scholarly journals Screening Suitability of Northern Hemisphere Algal Strains for Heterotrophic Cultivation and Fatty Acid Methyl Ester Production

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2107
Author(s):  
Jean Claude Nzayisenga ◽  
Calle Niemi ◽  
Lorenza Ferro ◽  
Andras Gorzsas ◽  
Francesco G. Gentili ◽  
...  

Rapid rises in atmospheric CO2 levels derived from fossil fuel combustion are imposing urgent needs for renewable substitutes. One environmentally friendly alternative is biodiesel produced from suitable microalgal fatty acids. Algal strains normally grow photoautotrophically, but this is problematic in Northern areas because of the light limitations for much of the year. Mixotrophic and particularly heterotrophic strains could be valuable, especially if they can be cultivated in municipal wastewater with contents of nutrients such as nitrogen and phosphorous that should be reduced before release into receiving water. Thus, the aim of this study was to screen for microalgal strains suitable for heterotrophic cultivation with a cheap carbon source (glycerol) for biodiesel production in Nordic, and other high-latitude, countries. One of the examined strains, a Desmodesmus sp. strain designated 2-6, accumulated biomass at similar rates in heterotrophic conditions with 40 mM glycerol as in autotrophic conditions. Furthermore, in heterotrophic conditions it produced more fatty acids, and ca. 50% more C18:1 fatty acids, as well as showing a significant decrease in C18:3 fatty acids, all of which are highly desirable features for biodiesel production.

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Sayeda M. Abdo ◽  
Guzine I. El Diwani ◽  
Kamel M. El-Khatib ◽  
Sanaa A. Abo El-Enin ◽  
Mohammed I. El-Galad ◽  
...  

Abstract Background Microalgae cells can be identified as a potential source for new and renewable energy. The economic investigation for biodiesel and bio-active compound production from the microalgae community (Bloom), which are collected from the high rate algal pond (HRAP) constructed to treat municipal wastewater at Zenin wastewater treatment plant, Giza, was the main target of study. Results The microscopical examination showed that Scenedesmus obliquus is the dominant species. The total carotenoids were extracted using jojoba oil and determined by high-performance liquid chromatography (HPLC) to reach 81.44 μg/g. The biodiesel production through acid transesterification reaction recorded 70.6% of fatty acid methyl ester content with high cetane number (44) and low acid value. Such results prove that the obtained biodiesel has better ignition quality. The total phenolic and flavonoid compounds have been derived from the remaining biomass to give 5.36 ± 0.03 and 1.50 ± 0.19 mg/g respectively. Finally, total proteins and carbohydrates content in algal cells were recorded 54.3 and 1.5 mg/g successively Conclusion The preliminary economic evaluation showed that the production of biodiesel and carotenoids from the microalgae growing in municipal wastewater can be considered, as a techno-economic feasible process.


Bioengineered ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 408-415 ◽  
Author(s):  
Ferruh Asci ◽  
Busra Aydin ◽  
Gulderen Uysal Akkus ◽  
Arzu Unal ◽  
Sevim Feyza Erdogmus ◽  
...  

2014 ◽  
Vol 1015 ◽  
pp. 610-614
Author(s):  
Ying Wang ◽  
Cun Zhou ◽  
Guo Zheng ◽  
Yu Sun

Lubricant base oil is an environmentally friendly lubricant with good lubricity and biodegradability. The thermostability and stability of rapeseed oil get improved through chemical modification. Fatty acid methyl ester (FAME),prepared by rapeseed oil as starting material with methanol by transesterification,the composition of FAME was detected by gas chromatograph-mass spectrometer (GC-MS).Trimethylolpropane (TMP) esters of fatty acids were synthesized by transesterifying FAME with TMP using zinc oxide as catalyst. The structures of products were characterized by mean of FTIR. The reaction conditions were studied and optimized, the optimum conditions were as follows: the temperature at 140°C~150°C, the reactant mass ratio of 1:9, the reaction time for 6 h, the mass content of catalyst of 0.5%.The thermal stability of product was conducted by thermogravimetry (TG) .It could be concluded that TMP esters of fatty acids possess better thermal stability.


1967 ◽  
Vol 34 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Ragnar Ryhage

SummaryThe identification and approximate quantitative determination of methyl esters of fatty acids from commercial butterfat was obtained with a combined gaschromatograph-mass spectrometer instrument. Fifty-two components, straight chain saturated and unsaturated, as well as branched chain compounds, were identified. Seven monomethyl saturated fatty acid methyl ester isomers were identified for both C15 and C17, i.e. with chain lengths of 14 and 16 carbon atoms, respectively. Multibranched fatty acids with molecular weights of 326 and 368 were found. The results were obtained in one day.


Food Research ◽  
2020 ◽  
Vol 4 (S1) ◽  
pp. 220-226
Author(s):  
Widayat ◽  
Hadiyanto ◽  
D.A. Putra ◽  
Nursafitri I. ◽  
H. Satriadi ◽  
...  

The objective of this research was to produce biodiesel using waste cooking oil and various magnetite catalysts with the esterification-transesterification process. Magnetite catalysts tested were α- Fe2O3, α- Fe2O3/Al2O3, α- Fe2O3/ZSM-5 catalysts. Catalysts were prepared through chemical precipitation and calcination. The esterificationtransesterification process was carried out with the conditions WCO: methanol molar ratio of 15:1, catalyst (1% wt of oil), heated at 65℃ for 3 hrs. The results showed biodiesel production using α- Fe2O3-ZSM-5 catalyst obtained higher %FAME (83.28%), yield (91.915%) and monoglyceride content (16.72%) compared to others due to larger pore volume. Biodiesel produced passed the requirement of Indonesian National Standard (SNI) based on density, acid number and viscosity.


2019 ◽  
Vol 6 (2) ◽  
pp. 101-106
Author(s):  
Ozadheoghene Eriarie Afieroho ◽  
L. Lawson ◽  
Nnamdi Emenyonu

This study investigated the triterpenoids and fatty acid derivatives, and the in vitro growth inhibitory effect against clinical strains of Mycobacteria tuberculosis of the stem bark of Ximenia Americanaa plant widely used in ethno-medicine for the treatment of bacterial and skin infections, poison, post-partum hemorrhage, anaemia, and dysentery. The macerated methanol extract (XAM) of the stem bark was evaluated for anti-tuberculosis activity using the Lowensten Jensen method against de-contaminated clinical strains of Mycobacterium tuberculosis. The XAM was fractionated by open column chromatography on a normal phase silica gel column with a 25 % stepwise gradient of chloroform-methanol as mobile phase. The constituents of the non-polar column fractions eluted with 100% chloroform were characterized using Gas Chromatography-Mass spectroscopic (GC-MS) techniques and by comparison with reference NIST library compound. The XAM (5 mg/mL) inhibited the growth of the Mycobacterium tuberculosis. GC-MS analysis of the non-polar column fractions afforded Two lupane-type triterpenoids: Lup-20-(29)-en-3-one (15) and lupeol (16), three phytosteroids: campesterol (11), stigmasterol (12) and gamma-sitosterol (14), one fridelane-type triterpenoid: Friedelan-3-one (8), one oleanane-type triterpenoid: 12-oleanen-3-one (13), and the fatty acids: Palmitic acid methyl ester (1), Palmitic acid (2), 11-octadecenoic acid methyl ester (3), Octadecanoic acid methyl ester (4), Cis-13-Octadecenoic acid (5), 10,13-octadecadiynoic acid methyl ester (6), Docosanoic acid (7), Tetracosanoic acid (9), and Hexacosanoic acid methyl ester (10). The presence of these bioactive triterpenoids and fatty acids could offer an explanation for the ethno-medicinal uses of this plant. Further work is on-going to isolate in pure form, and characterized the bioactive constituents in the XAM with the view of discovery lead compounds for the treatment of tuberculosis and associated opportunistic bacterial infections.  


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4609
Author(s):  
Adel W. Almutairi

In the present study, the marine microalga Tisochrysis lutea was cultivated mixotrophically in F2 growth medium with sodium acetate as exogenous carbon source. The medium was composed of different concentrations of nitrogen to determine the impact of nitrogen depletion on cellular growth and chemical composition. Nitrogen depletion led to severely decreased growth and protein content. However, mild nitrogen depletion (0.22 mM NaNO3) led to maximum lipid yield. The fatty acid methyl ester profile also showed increased unsaturation as the nitrogen content decreased. Growth in nitrogen-free medium increased the proportions of mono- and poly-unsaturated fatty acids, while the proportion of saturated fatty acids decreased. Growth under all tested nitrogen levels showed undetectable fatty acids with ≥4 double bonds, indicating these fatty acids had oxidative stability. In addition, all tested nitrogen concentrations led to specific gravity, kinematic viscosity, iodine value, and cetane number that meet the standards for Europe and the U.S.A. However, growth in the presence of nitrogen deficiency enhanced the higher heating value of the resulting biodiesel, a clear advantage from the perspective of energy efficiency. Thus, mixotrophic cultivation of T. lutea with nitrogen limitation provides a promising approach to achieve high lipid productivity and production of high-quality biodiesel.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Md. Mahbub Hasan ◽  
Sayla Aktar Chowdhory ◽  
A. S. M. Shafiqur Rahman ◽  
Christos G. Athanassiou

Abstract Diapause concerns the fascinating phenomenon in the biology of insect development which allows better understanding the local adaptation and phenotypic plasticity to seasonal variations in environment. There is lot of reasons to carry out the research on diapause both for fundamental and applied sciences. Photoperiod is one of the main environmental cues followed by insects to predict the forthcoming seasonal changes and to adapt these changes in their life-history traits. Thus, the effect of different photoperiod regimes on development and diapause induction of larvae of the Indian meal moth Plodia interpunctella (Hübner) was evaluated at a constant temperature of 17 °C. Development was significantly faster at a photoperiod of 12:12 light:darkness (L:D) than at 8:16, 10:14, 14:10 and 16:8 L:D. A photoperiod of 12:12 (L:D) induced most larvae (≥ 71%) to enter diapause, while this percentage was slightly lower (60%) at both shorter(8 h) and longer (16 h) day lengths (50%). The different photoperiod regimes did not affect the percentage of adult emergence. Fat and protein composition of the diapausing larvae differed significantly among treatments as well as between diapausing and non-diapausing larvae. Larvae developing from 8:16 (L:D) contained the maximum amount of protein (36.8%) compared to other regimes, while the minimum amount (21.0%) was noted in larvae that developed at 16:8 (L:D). Six types of fatty acids were detected in the larvae: myristic acid (methyl tetradecenoate), palmitoleic acid (9-hexadecenoic acid, methyl ester), palmitic acid (hexadecenoic acid, methyl ester), linoleic acid (9, 12-Octadecadienoic acid (Z, Z), methyl ester), oleic acid [9-octadecenoic acid, methyl ester (E)] and stearic acid (octadecanoic acid, methyl ester). The results also reveal that the percent of fatty acids detected in the diapausing larvae varies significantly and the same trends imply in the interaction of fatty acid and photoperiod regimes. Moreover, three quarters of the total variance was accounted for by the Principal Component Analysis (PCA) of the fatty acids. Different proportions of fatty acids were noted among treatments, suggesting that photoperiod influences a number of key biological traits in P. interpunctella, much more than the percentage of the diapausing larvae per se.


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