Statistical Approach of Nutrient Optimization for Microalgae Cultivation (original) (raw)
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Natural Science
In recent years, microalgae biodiesel has attracted expressive attention and investment, once it was considered a potential resource for energy. Although the wide use of microalgae biodiesel is restricted by its high production cost. For cost-efficient and sustainable production of biodiesel from microalgae, a proper understanding of the variables and their impacts on physiology of the strains is required. In this study, a simple factorial design 2 3 was used to find optimal conditions for the cultivation of Ankistrodesmus sp. and Chlamydomonas sp. in batch culture. The three components considered were nitrate, phosphate and sodium chloride, used to assess the metabolic versatility of the strains in brackish conditions. The results showed that culture medium with 0.04 g•L −1 nitrate, 0.01 g•L −1 phosphate and 5.0 g•L −1 sodium chloride resulted to be the most effective condition to growth and fatty acids accumulation. Using this optimal condition, Ankistrodesmus sp. and Chlamydomonas sp. increased in 2.1 and 2.4 folds their fatty acids yield, respectively. Importantly, this protocol reduced 75% of the nitrate and phosphate concentrations of the original medium (ASM-1). Additionally, fatty acids analysis found that these strains were mainly constituted of C16-C18, in accordance with the requirements for biodiesel production. The simple factorial design applied here proved to be an important tool towards a better understanding of synergistic effects of tested factors on microalgae metabolism, and the resulting information could be used effectively to improve microalgae cultivation.
Jurnal Teknologi
Synthesis of lipid and carbohydrate in microalgae simultaneously is essential for cost-effective microalgae-based biofuel production. Statistical optimisation approaches of the Plackett–Burman design (PBD) and central composite design (CCD) were applied to optimise the biomass, lipid, and carbohydrate productivities of the C. vulgaris UPSI-JRM01. The results obtained from PBD shown that NO3- concentration, light intensity and NaHCO3 concentration were the significant factors that affecting biomass productivity. Through CCD, optimum biomass, lipid, and carbohydrate productivities were obtained at 401.81 mg/L NO3–, 11238.20 lux light intensity, and 0.30 g/L NaHCO3, achieving the highest biomass productivity of 404.24 mg/L/day, highest lipid productivity of 65.3 mg/L/day, and highest carbohydrate productivity of 165.43 mg/L/day. The major fatty acid methyl esters (FAMEs) produced were palmitic acid (33.54%) and linoleic acid (30.29%), thus producing microalgae-based biodiesel with prop...
Algal Research, 2015
Microalgae invite the attention of scientists due to their unique properties, including their ability to grow quickly, accumulate lipids and other valuable materials, fix carbon dioxide and treat wastewater. Several studies have aimed to identify cost-effective production methods for microalgae biomass. In this paper, several potential inexpensive waste materials for microalgae Chlorella sp. biomass production rate were investigated, including technical glycerol and liquid waste (i.e., the liquid fraction of the digestate after biogas production). In addition, the cultivation of microalgae biomass was optimized using these materials. The optimization procedure was performed using response surface methodology. Biomass cultivation process was optimized depending on the amount of technical glycerol and the nitrogen concentrations in the growth medium, which was prepared using liquid waste. The highest Chlorella sp. biomass concentration of 2.41 g L −1 was achieved in the growth medium that contained 0.114 g L −1 nitrogen and 2.70 g L −1 technical glycerol.
Optimization of abiotic conditions suitable for the production of biodiesel from Chlorella vulgaris
Indian Journal of Science and …, 2011
The present study reports the production of fatty acids by microalgae under the influence of light and dark condition. Microalgae are renewable resource containing rich lipids in their body and has the potential to refill the partial energy demands in an eco-friendly way. We isolated an indigenous green alga (Chlorella vulgaris) as a potent source for biodiesel. To get better yield of biofuel, the growth of the microalgal isolate was optimized with the addition of nutrients and salts under light and dark conditions. The lipid fractions were extracted from the biomass through solvent extractions and the fractions were analyzed for biodiesel under GC-MS. The percentage of lipids synthesized from C. vulgaris under light and dark conditions were analyzed and compared. The algae from dark sample shows rich in saturated fatty acid (capric acid, lauric acid & myristic acid) and considerable amount of PUFA (hexadecatrienoic acid, stearidonic acid, eicosapenaenoic acid, docosahexaenoic acid) when compare to algae grown under light. So the algae grown in dark condition is an excellent source for high yield of saturated fatty acids.
International Journal of Applied and Natural Sciences (IJANS), 2018
Microalgae require a wide range of chemical and physical factors for their growth, proliferation, and differentiation. These factors affect the morphology, physiology and metabolic activities of the organism. Therefore, in the present investigation, lipid producing microalgae were isolated and identified, abiotic growth factors such as different autotropic media, pH, nutrients, and media optimization studies were carried out to obtain highest biomass and lipid from microalgae which have the potential for effective biodiesel production. Growth studies were carried out of the isolated algal strains, the optimum temperature for all the experiments was kept at 25 ± 1 o C and light intensity of 1.2 ± 0.2 klux was maintained. Four strains with highest percentage wise Biomass : Lipid ratio were considered for studies, these strains are Chlorella vulgaris AS-3, Chlorella pyrenoidosa AS-6, Scenedesmus dimorphus AS-13, all 3 strains were isolated from unkal lake and Scenedesmus quadricauda AS-18 was isolated from Rayanaal lake. Out of the four isolated strains Chlorella vulgaris (AS-3) showed a significant increase in lipid content by 3 %. The organism was found to grow well in the optimized BG-11 media with the pH of 6.5 and culture age of 6 weeks and concentration of sodium nitrate, FAC, potassium bicarbonate and magnesium sulphate of 2, 0.24, 0.3 and 0.8 g/L respectively. The data obtained by the by the above growth studies can be used for mass culturing of the organism in invivo conditions in open ponds and furthers studies can be done using different media compositions. Hence, AS-3 was found to be an ideal candidate for biodiesel production and further characterization of the microalgae was carried out.
Green microalga Chlorella vulgaris as a potential feedstock for biodiesel
BACKGROUND: A major bottleneck in microalgal biodiesel production is lipid content, which is often low in microalgal species. The present study examines Chlorella vulgaris as a potential feedstock for biodiesel by identifying and evaluating the relationships between the critical variables that enhance the lipid yield, and characterizes the biodiesel produced for various properties. RESULTS: Factors affecting lipid accumulation in a green microalga, Chlorella vulgaris were examined. Multifactor optimization raised the lipid pool to55%dry cell weight against9%control.WhenC. vulgaris cells pre-grown in glucose (0.7%)-supplemented medium were transferred to the optimized condition at the second stage, the lipid yield was boosted to 1974 mg L−1, a value almost 20-fold higher than for the control. The transesterified C. vulgaris oil showed the presence of∼82% saturated fatty acids, with palmitate and stearate as major components, thus highlighting the oxidative stability of C. vulgaris biodiesel. The fuel properties (density, viscosity, acid value, iodine value, calorific value, cetane index, ash and water contents) are comparable with the international (ASTM and EN) and Indian (IS) biodiesel standards. CONCLUSION: C. vulgaris biomass with 55% lipid content and adequate fuel properties is potentially a renewable feedstock for biodiesel.
… Journal of Green …, 2011
Study of six different freshwater microalgae, collected from Odisha, eastern region of India, has been carried out to find out their potential for biodiesel production. The growth, total lipid, and fatty acid composition of six microalgal strains were determined. Chlorella sp. IMMTCC-2, which exhibited high lipid content with considerable amount of unsaturated fatty acids, was selected for culture in a self-designed photobioreactor in order to study the scale-up possibilities. The result shows significant increase in lipid accumulation from logarithmic phase to stationary phase in the photobioreactor, i.e., from 12.4 to 28.3%. Analyses of the present results suggest that Chlorella sp. IMMTCC-2 is appropriate for biodiesel production.
2015
The application of microalgal oil for energy purposes continues to present a number of challenges, including the optimization of culture conditions. In this study, the two light intensities at 2.5 Klux and 5 Klux were used in light-dark cycles of 8:16, 16:8, 0:24 and 24:0 hour to investigate the effect of light intensity and photo period on biomass production and lipid productivities in microalgae, Chlorella vulgaris and Nannochloropsis sp. in view of optimizing the illumination level for biodiesel production through algal oil. Chlorella vulgaris and Nannochloropsis sp were cultured in Guillard and Rither`s f/2 media for 21 days and 14 days growth periods respectively in a laboratory scale closed experimental set-up. The cultures were aerated with mechanical aerators. Finally, cells were harvested by flocculation and dry weight and the percentage lipid content were estimated. Significantly higher average dry matter yield was observed when the cells cultured under 5 Klux light intens...
The effects of glucose, nitrate, and pH on cultivation of Chlorella sp. Microalgae
Global Journal of Environmental Science and Management, 2021
BACKGROUND AND OBJECTIVES: Bioenergy is a phenomenon that has attracted humans’ attention for about a century. The desirable biological properties of chlorella sp.microalgae have turned it to one of the most ideal options for the production of biodiesel. However, the economic issues must be taken into account in its industrial scale production. The present study aims to investigate chlorella sp. biomass production and growth conditions by studying the influence of glucose concentration as a carbon source, nitrate concentration as a nitrogen source and pH, as three of the most important factors. METHODS: For this purpose, design of experiment was done by response surface methodology and each factor was investigated simultaneously under glucose concentration in 2-20 g/L, nitrate concentration in 0-1 g/L and 6FINDINGS: The results indicated that carbon concentration has maximum effect on growth and biomass production. The best results were obtained in glucose concentration of 2.6-6 g/L...