THE KINETICS OF METABOLISM OF GIBBERELLA FUJIKUROI IN STIRRED CULTURE

1964 ◽  
Vol 10 (3) ◽  
pp. 407-444 ◽  
Author(s):  
A. Borrow ◽  
Sheila Brown ◽  
E. G. Jefferys ◽  
R. H. J. Kessell ◽  
Eithne C. Lloyd ◽  
...  
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Nitrogen Uptake ◽  
Exponential Growth ◽  
Ammonium Acetate ◽  
Specific Growth ◽  
Dry Weight ◽  
Gibberella Fujikuroi ◽  
Ammonium Tartrate ◽  
Kinetics Of

Some aspects are described of the kinetics of the growth of Gibberella fujikuroi in nitrogen-limited media containing either ammonium nitrate, ammonium acetate, ammonium tartrate, urea, or glycine. Also varied were inoculum size, agitation rate, pH, and initial concentrations of glucose and nitrogen source. The significance of kinetic parameters used in this, and published studies, is discussed.A lag phase was only found on ammonium acetate media or when high concentrations of glucose were present. Early growth was exponential on all nitrogen sources. On ammonium acetate the specific growth rate decreased at a dry weight of ca. 1 mg/g WS (Whole unfiltered Sample). On ammonium nitrate, early exponential growth utilized more NH3-nitrogen than NO3-nitrogen with a concomitant decrease in pH. In the range pH 3.0–2.8 NH3-nitrogen uptake and dry weight increase ceased, but NO3-nitrogen uptake continued, and the pH increased until growth and NH3-nitrogen uptake restarted. This pattern could be repeated. Finally, exponential growth was resumed at a low specific growth rate. On glycine, urea, and ammonium tartrate media, exponential growth continued to a dry weight of about 7 mg/g WS. During this period the uptakes relative to dry weight (contributions) of glucose, nitrogen, phosphate, and magnesium remained constant and were unaffected by the rate of agitation, as also was the specific growth rate, but the latter decreased with increasing glucose concentration.A period of linear growth could follow the exponential period. The contribution of glucose was greater, and that of phosphate and magnesium less, than during exponential growth. The dry weight at which exponential growth changed to linear growth was greater the higher the rate of agitation, and this change may be a response to oxygen restriction.After nitrogen exhaustion, fat and carbohydrate accumulation in the cells largely accounted for the increase in dry weight. The specific rates of dry weight increase and glucose uptake remained constant over the lower range of initial nitrogen concentrations. Both rates decreased with increasing nitrogen over the higher range.Gibberellic acid production began at, or soon after, nitrogen exhaustion. The amount present increased linearly with time. The productivity decreased with increasing glucose concentration, and first increased and then decreased with increasing initial nitrogen. The maximum amount produced was proportional to the initial nitrogen provided. Some published results are discussed in the light of these relations.

scholarly journals AKTIVITAS INULINASE OLEH Pichia manshurica DAN FUSAN F4 PADA FERMENTASI BATCH DENGAN UMBI DAHLIA (Dahlia sp) SEBAGAI SUBSTRAT

REAKTOR ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 187 ◽  
Author(s):  
Wijanarka Wijanarka ◽  
Endang Sutariningsih Soetarto ◽  
Kumala Dewi ◽  
Ari Indrianto
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Lag Phase ◽  
Growth Media ◽  
A Value ◽  
Inulinase Activity ◽  
Pichia Manshurica ◽  
Microbial Strains ◽  
Kinetics Of

ACTIVITY OF INULINASE OF Pichia Manshuria AND FUSAN F4 ON BATCH FERMENTATION UDING DAHLIA TUBER (Dahlia sp) AS A SUBSTRATE. A dahlia tuber is one of the common inulin rich crops. Inulin is formed by units of fructans, which are polymers of D-fructose. Inulinases (EC 3.2.1.7) catalyze the hydrolysis of inulin, producing fructooligosaccharides (FOS), inulooligosaccharides (IOS), pulullan, acetone, butanol and sorbitol, therefore dahlia tubers are used as growth media. The inulin hydrolyzing activity has been reported from various microbial strains Pichia manshurica and Fusan F4 which is the result of fusion protoplast. The objective of this study was to determine the activity of inulinase Pichia manshurica and Fusan F4 on the substrate dahlia tubers. Fusan F4 to increase inulinase activity compared with Pichia manshurica and to investigate the kinetics of specific growth rate (μ) and time double (g) from of Pichia manshurica and Fusan F4. The results showed that the exponential phase occurs at 0-12 hour without a lag phase. P. manshurica has a specific growth rate (μ) of 0.18/hour with time double (g) 3.90 hours and the inulinase enzyme activity of 0.56 IU, while for Fusan F4 consecutive has a value μ of 0.20/hour, g of 3.49 hours and the activity of 0.69 IU. The conclusion of this research is to improve Fusan F4 inulinase activity and the ability has to be better than the Pichia manshurica.Umbi dahlia merupakan salah satu umbi yang mengandung inulin. Inulin merupakan polimer fruktan yang dapat dipecah oleh enzim inulinase (E.C. 3.2.1.7) menjadi fruktosa. Fruktosa merupakan bahan baku dasar untuk pembuatan FOS, IOS, pulullan, aseton dan sorbitol, oleh karena itu umbi dahlia digunakan sebagai media pertumbuhan. Enzim inulinase ini secara indigenous dimiliki oleh Pichia manshurica dan Fusan F4 yang merupakan hasil fusi protoplas.Tujuan  penelitian ini adalah  untuk mengetahui aktivitas inulinase Pichia manshurica dan Fusan F4 pada substrat umbi dahlia, Fusan F4 mampu meningkatkan aktivitas inulinase dibandingkan dengan Pichia manshurica serta untuk mengetahui kinetika kecepatan pertumbuhan specifik (µ) dan waktu generasi (g) Pichia manshurica dan Fusan F4. Hasil penelitian menunjukkan bahwa fase  eksponensial terjadi pada jam ke-0 sampai jam ke-12 tanpa diikuti fase lag, Pichia manshurica mempunyai kecepatan pertumbuhan specific (µ)  sebesar 0,18/jam dengan waktu generasi (g) 3,90 jam dan aktivitas enzim inulinase yang dihasilkan sebesar 0,56 IU, sedangkan untuk fusan F4 secara berturut-turut mempunyai nilai µ sebesar 0,20/jam, g sebesar 3,49 jam dan aktivitas sebesar 0,69 IU. Kesimpulan dari penelitian ini adalah Fusan F4 mampu meningkatkan aktivitas inulinase dan mempunyai kemampuan lebih baik dibanding dengan Pichia manshurica.

scholarly journals Specific growth rate governs AOX1 gene expression, affecting the production kinetics of Pichia pastoris (Komagataella phaffii) PAOX1-driven recombinant producer strains with different target gene dosage

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Javier Garrigós-Martínez ◽  
Miguel Angel Nieto-Taype ◽  
Arnau Gasset-Franch ◽  
José Luis Montesinos-Seguí ◽  
Xavier Garcia-Ortega ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Rate ◽  
Pichia Pastoris ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Gene Dosage ◽  
Fed Batch ◽  
Komagataella Phaffii ◽  
Production Kinetics ◽  
Kinetics Of

Abstract Background The PAOX1-based expression system is the most widely used for producing recombinant proteins in the methylotrophic yeast Pichia pastoris (Komagataella phaffii). Despite relevant recent advances in regulation of the methanol utilization (MUT) pathway have been made, the role of specific growth rate (µ) in AOX1 regulation remains unknown, and therefore, its impact on protein production kinetics is still unclear. Results The influence of heterologous gene dosage, and both, operational mode and strategy, on culture physiological state was studied by cultivating the two PAOX1-driven Candida rugosa lipase 1 (Crl1) producer clones. Specifically, a clone integrating a single expression cassette of CRL1 was compared with one containing three cassettes over broad dilution rate and µ ranges in both chemostat and fed-batch cultivations. Chemostat cultivations allowed to establish the impact of µ on the MUT-related MIT1 pool which leads to a bell-shaped relationship between µ and PAOX1-driven gene expression, influencing directly Crl1 production kinetics. Also, chemostat and fed-batch cultivations exposed the favorable effects of increasing the CRL1 gene dosage (up to 2.4 fold in qp) on Crl1 production with no significant detrimental effects on physiological capabilities. Conclusions PAOX1-driven gene expression and Crl1 production kinetics in P. pastoris were successfully correlated with µ. In fact, µ governs MUT-related MIT1 amount that triggers PAOX1-driven gene expression—heterologous genes included—, thus directly influencing the production kinetics of recombinant protein.

scholarly journals Kinetika detoksifikasi umbi gadung (dioscorea hispida dennst.) secara fermentasi dengan kapang mucor racemosus

REAKTOR ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 81 ◽  
Author(s):  
Marissa Widiyanti ◽  
Andri Cahyo Kumoro
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Cyanogenic Glucosides ◽  
Mucor Racemosus ◽  
Dry Land ◽  
Physical Chemical ◽  
Fungal Fermentation ◽  
Biological Methods ◽  
Kinetics Of

Abstract THE KINETICS OF GADUNG (Dioscorea hispida dennst.) TUBER DETOXIFICATION VIA FUNGAL FERMENTATION USING Mucor racemosus. Bitter yam (Dioscorea hispida Dennst.) is one of carbohydrate sources used as staple food commonly found in Indonesian dry-land. However, this tuber has been underutilized due to the presence of an antinutrition compound, namely cyanogenic glucosides. Removal of cyanides from foodstuffs can be done either by physical, chemical or biological methods. In this study, the effect of time on the detoxification of gadung tuber chips from cyanides via fermentation using Mucor racemosus and its kinetics were investigated. Gadung chip samples were withdrawn from the fermentation system at every 24 hours interval for biomass and cyanides contents analysis. It was clear that the cyanides content decreased as the fermentation went by. Safely consumed gadung tuber chips were obtained from fermentation of the chips for 120 hours from which cyanides content as low as 49.41 mg/kg was achieved. The logistic equation successfully described the growth rate of Mucor racemosus under studied condition. The specific growth rate of Mucor racemosus in gadung chips was found to be 0.0297/hr or about a half of specific growth rate of that mold when grown in the readily consumed yeast-pepton-glucose (YPG) media. Keywords: fermentation; yam; monod; Mucor racemosus; cyanogen  Abstrak Umbi gadung (Dioscorea hispida Dennst.) merupakan salah satu sumber karbohidrat yang digunakan sebagai makanan pokok yang biasa ditemukan di lahan kering di wilayah Indonesia. Namun, umbi ini kurang dimanfaatkan karena adanya senyawa antinutrisi, yaitu cyanogenic glucosides. Penghilangan senyawa sianida dari bahan makanan dapat dilakukan baik dengan metode fisik, kimia atau biologi. Penelitian ini bertujuan untuk mengkaji pengaruh waktu pada detoksifikasi irisan umbi gadung dari senyawa sianida melalui fermentasi dengan menggunakan kapang Mucor racemosus dan kinetikanya. Cuplikan irisan umbi gadung diambil dari sistem fermentasi pada setiap jeda waktu 24 jam untuk dianalisis kadar biomassa dan sianidanya. Hasil penelitian menunjukkan bahwa kandungan sianida menurun seiring dengan bertambahnya waktu fermentasi. Irisan umbi gadung yang aman dikonsumsi dapat diperoleh dari fermentasi irisan ubi gadung selama 120 jam dengan kandungan sianida serendah 49,41 mg/kg. Persamaan logistik berhasil menggambarkan tingkat pertumbuhan kapang Mucor racemosus dengan baik. Tingkat pertumbuhan spesifik dari Mucor racemosus pada irisan umbi gadung adalah 0,0297/jam atau sekitar setengah dari laju pertumbuhan spesifik jamur tersebut saat dibudidayakan pada media yang siap dikonsumsi, seperti ragi-pepton-glukosa (YPG). Kata kunci: fermentasi; gadung; monod; Mucor racemosus; sianogen 

scholarly journals Poly(3-Hydroxybutyrate) Synthesis by Recombinant Escherichia coli arcA Mutants in Microaerobiosis

2006 ◽  
Vol 72 (4) ◽  
pp. 2614-2620 ◽  
Author(s):  
Pablo I. Nikel ◽  
M. Julia Pettinari ◽  
Miguel A. Galvagno ◽  
Beatriz S. Méndez
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Deletion Mutant ◽  
Specific Growth ◽  
Dry Weight ◽  
Low Oxygen ◽  
Oxygen Conditions ◽  
In The Wild ◽  
Microaerobic Conditions

ABSTRACT We assessed the effects of different arcA mutations on poly(3-hydroxybutyrate) (PHB) synthesis in recombinant Escherichia coli strains carrying the pha synthesis genes from Azotobacter sp. strain FA8. The arcA mutations used were an internal deletion and the arcA2 allele, a leaky mutation for some of the characteristics of the Arc phenotype which confers high respiratory capacity. PHB synthesis was not detected in the wild-type strain in shaken flask cultures under low-oxygen conditions, while ArcA mutants gave rise to polymer accumulation of up to 24% of their cell dry weight. When grown under microaerobic conditions in a bioreactor, the arcA deletion mutant reached a PHB content of 27% ± 2%. Under the same conditions, higher biomass and PHB concentrations were observed for the strain bearing the arcA2 allele, resulting in a PHB content of 35% ± 3%. This strain grew in a simple medium at a specific growth rate of 0.69 ± 0.07 h−1, whereas the deletion mutant needed several nutritional additives and showed a specific growth rate of 0.56 ± 0.06 h−1. The results presented here suggest that arcA mutations could play a role in heterologous PHB synthesis in microaerobiosis.

scholarly journals Cellular Microcystin Content in N-Limited Microcystis aeruginosa Can Be Predicted from Growth Rate

2001 ◽  
Vol 67 (1) ◽  
pp. 278-283 ◽  
Author(s):  
Benedict M. Long ◽  
Gary J. Jones ◽  
Philip T. Orr
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Cell Volume ◽  
Microcystis Aeruginosa ◽  
Specific Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
Cell Protein ◽  
Protein Ratio ◽  
Cell Quota

ABSTRACT Cell quotas of microcystin (Q MCYST; femtomoles of MCYST per cell), protein, and chlorophyll a(Chl a), cell dry weight, and cell volume were measured over a range of growth rates in N-limited chemostat cultures of the toxic cyanobacterium Microcystis aeruginosa MASH 01-A19. There was a positive linear relationship betweenQ MCYST and specific growth rate (μ), from which we propose a generalized model that enablesQ MCYST at any nutrient-limited growth rate to be predicted based on a single batch culture experiment. The model predicts Q MCYST from μ, μmax(maximum specific growth rate), Q MCYSTmax(maximum cell quota), and Q MCYSTmin (minimum cell quota). Under the conditions examined in this study, we predict aQ MCYSTmax of 0.129 fmol cell−1 at μmax and a Q MCYSTmin of 0.050 fmol cell−1 at μ = 0. Net MCYST production rate (R MCYST) asymptotes to zero at μ = 0 and reaches a maximum of 0.155 fmol cell−1 day−1at μmax. MCYST/dry weight ratio (milligrams per gram [dry weight]) increased linearly with μ, whereas the MCYST/protein ratio reached a maximum at intermediate μ. In contrast, the MCYST/Chla ratio remained constant. Cell volume correlated negatively with μ, leading to an increase in intracellular MCYST concentration at high μ. Taken together, our results show that fast-growing cells of N-limited M. aeruginosa are smaller, are of lower mass, and have a higher intracellular MCYST quota and concentration than slow-growing cells. The data also highlight the importance of determining cell MCYST quotas, as potentially confusing interpretations can arise from determining MCYST content as a ratio to other cell components.

scholarly journals Growth Kinetics of Hyphomicrobium and Thiobacillus spp. in Mixed Cultures Degrading Dimethyl Sulfide and Methanol

2010 ◽  
Vol 76 (16) ◽  
pp. 5423-5431 ◽  
Author(s):  
Alexander C. Hayes ◽  
Steven N. Liss ◽  
D. Grant Allen
Keyword(s):  
Growth Rate ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Specific Growth Rate ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Dimethyl Sulfide ◽  
Specific Growth ◽  
Rrna Gene ◽  
Kinetics Of

ABSTRACT The growth kinetics of Hyphomicrobium spp. and Thiobacillus spp. on dimethyl sulfide (DMS) and methanol (in the case of Hyphomicrobium spp.) in an enrichment culture created from a biofilter cotreating DMS and methanol were studied. Specific growth rates of 0.099 h−1 and 0.11 h−1 were determined for Hyphomicrobium spp. and Thiobacillus spp., respectively, growing on DMS at pH 7. These specific growth rates are double the highest maximum specific growth rate for bacterial growth on DMS reported to date in the literature. When the pH of the medium was decreased from pH 7 to pH 5, the specific growth rate of Hyphomicrobium spp. decreased by 85%, with a near 100-fold decline in the yield of Hyphomicrobium 16S rRNA gene copies in the mixed culture. Through the same pH shift, the specific growth rate and 16S rRNA gene yield of Thiobacillus spp. remained similar. When methanol was used as a substrate, the specific growth rate of Hyphomicrobium spp. declined much less over the same pH range (up to 30%) while the yield of 16S rRNA gene copies declined by only 50%. Switching from an NH4 +-N-based source to a NO3 −-N-based source resulted in the same trends for the specific growth rate of these microorganisms with respect to pH. This suggests that pH has far more impact on the growth kinetics of these microorganisms than the nitrogen source. The results of these mixed-culture batch experiments indicate that the increased DMS removal rates observed in previous studies of biofilters cotreating DMS and methanol are due to the proliferation of DMS-degrading Hyphomicrobium spp. on methanol at pH levels not conducive to high growth rates on DMS alone.

Growth kinetics of Escherichia coli with galactose and several other sugars in carbon-limited chemostat culture

1999 ◽  
Vol 46 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Urs Lendenmann ◽  
Mario Snozzi ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Steady State ◽  
Specific Growth Rate ◽  
Growth Kinetics ◽  
Specific Growth ◽  
Chemostat Culture ◽  
Monod Model ◽  
E Coli ◽  
Kinetics Of

Kinetic models for microbial growth describe the specific growth rate (μ) as a function of the concentration of the growth-limiting nutrient (s) and a set of parameters. A typical example is the model proposed by Monod, where μ is related to s using substrate affinity (Ks) and the maximum specific growth rate (μmax). The preferred method to determine such parameters is to grow microorganisms in continuous culture and to measure the concentration of the growth-limiting substrate as a function of the dilution rate. However, owing to the lack of analytical methods to quantify sugars in the microgram per litre range, it has not been possible to investigate the growth kinetics of Escherichia coli in chemostat culture. Using an HPLC method able to determine steady-state concentrations of reducing sugars, we previously have shown that the Monod model adequately describes glucose-limited growth of E. coli ML30. This has not been confirmed for any other sugar. Therefore, we carried out a similar study with galactose and found steady-state concentrations between 18 and 840 μg·L-1 for dilution rates between 0.2 and 0.8·h-1, respectively. With these data the parameters of several models giving the specific growth rate as a function of the substrate concentration were estimated by nonlinear parameter estimation, and subsequently, the models were evaluated statistically. From all equations tested, the Monod model described the data best. The parameters for galactose utilisation were μmax = 0.75·h-1 and Ks = 67 μg·L-1. The results indicated that accurate Ks values can be estimated from a limited set of steady-state data when employing μmax measured during balanced growth in batch culture. This simplified procedure was applied for maltose, ribose, and fructose. For growth of E. coli with these sugars, μmax and Ks were for maltose 0.87·h-1, 100 μg·L-1; for ribose 0.57·h-1, 132 μg·L-1, and for fructose 0.70·h-1, 125 μg·L-1. Key words: monod model, continuous culture, galactose, glucose, fructose, maltose, ribose.

scholarly journals Effect of soil extracts concentration on specific growth rate and lipid content of chlorella vulgaris in bolds basal medium

2014 ◽  
Vol 10 (2) ◽  
Author(s):  
Ani Idris ◽  
M. Atta ◽  
A. Bukhari
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Chlorella Vulgaris ◽  
Mass Culture ◽  
Specific Growth ◽  
Basal Medium ◽  
Dry Weight ◽  
Soil Extract ◽  
Soil Extracts ◽  
Key Factor

Effective nutrient medium is the key factor that significantly influences the specific growth rate and the final concentration of microalgae. The main objective of this study was to optimize the microalgal growth in mass culture system under the effect of soil extract in modified Bolds Basal medium. Chlorella vulgaris was grown aseptically for 10 days at five different concentrations of soil extract (10, 20, 30, 40, 50ml/L) at 25°C cultivation temperature. After 10 days of cultivation, Chlorella vulgaris showed maximum cell concentration of 5x107/ml at 30ml/L of soil extract concentration which corresponds to the maximum specific growth rate 1.56μd-1 with the doubling rate of 2.25d-1   andlipid yield of 22.74 % of dry weight.________________________________________GRAPHICAL ABSTRACT

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