Evaluation of the Growth Performance of Microalgae Based on Fine pH Changes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Filali R ◽  
◽  
Tian H ◽  
Micheils E ◽  
Taidi B ◽  
...  
Keyword(s):  
Growth Rate ◽  
Carbon Content ◽  
Specific Growth ◽  
Optimal Growth ◽  
Microalgae Cultivation ◽  
Photoautotrophic Growth ◽  
Microalgae Culture ◽  
Potential Applications ◽  
Photosynthetic Microorganisms ◽  
Range Of Values

Microalgae are photosynthetic microorganisms with many potential applications in the food, cosmetics, pharmaceutical and environmental industries. Currently, commercial microalgae production remains limited. Therefore, improving the growth and the culture density of the microalgae cultivation is one of the key enablers to open the way to mass production and commercialisation of these microorganisms. The effect of culture pH on the photoautotrophic growth of C. vulgaris over a large range of values has been investigated in pH-regulated cultures. For each microalgae culture, the specific growth rate, the cell density, the chlorophyll content, the intracellular carbon content and the nitrogen source consumption were monitored. Optimal growth and carbon incorporation have been observed at pH of 7.0. The fastest growth rate and highest biomass production of C. vulgaris were 0.074 h-1 and 0.896 g/L respectively. Under these conditions, a maximum carbon content of cells was 49 % (w/w).

scholarly journals Study on Haloalkaliphilic Sulfur-Oxidizing Bacterium for Thiosulfate Removal in Treatment of Sulfidic Spent Caustic

2016 ◽  
Vol 57 ◽  
pp. 49-57 ◽  
Author(s):  
Somaye Makzum ◽  
Mohammad Ali Amoozegar ◽  
Seyed Mohammad Mehdi Dastgheib ◽  
Hamid Babavalian ◽  
Hamid Tebyanian ◽  
...  
Keyword(s):  
Energy Source ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Sodium Thiosulfate ◽  
Optimal Growth ◽  
Chemical Oxidation ◽  
Caustic Treatment ◽  
Sulfur Oxidizing ◽  
Spent Caustic

Due to the disadvantages of physiochemical methods for sulfidic spent caustic treatment, attentions are drawn to the environmental-friendly biotreatments including sulfur-oxidizing halo-alkaliphiles.Thioalkalivibrio versutusDSM 13738 was grown at alkaline (pH10) autotrophic medium with sodium carbonate/bicarbonate as the sole source of carbon and amended with sodium thiosulfate as the electron and energy source. The effect of various parameters including temperature (25-40 °C), pH (8-11), NaCl concentration (0.5-5 % w/v) and sodium thiosulfate concentrations (100-750 mM) was evaluated on bacterial growth and thiosulfate removal. This strain could eliminate sodium thiosulfate at very high concentrations up to 750 mM. The results showed that the highest specific growth rate was pH 9.5 and thiosulfate removal ofThioalkalivibrio versutusoccurred at pH 10.5. The optimum salt concentration for thiosulfate removal was 2.5 % w/v and 5 % NaCl and specific growth rate elevated 2.5% w/v. It was also specified that this strain thrives occurred in 37 °C and at 35 and 37 °C higher removal of thiosulfate. Following chemical oxidation of sulfide to thiosulfate, application ofThioalkalivibrio versutuscould be promising for spent caustic treatment. Since thiosulfate is utilized as an energy source, highest removal efficiency occurred at marginally different conditions compared to optimal growth.

scholarly journals KEPADATAN DAN LAJU PERTUMBUHAN SPESIFIK Nannochloropsis sp. PADA KULTIVASI HETEROTROPIK MENGGUNAKAN MEDIA HIDROLISAT SINGKONG

Omni-Akuatika ◽  
2015 ◽  
Vol 11 (2) ◽  
Author(s):  
Mujizat Kawaroe ◽  
Tri Prartono ◽  
Ganjar Saefurahman
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Culture Medium ◽  
Specific Growth ◽  
Medium Composition ◽  
Cultivation Condition ◽  
Microalgae Cultivation ◽  
Heterotrophic Cultivation ◽  
Seawater Ph ◽  
Black Plastic

Growth of Nannochloropsis sp. was observed in laboratory cultivation condition with enrichment of cassava hydrolysate into culture medium as follow : 25 ml microalgae strain, 75 ml seawater, without cassava hydrolysate (A); 25 ml microalgae strain, 25 ml cassava hydrolysate, 50 ml seawater (B), 25 ml microalgae strain, 50 ml cassava hydrolysate, 25 ml seawater (C). Cultivation condition was fixed as follow temperature 29°C, seawater pH 8, and salinity 30 ‰. Microalgae cultivation was performed at microalgae laboratory of Surfactant and Bioenergy Research Center using 100 ml Erlenmeyer covered by black plastic to prevent the influence of light. The specific growth rate of Nannochloropsis sp. was observed in 7 days for different cultivation medium composition. The highest density of microalgae was in the 4th days with 50ml cassava hydrolysate’s feeding (C treatment) about 172.661 cell/mL. The highest specific growth rate for Nannochloropsis sp. cultivation was observed in the 6th days without cassava hydrolysate’s feeding. Result of statistical analysis showed that different cassava hydrolysate’s feeding treatments (ml) in heterotrophically microalgae cultivation influenced the density of microalgae (cell/mL) but not influenced the specific growth rate of microalgae (per day).Keywords: Cassava hydrolysate, Density, Heterotrophic cultivation, Spesific growth rate, Nannochloropsis sp.

scholarly journals Decolourization of chicken compost derived liquid fertilizer via synergic ultraviolet (UV) irradiation and ozonation for enhanced microalgae cultivation

2021 ◽  
Vol 287 ◽  
pp. 04013
Author(s):  
Yik Lam Kam ◽  
Man Kee Lam ◽  
Yoke Wang Cheng ◽  
Yaleeni Kanna Dasan ◽  
Sie Yon Lau ◽  
...  
Keyword(s):  
Growth Rate ◽  
Uv Irradiation ◽  
Specific Growth ◽  
Biomass Productivity ◽  
Dry Weight ◽  
Optimal Parameters ◽  
Microalgae Cultivation ◽  
Liquid Fertilizer ◽  
Decolorization Efficiency ◽  
Initial Ph

Compost-derived liquid fertilizers are uncostly and nutrient-enriched; however, its dark brown appearance limits light uptake of microalgae during autotrophic cultivation. Here, integrated UV irradiation/ozonation pretreatment was employed to decolourize the compost solution prior to microalgae cultivation. Aforesaid pretreatment could accomplish 16.52 % (8 h) or 40.88 % (24 h) decolorization efficiency by using optimal parameters (initial pH of 12, ozone concentration of 30 mg/L, and ozone flow rate of 3 L/min. Compared to untreated compost solution, microalgae Chlorella vulgaris grew better in the medium supplemented with decolourized compost solution (after 24 h UV irradiation/ozonation). For the autotrophic cultivation of C. vulgaris with 10 vol.% compost solution, UV irradiation/ozonation pretreatment eventually increases the microalgae dry weight, specific growth rate, and biomass productivity from 0.58 g/L, 0.14 d-1, and 0.040 g/(L·d) to 0.88 g/L, 0.19 d-1, and 0.065 g/(L·d), respectively. Furthermore, the lipid content of microalgae has been increased by 33.33% with pretreatment of compost solution.

Dynamics of the macromolecular composition of the biomass of microalgae in the morning under natural light. Model

2020 ◽  
pp. 45-52
Author(s):  
Alexander S. Lelekov ◽  
Anton V. Shiryaev
Keyword(s):  
Biochemical Composition ◽  
Initial Conditions ◽  
Natural Light ◽  
Photoautotrophic Growth ◽  
Structural Part ◽  
Basic Model ◽  
Microalgae Culture ◽  
Simulation Results ◽  
Structural Parts ◽  
Macromolecular Composition

The work is devoted to modeling the growth of optically dense microalgae cultures in natural light. The basic model is based on the idea of the two-stage photoautotrophic growth of microalgae. It is shown that the increase in the intensity of sunlight in the first half of the day can be described by a linear equation. Analytical equations for the growth of biomass of microalgae and its macromolecular components are obtained. As the initial conditions, it is assumed that at the time of sunrise, the concentration of reserve biomass compounds is zero. The simulation results show that after sunrise, the growth of the microalgae culture is due only to an increase in the reserve part of the biomass, while the structural part practically does not change over six hours. Changes in the ratio of the reserve and structural parts of the biomass indicate a change in the biochemical composition of cells.

Oscillating conditions for influencing the composition of mixed biological cultures

1998 ◽  
Vol 37 (4-5) ◽  
pp. 259-262 ◽  
Author(s):  
Bjarne R. Horntvedt ◽  
Morten Rambekk ◽  
Rune Bakke
Keyword(s):  
Growth Rate ◽  
Specific Growth ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Rate Reduction ◽  
Similar Strategy ◽  
Sinusoidal Oscillations ◽  
Specific Growth Rates ◽  
Rate Limiting ◽  
Concentration Levels

This paper presents a strategy in which mixed biological cultures are exposed to oscillating concentration levels, to improve the potential for coexistence of desired bacterial species. A mechanistic mathematical model is constructed to investigate and illustrate this strategy. This paper is focused on competition between nitrifying, denitrifying and aerobic heterotrophic bacteria in a CSTR with sludge recycle. For nitrifying and aerobic heterotrophic cultures, the effect of sinusoidal oscillations in DO levels with an amplitude of 1.0 mg/l is a 16% specific growth rate reduction compared to that at a constant DO level. The denitrifiers growth rate is increased by an average of 59%, compared to the constant DO level situation. A similar strategy has been tested in a pilot plant. It is concluded that the influence on specific growth rates is a function of the amplitude of the oscillations. The effects are greatest when concentrations fluctuate around the half saturation concentration of the rate limiting component(s).

scholarly journals Understanding the Interaction Effects between Dietary Lipid Content and Rearing Temperature on Growth Performance, Feed Utilization, and Fat Deposition of Sea Bass (Dicentrarchus labrax)

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 392
Author(s):  
Lydia Katsika ◽  
Mario Huesca Flores ◽  
Yannis Kotzamanis ◽  
Alicia Estevez ◽  
Stavros Chatzifotis
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Specific Growth ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Dietary Lipid ◽  
Lipid Levels ◽  
Final Body Weight ◽  
Temperature Regimes ◽  
Fish Group

This study was conducted to elucidate the interaction effects of temperature and dietary lipid levels (2 × 2 factorial experiment) on the growth performance, muscle, and liver composition in adult farmed European sea bass (Dicentrarchus labrax). Two groups of fish (190 g; 60 fish per group) were distributed in 12 tanks in triplicates and kept at two different temperature regimes; one starting at 23 °C and then changed to 17 °C for 61 days, and the other starting at 17 °C and then changed to 23 °C for 39 days. Two commercial diets containing both ~44% crude protein but incorporating different dietary lipid levels, 16.5% (D16) and 20.0% (D20) (dry matter (DM)), were fed to the fish to apparent satiation; the type of diet fed to each fish group remained constant throughout the experiment. Final body weight, weight gain, and specific growth rate were significantly higher for the fish group held at 23 °C compared to the fish group at 17 °C (before the temperature changes), while the dietary fat content did not have any profound effect in both groups. Furthermore, the different temperature regimes did not affect muscle or liver composition, but, on the contrary, dietary lipids affected hepatosomatic, perivisceral fat, and visceral indexes. Feed conversion ratio and specific growth rate were not affected by the dietary lipid level. An interaction of temperature and dietary lipid content was observed in daily feed consumption (DFC) and final body weight (FBW).

scholarly journals Effects of cofD gene knock-out on the methanogenesis of Methanobrevibacter ruminantium

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Ma ◽  
Xueying Wang ◽  
Ting Zhou ◽  
Rui Hu ◽  
Huawei Zou ◽  
...  
Keyword(s):  
Growth Rate ◽  
Specific Growth ◽  
Production Capacity ◽  
Maximum Amount ◽  
Logarithmic Phase ◽  
Wild Type ◽  
Knock Out ◽  
Maximum Biomass ◽  
Reproductive Ability ◽  
Methanobrevibacter Ruminantium

AbstractThis study aimed to investigate the effects of cofD gene knock-out on the synthesis of coenzyme F420 and production of methane in Methanobrevibacter ruminantium (M. ruminantium). The experiment successfully constructed a cofD gene knock-out M. ruminantium via homologous recombination technology. The results showed that the logarithmic phase of mutant M. ruminantium (12 h) was lower than the wild-type (24 h). The maximum biomass and specific growth rate of mutant M. ruminantium were significantly lower (P < 0.05) than those of wild-type, and the maximum biomass of mutant M. ruminantium was approximately half of the wild-type; meanwhile, the proliferation was reduced. The synthesis amount of coenzyme F420 of M. ruminantium was significantly decreased (P < 0.05) after the cofD gene knock-out. Moreover, the maximum amount of H2 consumed and CH4 produced by mutant were 14 and 2% of wild-type M. ruminantium respectively. In conclusion, cofD gene knock-out induced the decreased growth rate and reproductive ability of M. ruminantium. Subsequently, the synthesis of coenzyme F420 was decreased. Ultimately, the production capacity of CH4 in M. ruminantium was reduced. Our research provides evidence that cofD gene plays an indispensable role in the regulation of coenzyme F420 synthesis and CH4 production in M. ruminantium.

CONTINUOUS CULTURE OF BRUCELLA ABORTUS S.19

1961 ◽  
Vol 7 (4) ◽  
pp. 491-505 ◽  
Author(s):  
Andreas H. W. Hauschild ◽  
Hilliard Pivnick
Keyword(s):  
Growth Rate ◽  
Continuous Culture ◽  
Dilution Rate ◽  
Brucella Abortus ◽  
Specific Growth ◽  
Limiting Factor ◽  
Continuous Growth ◽  
Viable Cells ◽  
Metabolic Products ◽  
Growth Of Bacteria

An apparatus is described for the continuous growth of bacteria. Brucella abortus S.19 has been grown in continuous culture for periods up to 3 weeks with populations up to 2 × 1011viable cells per ml and without the establishment of nonsmooth variants.Concentrations between 3 × 109and 2 × 1011cells per ml could be maintained as a function of the dilution rate without the requirement of a known limiting factor in the medium. In a series of steady-state conditions, the specific growth rate increased steadily up to 0.28 hour−1with decreasing population levels.Incidence of mutants was governed by the dilution rate and could also be reduced by various chelating substances.In continuous growth combined with continuous dialysis, population levels were approximately twice those obtained in continuous growth without dialysis. The effect of dialysis appears to be the continuous removal of growth-limiting metabolic products.

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