scholarly journals Applicability of the FDA assay to determine the viability of marine phytoplankton under different environmental conditions

2007 ◽  
Vol 352 ◽  
pp. 17-26 ◽  
Author(s):  
M Garvey ◽  
B Moriceau ◽  
U Passow
Keyword(s):  
Environmental Conditions ◽  
Marine Phytoplankton

scholarly journals An Ancient Enzyme Finds a New Home: Prevalence and Neofunctionalization of Trypsin in Marine Phytoplankton

2021 ◽  
Author(s):  
Yanchun You ◽  
Xueqiong Sun ◽  
Senjie Lin
Keyword(s):  
Environmental Conditions ◽  
Aquatic Ecosystem ◽  
Digestive Enzyme ◽  
Research Direction ◽  
Potential Functions ◽  
Marine Phytoplankton ◽  
Global Ocean ◽  
Coastal Oceans ◽  
Genome Wide ◽  
New Research

Abstract Trypsin is an ancient protease best known as a digestive enzyme in animals, and traditionally believed to be absent in plants and protists. Here, we surveyed the distribution, diversity, evolution and potential functions of trypsin genes in global ocean phytoplankton, the major primary producers in the aquatic ecosystem. Our analysis indicates that trypsin genes are widely distributed both taxonomically and geographically in marine phytoplankton. Furthermore, by systematic comparative analyses we documented lineage-specific diversity and expansion of trypsin genes in the evolution of marine phytoplankton. Genome-wide analyses revealed that trypsin genes were more prevalent in diatoms than in other lineages. Moreover, the expression of trypsin genes in diatom tended to be more responsive to environmental stimuli. The duplication and neofunctionalization of trypsin genes may be important in diatoms to adapt to dynamical environmental conditions, contributing to diatoms’ dominance in the coastal oceans. This work advances our knowledge on the distributions and neofunctionalizations of this ancient enzyme and creates a new research direction in the phytoplankton biology.

scholarly journals Everything is not everywhere: can marine compartments shape phytoplankton assemblages?

2019 ◽  
Vol 286 (1914) ◽  
pp. 20191890 ◽  
Author(s):  
Sofie Spatharis ◽  
Vasiliki Lamprinou ◽  
Alexandra Meziti ◽  
Konstantinos A. Kormas ◽  
Daniel D. Danielidis ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Marine Phytoplankton ◽  
Phytoplankton Assemblages ◽  
Environmental Pressures ◽  
Assemblage Composition ◽  
Microbial Biogeography ◽  
Water Compartments ◽  
Environmental Selection ◽  
Principal Coordinates ◽  
The Impact

The idea that ‘everything is everywhere, but the environment selects' has been seminal in microbial biogeography, and marine phytoplankton is one of the prototypical groups used to illustrate this. The typical argument has been that phytoplankton is ubiquitous, but that distinct assemblages form under environmental selection. It is well established that phytoplankton assemblages vary considerably between coastal ecosystems. However, the relative roles of compartmentalization of regional seas and site-specific environmental conditions in shaping assemblage structures have not been specifically examined. We collected data from coastal embayments that fall within two different water compartments within the same regional sea and are characterized by highly localized environmental pressures. We used principal coordinates of neighbour matrices (PCNM) and asymmetric eigenvector maps (AEM) models to partition the effects that spatial structures, environmental conditions and their overlap had on the variation in assemblage composition. Our models explained a high percentage of variation in assemblage composition (59–65%) and showed that spatial structure consistent with marine compartmentalization played a more important role than local environmental conditions. At least during the study period, surface currents connecting sites within the two compartments failed to generate sufficient dispersal to offset the impact of differences due to compartmentalization. In other words, our findings suggest that, even for a prototypical cosmopolitan group, everything is not everywhere.

Theoretical and Experimental Analysis of the 14C Technique and Its Use in Studies of Primary Production

1976 ◽  
Vol 33 (8) ◽  
pp. 1715-1721 ◽  
Author(s):  
Louis A. Hobson ◽  
W. James Morris ◽  
Kathleen T. Pirquet
Keyword(s):  
Environmental Conditions ◽  
Experimental Analysis ◽  
Rate Constants ◽  
Net Photosynthesis ◽  
Field Studies ◽  
Marine Phytoplankton ◽  
Theoretical Studies ◽  
Continuous Irradiation ◽  
Gross Photosynthesis ◽  
Photosynthesis And Respiration

Theoretical and experimental field studies of 14C uptake by marine phytoplankton were carried out to determine environmental conditions required for the technique to measure net photosynthesis. Results of theoretical studies indicate that rapidly metabolizing populations (rate constants for gross photosynthesis and respiration of 0.1 h−1 and 0.007 h−1 respectively) may saturate with 14C after about 30 h of continuous irradiation. Results of field studies indicate that a minimum of 24 h are required for net photosynthesis to be measured when daily irradiations exceed 20 cal cm−2 and nutrient limitation of photosynthesis does not occur. Additional measurements that may be made to aid in interpreting results obtained by the 14C technique are briefly discussed.

scholarly journals Quantitative Proteomic Profiling of Marine Diatom Skeletonema dohrnii in Response to Temperature and Silicate Induced Environmental Stress

2021 ◽  
Vol 11 ◽  
Author(s):  
Satheeswaran Thangaraj ◽  
Satheesh Kumar Palanisamy ◽  
Guicheng Zhang ◽  
Jun Sun
Keyword(s):  
Pathway Analysis ◽  
Environmental Conditions ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Marine Phytoplankton ◽  
Marine Diatom ◽  
Biological Information ◽  
Proteomic Profiling ◽  
Protein Ratio ◽  
Oxidoreductase Activity

Global warming is expected to reduce the nutrient concentration in the upper ocean and affect the physiology of marine diatoms, but the underlying molecular mechanisms controlling these physiological changes are currently unknown. To understand these mechanisms, here we investigated iTRAQ based proteomic profiling of diatom Skeletonema dohrnii in a multifactorial experimental with a combining change of temperature and silicate concentrations. In total, 3369 differently abundant proteins were detected in four different environmental conditions, and the function of all proteins was identified using Gene Ontology and KEGG pathway analysis. For discriminating the proteome variation among samples, multivariate statistical analysis (PCA, PLS-DA) was performed by comparing the protein ratio differences. Further, performing pathway analysis on diatom proteomes, we here demonstrated downregulation of photosynthesis, carbon metabolism, and ribosome biogenesis in the cellular process that leads to decrease the oxidoreductase activity and affects the cell cycle of the diatom. Using PLS-DA VIP score plot analysis, we identified 15 protein biomarkers for discriminating studied samples. Of these, five proteins or gene (rbcL, PRK, atpB, DNA-binding, and signal transduction) identified as key biomarkers, induced by temperature and silicate stress in diatom metabolism. Our results show that proteomic finger-printing of S. dohrnii with different environmental conditions adds biological information that strengthens marine phytoplankton proteome analysis.

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

The influence of external conditions on sound pressure in the pistonphone at the infrasound frequency range

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin
Keyword(s):  
Environmental Conditions ◽  
Sound Pressure ◽  
Primary Method ◽  
Frequency Range ◽  
External Conditions ◽  
Numerical Estimations

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.

Disentangling the role of shared ancestry and the environment on leaf stable isotopes

2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1
Keyword(s):  
Stable Isotopes ◽  
Environmental Conditions ◽  
Evolutionary History ◽  
Environmental Control ◽  
Phylogenetic Signal ◽  
Individual Species ◽  
Habitat Types ◽  
Δ13c And Δ15n ◽  
Environmental Controls ◽  
Shared Ancestry

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.

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