scholarly journals INFLUENCE OF MICRO-ENVIRONMENT ON YEAST POPULATION DYNAMICS

2019 ◽  
pp. 5-13
Author(s):  
Jean-Yves Trosset ◽  
Sami Tliba ◽  
Ali El Ati ◽  
Hela Friha ◽  
Estelle Mogensen ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Warburg Effect ◽  
Energy Production ◽  
Metabolic Shift ◽  
Minimal Cost ◽  
Dynamics Modeling ◽  
Yeast Population ◽  
Auto Regressive ◽  
Cell Growth Model ◽  
Growth Experiments

Abundance or scarcity of external nutrients is a metabolic trigger, especially for highly proliferative cells such as bacteria, yeasts, parasites or tumors. In presence of oxygen cells usually adopt efficient metabolism in order to maximize energy production yield in poor diet. If nutrient resource increases, a metabolic shift from efficient metabolism (respiration) to inefficient metabolism (fermentation) is reflecting a minimal cost principle of living systems to optimize fitness. This is known as the Crabtree/Warburg effect. Identifying a model that describes the population dynamics of cells and the input growth condition are the goals of this study. Proof of principle has been constructed using a battery of growth experiments on Crabtree-positive yeasts–Saccharomyces under various conditions of glucose in aerobic and micro-aerobic conditions. General cell growth model estimating metabolic shift has been constructed based on an Auto Regressive approach. Keywords: Yeast, Population dynamics, Modeling, Identification

Population Dynamics Modeling

2009 ◽  
pp. 47-82
Author(s):  
Andrew Riddle ◽  
Grace Panter ◽  
Paul Robinson ◽  
Andrew Brown
Keyword(s):  
Population Dynamics ◽  
Dynamics Modeling

scholarly journals miR-206 regulates a metabolic switch in nasopharyngeal carcinoma by suppressing HK2 expression

2020 ◽  
Author(s):  
Chunying Luo ◽  
Min Liu ◽  
Jianwei Zhang ◽  
Guoqiang Su ◽  
Zhonghua Wei
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Warburg Effect ◽  
Carcinoma Cells ◽  
Luciferase Reporter ◽  
Metabolic Shift ◽  
Invasion And Metastasis ◽  
Metabolic Switch ◽  
And Function ◽  
The Relationship

Abstract Background: Many studies have shown that microRNAs play key functions in nasopharyngeal carcinoma proliferation, invasion and metastasis. However, whether the dysregulated level of miRNAs contributes to the metabolic shift in nasopharyngeal carcinoma is not completely understood.Objectives: This study was conducted to explore the expression and function of miR-206 in nasopharyngeal carcinoma.Methods: miR-206 expression level was examined by real-time PCR. miR-206 inhibitor, mimics, and scrambled control were transiently transfected into nasopharyngeal carcinoma cells and their effects on colony formation, glucose uptake, and lactate secretion were observed in vitro. Moreover, the relationship between the levels of miR-206 and HK2 was examined by luciferase reporter and assay western blot.Results: In our study, we reported downregulation of miR-206 expression leads to metabolic change in nasopharyngeal carcinoma cells. miR-206 controls this function by enhancing HK2 expression. The enhancement of aerobic metabolism activity induced by miR-206 leads to the rapid proliferation of nasopharyngeal carcinoma cells.Conclusions: Our data demonstrated that miR-206 was involved in the regulation of Warburg effect in nasopharyngeal carcinoma by suppressing HK2 expression.

scholarly journals Viability-PCR Allows Monitoring Yeast Population Dynamics in Mixed Fermentations Including Viable but Non-Culturable Yeasts

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1373
Author(s):  
Yurena Navarro ◽  
María-Jesús Torija ◽  
Albert Mas ◽  
Gemma Beltran
Keyword(s):  
Population Dynamics ◽  
Alcoholic Fermentation ◽  
Yeast Species ◽  
Culture Media ◽  
Microbial Interactions ◽  
Fast Method ◽  
Yeast Population ◽  
Final Population ◽  
Differential Medium ◽  
Yeast Interactions

The use of controlled mixed inocula of Saccharomyces cerevisiae and non-Saccharomyces yeasts is a common practice in winemaking, with Torulaspora delbrueckii, Lachancea thermotolerans and Metschnikowia pulcherrima being the most commonly used non-Saccharomyces species. Although S. cerevisiae is usually the dominant yeast at the end of mixed fermentations, some non-Saccharomyces species are also able to reach the late stages; such species may not grow in culture media, which is a status known as viable but non-culturable (VBNC). Thus, an accurate methodology to properly monitor viable yeast population dynamics during alcoholic fermentation is required to understand microbial interactions and the contribution of each species to the final product. Quantitative PCR (qPCR) has been found to be a good and sensitive method for determining the identity of the cell population, but it cannot distinguish the DNA from living and dead cells, which can overestimate the final population results. To address this shortcoming, viability dyes can be used to avoid the amplification and, therefore, the quantification of DNA from non-viable cells. In this study, we validated the use of PMAxx dye (an optimized version of propidium monoazide (PMA) dye) coupled with qPCR (PMAxx-qPCR), as a tool to monitor the viable population dynamics of the most common yeast species used in wine mixed fermentations (S. cerevisiae, T. delbrueckii, L. thermotolerans and M. pulcherrima), comparing the results with non-dyed qPCR and colony counting on differential medium. Our results showed that the PMAxx-qPCR assay used in this study is a reliable, specific and fast method for quantifying these four yeast species during the alcoholic fermentation process, being able to distinguish between living and dead yeast populations. Moreover, the entry into VBNC status was observed for the first time in L. thermotolerans and S. cerevisiae during alcoholic fermentation. Further studies are needed to unravel which compounds trigger this VBNC state during alcoholic fermentation in these species, which would help to better understand yeast interactions.

Influence of climatic and nutritional factors on yeast population dynamics in the phyllosphere of wheat

1992 ◽  
Vol 23 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Aleid J. Dik ◽  
Nyckle J. Fokkema ◽  
Johannes A. van Pelt
Keyword(s):  
Population Dynamics ◽  
Nutritional Factors ◽  
Yeast Population

scholarly journals Parameters of ontogeny and population dynamics modeling of Panagrolaimus detritophagus (Nematoda: Rhabditida) in vitro

2021 ◽  
Vol 325 (1) ◽  
pp. 91-98
Author(s):  
K.S. Polyanina ◽  
A.Y. Ryss
Keyword(s):  
Population Dynamics ◽  
Development Time ◽  
The Body ◽  
Individual Development ◽  
Population Cycle ◽  
Developmental Cycle ◽  
Dynamics Modeling ◽  
Average Life ◽  
Average Life Span

The parameters of individual development and population cycle in in vitro nematodes Panagrolaimus detritophagus were revealed. The nematodes are bacterial feeders and commensals of the cerambycid Monochamus galloprovincialis from the pine Pinus sylvestris; nematodes use beetles as vectors. Mean development time (T) from egg to juvenile is 1–2 days for J2, 3–4 days for J3, and 4–7 days for J4; to adults (G, generation) 7 (6–8) days. In vitro the population cycle is equal to 4 generations and ends with 90% of survival juveniles (J3, day 34). In the growth phase of the population, the proportion of eggs exceeds the proportion of other stages of the developmental cycle: 39±11% for 7 days; 53±10% for 21 days. The average oviposition rate of females is 4.5±1.3/day and only 56±12% of eggs proceed to immediate development (hatching and molting of juveniles). The remaining mass of eggs enter development only after 27 days (4 individual generations). This feature may be considered as a form of delay or a brief diapause at the egg stage. Individual females may accumulate up to 4 synchronous eggs in the body and lay them simultaneously. The average life span of an adult female is 13–20 days. Formulas for the exponential growth of the number of females and the total nematode population have been developed.

scholarly journals Transcriptomic characterization of tuberculous sputum reveals a host Warburg effect and microbial cholesterol catabolism

2020 ◽  
Author(s):  
Rachel PJ Lai ◽  
Teresa Cortes ◽  
Suzaan Marais ◽  
Neesha Rockwood ◽  
Melissa L Burke ◽  
...  
Keyword(s):  
Warburg Effect ◽  
Inflammatory Responses ◽  
Comprehensive Analysis ◽  
Metabolic Shift ◽  
Sequencing Technology ◽  
One Step ◽  
Hiv 1 ◽  
Transcriptional Landscape ◽  
Transmission Phase

AbstractThe crucial transmission phase of tuberculosis (TB) relies on infectious sputum yet cannot easily be modeled. We applied one-step RNA-Sequencing to sputum from infectious TB patients to investigate the host and microbial environments underlying transmission of Mycobacterium tuberculosis (Mtb). In such TB sputa, compared to non-TB controls, transcriptional upregulation of inflammatory responses and a metabolic shift towards glycolysis was observed in the host. Amongst all bacterial sequences in the sputum, only less than 1.5% originated from Mtb and its abundance is associated with HIV-1 coinfection status. The transcriptome of sputum Mtb more closely resembled aerobic replication and was characterized by evidence of cholesterol utilization, zinc deprivation and reduced expression of the virulence-associated PhoP regulon. Our study provides a comprehensive analysis of the transcriptional landscape associated with infectious sputum and demonstrates the feasibility of applying advanced sequencing technology to readily accessible pathological specimens in the study of host-pathogen adaptation.

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