scholarly journals The Meta-Organism Response of the Environmental Generalist Pocillopora damicornis Exposed to Differential Accumulation of Heat Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Jessica L. Bergman ◽  
William Leggat ◽  
Tracy D. Ainsworth
Keyword(s):  
Thermal Stress ◽  
Microbial Community ◽  
Coral Species ◽  
Similar Rate ◽  
Environmental Disturbance ◽  
Pocillopora Damicornis ◽  
Stress Exposure ◽  
Generalist Species ◽  
Rrna Sequencing ◽  
The Impact

Coral bleaching events in the marine environment are now occurring globally, and the frequency and severity of these events are increasing. Critically, these events can cause the symbiosis between Symbiodiniaceae and their coral hosts to break down, but how the microbial community within the coral responds to bleaching is still equivocal. We investigated the impact of thermal stress exposure on the meta-organism responses of the generalist scleractinian coral species Pocillopora damicornis. Using mesocosms to recreate warming scenarios previously observed at Heron Island, we show that P. damicornis symbiont densities and photophysiological parameters declined at a similar rate under thermal stress regardless of the length of pre-bleaching thermal stress, defined here as temperatures above the monthly maximum mean (MMM) for Heron Island but below the local bleaching threshold (MMM + 2°C). However, we find that the P. damicornis microbiome remains stable over time regardless of the degree of thermal stress and the accumulation of pre-bleaching thermal stress. Our study therefore suggests that while P. damicornis is physiologically impacted by bleaching temperatures, the microbial community identified through 16S rRNA sequencing remains unchanged at the ASV level throughout bleaching. Understanding the capacity of a generalist species to withstand bleaching events is imperative to characterizing what coral species will exist on coral reefs following disturbances, as it has been suggested that the success of environmental generalist species may simplify community structure and lead to changes in biodiversity following environmental disturbance.

scholarly journals Microplastics ingestion and heterotrophy in thermally stressed corals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jeremy B. Axworthy ◽  
Jacqueline L. Padilla-Gamiño
Keyword(s):  
Thermal Stress ◽  
Global Change ◽  
Coral Reefs ◽  
Coral Species ◽  
Pocillopora Damicornis ◽  
Montipora Capitata ◽  
Thermally Stressed

AbstractRising sea temperatures and increasing pollution threaten the fate of coral reefs and millions of people who depend on them. Some reef-building corals respond to thermal stress and subsequent bleaching with increases in heterotrophy, which may increase the risk of ingesting microplastics. Whether this heterotrophic plasticity affects microplastics ingestion or whether ingesting microplastics affects heterotrophic feeding in corals is unknown. To determine this, two coral species, Montipora capitata and Pocillopora damicornis, were exposed to ambient (~27 °C) and increased (~30 °C) temperature and then fed microplastics, Artemia nauplii, or both. Following thermal stress, both species significantly reduced feeding on Artemia but no significant decrease in microplastics ingestion was observed. Interestingly, P. damicornis only ingested microplastics when Artemia were also present, providing evidence that microplastics are not selectively ingested by this species and are only incidentally ingested when food is available. As the first study to examine microplastics ingestion following thermal stress in corals, our results highlight the variability in the risk of microplastics ingestion among species and the importance of considering multiple drivers to project how corals will be affected by global change.

scholarly journals The impact of mixtures of xylose and glucose on the microbial diversity and fermentative metabolism of sequencing-batch or continuous enrichment cultures

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
Julius L Rombouts ◽  
Galvin Mos ◽  
David G Weissbrodt ◽  
Robbert Kleerebezem ◽  
Mark C M Van Loosdrecht
Keyword(s):  
Microbial Community ◽  
Enrichment Culture ◽  
Batch Reactor ◽  
In Situ Hybridisation ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Generalist Species ◽  
Rrna Gene Sequencing ◽  
A Minor ◽  
The Impact

ABSTRACT Efficient industrial fermentation of lignocellulosic waste containing a large part of glucose and xylose is desirable to implement a circular economy. Mixed culture biotechnologies can aid in realizing this goal. The effect of feeding equivalent substrates to a microbial community, such a xylose and glucose, is not well understood in terms of the number of dominant species and how these species compete for the substrates. We compared the metabolism and microbial community structure in a continuous-flow stirred tank reactor (CSTR) and a sequencing batch reactor (SBR) fed with a mixture of xylose and glucose, inoculated with bovine rumen at pH 8, 30°C and a hydraulic retention time of 8 h. We hypothesised that a CSTR will select for generalist species, taking up both substrates. We used 16S rRNA gene sequencing and fluorescent in situ hybridisation to accurately determine the microbial community structures. Both enrichments were stoichiometrically and kinetically characterised. The CSTR enrichment culture was dominated by Clostridium intestinale (91% ± 2%). The SBR showed an abundance of Enterobacteriaceae (75% ± 8%), dominated by Citrobacter freundii and a minor fraction of Raoultella ornithinolytica. C. freundii ferments xylose and glucose in a non-diauxic fashion. Clearly, a non-diauxic generalist outcompetes specialists and diauxic generalists in SBR environments.

scholarly journals Comparative Analysis of Fecal Microbiota of Grazing Mongolian Cattle from Different Regions in Inner Mongolia, China

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1938
Author(s):  
Han Aricha ◽  
Huasai Simujide ◽  
Chunjie Wang ◽  
Jian Zhang ◽  
Wenting Lv ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Gut Microbiota ◽  
Inner Mongolia ◽  
Alpha Diversity ◽  
Fecal Microbiota ◽  
Composition Analysis ◽  
Geographical Factors ◽  
Rrna Sequencing ◽  
Xilingol Grassland

Mongolian cattle from China have strong adaptability and disease resistance. We aimed to compare the gut microbiota community structure and diversity in grazing Mongolian cattle from different regions in Inner Mongolia and to elucidate the influence of geographical factors on the intestinal microbial community structure. We used high throughput 16S rRNA sequencing to analyze the fecal microbial community and diversity in samples from 60 grazing Mongolian cattle from Hulunbuir Grassland, Xilingol Grassland, and Alxa Desert. A total of 2,720,545 high-quality reads and sequences that were 1,117,505,301 bp long were obtained. Alpha diversity among the three groups showed that the gut microbial diversity in Mongolian cattle in the grasslands was significantly higher than that in the desert. The dominant phyla were Firmicutes and Bacteroidetes, whereas Verrucomicrobia presented the highest abundance in the gut of cattle in the Alxa Desert. The gut bacterial communities in cattle from the grasslands versus the Alxa Desert were distinctive, and those from the grasslands were closely clustered. Community composition analysis revealed significant differences in species diversity and richness. Overall, the composition of the gut microbiota in Mongolian cattle is affected by geographical factors. Gut microbiota may play important roles in the geographical adaptations of Mongolian cattle.

scholarly journals Unravelling thermal stress due to thermal expansion mismatch in metal–organic frameworks for methane storage

2021 ◽  
Author(s):  
Jelle Wieme ◽  
Veronique Van Speybroeck
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Pressure Coefficient ◽  
Metal Organic Frameworks ◽  
Methane Storage ◽  
Thermal Expansion Mismatch ◽  
Thermal Pressure ◽  
Temperature Changes ◽  
Metal Organic ◽  
The Impact

Thermal stress is present in metal–organic frameworks undergoing temperature changes during adsorption and desorption. We computed the thermal pressure coefficient as a proxy for this phenomenon and discuss the impact of thermal expansion mismatch.

scholarly journals Thermal stress reduces pocilloporid coral resilience to ocean acidification by impairing control over calcifying fluid chemistry

2021 ◽  
Vol 7 (2) ◽  
pp. eaba9958
Author(s):  
Maxence Guillermic ◽  
Louise P. Cameron ◽  
Ilian De Corte ◽  
Sambuddha Misra ◽  
Jelle Bijma ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Ocean Acidification ◽  
Pocillopora Damicornis ◽  
Carbonate Chemistry ◽  
Negative Interaction ◽  
Saturation State ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Influence Of Temperature On ◽  
Different Time Scales

The combination of thermal stress and ocean acidification (OA) can more negatively affect coral calcification than an individual stressors, but the mechanism behind this interaction is unknown. We used two independent methods (microelectrode and boron geochemistry) to measure calcifying fluid pH (pHcf) and carbonate chemistry of the corals Pocillopora damicornis and Stylophora pistillata grown under various temperature and pCO2 conditions. Although these approaches demonstrate that they record pHcf over different time scales, they reveal that both species can cope with OA under optimal temperatures (28°C) by elevating pHcf and aragonite saturation state (Ωcf) in support of calcification. At 31°C, neither species elevated these parameters as they did at 28°C and, likewise, could not maintain substantially positive calcification rates under any pH treatment. These results reveal a previously uncharacterized influence of temperature on coral pHcf regulation—the apparent mechanism behind the negative interaction between thermal stress and OA on coral calcification.

scholarly journals Multi-domain probiotic consortium as an alternative to chemical remediation of oil spills at coral reefs and adjacent sites

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Denise P. Silva ◽  
Helena D. M. Villela ◽  
Henrique F. Santos ◽  
Gustavo A. S. Duarte ◽  
José Roberto Ribeiro ◽  
...  
Keyword(s):  
Microbial Community ◽  
Coral Reefs ◽  
Environmental Changes ◽  
Oil Spills ◽  
Anthropogenic Activities ◽  
Oil Contamination ◽  
Negative Effects ◽  
Corexit 9500 ◽  
Coral Health ◽  
The Impact

Abstract Background Beginning in the last century, coral reefs have suffered the consequences of anthropogenic activities, including oil contamination. Chemical remediation methods, such as dispersants, can cause substantial harm to corals and reduce their resilience to stressors. To evaluate the impacts of oil contamination and find potential alternative solutions to chemical dispersants, we conducted a mesocosm experiment with the fire coral Millepora alcicornis, which is sensitive to environmental changes. We exposed M. alcicornis to a realistic oil-spill scenario in which we applied an innovative multi-domain bioremediator consortium (bacteria, filamentous fungi, and yeast) and a chemical dispersant (Corexit® 9500, one of the most widely used dispersants), to assess the effects on host health and host-associated microbial communities. Results The selected multi-domain microbial consortium helped to mitigate the impacts of the oil, substantially degrading the polycyclic aromatic and n-alkane fractions and maintaining the physiological integrity of the corals. Exposure to Corexit 9500 negatively impacted the host physiology and altered the coral-associated microbial community. After exposure, the abundances of certain bacterial genera such as Rugeria and Roseovarius increased, as previously reported in stressed or diseased corals. We also identified several bioindicators of Corexit 9500 in the microbiome. The impact of Corexit 9500 on the coral health and microbial community was far greater than oil alone, killing corals after only 4 days of exposure in the flow-through system. In the treatments with Corexit 9500, the action of the bioremediator consortium could not be observed directly because of the extreme toxicity of the dispersant to M. alcicornis and its associated microbiome. Conclusions Our results emphasize the importance of investigating the host-associated microbiome in order to detect and mitigate the effects of oil contamination on corals and the potential role of microbial mitigation and bioindicators as conservation tools. Chemical dispersants were far more damaging to corals and their associated microbiome than oil, and should not be used close to coral reefs. This study can aid in decision-making to minimize the negative effects of oil and dispersants on coral reefs.

Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish ( Coregonus clupeaformis ) embryos

2017 ◽  
Vol 69 ◽  
pp. 294-301 ◽  
Author(s):  
Lindy M. Whitehouse ◽  
Chance S. McDougall ◽  
Daniel I. Stefanovic ◽  
Douglas R. Boreham ◽  
Christopher M. Somers ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Early Stage ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Shock Response ◽  
The Impact

Modelling of Convective Melt Flow and Interface Shape in Commercial Bridgman-Stockbarger Growth of CdZnTe

2000 ◽  
Author(s):  
Toby D. Rule ◽  
Ben Q. Li ◽  
Kelvin G. Lynn
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Solute Transport ◽  
Latent Heat ◽  
Thermal Stresses ◽  
Radiation Detector ◽  
Time History ◽  
High Quality ◽  
Melt Convection ◽  
The Impact

Abstract CdZnTe single crystals for radiation detector and IR substrate applications must be of high quality and controlled purity. The growth of such crystals from a melt is very difficult due to the low thermal conductivity and high latent heat of the material, and the ease with which dislocations, twins and precipitates are introduced during crystal growth. These defects may be related to solute transport phenomena and thermal stresses associated with the solidification process. As a result, production of high quality material requires excellent thermal control during the entire growth process. A comprehensive model is being developed to account for radiation and conduction within the furnace, thermal coupling between the furnace and growth crucible, and finally the thermal stress fields within the growing crystal which result from the thermal conditions imposed on the crucible. As part of this effort, the present work examines the heat transfer and fluid flow within the crucible, using thermal boundary conditions obtained from experimental measurements. The 2-D axisymetric numerical model uses the deforming finite element method, with allowance made for melt convection, solidification with latent heat release and conjugate heat transfer between the solid material and the melt. Results are presented for several stages of growth, including a time-history of the solid-liquid interface (1365 K isotherm). The impact of melt convection, thermal end conditions and furnace temperature gradient on the growth interface is evaluated. Future work will extend the present model to include radiation exchange within the furnace, and a transient analysis for studying solute transport and thermal stress.

Abstract 3760: Thiazolidinediones Do Not Reduce 1 Year Event Rates In Diabetic Patients Undergoing Percutaneous Coronary Intervention

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Abdul Sheikh ◽  
Khan Pohlel ◽  
Emir Veledar ◽  
Viola Vaccarino ◽  
John S Douglas ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Percutaneous Coronary Intervention ◽  
Meta Analysis ◽  
Composite Endpoint ◽  
Coronary Intervention ◽  
Similar Rate ◽  
Coronary Stenting ◽  
Diabetic Patients ◽  
Percutaneous Coronary ◽  
The Impact

Background: Thiazolidinediones (TZD) have been shown to decrease intimal hyperplasia by intravascular ultrasound after coronary stenting. However, a recent meta-analysis showed increased MI and suggested increased CV deaths with TZD use. We examined the impact of TZD use on the 1-year clinical outcomes of diabetic patients undergoing percutaneous coronary interventions. Methods: From 2000 through 2003, 598 diabetic patients underwent percutaneous coronary intervention at Emory University. Medication profiles were available for all patients who were divided into two groups: those that had a TZD as part of their diabetes regimen and those that did not. We compared the baseline clinical characteristics, angiographic characteristics, and 1 year rate of a composite endpoint of death, myocardial infarction, and revascularization between the two groups. Results: There was no difference between the two groups with regards to age, sex, baseline medical conditions, medication regimens, and overall glycemic control at the time of percutaneous coronary intervention. The lesions in both groups were of similar length, diameter, and characteristics. At 1 year the composite of death, non-fatal myocardial infarction (MI), and revascularization was not statistically different in the diabetics taking TZDs compared to those not taking TZDs (28.5% vs. 23.2%, p=0.15). There were also no differences in the rates of death and non-fatal MI. There was however a statistically significant increase in the rate of revascularization in diabetics taking TZDs compared to those not taking TZDs (25.4% vs. 17.3%, p=0.02). Conclusion: Diabetic patients undergoing coronary stenting who were on TZDs had a statistically significant increased rate of revascularization. However, there was a similar rate of the combined endpoint of death, non-fatal MI, and revascularization in all diabetic patients irrespective of TZD usages.

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