scholarly journals Phenotypic Convergence in Bacterial Adaptive Evolution to Ethanol Stress

2014 ◽  
Author(s):  
Takaaki Horinouchi ◽  
Shingo Suzuki ◽  
Takashi Hirasawa ◽  
Naoaki Ono ◽  
Tetsuya Yomo ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Ethanol Tolerance ◽  
Environmental Changes ◽  
Site Directed Mutagenesis ◽  
Genetic Mutations ◽  
Ethanol Stress ◽  
Bacterial Cells ◽  
Phenotypic Changes ◽  
Escherichia Coli Cells ◽  
Phenotypic Convergence

Bacterial cells have a remarkable ability to adapt and evolve to environmental changes, a phenomenon known as adaptive evolution. Adaptive evolution can be explained by phenotypic changes caused by genetic mutations, and by phenotypic plasticity that occur without genetic alteration, although far less is known about the contributions of the latter. In this study, we analyzed phenotypic and genotypic changes in Escherichia coli cells during adaptive evolution to ethanol stress. Phenotypic changes were quantified by transcriptome and metabolome analyses and found similar among independently evolved ethanol tolerant strains. The contribution of identified mutations in the tolerant strain was evaluated by using site-directed mutagenesis, which suggested that the fixation of these mutations cannot fully explain the observed ethanol tolerance. The phenotype of ethanol tolerance was stably maintained after an environmental change, suggesting that a mechanism of non-genetic memory contributed to at least part of the adaptation process.

scholarly journals Phenotypic convergence in bacterial adaptive evolution to ethanol stress

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Takaaki Horinouchi ◽  
Shingo Suzuki ◽  
Takashi Hirasawa ◽  
Naoaki Ono ◽  
Tetsuya Yomo ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Ethanol Stress ◽  
Phenotypic Convergence

scholarly journals Precise regulation of the relative rates of surface area and volume synthesis in bacterial cells growing in dynamic environments

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Handuo Shi ◽  
Yan Hu ◽  
Pascal D. Odermatt ◽  
Carlos G. Gonzalez ◽  
Lichao Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Time Delay ◽  
Surface Area ◽  
Environmental Changes ◽  
Volume Ratio ◽  
Dynamic Environments ◽  
Bacterial Cells ◽  
Bacterial Growth Rate ◽  
State Size ◽  
Insight Into

AbstractThe steady-state size of bacterial cells correlates with nutrient-determined growth rate. Here, we explore how rod-shaped bacterial cells regulate their morphology during rapid environmental changes. We quantify cellular dimensions throughout passage cycles of stationary-phase cells diluted into fresh medium and grown back to saturation. We find that cells exhibit characteristic dynamics in surface area to volume ratio (SA/V), which are conserved across genetic and chemical perturbations as well as across species and growth temperatures. A mathematical model with a single fitting parameter (the time delay between surface and volume synthesis) is quantitatively consistent with our SA/V experimental observations. The model supports that this time delay is due to differential expression of volume and surface-related genes, and that the first division after dilution occurs at a tightly controlled SA/V. Our minimal model thus provides insight into the connections between bacterial growth rate and cell shape in dynamic environments.

scholarly journals Environmental changes dictate selection and nonspecific epistasis in an empirical phenotype-environment-fitness landscape

2021 ◽  
Author(s):  
J.Z. Chen ◽  
D.M. Fowler ◽  
N. Tokuriki
Keyword(s):  
Selection Pressure ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Fitness Landscape ◽  
Resistance Level ◽  
Phenotypic Changes ◽  
Environmental Selection ◽  
Selection Environment ◽  
Data Points ◽  
Environmental Dependence

SummaryThe fitness landscape, a function that maps genotypic and phenotypic changes to their effects on fitness, is an invaluable concept in evolutionary biochemistry. Though widely discussed, measurements of phenotype-fitness landscapes in proteins remain scarce. Here, we quantify all single mutational effects on fitness and phenotype (antibiotic resistance level) of VIM-2 β-lactamase (5600 variants) across a 64-fold range of ampicillin concentrations by deep mutational scanning. We then construct a phenotype-fitness landscape that takes variations in environmental selection pressure into account (a phenotype-environment-fitness landscape). We found that a simple, empirical landscape accurately models the ~39,000 mutational data points, which suggests the evolution of VIM-2 can be predicted based on the selection environment. Our landscape provides new quantitative knowledge on the evolution of the β-lactamases and proteins in general, particularly their evolutionary dynamics under sub-inhibitory antibiotic concentrations, as well as the mechanisms and environmental dependence of nonspecific epistasis.

scholarly journals Honey Mead Fermentation from Thai Stingless Bee (Tetragonula leaviceps) Honey using Ethanol Tolerant Yeast

2021 ◽  
Vol 67 (5) ◽  
pp. 503-510
Author(s):  
Pimprapa Chaijak ◽  
Purimprach Sinkan ◽  
Santipap Sotha
Keyword(s):  
Ethanol Tolerance ◽  
Alcoholic Beverage ◽  
Invertase Activity ◽  
Stingless Bee ◽  
Ethanol Stress ◽  
Microbial Fermentation ◽  
Tolerance Level ◽  
Enrichment Technique ◽  
Selection Of

Honey mead is a well-known conventional alcoholic beverage made by microbial fermentation of diluted honey. The selection of prospective yeasts for inoculation of honey-must with regard to honey mead quality determines the quality of mead production. The yeast consortium tolerant to ethanol stress was selected for this study using an enrichment technique. The activity of the invertase enzyme and the level of ethanol tolerance have been investigated. Thai stingless bee honey was used as a substrate, and the selected ethanol tolerant yeast consortium was used for mead fermentation. The results revealed that the PP03 had the highest invertase activity of 75.13±9.16 U/mL and the highest ethanol tolerance level of 12%. This is the first study using an ethanol tolerant yeast consortium to ferment honey mead from Thai stingless bee honey.  

Microbial dispersal throgh dead-end cavities

2021 ◽  
Author(s):  
David Scheidweiler ◽  
Ankur Deep Bordoloi ◽  
Pietro de Anna
Keyword(s):  
Porous Media ◽  
Time Lapse ◽  
Breakthrough Curves ◽  
Bacterial Cells ◽  
Dispersal Patterns ◽  
Microbial Life ◽  
Sedimentary Environments ◽  
Escherichia Coli Cells ◽  
Dead End

<p>Predicting dispersal patterns is important to understand microbial life in porous media as soils and sedimentary environments. We studied active and passive dispersal of bacterial cells in porous media characterized by two main pore features: fast channels and dead-end cavities. We combined experiments with microfluidic devices and time-lapse microscopy to track individual bacterial trajectories and measure the breakthrough curves and pore scale bacterial abundance. Escherichia coli cells dispersed more efficiently than the non-motile mutants showing a different retention in the dead-end pores. Our findings highlight the role of diffusion dominated dead-end pores on the dispersal of microorganisms in porous media.</p>

scholarly journals Harvest-induced evolution: insights from aquatic and terrestrial systems

2017 ◽  
Vol 372 (1712) ◽  
pp. 20160036 ◽  
Author(s):  
Anna Kuparinen ◽  
Marco Festa-Bianchet
Keyword(s):  
Environmental Changes ◽  
Current Knowledge ◽  
Aquatic Systems ◽  
Phenotypic Traits ◽  
Size At Maturity ◽  
Phenotypic Changes ◽  
Harvest Intensity ◽  
Evolutionary Changes ◽  
Key Points ◽  
Ecological Implications

Commercial and recreational harvests create selection pressures for fitness-related phenotypic traits that are partly under genetic control. Consequently, harvesting can drive evolution in targeted traits. However, the quantification of harvest-induced evolutionary life history and phenotypic changes is challenging, because both density-dependent feedback and environmental changes may also affect these changes through phenotypic plasticity. Here, we synthesize current knowledge and uncertainties on six key points: (i) whether or not harvest-induced evolution is happening, (ii) whether or not it is beneficial, (iii) how it shapes biological systems, (iv) how it could be avoided, (v) its importance relative to other drivers of phenotypic changes, and (vi) whether or not it should be explicitly accounted for in management. We do this by reviewing findings from aquatic systems exposed to fishing and terrestrial systems targeted by hunting. Evidence from aquatic systems emphasizes evolutionary effects on age and size at maturity, while in terrestrial systems changes are seen in weapon size and date of parturition. We suggest that while harvest-induced evolution is likely to occur and negatively affect populations, the rate of evolutionary changes and their ecological implications can be managed efficiently by simply reducing harvest intensity. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences'.

scholarly journals The ethanol stress response and ethanol tolerance ofSaccharomyces cerevisiae

2010 ◽  
Author(s):  
D. Stanley ◽  
A. Bandara ◽  
S. Fraser ◽  
P.J. Chambers ◽  
G.A. Stanley
Keyword(s):  
Stress Response ◽  
Ethanol Tolerance ◽  
Ethanol Stress

scholarly journals Mitochondrial Superoxide Dismutase and Yap1p Act as a Signaling Module Contributing to Ethanol Tolerance of the Yeast Saccharomyces cerevisiae

2016 ◽  
Vol 83 (3) ◽  
Author(s):  
Anna N. Zyrina ◽  
Ekaterina A. Smirnova ◽  
Olga V. Markova ◽  
Fedor F. Severin ◽  
Dmitry A. Knorre
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Ethanol Tolerance ◽  
Yeast Cells ◽  
Ethanol Stress ◽  
Mitochondrial Enzymes ◽  
Mitochondrial Superoxide ◽  
Mitochondrial Superoxide Dismutase

ABSTRACT There are two superoxide dismutases in the yeast Saccharomyces cerevisiae—cytoplasmic and mitochondrial enzymes. Inactivation of the cytoplasmic enzyme, Sod1p, renders the cells sensitive to a variety of stresses, while inactivation of the mitochondrial isoform, Sod2p, typically has a weaker effect. One exception is ethanol-induced stress. Here we studied the role of Sod2p in ethanol tolerance of yeast. First, we found that repression of SOD2 prevents ethanol-induced relocalization of yeast hydrogen peroxide-sensing transcription factor Yap1p, one of the key stress resistance proteins. In agreement with this, the levels of Trx2p and Gsh1p, proteins encoded by Yap1 target genes, were decreased in the absence of Sod2p. Analysis of the ethanol sensitivities of the cells lacking Sod2p, Yap1p, or both indicated that the two proteins act in the same pathway. Moreover, preconditioning with hydrogen peroxide restored the ethanol resistance of yeast cells with repressed SOD2. Interestingly, we found that mitochondrion-to-nucleus signaling by Rtg proteins antagonizes Yap1p activation. Together, our data suggest that hydrogen peroxide produced by Sod2p activates Yap1p and thus plays a signaling role in ethanol tolerance. IMPORTANCE Baker's yeast harbors multiple systems that ensure tolerance to high concentrations of ethanol. Still, the role of mitochondria under severe ethanol stress in yeast is not completely clear. Our study revealed a signaling function of mitochondria which contributes significantly to the ethanol tolerance of yeast cells. We found that mitochondrial superoxide dismutase Sod2p and cytoplasmic hydrogen peroxide sensor Yap1p act together as a module of the mitochondrion-to-nucleus signaling pathway. We also report cross talk between this pathway and the conventional retrograde signaling cascade activated by dysfunctional mitochondria.

Phenotypic changes associated with the fitness cost in antibiotic resistant Escherichia coli strains

2016 ◽  
Vol 12 (2) ◽  
pp. 414-420 ◽  
Author(s):  
Shingo Suzuki ◽  
Takaaki Horinouchi ◽  
Chikara Furusawa
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Fitness Cost ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Phenotypic Changes

Background: the acquisition of antibiotic resistance in bacterial cells is often accompanied with a reduction of fitness in the absence of antibiotics, known as the “fitness cost”.

scholarly journals RNase E Maintenance of Proper FtsZ/FtsA Ratio Required for Nonfilamentous Growth of Escherichia coli Cells but Not for Colony-Forming Ability

2006 ◽  
Vol 188 (14) ◽  
pp. 5145-5152 ◽  
Author(s):  
Masaru Tamura ◽  
Kangseok Lee ◽  
Christine A. Miller ◽  
Christopher J. Moore ◽  
Yukio Shirako ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Liquid Culture ◽  
Bacterial Cells ◽  
Rnase E ◽  
Null Mutant ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Solid Media ◽  
Rnase G

ABSTRACT Inactivation or deletion of the RNase E-encoding rne gene of Escherichia coli results in the growth of bacterial cells as filamentous chains in liquid culture (K. Goldblum and D. Apirion, J. Bacteriol. 146:128-132, 1981) and the loss of colony-forming ability (CFA) on solid media. RNase E dysfunction is also associated with abnormal processing of ftsQAZ transcripts (K. Cam, G. Rome, H. M. Krisch, and J.-P. Bouché, Nucleic Acids Res. 24:3065-3070, 1996), which encode proteins having a central role in septum formation during cell division. We show here that RNase E regulates the relative abundances of FtsZ and FtsA proteins and that RNase E depletion results in decreased FtsZ, increased FtsA, and consequently an altered FtsZ/FtsA ratio. However, while restoration of the level of FtsZ to normal in rne null mutant bacteria reverses the filamentation phenotype, it does not restore CFA. Conversely, overexpression of a related RNase, RNase G, in rne-deleted bacteria restores CFA, as previously reported, without affecting FtsZ abundance. Our results demonstrate that RNase E activity is required to maintain a proper cellular ratio of the FtsZ and FtsA proteins in E. coli but that FtsZ deficiency does not account for the nonviability of cells lacking RNase E.

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