechanisms and logistics of maritime trade, as well as fluctuations in its quality and quantity. It also sheds new light on the significance of the effect that local and regional palaeoclimatic, landscape, seascape and environmental changes had on the development and decline of the port, and its changing role within the Red Sea–Indian Ocean maritime network.

scholarly journals Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Mohamed F. Haroon ◽  
Luke R. Thompson ◽  
Ulrich Stingl
Keyword(s):  
Saudi Arabia ◽  
Surface Water ◽  
Water Sample ◽  
Water Column ◽  
Red Sea ◽  
Genome Sequence ◽  
Draft Genome ◽  
Surface Water Sample ◽  
Genomic Information ◽  
Different Depths

A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

A temperate phage with cohesive ends induced by mitomycin C treatment of Lactobacillus casei

1998 ◽  
Vol 143 (8) ◽  
pp. 1621-1626 ◽  
Author(s):  
Y. Nakashima ◽  
H. Hasuwa ◽  
Y. Kakita ◽  
K. Murata ◽  
A. Kuroiwa ◽  
...  
Keyword(s):  
Mitomycin C ◽  
Lactobacillus Casei ◽  
Temperate Phage

scholarly journals Nonylphenol Ethoxylate Surfactants Modified by Carboxyl Groups for Foam EOR at High-Salinity Conditions

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8205
Author(s):  
Emil R. Saifullin ◽  
Shinar Zhanbossynova ◽  
Dmitrii A. Zharkov ◽  
Roman S. Pavelyev ◽  
Chengdong Yuan ◽  
...  
Keyword(s):  
Nonionic Surfactants ◽  
High Salinity ◽  
High Surface ◽  
Foaming Ability ◽  
High Salinity Water ◽  
Nonylphenol Ethoxylate ◽  
Long Term Stability ◽  
Reservoir Conditions ◽  
Carboxylic Groups ◽  
Foam Properties

High mineralization of water complicates the use of foam in reservoir conditions. Anionic–nonionic surfactants are one of the best candidates for these conditions since they have both high surface activity and salt tolerance. One of the ways to obtain anionic–nonionic surfactants is to modify nonionic surfactants by an anionic group. The type of the group and its chemical structure can strongly affect the properties of the surfactant. In this work, widely-produced nonionic surfactant nonylphenol (12) ethoxylate (NP12EO) was modified by new types of carboxylic groups through the implementation of maleic (NP12EO-MA) and succinic (NP12EO-SA) anhydrides with different saturation levels. The main objectives of this work were to compare synthesized surfactants with nonionic precursor and to reveal the influence of unsaturated bonds in the carboxyl group on the properties of the foam. NaCl concentration up to 20 wt% was used to simulate high mineralization conditions, as well as to assess the effect of unsaturated bonds on foam properties. Synthesized anionic–nonionic surfactants retained surfactant solubility and long-term stability in high-salinity water, but have better foaming ability, as well as higher apparent viscosity, in porous media. The presence of an unsaturated bond in NP12EO-MA surfactant lowers foaming ability at high mineralization.

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