The Study of the Kinetic Model of Halomonas Salina Fermenting Ectoine

2013 ◽  
Vol 781-784 ◽  
pp. 647-652
Author(s):  
Shuang Gao ◽  
Ling Hua Zhang ◽  
Qing Chen ◽  
Lin Bai ◽  
Ya Jun Lang
Keyword(s):  
Cell Growth ◽  
Kinetic Model ◽  
Monosodium Glutamate ◽  
Biomass Concentration ◽  
Correlation Coefficients ◽  
Kinetic Mechanism ◽  
Product Formation ◽  
Substrate Consumption ◽  
Nonlinear Fitting ◽  
Potential Applications

Ectoine had important physiological functions and superior potential applications, so the study of ectoine was extensively attented. This article was related to kinetic models of cell growth, product formation and substrate consumption, which was not only established according to the characteristics of ectoine batch fermentation by Halomonas salina DSM 5928 but also obtained the kinetic parameters by the nonlinear fitting method in the Microcal Origin software. Logistic, Luedeking-Piret and Luedeking-Piret-like equations was applied to analyze the cell growth, the ectoine formation and the substrate consumption by the kinetic model，respectively. The results between calculated values and experimental data were coincident. By fitting, correlation coefficients R2 were ≥ 0.989. The fermentation conditions of ectoine were analyzed according to the model. The results showed that ectoine productivity (0.28 g/L/h) was the highest when initial monosodium glutamate concentration (S0) was 60 g/L. However, when S0 was 80 g/L, the ectoine concentration was maximal, i.e., 7.59 g/L. The research suggested that ectoine formation belonged to the mixed kinetic mechanism of cell growth and biomass concentration, while the ectoine production mainly depended on instantaneous biomass concentration. The fermentation method for improving ectoine concentration was further proved. The established kinetic model will be of significant value to provide the optimal conditions of present process.

scholarly journals Application Of The Z And Laplace Transforms To Panification Yeast Production Using An Airlift Bioreactor

2020 ◽  
Author(s):  
Arnaldo Silva Oliveira ◽  
Juan C. B. Neto ◽  
Igor J. B. Santos ◽  
Edson R. Nucci
Keyword(s):  
Cell Growth ◽  
Product Formation ◽  
Laplace Transforms ◽  
Discrete Models ◽  
Average Error ◽  
Growth Substrate ◽  
Substrate Consumption ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mathematical Techniques ◽  
Discrete Time Models

Abstract The Z- and Laplace transforms are mathematical techniques applied to solve difference equations and differential equations, respectively. Mathematical models used to describe cell growth, substrate consumption and product formation in bioprocesses can be represented by these types of equations. Thus, in this work, the fermentation process of the yeast Saccharomyces cerevisiae was modeled using different models from the literature, and the Z- and Laplace transforms were applied to solve the equations. Once the equations were solved, the models were represented in state space and simulated in Octave® software. Finally, the models were compared to experimental data from previous studies and to each other. Verhulst was the model that best described the process, with an average error of 4.74% for cell growth and 13.9% for substrate consumption. This work is unprecedented since no works that use the Z transform and discrete models for the representation of fermentation of this yeast were found in the literature. Even more importantly, this work proved that discrete-time models can be applied to bioprocesses with the same precision as continuous-time models.

Effect of Medium Composition and Kinetic Studies on Extracellular and Intracellular Production of L-asparaginase from Pectobacterium carotovorum

2010 ◽  
Vol 16 (2) ◽  
pp. 115-125 ◽  
Author(s):  
S. Arrivukkarasan ◽  
M. Muthusivaramapandian ◽  
R. Aravindan ◽  
T. Viruthagiri
Keyword(s):  
Cell Growth ◽  
Monosodium Glutamate ◽  
Kinetic Studies ◽  
Product Formation ◽  
Medium Composition ◽  
Coefficient Of Determination ◽  
Logarithmic Phase ◽  
Pectobacterium Carotovorum ◽  
Medium Components ◽  
Asparaginase Activity

Microbial L-asparaginase occupies a prominent place among biocatalysts owing to their ability to catalyze the reaction that hydrolyze the asparagine molecule. Effect of various medium components on the production of L-asparaginase in submerged fermentation by Pectobacterium carotovorum was studied for optimal nutrient requirements. Six different media compositions were tested for the L-asparaginase production keeping fermentation conditions constant at temperature 30 °C, initial pH 7.0 and agitation speed of 120 rpm. Maximum intracellular and extracellular L-asparaginase activity was obtained in the medium containing tryptone, yeast extract, monosodium glutamate, K2HPO4 and L-asparagine. These medium components were further optimized by central composite experimental design using response surface methodology. Maximum intracellular and extracellular L-asparaginase activity of 2.282 U/mL and 0.587 U/mL were obtained respectively at the late logarithmic phase in optimized media. Unstructured kinetic models were used to describe the cell growth and product formation kinetics. The unstructured models predicted the cell growth and product formation profile accurately with high coefficient of determination.

Ammonium Phosphate as a Sole Nutritional Supplement for the Fermentative Production of 2,3-Butanediol from Sugar Cane Juice

2001 ◽  
Vol 56 (9-10) ◽  
pp. 787-791 ◽  
Author(s):  
Marília A. Berbert-Molina ◽  
Sunao Sato ◽  
Mauricio M. Silveira
Keyword(s):  
Cell Growth ◽  
Sugar Cane ◽  
Ammonium Phosphate ◽  
Nutritional Supplement ◽  
Product Formation ◽  
Complete Medium ◽  
Substrate Consumption ◽  
Cane Juice ◽  
Fermentative Production ◽  
Sugar Cane Juice

AbstractThe production of 2,3-butanediol by Klebsiella pneumoniae from sugar cane juice supplemented with different salts was studied. This microorganism is able to degrade sucrose present in sugar cane juice containing ammonium phosphate as the sole nutritional supplement. With a sugar cane juice-based medium containing ~180 g sucrose /1 and 8.0 g (NH4)2HPO4, / 1, over 70 g 2,3-butanediol plus acetoin / 1 were formed. This result is comparable to that achieved with a sugar cane juice-based medium containing several nutrients, although the kinetic profiles of these runs presented significant differences. With the ammonium phosphate- enriched medium, cell growth was initially favoured by both the strong oxygen supply and the higher water activity due to the lower concentration of nutrients. After 14 h, the limitation in some nutrients led to the interruption of cell growth, and decreasing rates for product formation and substrate consumption were observed. During the stationary phase of this run, sucrose was preferentially converted to product, and the substrate was completely depleted after 35 h of the process. With the complete medium, the substrate was totally consumed after 36 h of run. In this case, the higher initial concentration of nutrients reduced the overall process rate but sustained the cell growth for 27 h. Conversion yields of 0.40 g product / g sucrose and productivities close to 2.0 g/ lxh were obtained under both conditions.

scholarly journals Development of a Decellularized Porcine Esophageal Matrix for Potential Applications in Cancer Modeling

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1055
Author(s):  
Hersh Chaitin ◽  
Michael L. Lu ◽  
Michael B. Wallace ◽  
Yunqing Kang
Keyword(s):  
Cell Growth ◽  
Lymphatic Vessels ◽  
Significant Loss ◽  
Cancer Cell Growth ◽  
Cell Growth And Migration ◽  
Decellularized Extracellular Matrix ◽  
Cancer Models ◽  
The Matrix ◽  
Potential Applications ◽  
And Migration

Many decellularized extracellular matrix-derived whole organs have been widely used in studies of tissue engineering and cancer models. However, decellularizing porcine esophagus to obtain decellularized esophageal matrix (DEM) for potential biomedical applications has not been widely investigated. In this study a modified decellularization protocol was employed to prepare a porcine esophageal DEM for the study of cancer cell growth. The cellular removal and retention of matrix components in the porcine DEM were fully characterized. The microstructure of the DEM was observed using scanning electronic microscopy. Human esophageal squamous cell carcinoma (ESCC) and human primary esophageal fibroblast cells (FBCs) were seeded in the DEM to observe their growth. Results show that the decellularization process did not cause significant loss of mechanical properties and that blood ducts and lymphatic vessels in the submucosa layer were also preserved. ESCC and FBCs grew on the DEM well and the matrix did not show any toxicity to cells. When FBS and ESCC were cocultured on the matrix, they secreted more periostin, a protein that supports cell adhesion on matrix. This study shows that the modified decellularization protocol can effectively remove the cell materials and maintain the microstructure of the porcine esophageal matrix, which has the potential application of studying cell growth and migration for esophageal cancer models.

Improved Dynamic System of Microbial Continuous Fermentation and its Parameter Identification

2014 ◽  
Vol 633-634 ◽  
pp. 545-549
Author(s):  
Hong Li Xiao ◽  
Lan Zhang Chong ◽  
Fei Li Hang ◽  
Wang Yong
Keyword(s):  
Dynamic System ◽  
Consumption Rate ◽  
Continuous Fermentation ◽  
Formation Rate ◽  
Product Formation ◽  
Cellular Growth ◽  
Specific Substrate ◽  
Substrate Consumption ◽  
Specific Product ◽  
Product Formation Rate

In this paper, the nonlinear dynamic system of microbe continuous fermentation products 1,3-propanediol (1,3-PD) is rewritten by improving the specific cellular growth rate, specific substrate consumption rate and specific product formation rate. Firstly, under the condition of substrate glycol excess and active trans-membrane transport, according to the dynamic behavior the fermentation process, we consider the glycerol and 1,3–PD concentration within the cell, and improve the specific cellular growth rate, specific substrate consumption rate and specific product formation rate, then rewrite the dynamic system of microbial continuous fermentation process. Secondly, taking the dynamic system as main constraint condition, we establish the parameter identification model and prove the existence of the optimal solution. Lastly, the numerical results calculated by particle swarm algorithm show that the improved model is suitable for describe the dynamic behavior of 1,3-PD, but is not accurate enough for by-products.

Ignition Characteristics of a Fischer-Tropsch Synthetic Jet Fuel

2008 ◽  
Author(s):  
P. Gokulakrishnan ◽  
M. S. Klassen ◽  
R. J. Roby
Keyword(s):  
Kinetic Model ◽  
Ignition Delay ◽  
Flow Reactor ◽  
Kinetic Mechanism ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Ignition Characteristics

Ignition delay times of a “real” synthetic jet fuel (S8) were measured using an atmospheric pressure flow reactor facility. Experiments were performed between 900 K and 1200 K at equivalence ratios from 0.5 to 1.5. Ignition delay time measurements were also performed with JP8 fuel for comparison. Liquid fuel was prevaporized to gaseous form in a preheated nitrogen environment before mixing with air in the premixing section, located at the entrance to the test section of the flow reactor. The experimental data show shorter ignition delay times for S8 fuel than for JP8 due to the absence of aromatic components in S8 fuel. However, the ignition delay time measurements indicate higher overall activation energy for S8 fuel than for JP8. A detailed surrogate kinetic model for S8 was developed by validating against the ignition delay times obtained in the present work. The chemical composition of S8 used in the experiments consisted of 99.7 vol% paraffins of which approximately 80 vol% was iso-paraffins and 20% n-paraffins. The detailed kinetic mechanism developed in the current work included n-decane and iso-octane as the surrogate components to model ignition characteristics of synthetic jet fuels. The detailed surrogate kinetic model has approximately 700 species and 2000 reactions. This kinetic mechanism represents a five-component surrogate mixture to model generic kerosene-type jets fuels, namely, n-decane (for n-paraffins), iso-octane (for iso-paraffins), n-propylcyclohexane (for naphthenes), n-propylbenzene (for aromatics) and decene (for olefins). The sensitivity of iso-paraffins on jet fuel ignition delay times was investigated using the detailed kinetic model. The amount of iso-paraffins present in the jet fuel has little effect on the ignition delay times in the high temperature oxidation regime. However, the presence of iso-paraffins in synthetic jet fuels can increase the ignition delay times by two orders of magnitude in the negative temperature (NTC) region between 700 K and 900 K, typical gas turbine conditions. This feature can have a favorable impact on preventing flashback caused by the premature autoignition of liquid fuels in lean premixed prevaporized (LPP) combustion systems.

Adsorption–Desorption Characteristics of ss-DNA on 2D TpTta-COF Studied by Fluorescently Labeled Oligonucleotides

NANO ◽  
2021 ◽  
pp. 2150050
Author(s):  
Zhaoyu Han ◽  
Sen Li ◽  
Shaoxian Yin ◽  
Zhi-Qin Wang ◽  
Yanfei Cai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Kinetic Mechanism ◽  
Optical Biosensors ◽  
Desorption Kinetic ◽  
Wide Range ◽  
Potential Applications ◽  
Fluorescently Labeled Oligonucleotides ◽  
Adsorption Desorption ◽  
Physical And Chemical ◽  
And Chemical Properties

Being the newest member of the 2D materials family, 2D-nanosheet possesses many distinctive physical and chemical properties resulting in a wide range of potential applications. Recently, it was discovered that 2D COF can adsorb single-stranded DNA (ss-DNA) efficiently as well as usefully to quench fluorophores. These properties make it possible to prepare DNA-based optical biosensors using 2D COF. While practical analytical applications are being demonstrated, the fundamental understanding of binding between 2D COF and DNA in solution received relatively less attention. In this work, we carried out a systematic study to understand the adsorption and desorption kinetic, mechanism, and influencing factors of ss-DNA on the surface of 2D COF. We demonstrated that shorter DNAs are adsorbed more rapidly and bind more tightly to the surface of 2D COF. The adsorption is favored by a higher pH. The different buffer types also can affect the adsorption. In Tris-HCl solution, the adsorption reached highest efficiency. By adding the complementary DNA (cDNA), desorption of the absorbed DNA on 2D COF can be achieved. Further, desorption efficiency can also be exchanged by various surfactant in solution. These findings are important for further understanding of the interactions between DNA and COFs and for the optimization of DNA and COF-based devices and sensors.

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