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

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 Effect of Physical Factors on the Growth of Chlorella Vulgaris on Enriched Media Using the Methods of Orthogonal Analysis and Response Surface Methodology

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Lile He ◽  
Yongcan Chen ◽  
Xuefei Wu ◽  
Shu Chen ◽  
Jing Liu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Response Surface Methodology ◽  
Specific Growth Rate ◽  
Chlorella Vulgaris ◽  
Specific Growth ◽  
Liquid Ratio ◽  
Physical Conditions ◽  
Orthogonal Analysis ◽  
Solid Liquid

In addition to chemical factors, physical conditions also play a key role in the growth of microalgae. In this study, solid sediment in rivers was simulated by pure quartz sand with different particle sizes and the physical effects of disturbance rate, solid–liquid ratio and particle size on the growth of Chlorella vulgaris (C. vulgaris) were investigated through orthogonal analysis and response surface methodology (RSM) during co-cultivation of C. vulgaris and sediment. The result of ANOVA in orthogonal analysis showed that the effect ability of a single factor on biomass can be ranked as disturbance rate > particle size > solid–liquid ratio, 100 r/min disturbance rate and 30–40 M particle size are the most significant at the 0.05 level. Furthermore, the specific growth rate can reach 0.25/d and 0.27/d, respectively. With the growth of C. vulgaris, the pH of the solution reached a maximum of 10.7 in a week. The results from the RSM showed that strong interactions are reflected in the combinations of disturbance rate and solid–liquid ratio, and disturbance rate and particle size. Ramp desirability of the biomass indicates that the optimum levels of the three variables are 105 r/min disturbance rate, 0.117 g/mL solid–liquid ratio and 30–40 M particle size. In this case, the biomass can grow seven times in a week with 0.27/d specific growth rate and a pH value of 7–10.4. This study shows that the growth of C. vulgaris can be regulated by changing physical conditions simultaneously, and the optimization of physical conditions can be applied to biomass production, algae prediction and acid water treatment in rivers, lakes and reservoirs.

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.

Osmotic effects on radial growth rate and specific growth rate of three soil fungi

1978 ◽  
Vol 24 (11) ◽  
pp. 1434-1437 ◽  
Author(s):  
R. E. Sterne ◽  
T. H. McCarver
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Liquid Medium ◽  
Growth Rates ◽  
Radial Growth ◽  
Specific Growth ◽  
Basal Medium ◽  
Pythium Ultimum ◽  
Radial Growth Rate ◽  
Osmotic Potentials

The radial growth rate on osmotically adjusted agar medium and the relative specific growth rate in osmotically adjusted liquid medium were determined for Rhizoctonia solani, Pythium ultimum, and Verticillium dahliae. On basal medium, an isolate of P. ultimum and R. solani had similar radial growth rates of 0.52 and 0.47 mm/h, respectively, whereas V. dahliae grew at a rate of 0.08 mm/h. Radial growth rate was reduced 50% at osmotic potentials of −16, −27, and −32 bars for P. ultimum, R. solani, and V. dahliae, respectively. No growth occurred at −32 bars for P. ultimum, −56.2 bars for R. solani, and −100 bars for V. dahlia. Specific growth rates in liquid culture were 0.011 h−1 for P. ultimum, 0.008 h−1 for V. dahliae, and 0.026 h−1 for R. solani. Ratios of radial growth rate (Kr) to specific growth rate (αs) were computed for each fungus growing at different osmotic potentials. There was not a constant relationship between Kr on agar and αs in liquid medium, e.g., Kr/αs ratios varied from 8–41% from a mean ratio for a particular species. The results indicated that radial growth rate on osmotic agar was not useful as a measure of relative specific growth rate of a fungus in osmotically adjusted liquid medium.

On-line viable biomass measurement and estimation of the specific growth rate of activated sludge from municipal wastewater treatment

2001 ◽  
Vol 43 (7) ◽  
pp. 97-102 ◽  
Author(s):  
E. J. November ◽  
J. F. Van Impe
Keyword(s):  
Growth Rate ◽  
Activated Sludge ◽  
Specific Growth Rate ◽  
Municipal Wastewater ◽  
Specific Growth ◽  
Dry Weight ◽  
Municipal Wastewater Treatment ◽  
Experimental Conditions ◽  
On Line ◽  
Viable Biomass

In order to control wastewater processes, on-line measurements of important process variables are crucial. This contribution focuses on the applicability of the Biomass Monitor for on-line viable biomass measurement of activated sludge from a municipal wastewater plant. In addition, the specific growth rate of the sludge is estimated on-line, based on the information derived from the device under study. Compared to dry weight measurements, the Biomass Monitor hardware offers the advantage of a biologically more appropriate observation of the biomass by only taking into account the viable cells in the population. The optimal measurement frequency of the biomass monitoring device for the given experimental conditions has been determined. Furthermore, the capacitance readings have been correlated with off-line analyses of dry weight of the sludge during the experimental phase in which no death of cells occurred. Finally, an evaluation of the estimator of the specific growth rate including its tuning is presented.

scholarly journals Influence of Carbon Source on Nitrate Removal by Nitrate-TolerantKlebsiella oxytoca CECT 4460 in Batch and Chemostat Cultures

1998 ◽  
Vol 64 (8) ◽  
pp. 2970-2976 ◽  
Author(s):  
Guadalupe Piñar ◽  
Karin Kovárová ◽  
Thomas Egli ◽  
Juan L. Ramos
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Nitrate Removal ◽  
Dry Weight ◽  
Specific Rate ◽  
Continuous Cultures ◽  
Batch Cultures ◽  
Chemostat Cultures ◽  
C And N

ABSTRACT The nitrate-tolerant organism Klebsiella oxytoca CECT 4460 tolerates nitrate at concentrations up to 1 M and is used to treat wastewater with high nitrate loads in industrial wastewater treatment plants. We studied the influence of the C source (glycerol or sucrose or both) on the growth rate and the efficiency of nitrate removal under laboratory conditions. With sucrose as the sole C source the maximum specific growth rate was 0.3 h−1, whereas with glycerol it was 0.45 h−1. In batch cultures K. oxytocacells grown on sucrose or glycerol were able to immediately use sucrose as a sole C source, suggesting that sucrose uptake and metabolism were constitutive. In contrast, glycerol uptake occurred preferentially in glycerol-grown cells. Independent of the preculture conditions, when sucrose and glycerol were added simultaneously to batch cultures, the sucrose was used first, and once the supply of sucrose was exhausted, the glycerol was consumed. Utilization of nitrate as an N source occurred without nitrite or ammonium accumulation when glycerol was used, but nitrite accumulated when sucrose was used. In chemostat cultures K. oxytoca CECT 4460 efficiently removed nitrate without accumulation of nitrate or ammonium when sucrose, glycerol, or mixtures of these two C sources were used. The growth yields and the efficiencies of C and N utilization were determined at different growth rates in chemostat cultures. Regardless of the C source, yield carbon (YC) ranged between 1.3 and 1.0 g (dry weight) per g of sucrose C or glycerol C consumed. Regardless of the specific growth rate and the C source, yield nitrogen (YN) ranged from 17.2 to 12.5 g (dry weight) per g of nitrate N consumed. In contrast to batch cultures, in continuous cultures glycerol and sucrose were utilized simultaneously, although the specific rate of sucrose consumption was higher than the specific rate of glycerol consumption. In continuous cultures double-nutrient-limited growth appeared with respect to the C/N ratio of the feed medium and the dilution rate, so that for a C/N ratio between 10 and 30 and a growth rate of 0.1 h−1 the process led to simultaneous and efficient removal of the C and N sources used. At a growth rate of 0.2 h−1the zone of double limitation was between 8 and 11. This suggests that the regimen of double limitation is influenced by the C/N ratio and the growth rate. The results of these experiments were validated by pulse assays.

STUDY OF GROWTH AND N, P CONTENT OF MICROALGAE Chlorella vulgaris CULTIVATED IN DIFFERENT CULTURE MEDIA AND LIGHT INTENSITY

2016 ◽  
Vol 78 (4-2) ◽  
Author(s):  
Dedi Edwin Satriaji ◽  
Muhammad Zainuri ◽  
Ita Widowati
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Specific Growth Rate ◽  
Chlorella Vulgaris ◽  
Specific Growth ◽  
Culture Media ◽  
Algal Growth ◽  
Nitrogen And Phosphorus ◽  
Cell Content ◽  
Media Type

Different light intensity and different media types were used to test their effects on algal growth and biochemical composition of cell content to optimize the growth of algal biomass production. Analysis of the results includes growth calculation of Chlorella vulgaris obtained from 6 d observations for 12 h a day (06:00 am to 06:00 pm) with 3 h breaks in between observation. Laboratory analysis was done at the end of day 5th to determine the content of N, and P. Density of C. vulgaris were influenced by both light intensity and media. Differences media type and light intensity as separated parameters and their interactions significantly (p < 0.05) affected on the growth and nitrogen and phosphor content of C. vulgaris. The highest density of  2 310 × 104 cells · mL–1 was on day 4 with walne media resulting in specific growth rate (µ) of 0.43 per day with a  light intensity of 5 000 lux, and the lowest density of 725 × 104 cells · mL–1 was in day 4 with the NPK media and specific growth rate (µ) 0.25 per day with a light intensity of 4 000 lux. The highest nitrogen and phosphorus content (16.12 mg and 28.19 mg) was obtained from walne medium with a light intensity of 5000 lux, and the lowest (3.43 mg and 2.17 mg) was obtained from NPK with a light intensity of 4 000 lux.

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