scholarly journals The effect of inoculation time and inoculum concentration on the productive response of Tetraselmis chuii (Butcher, 1958) mass cultured in F/2 and 2-F media

2011 ◽  
Vol 63 (3) ◽  
pp. 557-562 ◽  
Author(s):  
José López-Elías ◽  
Edgard Esquer-Miranda ◽  
Marcel Martínez-Porchas ◽  
María Garza-Aguirre ◽  
Martha Rivas-Vega ◽  
...  
Keyword(s):  
Cell Density ◽  
Initial Density ◽  
Inoculum Concentration ◽  
Tetraselmis Chuii ◽  
Shrimp Industry ◽  
Inoculation Time ◽  
High Initial Density ◽  
Outdoor Cultures

Diverse protocols have been used in the shrimp industry to produce microalgae. In this work, we evaluated the effect of inoculation time (0600 and 1200) and initial microalgae density (0.4 and 0.8 x105cells mL-1) in static outdoor cultures of Tetraselmis chuii, using F/2 and 2-F media. A significant effect on cell density (> 6.7 x 105 cells mL-1) was found after treatments with a high initial density and in the F/2 medium. The higher productive responses were observed in treatments inoculated at 0600. The better productive response was found in treatments inoculated at 0600 with 0.8 x 105 cells?mL-1 in the F/2 medium.

scholarly journals Quality of Chaetoceros calcitrans Cultured with Different Concentrations of Potassium Nitrate (KNO3)

2020 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Alfarisi Prafanda ◽  
Pande Gde Sasmita Julyantoro ◽  
Ni Putu Putri Wijayanti
Keyword(s):  
Treatment Group ◽  
Cell Density ◽  
Initial Density ◽  
Potassium Nitrate ◽  
Control Treatment ◽  
Microalgae Culture ◽  
Starting Point ◽  
Group A ◽  
Chaetoceros Calcitrans

Addition of different fertilizer concentrations into cultivation media affects the cell density of microalgae. Potassium nitrate (KNO3), is one of the components in Guillard fertilizer composition commonly used for microalgae culture. This study aims to determine the quality of Chaetoceros calcitrans when cultured with different concentration of KNO3. This research was conducted from November 2019 to January 2020 at Balai Perikanan Budidaya Air Payau (BPBAP) Situbondo and Biosain Laboratory, Jember State Politeknik, East Java. This study consists of four treatments and three replicates. The object in this study was C. calcitrans culture with initial density 105 cells/ml. The main parameters observed were cell density, biomass, protein and amino acids contents and medium parameters such as temperature, pH, DO, salinity, nitrate and phosphate. There were four concentrations of KNO3 used in this study, namely control (75 g/l), treatment Group A (100 g/l), treatment B (125 g/l) and treatment C (150 g/l). The results showed that the cells density of C. calcitrans at control, treatment Group A, B and C were 110.4; 105.2; 108.3; and 100.8 (×104 cells/ml), respectively. This study indicated that different concentration of KNO3 affect the starting point of stationary phase, but One Way ANOVA test showed that those treatments had no significant effect (P?0,05) on the growth rate and dry biomass of C. calcitrans. Finally, we found that the protein content in addition of 75, 100, 125 and 150 g/l KNO3 were 9.748; 8.802; 6.812; and 3.776%, respectively.

scholarly journals Determination Number Of Magnesium Nutritions From MgSO4.7H2O AND IRON FROM FeSO4.7H2O on Tetraselmiss chuii Cultivation To The Maximum Lipid Contact

2019 ◽  
Vol 7 (1) ◽  
pp. 75
Author(s):  
Anggi Pratiwi
Keyword(s):  
Light Intensity ◽  
Cell Density ◽  
Sea Water ◽  
Extraction Process ◽  
Lipid Levels ◽  
Optimum Time ◽  
Microalgae Culture ◽  
Tetraselmis Chuii ◽  
Lipid Mass ◽  
Ether Solvents

This study discusses the effect of adding magnesium nutrients from MgSO4.7H2O and iron from FeSO4.7H2O to obtain maximum lipid levels in Tetraselmis chuii microalgae. The nutritional variations used were 0, 4, 6, 8 gr / L MgSO4.7H2O and 0, 24, 30, and 36 µM / L FeSO4.7H2O. Microalgae was cultivated with a photobioreactor filled with 1 L microalgae culture with a ratio of microalgae and sea water 3: 7, namely 300 ml of microalgae and 700 ml of sea water with salinity of 30 ppt. The light intensity is 2000 lux. The study began with culturing microalgae with variations in these nutrients. Then, the cell density is observed every 3 hours until the optimum time is obtained where the cell density is high. Then the microalgae is harvested and extracted so that the lipids are obtained. The extraction process was carried out using diethyl ether solvents. After obtaining the lipid mass, the microalgae lipid levels were calculated. The results showed that the highest lipid levels in Tetraselmis chuii microalgae were obtained by the addition of MgSO4.7H2O 6 gram and the addition of FeSO4.7H2O 36 µM which was 20,175%.

scholarly journals Optimal initial cell density that yields the highest number of primary synovial mesenchymal stem cells in a clinical setting

2020 ◽  
Author(s):  
Kiyotaka Horiuchi ◽  
Mitsuru Mizuno ◽  
Hisako Katano ◽  
Kentaro Endo ◽  
Nobutale Ozeki ◽  
...  
Keyword(s):  
Human Serum ◽  
Cell Density ◽  
Clinical Setting ◽  
Clinical Studies ◽  
Initial Density ◽  
Fold Increase ◽  
Cell Number ◽  
Autologous Serum ◽  
Initial Cell ◽  
Initial Cell Density

Abstract Background Synovial mesenchymal stem cell (MSC) transplantation improved clinical outcomes in knees with cartilage defects and after repairs of degenerative torn menisci. For these, nucleated cells were cultured with 10% autologous serum for 14 days. Importantly, nucleated cell number and serum volume practically varied by patient, and initial cell density and dish number affected yield/donor. Our purpose was to examine the effect of plating density within range in clinical studies on fold increase and to estimate the MSC yield/donor, which are affected by the nucleated cell number and serum volume. Methods We obtained the data of the autologous serum volume, nucleated cell number, and initial plating cell density from 10 patients who participated in our previous clinical studies. Experimentally, synovial nucleated cells harvested from three patients with osteoarthritis during total knee arthroplasty were cultured with 10% mixed allogenic human serum for 14 days to examine the effect of initial cell density on fold increase. We used both our previous clinical data and our current experimental data to predict the yields of synovial MSCs in nine cases within the range of clinical studies. Results In the clinical studies, collected serum ranged between 87 and 186 ml, harvested nucleated cells ranged between 6.2 and 23 million, and the top five total MSC yields were obtained from donors when the initial plating cell density ranged from 919 to 1905 cells/cm 2 . Experimentally, fold increase significantly decreased between 700 and 1,900 cells/cm 2 . In cases where the cell number was low and the serum volume was high, the estimated yield/donor decreased along with the initial density, while in cases where the cell number was high and the serum volume was low, the estimated yield/donor increased along with the initial density. In cases both where some nucleated cells were discarded at low density and no cells were discarded at high density, the maximum yield/donor were obtained when the initial density was the lowest density that does not discard cells. Conclusions There was an optimal initial density that yields the highest number of primary MSCs in a clinical setting when cell numbers and human serum volumes are limited.

scholarly journals Inoculum concentration and inoculation time for propionic acid production from whey using mixed culture of Lactobacillus helveticus and Propionibacterium freudenreichii PS-1

2017 ◽  
Vol 39 (5) ◽  
pp. 543 ◽  
Author(s):  
Moisés Tomás Ngome ◽  
José Guilherme Lembi Ferreira Alves ◽  
Roberta Hilsdorf Piccoli ◽  
Elisângela De Carmo Domingo ◽  
Sheyla Anália Pinto ◽  
...  
Keyword(s):  
Mixed Culture ◽  
Propionic Acid ◽  
Acid Production ◽  
Lactobacillus Helveticus ◽  
Propionibacterium Freudenreichii ◽  
Inoculum Concentration ◽  
Propionic Acid Production ◽  
Inoculation Time

scholarly journals Initial cell density encodes proliferative potential in cancer cell populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chiara Enrico Bena ◽  
Marco Del Giudice ◽  
Alice Grob ◽  
Thomas Gueudré ◽  
Mattia Miotto ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Cancer Cells ◽  
Cell Density ◽  
Cancer Cell ◽  
Initial Density ◽  
Logistic Growth ◽  
Cell Populations ◽  
Initial Cell ◽  
Initial Cell Density

AbstractIndividual cells exhibit specific proliferative responses to changes in microenvironmental conditions. Whether such potential is constrained by the cell density throughout the growth process is however unclear. Here, we identify a theoretical framework that captures how the information encoded in the initial density of cancer cell populations impacts their growth profile. By following the growth of hundreds of populations of cancer cells, we found that the time they need to adapt to the environment decreases as the initial cell density increases. Moreover, the population growth rate shows a maximum at intermediate initial densities. With the support of a mathematical model, we show that the observed interdependence of adaptation time and growth rate is significantly at odds both with standard logistic growth models and with the Monod-like function that governs the dependence of the growth rate on nutrient levels. Our results (i) uncover and quantify a previously unnoticed heterogeneity in the growth dynamics of cancer cell populations; (ii) unveil how population growth may be affected by single-cell adaptation times; (iii) contribute to our understanding of the clinically-observed dependence of the primary and metastatic tumor take rates on the initial density of implanted cancer cells.

scholarly journals Inoculum effect of antimicrobial peptides

2020 ◽  
Author(s):  
M. R. Loffredo ◽  
F. Savini ◽  
S. Bobone ◽  
B. Casciaro ◽  
H. Franzyk ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Cell Density ◽  
Bacterial Load ◽  
Initial Density ◽  
Resistant Bacteria ◽  
Bacterial Killing ◽  
Initial Inoculum ◽  
Bacteria Growth ◽  
Bacterial Drug Resistance ◽  
Inoculum Effect

AbstractThe activity of many antibiotics depends on the initial density of cells used in bacteria growth inhibition assays. This phenomenon, termed the inoculum effect, can have important consequences for the therapeutic efficacy of the drugs, since bacterial loads vary by several orders of magnitude in clinically relevant infections. Antimicrobial peptides are a promising class of molecules to fight drug-resistant bacteria, since they act mainly by perturbing the cell membranes rather than by inhibiting intracellular targets. Here we report the first systematic characterization of the inoculum effect for this class of antibacterial compounds. Thirteen peptides (including all-D enantiomers) and peptidomimetics were analyzed by measuring minimum inhibitory concentration values, covering more than 7 orders of magnitude in inoculated cell density. In all cases, we observed a significant inoculum effect for cell densities above 5 × 104 cells/mL, while the active concentrations remained constant (within the micromolar range) for lower densities. In the case of membrane-active peptides, these data can be rationalized by considering a simple model, taking into account peptide-cell association and hypothesizing that a threshold number of cell-bound peptide molecules is required in order to cause a killing effect. The observed effects question the clinical utility of activity and selectivity determinations performed at a fixed, standardized cell density. A routine evaluation of the inoculum dependence of the activity of antimicrobial peptides and peptidomimetics should be considered.Significance statementBacterial drug resistance is a crucial threat to global health and antimicrobials with novel mechanisms of action are severely needed. Antimicrobial peptides are natural molecules that kill bacteria mostly by perturbing their membranes and represent promising compounds to fight resistant microbes. Their activity is normally tested under standardized conditions of bacterial density. However, the bacterial load in clinically relevant infections varies by many orders of magnitude. Here we showed that the minimum peptide concentration needed for bacterial killing can vary by more than 100 times with an increase in the density of cells in the initial inoculum of the assay (inoculum effect) These findings question utility of the presently used activity screening assays and our current understanding of antimicrobial peptides.

Optimizing bio-ethanol production from cabbage and onion peels waste using yeast (Saccharomyces cerevisiae) as fermenting agent

2021 ◽  
Vol 1 (1) ◽  
pp. 024-035
Author(s):  
Temam Gemeda Genemo ◽  
Desta Lamore Erebo ◽  
Aschalew Kasu Gabre
Keyword(s):  
Ethanol Production ◽  
Cell Density ◽  
Substrate Concentration ◽  
Reducing Sugars ◽  
Negative Impact ◽  
Yeast Saccharomyces Cerevisiae ◽  
Inoculum Concentration ◽  
Pre Treatment ◽  
Production Cell

Production of bio-ethanol from lingocellulosic materials is providing a long-term sustainable for fuel supply. Cabbage and onion peels waste is one of cheap source of lignocellosic materials to serve as feedstock for bio-ethanol production. With the objective of evaluating its potential for bio-ethanol production, different concentrations (50g, and 100g) of Cabbage and onion peels waste treated with 1% diluted sulfuric acid and untreated were subjected to batch fermentation for 12 days with 0.5% and 1% yeast inoculums. Percent of bio-ethanol production, cell density and reducing sugars were measured at an interval of 4 days starting from the beginning. Results of these study showed that ethanol production was observed starting from the 4th day of fermentation, but its amount peaked 26.51 from 100g substrate with 1% inoculum on the 8th day of fermentation, and declined on 12th days (21.06%) from the same substrate concentration. Pretreated substrate showed significantly higher ethanol production than untreated. In agreement with ethanol production, cell density and reduction in reducing sugar were observed in the same pattern. Compared ethanol production between untreated substrates yield of 20.96%, and treated substrates yielded of 26.51%. Overall, this study showed that acid pre-treatment, inoculum concentration, fermentation period and substrate concentration affect the amount of bio-ethanol production. Finally, it can be concluded that the production of bioethanol from Cabbage and onion peels waste is economically and environmentally viable. Extensive use of these Wastes for bioethanol production may have twofold advantages, viz. reduction of its negative impact on environmental hygiene and generation of bio-ethanol.

THE EFFECT OF DAMAGED VEHICLES EVACUATION ON TRAFFIC FLOW BEHAVIOR

2009 ◽  
Vol 20 (12) ◽  
pp. 1989-1998 ◽  
Author(s):  
ABDELAZIZ MHIRECH ◽  
HAMID EZ-ZAHRAOUY ◽  
ASSIA ALAOUI ISMAILI
Keyword(s):  
Steady State ◽  
Traffic Flow ◽  
Flow Behavior ◽  
Initial Density ◽  
Realistic Model ◽  
Collision Probability ◽  
One Dimensional ◽  
Parallel Dynamics ◽  
The One ◽  
High Initial Density

The effect of the damaged car evacuation on the traffic flow behavior is investigated, in the one-dimensional deterministic Nagel–Schreckenberg model, using parallel dynamics. A realistic model applied to the cars involved in collisions is considered. Indeed, in this model we suppose that the damaged cars must be removed from the ring with a probability P exit . This investigation enables us to understand how the combination of the two probabilities, namely P col and P exit , acts on density and current. It is found that the current and density at the steady state, depend strongly on the initial density of cars in the ring. However, for the intermediate initial density ρi, the current J decreases when increasing either P exit and/or P col . While, for high initial density, J increases passes through a maximum and decreases for large values of P exit . Furthermore, the current can decrease or increase with the collision probability depending on the initial density.

Detonation parameters of hydrogen-oxygen and hydrogen-air mixtures at high initial density

1984 ◽  
Vol 20 (1) ◽  
pp. 89-96 ◽  
Author(s):  
N. S. Astapov ◽  
Yu. A. Nikolaev ◽  
V. Yu. Ul'yanitskii
Keyword(s):  
Initial Density ◽  
Detonation Parameters ◽  
High Initial Density

scholarly journals Inoculum effect of antimicrobial peptides

2021 ◽  
Vol 118 (21) ◽  
pp. e2014364118
Author(s):  
Maria Rosa Loffredo ◽  
Filippo Savini ◽  
Sara Bobone ◽  
Bruno Casciaro ◽  
Henrik Franzyk ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Cell Density ◽  
Initial Density ◽  
Resistant Bacteria ◽  
Bacterial Killing ◽  
Drug Resistant Bacteria ◽  
Cell Association ◽  
Inoculum Effect ◽  
Cell Densities ◽  
Bacterial Growth Inhibition

The activity of many antibiotics depends on the initial density of cells used in bacterial growth inhibition assays. This phenomenon, termed the inoculum effect, can have important consequences for the therapeutic efficacy of the drugs, because bacterial loads vary by several orders of magnitude in clinically relevant infections. Antimicrobial peptides are a promising class of molecules in the fight against drug-resistant bacteria because they act mainly by perturbing the cell membranes rather than by inhibiting intracellular targets. Here, we report a systematic characterization of the inoculum effect for this class of antibacterial compounds. Minimum inhibitory concentration values were measured for 13 peptides (including all-D enantiomers) and peptidomimetics, covering more than seven orders of magnitude in inoculated cell density. In most cases, the inoculum effect was significant for cell densities above the standard inoculum of 5 × 105 cells/mL, while for lower densities the active concentrations remained essentially constant, with values in the micromolar range. In the case of membrane-active peptides, these data can be rationalized by considering a simple model, taking into account peptide–cell association, and hypothesizing that a threshold number of cell-bound peptide molecules is required in order to cause bacterial killing. The observed effect questions the clinical utility of activity and selectivity determinations performed at a fixed, standardized cell density. A routine evaluation of the dependence of the activity of antimicrobial peptides and peptidomimetics on the inoculum should be considered.

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