scholarly journals Phospholipid turnover rates suggest that bacterial community growth rates in the open ocean are systematically underestimated

2020 ◽  
Vol 65 (8) ◽  
pp. 1876-1890
Author(s):  
Kimberly J. Popendorf ◽  
Michal Koblížek ◽  
Benjamin A. S. Van Mooy
Keyword(s):  
Bacterial Community ◽  
Growth Rates ◽  
Open Ocean ◽  
Turnover Rates ◽  
Phospholipid Turnover ◽  
Community Growth

scholarly journals Effect of Oxytetracycline and Chlortetracycline on Bacterial Community Growth in Agricultural Soils

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1011 ◽  
Author(s):  
Vanesa Santás-Miguel ◽  
Manuel Arias-Estévez ◽  
Montserrat Díaz-Raviña ◽  
María José Fernández-Sanjurjo ◽  
Esperanza Álvarez-Rodríguez ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Bacterial Community ◽  
Total Organic Carbon ◽  
Agricultural Soils ◽  
Exchange Capacity ◽  
Soil Parameters ◽  
Leucine Incorporation ◽  
Negative Effects ◽  
Input Variables ◽  
Community Growth

Toxicity on soil bacterial community growth caused by the antibiotics oxytetracycline (OTC) and chlortetracycline (CTC) was studied in 22 agricultural soils after 1, 8 and 42 incubation days. The leucine incorporation method was used with this aim, estimating the concentration of each antibiotic which caused an inhibition of 50% in bacterial community growth (log IC50). For OTC, the mean log IC50 was 2.70, 2.81, 2.84 for each of the three incubation times, while the values were 2.05, 2.22 and 2.47 for CTC, meaning that the magnitude of OTC toxicity was similar over time, whereas it decreased significantly for CTC with incubation time. In addition, results showed that the toxicity on bacterial community growth due to CTC is significantly higher than when due to OTC. Moreover, the toxicity on bacterial community growth due to both antibiotics is dependent on soil properties. Specifically, an increase in soil pH and silt content resulted in higher toxicity of both antibiotics, while increases in total organic carbon and clay contents caused decreases in OTC and CTC toxicities. The results also show that OTC toxicity can be well predicted by means of specific equations, using the values of pH measured in KCl and those of effective cation exchange capacity as input variables. CTC toxicity may be predicted (but with low precision) using pH measured in KCl and total organic carbon. These equations may help to predict the negative effects caused by OTC and CTC on soil bacteria using easily measurable soil parameters.

The Effects of Local Government Finances on Community Growth Rates

1982 ◽  
Vol 18 (1) ◽  
pp. 91-105 ◽  
Author(s):  
Mark Schneider ◽  
John R. Logan
Keyword(s):  
Local Government ◽  
Growth Rates ◽  
Community Growth

Effect of protozoan predation on relative abundance of fast- and slow-growing bacteria

1989 ◽  
Vol 35 (5) ◽  
pp. 578-582 ◽  
Author(s):  
James L. Sinclair ◽  
Martin Alexander
Keyword(s):  
Growth Rate ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Growth Rates ◽  
Bacterial Species ◽  
Test Species ◽  
Fast Growing ◽  
Population Sizes ◽  
Slow Growing ◽  
Fast Growing Species

The survival of six bacterial species that had different growth rates was tested in raw sewage and sewage that was rendered free of protozoa. When test bacteria were added to protozoa-free sewage at densities of approximately 105 to 106 cells/mL, five of the six species did not decline below 105 cells/mL. If protozoa were present, the population sizes of all test species were markedly reduced, but bacterial species able to grow faster in artificial media had the larger number of survivors. When the same bacteria were inoculated into protozoa-free sewage at densities of less than 103 cells/mL, only the three species able to grow quickly in artificial media increased in abundance. When the six species were inoculated at the same densities into sewage containing protozoa, the three slow-growing species were rapidly eliminated, and two of the three fast-growing species survived in detectable numbers. We suggest that in environments with intense protozoan predation, protozoa may alter the composition of the bacterial community by eliminating slow-growing bacteria.Key words: growth rate, predation, protozoa, sewage.

Growth Rate Responses of Lotic Periphytic Diatoms to Experimental Phosphorus Enrichment: The Influence of Temperature and Light

1988 ◽  
Vol 45 (2) ◽  
pp. 261-270 ◽  
Author(s):  
Max L. Bothwell
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Phosphorus Enrichment ◽  
Enrichment Experiments ◽  
Community Growth ◽  
Specific Growth Rates ◽  
The Relationship ◽  
River Water Temperature

Phosphate enrichment experiments were conducted year-round at the experimental troughs research apparatus (EXTRA) on the South Thompson River in British Columbia to determine the relationship between external concentration of orthophosphate and the growth rates of lotic periphytic diatom communities. Growth rate saturation always occurred at a phosphate concentration of approximately 0.3–0.6 μg P∙L−1. The maximum growth rate (μmax-P) with phosphorus enrichment varied seasonally with temperature. The relative specific growth rates (μ:μmax-P) as a function of external phosphate were constant. Seasonal changes in solar insolation (PAR) had no effect on the autotrophic community growth rates in unamended river water. Temperature exerted the most dominant influence on phosphorus-replete growth rates.

Growth rates of cobia (Rachycentron canadum) cultured in open ocean submerged cages in the Caribbean

Aquaculture ◽  
2010 ◽  
Vol 302 (3-4) ◽  
pp. 195-201 ◽  
Author(s):  
Daniel D. Benetti ◽  
Brian O'Hanlon ◽  
José A. Rivera ◽  
Aaron W. Welch ◽  
Christopher Maxey ◽  
...  
Keyword(s):  
Growth Rates ◽  
Open Ocean ◽  
Rachycentron Canadum ◽  
The Caribbean

scholarly journals Copepod community growth rates in relation to body size, temperature, and food availability in the East China Sea: a test of metabolic theory of ecology

2013 ◽  
Vol 10 (3) ◽  
pp. 1877-1892 ◽  
Author(s):  
K. Y. Lin ◽  
A. R. Sastri ◽  
G. C. Gong ◽  
C. H. Hsieh
Keyword(s):  
Body Size ◽  
East China Sea ◽  
Food Availability ◽  
Growth Rates ◽  
Specific Growth ◽  
Metabolic Theory ◽  
The East China Sea ◽  
Copepod Community ◽  
Community Growth ◽  
Specific Growth Rates

Abstract. Zooplankton play an essential role in marine food webs, and understanding how community-level growth rates of zooplankton vary in the field is critical for predicting how marine ecosystem function may vary in the face of environmental changes. Here, we used the artificial cohort method to examine the effects of temperature, body size, and chlorophyll concentration (a proxy for food) on weight-specific growth rates for copepod communities in the East China Sea. Specifically, we tested the hypothesis that copepod community growth rates can be described by the metabolic theory of ecology (MTE), linking spatio-temporal variation of copepod growth rate with temperature and their body size. Our results generally agree with predictions made by the MTE and demonstrate that weight-specific growth rates of copepod communities in our study area are positively related with temperature and negatively related to body size. However, the regression coefficients of body size do not approach the theoretical predictions. Furthermore, we find that the deviation from the MTE predictions may be partly attributed to the effect of food availability (which is not explicitly accounted for by the MTE). In addition, significant difference in the coefficients of temperature and body size exists among taxonomic groups. Our results suggest that considering the effects of food limitation and taxonomy is necessary to better understand copepod growth rates under in situ conditions, and such effects on the MTE-based predictions need further investigation.

scholarly journals Poor correlation between phytoplankton community growth rates and nutrient concentration in the sea

2015 ◽  
Vol 12 (6) ◽  
pp. 1915-1923 ◽  
Author(s):  
A. Regaudie-de-Gioux ◽  
S. Sal ◽  
Á. López-Urrutia
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Nutrient Concentration ◽  
Phytoplankton Community ◽  
Size Structure ◽  
Poor Correlation ◽  
Phytoplankton Species ◽  
Monod Equation ◽  
Biogeochemical Models ◽  
Community Growth

Abstract. Nutrient availability is one of the major factors regulating marine productivity and phytoplankton community structure. While the response of phytoplankton species to nutrient variation is relatively well known, that of phytoplankton community remains unclear. We question whether phytoplankton community growth rates respond to nutrient concentration in a similar manner to phytoplankton species composing the community, that is, following Monod's model. Data on in situ marine community growth rates in relation to nutrient concentration and the behaviour of a simple multi-species community model suggest that community growth rate does not respond to nutrient concentration according to the Monod equation. Through a simulation study we show this can be explained as a consequence of changes in size structure. Marine biogeochemical models must not parameterize phytoplankton community growth rate response to nutrient concentration using a single Monod equation but rather involve different phytoplankton functional groups each with different equation parameters.

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