Endoplasmic Reticulum-Associated rht-PA Processing in CHO Cells: Influence of Mild Hypothermia and Specific Growth Rates in Batch and Chemostat Cultures

When deprived of biotin, Arthrobacter globiformis 425 exhibits abnormal morphology (large, branched forms of variable size) and a retardation of its normal growth rate. In chemostat cultures, when cells were grown under glucose limitation, the morphology was normal (coccoids or rods) at specific growth rates between 0.05 and 0.125 h−1 (doubling times between 14 and 5.5 h, respectively) at 25 °C. The coccoid-to-rod morphogenesis occurs at a specific growth rate of 0.11 h−1. At the same specific growth rates and temperature, but under biotin limitation, abnormal morphology was observed.

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Pichia pastoris Exhibits High Viability and a Low Maintenance Energy Requirement at Near-Zero Specific Growth Rates

Applied and Environmental Microbiology ◽

10.1128/aem.00638-16 ◽

2016 ◽

Vol 82 (15) ◽

pp. 4570-4583 ◽

Cited By ~ 28

Author(s):

Corinna Rebnegger ◽

Tim Vos ◽

Alexandra B. Graf ◽

Minoska Valli ◽

Jack T. Pronk ◽

...

Keyword(s):

Pichia Pastoris ◽

Growth Rates ◽

Specific Growth ◽

Energy Requirement ◽

Maintenance Energy ◽

Content Type ◽

Chemostat Cultures ◽

Zero Growth ◽

Maintenance Energy Requirement ◽

Specific Growth Rates

ABSTRACTThe yeastPichia pastorisis a widely used host for recombinant protein production. Understanding its physiology at extremely low growth rates is a first step in the direction of decoupling product formation from cellular growth and therefore of biotechnological relevance. Retentostat cultivation is an excellent tool for studying microbes at extremely low specific growth rates but has so far not been implemented forP. pastoris. Retentostat feeding regimes were based on the maintenance energy requirement (mS) and maximum biomass yield on glucose (YX/Smax) estimated from steady-state glucose-limited chemostat cultures. Aerobic retentostat cultivation enabled reproducible, smooth transitions from a specific growth rate (μ) of 0.025 h−1to near-zero specific growth rates (μ < 0.001 h−1). At these near-zero specific growth rates, viability remained at least 97%. The value ofmSat near-zero growth rates was 3.1 ± 0.1 mg glucose per g biomass and h, which was 3-fold lower than themSestimated from faster-growing chemostat cultures. This difference indicated thatP. pastorisreduces its maintenance energy requirement at extremely low μ, a phenomenon not previously observed in eukaryotes. Intracellular levels of glycogen and trehalose increased, while μ progressively declined during retentostat cultivation. Transcriptional reprogramming toward zero growth included the upregulation of many transcription factors as well as stress-related genes and the downregulation of cell cycle genes. This study underlines the relevance of comparative analysis of maintenance energy metabolism, which has an important impact on large-scale industrial processes.IMPORTANCEThe yeastPichia pastorisnaturally lives on trees and can utilize different carbon sources, among them glucose, glycerol, and methanol. In biotechnology, it is widely used for the production of recombinant proteins. For both the understanding of life in its natural habitat and optimized production processes, a better understanding of cell physiology at an extremely low growth rate would be of extraordinary value. Therefore, we have grownP. pastorisin a retentostat, which allows the cultivation of metabolically active cells even at zero growth. Here we reached doubling times as long as 38 days and found thatP. pastorisdecreases its maintenance energy demand 3-fold during very slow growth, which enables it to survive with a much lower substrate supply than baker's yeast.

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Heat Production and Growth Kinetics of E. coli K12 from Flow Calorimetric Measurements on Chemostat Cultures

Zeitschrift für Naturforschung C ◽

10.1515/znc-1989-11-1226 ◽

1989 ◽

Vol 44 (11-12) ◽

pp. 1036-1048 ◽

Cited By ~ 1

Author(s):

H. P. Leiseifer

Keyword(s):

Heat Production ◽

Growth Rates ◽

Specific Growth ◽

Batch Cultures ◽

E Coli ◽

Chemostat Cultures ◽

Basic Parameters ◽

Specific Growth Rates ◽

The Relationship ◽

Kinetics Of

The heat production of E. coli K12 growing aerobically in glucose limited chemostat cultures is determined in the range of specific growth rates μ ( = dilution rates D) from 0,058 h-1 to 0.852 h-1 for two different glucose concentrations Se in the instream of the chemostat. namely Se1=0.3182 g·1-1 and Se2 = 0.6364 g·1-1. Heat production Q and biomass production P per unit of culture volume show well correlated patterns for Se1 and Se2. For Se1 the highest value Q actually measured is 443-10-3 W·1-1 at D = 0.74 h-1 with P = 0.068 g·1-1·h-1 and for Se2 593·10-3 W·1-1 at D = 0.497 h-1 with P = 0.108 g·1-1·h-1. Heat production QB per unit of biomass appears to be independent of Se at least up to D - 0.5 h-1.At higher D there is strong indication that QB possesses a real maximum. The highest value of QB actually measured is 4.8 W·g-1 at D = 0.74 h-1. For Se1 and Se2 there were significantly higher specific growth rates verified in chemostat culture than μmaxBatch= 0.717 h-1 which is the maximum specific growth rate in comparable, unlimited batch cultures. The real maximum of QB is estimated to be in the vicinity of μmaxBatch. This suggests the hypothesis of a maximum principle for the growth in batch culture. For Se1 a closed analytical expression is derived for the relationship between μ and the substrate concentration S. μ[S] features a S-shaped characteristic with μmaxChemostat= 0.905 h-1; 1/2 μmaxChemostat is reached at S = 2.85·10-3 g·1-1. Three basic parameters which characterize the overall metabolism of the cells, namely the heat released per unit of substrate consumed, (Qs, the effective yield of biomass, Yeff, and μmaxChemostat are identified to depend on Se.

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Effects of turbidity on prey consumption and growth in brook trout and implications for bioenergetics modeling

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-260 ◽

2001 ◽

Vol 58 (2) ◽

pp. 386-393 ◽

Cited By ~ 38

Author(s):

John A Sweka ◽

Kyle J Hartman

Keyword(s):

Growth Rates ◽

Brook Trout ◽

Specific Growth ◽

Abiotic Factors ◽

Foraging Strategies ◽

Turbid Water ◽

Daily Consumption ◽

Consumption Rates ◽

The Difference ◽

Specific Growth Rates

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.

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Sex Ratio and Sex-Specific Growth Rates of Immature Green Turtles, Chelonia mydas, in the Southern Bahamas

Copeia ◽

10.2307/1446647 ◽

1992 ◽

Vol 1992 (4) ◽

pp. 1098 ◽

Cited By ~ 17

Author(s):

Alan B. Bolten ◽

Karen A. Bjorndal ◽

Janice S. Grumbles ◽

David W. Owens

Keyword(s):

Sex Ratio ◽

Growth Rates ◽

Specific Growth ◽

Chelonia Mydas ◽

Green Turtles ◽

Specific Growth Rates

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Physiological and cell morphology adaptation ofBacillus subtilisat near-zero specific growth rates: a transcriptome analysis

Environmental Microbiology ◽

10.1111/1462-2920.12676 ◽

2014 ◽

Vol 17 (2) ◽

pp. 346-363 ◽

Cited By ~ 20

Author(s):

Wout Overkamp ◽

Onur Ercan ◽

Martijn Herber ◽

Antonius J. A. van Maris ◽

Michiel Kleerebezem ◽

...

Keyword(s):

Cell Morphology ◽

Transcriptome Analysis ◽

Growth Rates ◽

Specific Growth ◽

Specific Growth Rates

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The Labeled Chlorophyll a Technique for Determining Photoautotrophic Carbon Specific Growth Rates and Carbon Biomass

Handbook of Methods in Aquatic Microbial Ecology ◽

10.1201/9780203752746-67 ◽

2018 ◽

pp. 563-572

Author(s):

Donald G. Redalje

Keyword(s):

Chlorophyll A ◽

Growth Rates ◽

Specific Growth ◽

Carbon Biomass ◽

Specific Growth Rates

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Investigation of the Biological Treatability of Pistachio Processing Industry Wastewaters in a Batch-operated Aerobic Bioreactor

10.21203/rs.3.rs-448821/v1 ◽

2021 ◽

Author(s):

Sevtap Tırınk ◽

Alper Nuhoğlu ◽

Sinan Kul

Keyword(s):

Kinetic Parameters ◽

Growth Rates ◽

Specific Growth ◽

Batch Reactor ◽

The Other ◽

Batch Experiments ◽

Processing Industry ◽

Specific Growth Rates ◽

Biological Treatability ◽

Best Fit

Abstract This study encompasses investigation of treatment of pistachio processing industry wastewaters in a batch reactor under aerobic conditions, calculation of kinetic parameters and comparison of different inhibition models. The mixed microorganism culture used in the study was adapted to pistachio processing industry wastewaters for nearly one month and then concentrations from 50-1000 mg L− 1 of pistachio processing industry wastewaters were added to the medium and treatment was investigated in batch experiments. The Andrews, Han-Levenspiel, Luong and Aiba biokinetic equations were chosen for the correlations between the concentration of pistachio processing industry wastewaters and specific growth rates, and the kinetic parameters in these biokinetic equations were calculated. The µmax, Ks and Ki parameters, included in the Aiba biokinetic equation providing best fit among the other equations, had values calculated as 0.25 h− 1, 19 mg L− 1, and 516 mg L− 1, respectively.

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Isolated Microbial Single Cells and Resulting Micropopulations Grow Faster in Controlled Environments

Applied and Environmental Microbiology ◽

10.1128/aem.01624-12 ◽

2012 ◽

Vol 78 (19) ◽

pp. 7132-7136 ◽

Cited By ~ 31

Author(s):

Christian Dusny ◽

Frederik Sven Ole Fritzsch ◽

Oliver Frick ◽

Andreas Schmid

Keyword(s):

Pichia Pastoris ◽

Corynebacterium Glutamicum ◽

Growth Rates ◽

Specific Growth ◽

Single Cells ◽

Hansenula Polymorpha ◽

Content Type ◽

Controlled Environments ◽

Specific Growth Rates ◽

Extracellular Environment

ABSTRACTSingularized cells ofPichia pastoris,Hansenula polymorpha, andCorynebacterium glutamicumdisplayed specific growth rates under chemically and physically constant conditions that were consistently higher than those obtained in populations. This highlights the importance of single-cell analyses by uncoupling physiology and the extracellular environment, which is now possible using the Envirostat 2.0 concept.

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

Biogeosciences ◽

10.5194/bg-10-5267-2013 ◽

2013 ◽

Vol 10 (8) ◽

pp. 5267-5280 ◽

Cited By ~ 8

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.

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