The inverse correlation between growth rate and cell carbohydrate content of Microcystis aeruginosa

2009 ◽  
Vol 22 (1) ◽  
pp. 105-107 ◽  
Author(s):  
Chong Wang ◽  
Hai-nan Kong ◽  
Sheng-bing He ◽  
Xiang-yong Zheng ◽  
Chun-jie Li
Keyword(s):  
Growth Rate ◽  
Microcystis Aeruginosa ◽  
Inverse Correlation ◽  
Carbohydrate Content

scholarly journals TOR and RAS pathways regulate desiccation tolerance inSaccharomyces cerevisiae

2013 ◽  
Vol 24 (2) ◽  
pp. 115-128 ◽  
Author(s):  
Aaron Z. Welch ◽  
Patrick A. Gibney ◽  
David Botstein ◽  
Douglas E. Koshland
Keyword(s):  
Growth Rate ◽  
Stress Response ◽  
Heat Shock ◽  
Desiccation Tolerance ◽  
Ribosome Biogenesis ◽  
Inverse Correlation ◽  
Fold Increase ◽  
Nutrient Deprivation ◽  
Camp Pathway ◽  
Dividing Cells

Tolerance to desiccation in cultures of Saccharomyces cerevisiae is inducible; only one in a million cells from an exponential culture survive desiccation compared with one in five cells in stationary phase. Here we exploit the desiccation sensitivity of exponentially dividing cells to understand the stresses imposed by desiccation and their stress response pathways. We found that induction of desiccation tolerance is cell autonomous and that there is an inverse correlation between desiccation tolerance and growth rate in glucose-, ammonia-, or phosphate-limited continuous cultures. A transient heat shock induces a 5000–fold increase in desiccation tolerance, whereas hyper-ionic, -reductive, -oxidative, or -osmotic stress induced much less. Furthermore, we provide evidence that the Sch9p-regulated branch of the TOR and Ras-cAMP pathway inhibits desiccation tolerance by inhibiting the stress response transcription factors Gis1p, Msn2p, and Msn4p and by activating Sfp1p, a ribosome biogenesis transcription factor. Among 41 mutants defective in ribosome biogenesis, a subset defective in 60S showed a dramatic increase in desiccation tolerance independent of growth rate. We suggest that reduction of a specific intermediate in 60S biogenesis, resulting from conditions such as heat shock and nutrient deprivation, increases desiccation tolerance.

Microborings and growth in Late Ordovician halysitids and other corals

1993 ◽  
Vol 67 (6) ◽  
pp. 922-934 ◽  
Author(s):  
Robert J. Elias ◽  
Dong-Jin Lee
Keyword(s):  
Growth Rate ◽  
Linear Growth ◽  
Inverse Correlation ◽  
Weight Percent ◽  
Late Ordovician ◽  
Coral Growth ◽  
Linear Growth Rate ◽  
Skeletal Density ◽  
Rugose Coral ◽  
Endolithic Algae

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.

Prospects for Cooperation Between Russia and Syria in Various Scenarios of Military Conflict Development

2021 ◽  
pp. 50-55
Author(s):  
Alheder Haled
Keyword(s):  
Growth Rate ◽  
Inverse Correlation ◽  
Foreign Economic Policy ◽  
Military Conflict ◽  
Political Situation ◽  
Gdp Growth Rate ◽  
Initial Stage ◽  
Military Conflicts ◽  
The Military ◽  
The Relationship

The paper is devoted to determining the prospects for cooperation between Russia and the Syrian Arab Republic in various scenarios of military conflicts. In order to identify the relationship between the success of the country's foreign economic policy and the military conflicts waged on its territory, a study was conducted of such indicators of Syria as: the growth rate of the peace index and the GDP growth rate. A strong inverse correlation is revealed, which means that the level of political situation and peace in the state determines the efficiency of the economy. In view of this, various scenarios of the development of the military conflict in Syria have been studied: at the initial stage, at the stage of active hostilities, at the present stage of overcoming the crisis. The last stage involves four different scenarios for the development of a military conflict, including a local nature and a protracted nature with the involvement of other countries of the world. Options for developing cooperation between Russia and Syria have been identified for each scenario. Taking into account the assessment of the international political situation, the two most likely scenarios for further military events in Syria are identified, and the prospects for cooperation between Russia and Syria in these conditions are outlined.

Inhibitory effects of golden thread (Coptis chinensis) and berberine on Microcystis aeruginosa

2010 ◽  
Vol 61 (3) ◽  
pp. 763-769 ◽  
Author(s):  
Shulin Zhang ◽  
Bo Zhang ◽  
Kezhi Xing ◽  
Xiumei Zhang ◽  
Xiuping Tian ◽  
...  
Keyword(s):  
Protein Content ◽  
Chlorophyll A ◽  
Cell Density ◽  
Microcystis Aeruginosa ◽  
Carbohydrate Content ◽  
Chinese Herbs ◽  
Inhibitory Effects ◽  
Coptis Chinensis ◽  
Golden Thread ◽  
Chlorophyll A Content

The effects of 40 Chinese herbs on Microcystis aeruginosa growth were monitored spectrophotometrically. Golden thread (Coptis chinensis) exhibited the best inhibitory effects. Cell density of M. aeruginosa decreased with the increasing concentrations of golden thread and the prolongation of exposure time. Decreases in protein content, carbohydrate content, and chlorophyll a content were observed in a golden thread concentration-dependent manner after 96 h exposure. Changes in cell density, protein content, carbohydrate content, and chlorophyll a content of M. aeruginosa exposed to berberine, the main component of golden thread, were also investigated. It was observed that berberine exhibited the same inhibitory effects on M. aeruginosa. The results suggested that golden thread could inhibit M. aeruginosas growth effectively, and berberine might be the main allelochemical implementing the inhibitory effects of golden thread.

Miniaturized culture method for the statistical study of growth rate and carbohydrate content of Picochlorum sp. D8 isolated from the Persian Gulf

2020 ◽  
Vol 149 ◽  
pp. 479-488 ◽  
Author(s):  
Mahroo Seyed Jafari Olia ◽  
Mehrdad Azin ◽  
Abbas Akhavan Sepahi ◽  
Nasrin Moazami
Keyword(s):  
Growth Rate ◽  
Persian Gulf ◽  
Statistical Study ◽  
Culture Method ◽  
Carbohydrate Content ◽  
The Persian Gulf

scholarly journals Experimental Study of the Quantitative Impact of Flow Turbulence on Algal Growth

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 659
Author(s):  
Haiping Zhang ◽  
Yafei Cui ◽  
Yuehong Zhang ◽  
Hanling Xu ◽  
Feipeng Li
Keyword(s):  
Growth Rate ◽  
Oxygen Evolution ◽  
Microcystis Aeruginosa ◽  
Algal Growth ◽  
Turbulent Intensity ◽  
Photosynthetic Oxygen Evolution ◽  
Photosynthetic Oxygen ◽  
Flow Turbulence ◽  
Study Laboratory ◽  
Algal Growth Rate

Flow turbulence has been widely accepted as one of the essential factors affecting phytoplankton growth. In this study, laboratory cultures of Microcystis aeruginosa in beakers were carried out under different turbulent conditions to identify the quantitative relationship between the algal growth rate and the turbulent intensity. The turbulent intensity (represented by energy dissipation rate, ε) was simulated with the software FLUENT. Daily measurement of the two parameters (algal biomass and chlorophyll-a concentration) was carried out during the experimental period to represent the algal growth rate. Meanwhile, the rates of photosynthetic oxygen evolution and chlorophyll fluorescence intensity were calculated to investigate the photosynthetic efficiency. The results indicated that the growth rate of Microcystis aeruginosa became higher in the turbulent environment than in the still water environment under the designed experimental conditions. The peak growth rate of Microcystis aeruginosa occurred when ε was 6.44 × 10−2 m2/s3, over which the rate declined, probably due to unfavorable impacts of strong turbulence. In comparison, the maximum rate of photosynthetic oxygen evolution occurred when ε was 0.19 m2/s3. Based on the findings of this study, an exponential function was proposed in order to incorporate the effect of flow turbulence into the existing algal growth models, which usually just consider the impacts of nutrient availability, illumination, and temperature.

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