scholarly journals Mycobacterial Populations Partly Change the Proportions of the Cells Undergoing Asymmetric/Symmetric Divisions in Response to Glycerol Levels in Growth Medium

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1160
Author(s):  
Atul Pradhan ◽  
Nagaraja Mukkayyan ◽  
Kishor Jakkala ◽  
Parthasarathi Ajitkumar
Keyword(s):  
Cell Growth ◽  
Growth Medium ◽  
Differential Susceptibility ◽  
Physiological Significance ◽  
Glycerol Concentration ◽  
Diadenosine Tetraphosphate ◽  
Qpcr Data ◽  
Daughter Cells ◽  
Glycerol Level ◽  
Phase Population

Twenty to thirty percent of the septating mycobacterial cells of the mid-log phase population showed highly deviated asymmetric constriction during division (ACD), while the remaining underwent symmetric constriction during division (SCD). The ACD produced short-sized cells (SCs) and normal/long-sized cells (NCs) as the sister–daughter cells, but with significant differential susceptibility to antibiotic/oxidative/nitrite stress. Here we report that, at 0.2% glycerol, formulated in the Middlebrook 7H9 medium, a significantly high proportion of the cells were divided by SCD. When the glycerol concentration decreased to 0.1% due to cell-growth/division, the ACD proportion gradually increased until the ACD:SCD ratio reached ~50:50. With further decrease in the glycerol levels, the SCD proportion increased with concomitant decrease in the ACD proportion. Maintenance of glycerol at 0.1%, through replenishment, held the ACD:SCD proportion at ~50:50. Transfer of the cells from one culture with a specific glycerol level to the supernatant from another culture, with a different glycerol level, made the cells change the ACD:SCD proportion to that of the culture from which the supernatant was taken. RT-qPCR data showed the possibility of diadenosine tetraphosphate phosphorylase (MSMEG_2932), phosphatidylinositol synthase (MSMEG_2933), and a Nudix family hydrolase (MSMEG_2936) involved in the ACD:SCD proportion-change in response to glycerol levels. We also discussed its physiological significance.

Intracellular distribution of lead in Tetrahymena during continuous exposure to the metal

1979 ◽  
Vol 39 (1) ◽  
pp. 383-396
Author(s):  
J.R. Nilsson
Keyword(s):  
Cell Growth ◽  
Growth Medium ◽  
Food Vacuole ◽  
Continuous Exposure ◽  
Organic Growth ◽  
Food Vacuoles ◽  
Entire Cell ◽  
Membrane Bound ◽  
Lag Period ◽  
High Concentrations

Lead acetate (0.1–0.2%) forms a precipitate with the organic growth medium. The Tetrahymena cells ingest this lead-containing precipitate and cell growth is resumed after a variable lag period. Ingested lead is observed as electron-dense material in food vacuoles. Soon after exposure, cytoplasmic lead (preserved with certain fixation only) is revealed as electron-dense particles in cilia and in a halo around digestive vacuoles. Later the lead particles pervade the entire cell but after the lag period they are confined to membrane-bound spaces. In dilute growth medium, high concentrations of lead inhibit food-vacuole formation and cell growth. Under these conditions lead is deposited in alveoli of the pellicle and is also found in autophagic vacuoles and other membrane-limited structures. The study has revealed that lead enters Tetrahymena through the membrane of digestive vacuoles and through the cell surface. The change in distribution of lead during the lag period indicates that a mechanism is activated for removal of lead into membrane-bound spaces. The final storage of lead seems to be in lysosomes.

Lack of antilipolytic effect of lactate in subcutaneous abdominal adipose tissue during exercise

1999 ◽  
Vol 86 (6) ◽  
pp. 1800-1804 ◽  
Author(s):  
François Trudeau ◽  
Sylvain Bernier ◽  
Isabelle de Glisezinski ◽  
François Crampes ◽  
François Dulac ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Tissue ◽  
Maximal Oxygen Consumption ◽  
Physiological Saline ◽  
Tissue Blood Flow ◽  
Glycerol Concentration ◽  
Abdominal Adipose Tissue ◽  
Glycerol Level ◽  
Good Physical Condition ◽  
Subcutaneous Abdominal Adipose Tissue

The purpose of our study was to evaluate the potential inhibition of adipose tissue mobilization by lactate. Eight male subjects (age, 26.25 ± 1.75 yr) in good physical condition (maximal oxygen uptake, 59.87 ± 2.77 ml ⋅ kg−1 ⋅ min−1; %body fat, 10.15 ± 0.89%) participated in this study. For each subject, two microdialysis probes were inserted into abdominal subcutaneous tissue. Lactate (16 mM) was perfused via one of the probes while physiological saline only was perfused via the other, both at a flow rate of 2.5 μl/min. In both probes, ethanol was also perfused for adipose tissue blood flow estimation. Dialysates were collected every 10 min during rest (30 min), exercise at 50% maximal oxygen consumption (120 min), and recovery (30 min) for the measurement of glycerol concentration. During exercise, glycerol increased significantly in both probes. However, no differences in glycerol level and ethanol extraction were observed between the lactate and control probes. These findings suggest that lactate does not impair subcutaneous abdominal adipose tissue mobilization during exercise.

The Citrate Transport System of Lactococcus lactis subsp. lactis biovar diacetylactis Is Induced by Acid Stress

1998 ◽  
Vol 64 (3) ◽  
pp. 850-857 ◽  
Author(s):  
Nieves García-Quintáns ◽  
Christian Magni ◽  
Diego de Mendoza ◽  
Paloma López
Keyword(s):  
Stress Response ◽  
Cell Growth ◽  
Lactococcus Lactis ◽  
Growth Medium ◽  
Transport System ◽  
Acid Stress ◽  
Selective Advantage ◽  
Transcriptional Level ◽  
Transport Activity ◽  
Citrate Transport

ABSTRACT Citrate transport in Lactococcus lactis subsp.lactis biovar diacetylactis is catalyzed by citrate permease P (CitP), which is encoded by the plasmidic citPgene. We have shown previously that citP is included in thecitQRP operon, which is mainly transcribed from the P1 promoter in L. lactis subsp. lactis biovar diacetylactis. Furthermore, transcription of citQRP and citrate transport are not induced by the presence of citrate in the growth medium. In this work, we analyzed the influence of the extracellular pH on the expression of citP. The citrate transport system is induced by natural acidification of the medium during cell growth and by a shift to media buffered at acidic pHs. This inducible response to acid stress takes place at the transcriptional level and seems to be due to increased utilization of the P1 promoter. Increased transcription correlates with increased synthesis of CitP and results in higher citrate transport activity catalyzed by the cells. Finally, this acid stress response seems to provide L. lactis subsp. lactis biovar diacetylactis with a selective advantage resulting from cometabolism of glucose and citrate at low pHs.

scholarly journals Synthesis, characterization and in vitro biocompatibility assessment of a novel tripeptide hydrogelator, as a promising scaffold for tissue engineering applications

2016 ◽  
Vol 4 (10) ◽  
pp. 1412-1416 ◽  
Author(s):  
Tihomir Pospišil ◽  
Lejla Ferhatović Hamzić ◽  
Lada Brkić Ahmed ◽  
Marija Lovrić ◽  
Srećko Gajović ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Growth Medium ◽  
Engineering Applications ◽  
In Vitro Biocompatibility ◽  
Hydrogel Matrix

The supramolecular self-assembles of a simple tripeptide Ac-l-Phe-l-Phe-l-Ala-NH2form a hydrogel matrix which may serve as the cell growth medium.

scholarly journals The Effect of Created Local Hyperosmotic Microenvironment in Microcapsule for the Growth and Metabolism of Osmotolerant YeastCandida krusei

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Guo Chen ◽  
Shanjing Yao
Keyword(s):  
Cell Growth ◽  
Osmotic Stress ◽  
Shake Flask ◽  
Culture Medium ◽  
Free Cell ◽  
Candida Krusei ◽  
Hyperosmotic Stress ◽  
Glycerol Concentration ◽  
Encapsulated Cells ◽  
Osmotolerant Yeast

Candida kruseiis osmotolerant yeast used for the production of glycerol. Addition of osmolyte such as NaCl into culture medium can increase the production of glycerol from glucose, but osmolytes may burden the glycerol separation. A coencapsulation method was suggested to create local extracellular hyperosmotic stress for glycerol accumulation. Firstly, the influence of osmotic stress induced by the addition of PEG4000 on growth and metabolism of free cell was studied in detail. Glycerol accumulation could be improved by employing PEG4000 as osmoregulator. Secondly, cells and PEG4000 were coentrapped in NaCS/PDMDAAC capsules to create local hyperosmotic stress. The effects of local hyperosmotic microenvironment on the cell growth and metabolism were studied. The coentrapment method increased the glycerol concentration by 25%, and the glycerol concentration attained 50 gL−1with productivity of 18.8 gL−1Day−1in shake flask. More importantly, the glycerol could be directly separated from the encapsulated cells. The entrapped cells containing PEG4000 were also cultivated for 15 days in an airlift reactor. The yield and productivity were ca. 35% and 21 gL−1Day−1, respectively.

scholarly journals Effect of different aeration and polyethylene glycol concentration on growth of Escherichia coli DH5α in a 1L bioreactor

2018 ◽  
Author(s):  
Wenfa Ng
Keyword(s):  
Escherichia Coli ◽  
Polyethylene Glycol ◽  
Cell Growth ◽  
Growth Medium ◽  
Growth Rates ◽  
Shake Flask ◽  
Foam Formation ◽  
Biomass Formation ◽  
E Coli ◽  
Toxicity Effect

Large culture volume in bioreactor necessitates aeration for providing sufficient oxygen for cell growth. Thus, extend of aeration and amount of anti-foam needed for suppressing foam formation are key parameters determining the success of bioreactor fermentation. Specifically, while aeration provides more oxygen for powering cellular metabolism and could lead to faster growth rate and more efficient metabolism, it also introduces greater shear stress, mixing and foam formation. On the other hand, anti-foaming agents such as polyethylene glycol (PEG) could exert a toxicity effect on cells as well as introducing increased osmolarity and viscosity that could hamper cell growth. In this preliminary study, effect of different PEG concentrations and extent of aeration on growth of Escherichia coli DH5α (ATCC 53868) in a 1L bioreactor at 37 oC with LB Lennox growth medium was investigated. Experiment results revealed that E. coli DH5α growth in bioreactor at 1 VVM aeration with 1 g/L PEG was faster than that in a 250 mL glass shake flask, and with greater secretion of alkaline metabolites. Similar optical density obtained between bioreactor and shake flask cultivation pointed to the maximized utilization of growth medium nutrients for biomass formation. Increase in bioreactor aeration to 3 VVM at 1 g/L PEG, however, resulted in increased secretion of acidic metabolites into the culture broth while allowing similar maximal optical density to be obtained compared to aeration of 1 VVM at 1 g/L PEG. This indicated that E. coli DH5α was able to adapt to physiological impacts from increased aeration and highlighted that no significant metabolic energy was diverted from biomass formation. Finally, increase in PEG concentration to 10 g/L from 1 g/L did not introduce additional toxicity effect given that growth profile of E. coli DH5α under the two PEG concentrations overlapped each other. However, observations of reduced secretion of acidic metabolites at the outset of growth in 10 g/L PEG pointed to physiological impacts that did not affect growth rates and biomass formation. Collectively, E. coli DH5α was able to tolerate enhanced aeration of 3 VVM and 10 g/L PEG anti-foam without significant detrimental impacts on growth rates and biomass formation.

The Influence of Mesenchymal Stem Cell Growth Medium for Isolation of STRO-1 Positive Cells from Human Periodontal Ligament

2012 ◽  
pp. 122-124
Author(s):  
Naoki Endo ◽  
Yoko Iwamatsu-Kobayashi ◽  
Daisuke Nishihara ◽  
Masaaki Iwamatsu ◽  
Masashi Komatsu ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Growth ◽  
Mesenchymal Stem Cell ◽  
Growth Medium ◽  
Periodontal Ligament
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