scholarly journals Bacterial glycogen provides short-term benefits in changing environments

2019 ◽  
Author(s):  
Karthik Sekar ◽  
Stephanie M. Linker ◽  
Jen Nguyen ◽  
Alix Grünhagen ◽  
Roman Stocker ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Physiological Adaptation ◽  
Short Term ◽  
Changing Environments ◽  
Nutritional Conditions ◽  
Mutant Strains ◽  
Glycogen Utilization ◽  
Lag Times ◽  
Glucose Availability

AbstractChanging nutritional conditions challenge microbes and shape their evolutionary optimization. Here we investigated the role of glycogen in dynamic physiological adaptation of Escherichia coli to fluctuating nutrients following carbon starvation using real-time metabolomics. We found significant metabolic activity remaining after the depletion of environmental glucose that was linked to a rapid utilization of intracellular glycogen. Glycogen was depleted by 80% within minutes of glucose starvation and similarly replenished within minutes of glucose availability. These fast timescales of glycogen utilization correspond to the short-term benefits that glycogen provided to cells undergoing various physiological transitions. Cells capable of utilizing glycogen exhibited shorter lag times than glycogen mutants when starved between different carbon sources. The ability to utilize glycogen was also important for the transition between planktonic and biofilm lifestyles and enabled increased glucose uptake during pulses of limited glucose availability. While wild-type and mutant strains exhibited comparable growth rates in steady environments, mutants deficient in glycogen utilization grew more poorly in environments that fluctuated on minute-scales between carbon availability and starvation. Altogether, these results highlight an underappreciated role of glycogen to rapidly provide carbon and energy in changing environments, thereby increasing survival and competition capabilities in fluctuating and nutrient poor conditions.

scholarly journals Bacterial Glycogen Provides Short-Term Benefits in Changing Environments

2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Karthik Sekar ◽  
Stephanie M. Linker ◽  
Jen Nguyen ◽  
Alix Grünhagen ◽  
Roman Stocker ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Glucose Starvation ◽  
Wild Type ◽  
Short Term ◽  
Changing Environments ◽  
Mutant Strains ◽  
Glycogen Utilization ◽  
Lag Times ◽  
Glucose Availability

ABSTRACT Changing nutritional conditions challenge microbes and shape their evolutionary optimization. Here, we used real-time metabolomics to investigate the role of glycogen in the dynamic physiological adaptation of Escherichia coli to fluctuating nutrients following carbon starvation. After the depletion of environmental glucose, we found significant metabolic activity remaining, which was linked to rapid utilization of intracellular glycogen. Glycogen was depleted by 80% within minutes of glucose starvation and was similarly replenished within minutes of glucose availability. These fast time scales of glycogen utilization correspond to the short-term benefits that glycogen provided to cells undergoing various physiological transitions. Cells capable of utilizing glycogen exhibited shorter lag times than glycogen mutants when starved between periods of exposure to different carbon sources. The ability to utilize glycogen was also important for the transition between planktonic and biofilm lifestyles and enabled increased glucose uptake during pulses of limited glucose availability. While wild-type and mutant strains exhibited comparable growth rates in steady environments, mutants deficient in glycogen utilization grew more poorly in environments that fluctuated on minute scales between carbon availability and starvation. Taken together, these results highlight an underappreciated role of glycogen in rapidly providing carbon and energy in changing environments, thereby increasing survival and competition capabilities under fluctuating and nutrient-poor conditions. IMPORTANCE Nothing is constant in life, and microbes in particular have to adapt to frequent and rapid environmental changes. Here, we used real-time metabolomics and single-cell imaging to demonstrate that the internal storage polymer glycogen plays a crucial role in such dynamic adaptations. Glycogen is depleted within minutes of glucose starvation and similarly is replenished within minutes of glucose availability. Cells capable of utilizing glycogen exhibited shorter lag times than glycogen mutants when starved between periods of exposure to different carbon sources. While wild-type and mutant strains exhibited comparable growth rates in steady environments, mutants deficient in glycogen utilization grew more poorly in environments that fluctuated on minute scales between carbon availability and starvation. These results highlight an underappreciated role of glycogen in rapidly providing carbon and energy in changing environments, thereby increasing survival and competition capabilities under fluctuating and nutrient-poor conditions.

THE ROLE OF PROTON ATPase SPECIFIC INHIBITOR $N,N'$-DICYCLOHEXYLCARBODIIMIDE AND EXTERNAL FORMATE CONCENTRATION ON $E.~COLI$ GROWTH DURING MIXED CARBON SOURCES FERMENTATION AT DIFFERENT pHs.

2021 ◽  
Vol 55 (1 (254)) ◽  
pp. 67-74
Author(s):  
Heghine Kh. Gevorgyan ◽  
Anait V. Vassilian ◽  
Karen A. Trchounian
Keyword(s):  
Regulatory Protein ◽  
Carbon Sources ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
E Coli ◽  
Proton Atpase ◽  
Mutant Strains ◽  
Atpase Inhibition ◽  
Compensatory Effect

This research is focused on the investigation of specific growth rate changes of $E.~coli$ wild type and mutant strains with defect of Hyd, FDH enzymes and FhlA regulatory protein in the presence of $N,N'$-dicyclohexylcarbodiimide (DCCD) and external formate various concentration during co-fermentation of glucose, glycerol and formate at pHs $5.5-7.5.$ The highest value of SGR was observed at pH 7.5. It was revealed that SGR depends on external formate concentration at all pHs. DCCD inhibitory effect was shown mainly at pH 7.5 and partially at pH 6.5 and 5.5. In the case of the F0F1-ATPase inhibition FhlA compensatory effect on SGR was revealed.

scholarly journals Role of Pseudomonas putida tol-oprL Gene Products in Uptake of Solutes through the Cytoplasmic Membrane

2003 ◽  
Vol 185 (16) ◽  
pp. 4707-4716 ◽  
Author(s):  
María A. Llamas ◽  
José J. Rodríguez-Herva ◽  
Robert E. W. Hancock ◽  
Wilbert Bitter ◽  
Jan Tommassen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Pseudomonas Putida ◽  
Outer Membrane ◽  
Cytoplasmic Membrane ◽  
Carbon Sources ◽  
Membrane Integrity ◽  
Mutant Strains ◽  
Transport Defect ◽  
Membrane Growth

ABSTRACT Proteins of the Tol-Pal (Tol-OprL) system play a key role in the maintenance of outer membrane integrity and cell morphology in gram-negative bacteria. Here we describe an additional role for this system in the transport of various carbon sources across the cytoplasmic membrane. Growth of Pseudomonas putida tol-oprL mutant strains in minimal medium with glycerol, fructose, or arginine was impaired, and the growth rate with succinate, proline, or sucrose as the carbon source was lower than the growth rate of the parental strain. Assays with radiolabeled substrates revealed that the rates of uptake of these compounds by mutant cells were lower than the rates of uptake by the wild-type strain. The pattern and amount of outer membrane protein in the P. putida tol-oprL mutants were not changed, suggesting that the transport defect was not in the outer membrane. Consistently, the uptake of radiolabeled glucose and glycerol in spheroplasts was defective in the P. putida tol-oprL mutant strains, suggesting that there was a defect at the cytoplasmic membrane level. Generation of a proton motive force appeared to be unaffected in these mutants. To rule out the possibility that the uptake defect was due to a lack of specific transporter proteins, the PutP symporter was overproduced, but this overproduction did not enhance proline uptake in the tol-oprL mutants. These results suggest that the Tol-OprL system is necessary for appropriate functioning of certain uptake systems at the level of the cytoplasmic membrane.

scholarly journals Hormonally mediated maternal effects, individual strategy and global change

2012 ◽  
Vol 367 (1596) ◽  
pp. 1647-1664 ◽  
Author(s):  
Sandrine Meylan ◽  
Donald B. Miles ◽  
Jean Clobert
Keyword(s):  
Life History ◽  
Global Change ◽  
Maternal Effects ◽  
Stress Hormones ◽  
Metapopulation Dynamics ◽  
Short Term ◽  
Changing Environments ◽  
Individual Strategy ◽  
Abiotic Stressors

A challenge to ecologists and evolutionary biologists is predicting organismal responses to the anticipated changes to global ecosystems through climate change. Most evidence suggests that short-term global change may involve increasing occurrences of extreme events, therefore the immediate response of individuals will be determined by physiological capacities and life-history adaptations to cope with extreme environmental conditions. Here, we consider the role of hormones and maternal effects in determining the persistence of species in altered environments. Hormones, specifically steroids, are critical for patterning the behaviour and morphology of parents and their offspring. Hence, steroids have a pervasive influence on multiple aspects of the offspring phenotype over its lifespan. Stress hormones, e.g. glucocorticoids, modulate and perturb phenotypes both early in development and later into adulthood. Females exposed to abiotic stressors during reproduction may alter the phenotypes by manipulation of hormones to the embryos. Thus, hormone-mediated maternal effects, which generate phenotypic plasticity, may be one avenue for coping with global change. Variation in exposure to hormones during development influences both the propensity to disperse, which alters metapopulation dynamics, and population dynamics, by affecting either recruitment to the population or subsequent life-history characteristics of the offspring. We suggest that hormones may be an informative index to the potential for populations to adapt to changing environments.

Role of affect in short-term memory for paired associates.

1968 ◽  
Vol 78 (3, Pt.1) ◽  
pp. 494-501 ◽  
Author(s):  
Calvin F. Nodine ◽  
James H. Korn
Keyword(s):  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Paired Associates

The capacity of short term memory from an evolutionary perspective

2019 ◽  
Author(s):  
Majid Manoochehri
Keyword(s):  
Short Term Memory ◽  
Memory Span ◽  
Critical Role ◽  
Experimental Studies ◽  
Cognitive System ◽  
Evolutionary Approach ◽  
Evolutionary Perspective ◽  
Short Term ◽  
Term Memory

Memory span in humans has been intensely studied for more than a century. In spite of the critical role of memory span in our cognitive system, which intensifies the importance of fundamental determinants of its evolution, few studies have investigated it by taking an evolutionary approach. Overall, we know hardly anything about the evolution of memory components. In the present study, I briefly review the experimental studies of memory span in humans and non-human animals and shortly discuss some of the relevant evolutionary hypotheses.

Impact of FII’s and FDI’s on Indian Stock Market

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Dr. Kamlesh Kumar Shukla
Keyword(s):  
Stock Market ◽  
Financial Markets ◽  
Global Economy ◽  
Short Term ◽  
Earnings Growth ◽  
The Past ◽  
Bull Market ◽  
Indian Stock Market

FIIs are companies registered outside India. In the past four years there has been more than $41 trillion worth of FII funds invested in India. This has been one of the major reasons on the bull market witnessing unprecedented growth with the BSE Sensex rising 221% in absolute terms in this span. The present downfall of the market too is influenced as these FIIs are taking out some of their invested money. Though there is a lot of value in this market and fundamentally there is a lot of upside in it. For long-term value investors, there’s little because for worry but short term traders are adversely getting affected by the role of FIIs are playing at the present. Investors should not panic and should remain invested in sectors where underlying earnings growth has little to do with financial markets or global economy.

Introduction: Kinship Bereavement in Later Life

1997 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Brian De Vries
Keyword(s):  
Adult Child ◽  
Later Life ◽  
Short Term ◽  
Traumatic Grief ◽  
Death Of A Parent ◽  
De Vries ◽  
Longitudinal Effects ◽  
Analysis Of Variation

This article introduces a volume devoted to the examination of later-life bereavement: an analysis of variation in cause, course, and consequence. Six articles address and represent this variation and comprise this volume: 1) Prigerson et al. present case histories of the traumatic grief of spouses; 2) Hays et al. highlight the bereavement experiences of siblings in contrast to those spouses and friends; 3) Moss et al. address the role of gender in middle-aged children's responses to parent death; 4) Bower focuses on the language adopted by these adult children in accepting the death of a parent; 5) de Vries et al. explore the long-term, longitudinal effects on the psychological and somatic functioning of parents following the death of an adult child; and 6) Fry presents the short-term and longitudinal reactions of grandparents to the death of a grandchild. A concluding article is offered by de Vries stressing both the unique and common features of these varied bereavement experiences touching on some of the empirical issues and suggesting potential implications and applications.

Role of Nitric Oxide in Short-term and Prolonged Effects of Angiotensin II on Renal Hemodynamics

Hypertension ◽  
1996 ◽  
Vol 27 (5) ◽  
pp. 1173-1179 ◽  
Author(s):  
Xiaolin Deng ◽  
William J. Welch ◽  
Christopher S. Wilcox
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Renal Hemodynamics ◽  
Short Term

Literalism and Moral Status

2018 ◽  
Author(s):  
Carrie Figdor
Keyword(s):  
Moral Status ◽  
Moral Standing ◽  
Short Term ◽  
Long Run ◽  
Moral Boundaries ◽  
Psychological Capacities

Chapter 9 presents the idea that Literalism undermines current social and moral boundaries for moral status. Possession of psychological capacities, moral standing, and respectful treatment are a standard package deal. So either many more beings enjoy moral status than we now think, or the relative superiority of human moral status over other beings is diminished. It introduces the role of psychological ascriptions in drawing social and moral boundaries by examining dehumanization and anthropomorphism. It argues that in the short term Literalism does not motivate us to do more than make minor adjustments to current moral boundaries. We can distinguish the kinds of psychological capacities that matter for moral status from the kinds that best divide nature at its joints. In the long run, however, Literalism prompts us to reconsider the anthropocentric standards that govern current moral boundaries.

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