scholarly journals Scaling of growth rate and mortality with size and its consequence on size spectra of natural microphytoplankton assemblages in the East China Sea

2012 ◽  
Vol 9 (11) ◽  
pp. 16589-16623
Author(s):  
F. H. Chang ◽  
E. C. Marquis ◽  
C. W. Chang ◽  
G. C. Gong ◽  
C. H. Hsieh
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Specific Growth Rate ◽  
East China Sea ◽  
Growth Rates ◽  
Specific Growth ◽  
Size Structure ◽  
The East China Sea ◽  
Grazing Mortality ◽  
Specific Growth Rates

Abstract. Allometric scaling of body size versus growth rate and mortality has been suggested to be a universal macroecological pattern, as described by the Metabolic Theory of Ecology (MTE). However, whether such scaling generally holds in natural assemblages remains debated. Here, we test the hypothesis that the size-specific growth rate and grazing mortality scales with the body size with an exponent of −1/4 after temperature correction, as MTE predicts. To do so, we couple the dilution experiment with the FlowCAM imaging system to obtain size-specific growth rates and grazing mortality of natural microphytoplankton assemblages in the East China Sea. This novel approach allows us to achieve highly resolved size-specific measurements that could be hardly obtained in traditional size-fractionated measurements using filters. Our results do not support the MTE prediction. The size-specific growth rates scale positively with body size (with scaling exponent ~ 0.1), and the size-specific grazing mortality is independent of body size. Furthermore, results of path analysis indicate that size-specific grazing mortality is mainly determined by size-specific growth rate. We further investigate how the variation of size-specific growth rate and grazing mortality can interact to determine the microphytoplankton size structure, described by Normalized Biomass Size Spectrum (NB-SS). We test if the variation of microphytoplankton NB-SS slopes is determined by (1) differential grazing mortality of small versus large individuals, (2) differential growth rate of small versus large individuals, or (3) combinations of these scenarios. Our results indicate that the relative grazing mortality of small over large size category best explains the variation of NB-SS slopes across environments. These results suggest that higher grazing mortality of small microphytoplankton may release the large phytoplankton from grazing, which in turn leads to a flatter NB-SS slope. This study contributes to an understanding of the relative importance of bottom-up versus top-down control in shaping the microphytoplankton size structure.

scholarly journals Scaling of growth rate and mortality with size and its consequence on size spectra of natural microphytoplankton assemblages in the East China Sea

2013 ◽  
Vol 10 (8) ◽  
pp. 5267-5280 ◽  
Author(s):  
F. H. Chang ◽  
E. C. Marquis ◽  
C. W. Chang ◽  
G. C. Gong ◽  
C. H. Hsieh
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Rates ◽  
Specific Growth ◽  
Size Structure ◽  
Scaling Exponent ◽  
The East China Sea ◽  
Size Category ◽  
Grazing Mortality ◽  
Specific Growth Rates

Abstract. Allometric scaling of body size versus growth rate and mortality has been suggested to be a universal macroecological pattern, as described by the metabolic theory of ecology (MTE). However, whether such scaling generally holds in natural assemblages remains debated. Here, we test the hypothesis that the size-specific growth rate and grazing mortality scale with the body size with an exponent of −1/4 after temperature correction, as MTE predicts. To do so, we couple a dilution experiment with the FlowCAM imaging system to obtain size-specific growth rates and grazing mortality of natural microphytoplankton assemblages in the East China Sea. This novel approach allows us to achieve highly resolved size-specific measurements that would be very difficult to obtain in traditional size-fractionated measurements using filters. Our results do not support the MTE prediction. On average, the size-specific growth rates and grazing mortality scale almost isometrically with body size (with scaling exponent ∼0.1). However, this finding contains high uncertainty, as the size-scaling exponent varies substantially among assemblages. The fact that size-scaling exponent varies among assemblages prompts us to further investigate how the variation of size-specific growth rate and grazing mortality can interact to determine the microphytoplankton size structure, described by normalized biomass size spectrum (NBSS), among assemblages. We test whether the variation of microphytoplankton NBSS slopes is determined by (1) differential grazing mortality of small versus large individuals, (2) differential growth rate of small versus large individuals, or (3) combinations of these scenarios. Our results indicate that the ratio of the grazing mortality of the large size category to that of the small size category best explains the variation of NBSS slopes across environments, suggesting that higher grazing mortality of large microphytoplankton may release the small phytoplankton from grazing, which in turn leads to a steeper NBSS slope. This study contributes to understanding the relative importance of bottom-up versus top-down control in shaping microphytoplankton size structure.

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 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

2012 ◽  
Vol 9 (11) ◽  
pp. 16303-16346
Author(s):  
K. Y. Lin ◽  
A. 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 prediction needs further investigation.

scholarly journals Effect of Specific Growth Rate on Fermentative Capacity of Baker’s Yeast

1998 ◽  
Vol 64 (11) ◽  
pp. 4226-4233 ◽  
Author(s):  
Pim Van Hoek ◽  
Johannes P. Van Dijken ◽  
Jack T. Pronk
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Ethanol Production ◽  
Growth Rates ◽  
Specific Growth ◽  
Pyruvate Decarboxylase ◽  
Baker's Yeast ◽  
Fermentative Capacity ◽  
Yeast Biomass ◽  
Specific Growth Rates

ABSTRACT The specific growth rate is a key control parameter in the industrial production of baker’s yeast. Nevertheless, quantitative data describing its effect on fermentative capacity are not available from the literature. In this study, the effect of the specific growth rate on the physiology and fermentative capacity of an industrialSaccharomyces cerevisiae strain in aerobic, glucose-limited chemostat cultures was investigated. At specific growth rates (dilution rates, D) below 0.28 h−1, glucose metabolism was fully respiratory. Above this dilution rate, respirofermentative metabolism set in, with ethanol production rates of up to 14 mmol of ethanol · g of biomass−1 · h−1at D = 0.40 h−1. A substantial fermentative capacity (assayed offline as ethanol production rate under anaerobic conditions) was found in cultures in which no ethanol was detectable (D < 0.28 h−1). This fermentative capacity increased with increasing dilution rates, from 10.0 mmol of ethanol · g of dry yeast biomass−1 · h−1 at D= 0.025 h−1 to 20.5 mmol of ethanol · g of dry yeast biomass−1 · h−1 atD = 0.28 h−1. At even higher dilution rates, the fermentative capacity showed only a small further increase, up to 22.0 mmol of ethanol · g of dry yeast biomass−1 · h−1 at D= 0.40 h−1. The activities of all glycolytic enzymes, pyruvate decarboxylase, and alcohol dehydrogenase were determined in cell extracts. Only the in vitro activities of pyruvate decarboxylase and phosphofructokinase showed a clear positive correlation with fermentative capacity. These enzymes are interesting targets for overexpression in attempts to improve the fermentative capacity of aerobic cultures grown at low specific growth rates.

The effect of specific growth rate on protein synthesis and secretion in the filamentous fungus Trichoderma reesei

Microbiology ◽  
2005 ◽  
Vol 151 (1) ◽  
pp. 135-143 ◽  
Author(s):  
Tiina M. Pakula ◽  
Katri Salonen ◽  
Jaana Uusitalo ◽  
Merja Penttilä
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Specific Growth Rate ◽  
Trichoderma Reesei ◽  
Growth Rates ◽  
Protein Production ◽  
Specific Growth ◽  
Synthesis Rate ◽  
Specific Rate ◽  
Specific Growth Rates

Trichoderma reesei was cultivated in chemostat cultures on lactose-containing medium. The cultures were characterized for growth, consumption of the carbon source and protein production. Secreted proteins were produced most efficiently at low specific growth rates, 0·022–0·033 h−1, the highest specific rate of total protein production being 4·1 mg g−1 h−1 at the specific growth rate 0·031 h−1. At low specific growth rates, up to 29 % of the proteins produced were extracellular, in comparison to only 6–8 % at high specific growth rates, 0·045–0·066 h−1. To analyse protein synthesis and secretion in more detail, metabolic labelling of proteins was applied to analyse production of the major secreted protein, cellobiohydrolase I (CBHI, Cel7A). Intracellular and extracellular labelled CBHI was quantified and analysed for pI isoforms in two-dimensional gels, and the synthesis and secretion rates of the molecule were determined. Both the specific rates of CBHI synthesis and secretion were highest at low specific growth rates, the optimum being at 0·031 h−1. However, at low specific growth rates the secretion rate/synthesis rate ratio was significantly lower than that at high specific growth rates, indicating that at low growth rates the capacity of cells to transport the protein becomes limiting. In accordance with the high level of protein production and limitation in the secretory capacity, the transcript levels of the unfolded protein response (UPR) target genes pdi1 and bip1 as well as the gene encoding the UPR transcription factor hac1 were induced.

Examining the influence of substrates and temperature on maximum specific growth rate of denitrifiers

2006 ◽  
Vol 54 (8) ◽  
pp. 155-162 ◽  
Author(s):  
Y. Mokhayeri ◽  
A. Nichols ◽  
S. Murthy ◽  
R. Riffat ◽  
P. Dold ◽  
...  
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
Treatment Plant ◽  
Capacity Utilization ◽  
Maximum Specific Growth Rate ◽  
Corn Syrup ◽  
Plant Uses ◽  
Specific Growth Rates

Facilities across North America are designing plants to meet stringent limits of technology (LOT) treatment for nitrogen removal (3–5 mg/L total effluent nitrogen). The anoxic capacity requirements for meeting LOT treatment are dependent on the growth rates of the denitrifying organisms. The Blue Plains Advanced Wastewater Treatment Plant (AWTP) is one of many facilities in the Chesapeake Bay region that is evaluating its ability to meet LOT treatment capability. The plant uses methanol as an external carbon source in a post-denitrification process. The process is very sensitive to denitrification in the winter. One approach to improve anoxic capacity utilization is to use an alternative substrate for denitrification in the winter to promote the growth of organisms that denitrify at higher rates. The aim of this study was to evaluate denitrification maximum specific growth rates for three substrates, acetate, corn syrup and methanol, at two temperatures (13 °C and 19 °C). These temperatures approximately reflect the minimum monthly and average annual wastewater temperature at the Blue Plains AWTP. The results suggest that the maximum specific growth rate (μmax) for corn syrup (1.3 d−1) and acetate (1.2 d−1) are higher than that for methanol (0.5 d−1) at low temperature of 13 °C. A similar trend was observed at 19 °C.

The Growth of Brown trout (Salmo Trutta Linn.)

1946 ◽  
Vol 22 (3-4) ◽  
pp. 118-129
Author(s):  
MARGARET E. BROWN
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Specific Rate ◽  
Size Hierarchy ◽  
Living Space ◽  
Brown Trout Salmo Trutta ◽  
Specific Growth Rates

1. Groups of trout fry of the same parentage were grown in environments where the following factors were controlled: temperature, amount and intensity of illumination, rate of water flow, aeration and chemical composition of the water, amount of living space and quality of food supply. They were allowed to eat as much as they would, and individual weights were recorded during the first 8 months after the beginning of feeding. 2. There was soon an increase in the range of individual weight in each group of fry, and thereafter the larger fry grew faster than smaller ones. When the larger fry were removed, the smaller ones grew at an increased specific rate, and when larger fry were added, the smaller ones grew more slowly. It is suggested that a ‘size hierarchy’ was established within each group, and an individual's specific growth rate depended on its position in the order of decreasing weight. 3. There was an optimum degree of crowding for maximum productivity. Compared with the fry in this group, the specific growth rates of individuals in larger, more crowded groups depended on the number of fish of larger size, while in smaller, less crowded groups, individuals grew at rates depending on the proportion of fish which were larger and smaller. 4. Alevin weight had little effect on the specific growth rates of fry. 5. There were differences between the growth histories of fry derived from alevins of the same weight and descended from the same father but different mothers (all of the same stock, age and size). 6. The specific growth rates decreased as the fry grew older, but there was no correlation between body weight and specific growth rate, except for the size hierarchy effect within each group. This effect had a greater influence on the size of individual fry than had either alevin weight or heredity.

scholarly journals Novel Strategy for the Calorimetry-Based Control of Fed-Batch Cultivations of Saccharomyces cerevisiae

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 723
Author(s):  
Jérémy Kottelat ◽  
Brian Freeland ◽  
Michal Dabros
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
Fed Batch ◽  
Estimation And Control ◽  
Novel Strategy ◽  
Specific Growth Rates ◽  
Mean Square Errors

Typical controllers for fed-batch cultivations are based on the estimation and control of the specific growth rate in real time. Biocalorimetry allows one to measure a heat signal proportional to the substrate consumed by cells. The derivative of this heat signal is usually used to evaluate the specific growth rate, introducing noise to the resulting estimate. To avoid this, this study investigated a novel controller based directly on the heat signal. Time trajectories of the heat signal setpoint were modelled for different specific growth rates, and the controller was set to follow this dynamic setpoint. The developed controller successfully followed the setpoint during aerobic cultivations of Saccharomyces cerevisiae, preventing the Crabtree effect by maintaining low glucose concentrations. With this new method, fed-batch cultivations of S. cerevisiae could be reliably controlled at specific growth rates between 0.075 h−1 and 0.20 h−1, with average root mean square errors of 15 ± 3%.

scholarly journals Growth rate of Eucheuma denticulatum cultivated in horizontal net and vertical net

2021 ◽  
Vol 925 (1) ◽  
pp. 012018
Author(s):  
Munawan ◽  
M Kasim ◽  
Ruslaini
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
T Test ◽  
Raw Material ◽  
Initial Weight ◽  
Eucheuma Denticulatum ◽  
Specific Growth Rates

Abstract Eucheuma denticulatum is one of the most widely cultivated macroalga commodities. This commodity produces carrageenan iota as raw material for various industries. This study aims to compare the growth rate of E. denticulatum cultivated by the horizontal net (Horinet) and vertical net (Vertinet) methods. This research was conducted in September-December 2019 and located in Lakeba waters, Bau-Bau City, Southeast Sulawesi, Indonesia. The results showed that the specific growth rate of E. denticulatum seaweed cultivated with Horinet and Vertinet was significantly different. The growth of the thallus at an initial weight of 20 g developed to 67 g and 112.5 g as viewed with a horinet and vertnet, respectively. The specific growth rates of these two methods were 5.01 and 6.59%/day using vertinet and horinet, respectively. Based on the results of the t-test showed that the use of the two methods were significantly different by 0.46 and 0.36 (P<0.05) on the specific growth rate of E. denticulatum seaweed. Both of these methods can be used to cultivate seaweed with good results. However, these two methods have differences in the growth results obtained.

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