Influence of Inorganic Nutrients on Parameters of Biomass Production in a Local Strain of the Microalga Scenedesmus Acuminatus (original) (raw)
Related papers
Journal of Basic Microbiology, Wiley, 2019
The present investigation ascertains the impact of gradient concentrations of sodium nitrate on the physiology and biochemical composition of isolated microalga Scenedesmus rotundus-MG910488. The concentrations of nitrate were selected as 0, 3.5, 7.0, 10.5, 14.0, and 17.6 mM/L in BG 11 medium. The lower concentrations of nitrogen were found to be significantly decreasing the cell count and photosynthetic activity in the microalga as well as changing cell morphology. The amount of biomass, its productivity and lipid yield were significantly affected. The highest biomass of 689.15 ± 14.27 mg/L was achieved in the concentration of 17.6 mM/L with the biomass productivity of 38.28 ± 0.78 mg/L. The highest lipid accumulation of 41.46 ± 1.94% dry-cell weight was obtained at a concentration of 3.5 mM/L, whereas the lowest lipid accumulation of 29.22 ± 1.65% at the concentration of 17.6 mM/L sodium nitrate. The fatty acid composition determines the quality of the fuel, so the characterization of fatty acid methyl esters (FAMEs) was performed by GC, and the assessment of methyl esters of fatty acid confirmed the existence of palmitic acid, oleic acid, and linoleic acid, which are essential components suitable for biodiesel production. FTIR confirms the presence of FAME components by estimating the bending and stretching of functional groups.
Influence of Different Culture Conditions on Yield of Biomass and Value Added Products in Microalgae
Microalgae viz., Botryococcus, Haematococcus and Dunaliella, were studied for their adaptability to different culture conditions. Botryococcus strains of indigenous origin and culture collection centres were studied for their growth, hydrocarbon and lipid profile and for their biomass yields under different bicarbonate concentrations. Growth of Haematococcus was compared in autotrophic (ambient and enriched CO 2 atmosphere) and heterotrophic culture conditions. Influence of ammonium salts, urea and commercial fertilizers as nitrogen source under autotrophic conditions and different amino acids as nitrogen source under heterotrophic culture conditions, was studied on growth and astaxanthin content of Haematococcus. Influence of different salinities was studied on growth and-Carotene content of Dunaliella in AS100 and De Walnes media. Results indicated that Botryococcus strains varied in their biomass yields (0.25-2 g L-1), hydrocarbon content (15-60% w/w) and lipid content (15-30%, w/w). An indigenous strain was able to grow at all the tested concentrations of bicarbonate with maximum biomass yield at 0.25 g L-1. The growth rate of Haematococcus was higher in heterotrophic medium with a cell count of 41-44 × 10 4 on 5 th day after inoculation. The supplementation of autotrophic medium with 2% CO 2 led to a 4-fold increase in cell count. Use of DAP as nitrogen source showed a 20% increase in yield of encysted biomass. Both DAP and Suphala led to astaxanthin productivity of 46-48 g L-1. Haematococcus was able to utilize all the amino acids at tested concentrations in heterotrophic culture conditions. Enhanced growth of Dunaliella was observed at 1.0 M NaCl concentration in both the AS 100 and De Walnes media while 2.0M NaCl in De Walnes medium showed higher-carotene content (45.6 mg g-1).
Effect of de Carbon/Nitrogen ratio on the production of microalgae - based carotenoids
2020
This study investigates the effect of C/N ratio on the production of biomass and total carotenoids on a Scenedesmus sp. Initially, three different carbon sources (sodium carbonate, sodium bicarbonate and sodium acetate) were tested under different concentrations of a nitrogen source (sodium nitrate) in 250 mL tubular air-lift reactors. The reactors were operated at 25 °C for 40 days. in light:dark cycle of 12:12, under a continuous flow of air. Results showed that by the adjustment of the concentration of the carbon and nitrogen source, it is possible to increase the concentration of biomass up to 0.8 g/L. However, by the regulation on the concentration of sodium carbonate and sodium nitrate, the final content of total carotenoids was increased two times (from 0.3 to 0.66 % w/w). Results from this study shows that an specific ratio between the carbon source employed and the concentration of the nitrogen source shows that an outstanding increase on the final biomass and the concentra...
Journal of Chemical Technology & Biotechnology, 2015
BACKGROUND: The quality and quantity of lipids in microalgae mainly depend on nitrogen and phosphorous supply. In the present study, growth of newly isolated microalgal strain, Chlorococcum sp. IM-03 has been studied under nitrogen stressed conditions. Fluorescence microscopy and Fourier transform infrared spectroscopy have been used to observe changes in lipid and carbohydrate content. RESULTS: Growth of selected species is monitored in terms of dry biomass and chlorophyll content under varying sodium nitrate concentration, viz. 0, 100 and 1500 mg L −1 (designated as N 0 , N 100 and N 1500 , respectively). N 100 was selected in the experimental plan as similar levels were observed in domestic wastewater, which can be used as possible culture media for mass cultivation. Maximum chlorophyll concentration (72.65 g mg −1) was found at N 100. It was also observed that cultivation at N 100 resulted in highest lipid content of 17.8%. Carbohydrate content was 18% at N 100 with moderate increase to 19.8% at N 1500. CONCLUSIONS: On the basis of the current study, it can be concluded that sodium nitrate concentration of 100 mg L −1 (N 100) offers enhanced production of lipids in Chlorococcum sp. without compromising growth.
Bioprocess and Biosystems Engineering, 2014
The growth and total lipid content of four green microalgae (Chlorella sp., Chlorella vulgaris CCAP211/ 11B, Botryococcus braunii FC124 and Scenedesmus obliquus R8) were investigated under different culture conditions. Among the various carbon sources tested, glucose produced the largest biomass or microalgae grown heterotrophically. It was found that 1 % (w/v) glucose was actively utilized by Chlorella sp., C. vulgaris CCAP211/ 11B and B. braunii FC124, whereas S. obliquus R8 preferred 2 % (w/v) glucose. No significant difference in biomass production was noted between heterotrophic and mixotrophic (heterotrophic with light illumination/exposure) growth conditions, however, less production was observed for autotrophic cultivation. Total lipid content in cells increased by approximately twofold under mixotrophic cultivation with respect to heterotrophic and autotrophic cultivation. In addition, light intensity had an impact on microalgal growth and total lipid content. The highest total lipid content was observed at 100 lmol m-2 s-1 for Chlorella sp. (22.5 %) and S. obliquus R8 (23.7 %) and 80 lmol m-2 s-1 for C. vulgaris CCAP211/ 11B (20.1 %) and B. braunii FC124 (34.9 %).
Natural Science, 2014
The effects of nitrogen, phosphorus and vitamin on growth and lipid content of a freshwater microalgae Scenedesmus sp. were investigated under indoor conditions. Nitrogen, phosphorus and vitamin presented significant statistical effect on lipid content, and a maximum lipid content of 29.3% was obtained, corresponded to increases of 90% when compared to those obtained with the original nutrients medium. On the other hand, only nitrogen and phosphorus presented significant statistical effect on cell growth, achieving ash free dry biomass, algal density, and specific growth rate of 1.3 g•L −1 , 1.5E+07 cells mL −1 , and 0.62 d −1 , respectively. By the use of the desirability function, it was possible to maximize the cell growth and lipid content simultaneously. The fatty acid composition of the microalgal lipid comprises over 80% of saturated and monounsaturated fatty acids. Thus, Scenedesmus sp. biomass could be used as suitable feedstock for biodiesel production.
The Journal of General and Applied Microbiology, 2016
The potential of an inorganic fertilizer as an alternative nutrient source for the cultivation of Scenedesmus sp. IMMTCC-6 was investigated. With a preliminary study at a shake-flask scale, the microalgae cultivation was scaled up in a photobioreactor containing an inorganic fertilizer medium. Microalgae cultured in a shake flask containing 0.1 g L-1 of urea and 1.0 g L-1 of NPK (Nitrogen: Phosphorus: Potassium) fertilizers showed a promising result in biomass productivity. During the scale-up study in a photobioreactor the specific growth rate (µ µ µ µ µ d-1), biomass yield (g L-1), and total biomass productivity (mg L-1 d-1), was found to be 0.265, 1.19 and 66.1, respectively. The lipid yield (%) as per dry cell weight (DCW) and lipid productivity (mg L-1 d-1) was found to be a maximum of 28.55 and 18.87, respectively, in a stationary phase of the microalgae growth. The fatty acids methyl ester profile was proven to be desirable for biodiesel production.