scholarly journals Direct Biodiesel Production from Wet Microalgae Biomass ofChlorella pyrenoidosathroughIn SituTransesterification

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hechun Cao ◽  
Zhiling Zhang ◽  
Xuwen Wu ◽  
Xiaoling Miao
Keyword(s):  
Water Content ◽  
Dry Weight ◽  
Chlorella Pyrenoidosa ◽  
Biodiesel Production ◽  
Optimal Conditions ◽  
Microalgae Biomass ◽  
Negative Effect ◽  
One Step ◽  
Lower Temperature ◽  
Wet Microalgae

A one-step process was applied to directly converting wet oil-bearing microalgae biomass ofChlorella pyrenoidosacontaining about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

Enhanced biodiesel production from wet microalgae biomass optimized via response surface methodology and artificial neural network

2022 ◽  
Vol 184 ◽  
pp. 753-764
Author(s):  
Gul Muhammad ◽  
Ange Douglas Potchamyou Ngatcha ◽  
Yongkun Lv ◽  
Wenlong Xiong ◽  
Yaser A. El-Badry ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Biodiesel Production ◽  
Microalgae Biomass ◽  
Artificial Neural ◽  
Wet Microalgae

scholarly journals Optimization of cell wall disruption and lipid extraction methods by combining different solvents from wet microalgae

2021 ◽  
Author(s):  
Daryush Arabian
Keyword(s):  
Cell Wall ◽  
Lipid Extraction ◽  
Dry Weight ◽  
Extraction Methods ◽  
Biodiesel Production ◽  
Cell Wall Disruption ◽  
Bead Mill ◽  
Wet Microalgae ◽  
Disruption Method ◽  
Chloroform Methanol

Microalgae have emerged as one of the most promising options for biodiesel production over the past few decades. Lipid extraction from microalgae for biodiesel production as a bottleneck of biodiesel production technology was the main purpose of this study. In this study different methods of the cell wall disruption were compared. Then, two methods of ultrasound and bead mill were used as methods of the cell wall disruption. The maximum lipid extracted by ultrasound was 17.10% and by bead mill was 15.16% (based on microalgae biomass dry weight). After the cell wall disruption of microalgae, for lipid extraction, chloroform-methanol solvent combination was used as a high extraction method and hexane-ethanol solvent combination was used as an environmentally friendly method. In this regard, the effect of solvent to biomass ratio, temperature and extraction time was investigated and the optimal results for chloroform-methanol solvent combination were 8 ml/g, 45°C and 60 minutes, respectively, and for hexane-ethanol combination were 6 ml/g, 35◦C and 73 minutes, respectively. Under these optimal conditions, the highest amount of extracted lipid from Chlorella vulgaris with a moisture content of 87.50%, and ultrasound as a cell wall disruption method were obtained 20.39% and 16.41% (based on microalgae dry weight) with a combination of chloroform-methanol solvents and hexane-ethanol respectively. Also the highest extraction rates of 17.63% and 13.85% were obtained for the combination of chloroform-methanol and hexane-ethanol solvents, respectively by bead milling as cell wall disruption method

scholarly journals Bioconversion of pomegranate residues into biofuels and bioactive lipids

2021 ◽  
Author(s):  
Marianna Dourou ◽  
Christina N. Economou ◽  
Lida Aggeli ◽  
Miroslav Janák ◽  
Gabriela Valdés ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Dry Weight ◽  
Raw Material ◽  
Biodiesel Production ◽  
Bioactive Lipids ◽  
Chemical Reagents ◽  
Juice Extraction ◽  
Oleaginous Fungus ◽  
One Step ◽  
Biotechnological Processes

AbstractPomegranate residues (PRs) (i.e. the solid residues remaining after juice extraction), generated currently in abundance in Greece, contain a variety of carbon sources and therefore can be regarded as a potential feedstock for chemical and biotechnological processes rather than as waste materials. In the current project, the polysaccharides contained in PRs were extracted and hydrolyzed in a one-step process without the use of chemical reagents and the resulting broth was used as substrate in biotechnological applications, including ethanol and single cell oil (SCO) production. The yeasts Meyerozyma guilliermondii, Scheffersomyces coipomoensis, Sugiyamaella paludigena and especially Saccharomyces cerevisiae, were able to efficiently convert PR derived reducing sugars into bioethanol. Ethanol production under anaerobic conditions ranged from 3.6 to 12.5 g/L. In addition, the oleaginous yeasts Lipomyces lipofer and Yarrowia lipolytica as well as M. guilliermondii, S. coipomoensis and S. paludigena were tested for their ability to accumulate lipids suitable as feedstock for biodiesel production. Lipids were accumulated at concentrations up to 18% and were rich in palmitic acid (C16:0) and oleic acid (C18:1). Finally, the oleaginous fungus Cunnichamella echinulata was cultivated on PR based solid substrates for γ-linolenic acid (GLA) production. The fermented bio-products (i.e. fermented substrate plus fungal mycelia) contained up to 4.8 mg GLA/g of dry weight. Phenolic removal (up to 30%) was achieved by several of the above mentioned microorganisms, including C. echinulata, L. lipofer, M. guilliermondii, S. paludigena and Y. lipolytica. We conclude that PRs can be used as a raw material for microbial growth, ethanol and SCO production, which is of economic and environmental importance.

scholarly journals Substrate Water Content and Fertilizer Rate Affect Growth and Flowering of Potted Petunia

HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 582-589 ◽  
Author(s):  
Peter Alem ◽  
Paul A. Thomas ◽  
Marc W. van Iersel
Keyword(s):  
Water Content ◽  
Interactive Effect ◽  
Leaf Size ◽  
Dry Weight ◽  
Optimal Conditions ◽  
Fertilizer Rate ◽  
Shoot Dry Weight ◽  
Four Levels ◽  
Fertilizer Rates ◽  
Excessive Water

Rising concerns over environmental impacts of excessive water and fertilizer use in the horticultural industry necessitate more efficient use of water and nutrients. Both substrate volumetric water content (θ) and fertilizer affect plant growth, but their interactive effect is poorly understood. The objective of this study was to determine the optimal fertilizer rates for petunia (Petunia ×hybrida) ‘Dreams White’ grown at different θ levels. Petunia seedlings were grown at four levels of θ (0.10, 0.20, 0.30, and 0.40 m3·m−3) with eight different rates of controlled-release fertilizer (CRF) (Osmocote 14-14-14; 14N–6.1P–11.6K; rates of 0 to 2.5 g/plant, equivalent to 0 to 6.25 kg·m−3 substrate). Shoot dry weight increased as the CRF rate increased from 0 to 1.67 g/plant but decreased again at even higher CRF rates. The effect of CRF rate on growth was more pronounced at higher θ. Leaf size doubled as the θ thresholds increased from 0.10 to 0.40 m3·m−3. Flowering was reduced by a combination of high CRF rates (greater than 0.63 g/plant) and high θ (0.30 and 0.40 m3·m−3), indicating that optimal conditions for vegetative growth are different from those for maximal flowering. These results suggest that without leaching, high-quality petunias can be grown with lower CRF rates than commercially recommended rates.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

STEM measurement of subcellular water distributions

1993 ◽  
Vol 51 ◽  
pp. 568-569
Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews
Keyword(s):  
Water Content ◽  
Internal Standard ◽  
Dry Weight ◽  
Dry Mass ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Bulk Water ◽  
Inelastic Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.

scholarly journals Functional ecology of the biological soil crust in semiarid SE Spain: sun and shade populations of Diploschistes diacapsis (Ach.) Lumbsch.

2005 ◽  
Vol 37 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Ana PINTADO ◽  
Leopoldo G. SANCHO ◽  
T. G. Allan GREEN ◽  
José Manuel BLANQUER ◽  
Roberto LÁZARO
Keyword(s):  
Water Content ◽  
Chlorophyll Content ◽  
Unit Area ◽  
Biological Soil Crust ◽  
Dry Weight ◽  
Mean Annual Precipitation ◽  
Plant Colonization ◽  
Soil Crust ◽  
Active Time ◽  
Exposed Population

The Tabernas badlands in semiarid south-east Spain is one of the driest regions in Europe with a mean annual precipitation of c. 240 mm. The landscape is deeply dissected, with canyons, ramblas and sparsely vegetated eroded badland slopes. The vegetation is predominantly a biological soil crust consisting of different types of lichen-rich communities, one of the more conspicuous being dominated by Diploschistes diacapsis (Ach.) Lumbsch. This lichen is mainly restricted to the north- facing slopes, where it forms extensive whitish carpets and probably plays an important role in preventing erosion of the slopes and allowing plant colonization. South-facing slopes are much more eroded and generally lack vegetation. %The photosynthetic performance of north (shade) and south-facing (sun) populations of D. diacapsis was studied to determine if these different populations showed any adaptations to the microclimatic conditions of their individual habitats. The response of CO2 exchange to light intensity, temperature and water content was measured under controlled conditions in the laboratory. Dry weight-based net photosynthetic rates were higher in the southern-exposed population but quantum efficiency, and light compensation points were similar. Thallus weight per unit area (LMA) was considerably higher for shade specimens but maximum water content and optimal water content were very similar and chlorophyll content on a dry weight basis was also similar. Chlorophyll content on an area basis was higher in the northern-exposed population and always much larger than those reported in other studies on the same species (up to 8 times larger) with the result that NP values on a chlorophyll basis were relatively low. The larger LMA meant that shade thalli stored more water per unit area which should ensure longer active periods than sun thalli. The results support a strategy pair of high NP and short active time versus low NP and long active time, both having been reported for other soil crust species. However, the visibly larger biomass of the shade D. diacapsis suggests that the lichen is at the limit of its adaptability in these habitats.

scholarly journals Variability in Macro- and Micronutrients of 15 Commercially Available Microalgae Powders

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 310
Author(s):  
Fabian Sandgruber ◽  
Annekathrin Gielsdorf ◽  
Anja C. Baur ◽  
Benjamin Schenz ◽  
Sandra Marie Müller ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Dunaliella Salina ◽  
Haematococcus Pluvialis ◽  
Saturated Fatty Acids ◽  
Dry Weight ◽  
Chlorella Pyrenoidosa ◽  
Essential Amino Acids ◽  
Arthrospira Platensis ◽  
Omega 3 ◽  
Tetraselmis Chuii

The nutrient composition of 15 commercially available microalgae powders of Arthrospira platensis, Chlorella pyrenoidosa and vulgaris, Dunaliella salina, Haematococcus pluvialis, Tetraselmis chuii, and Aphanizomenon flos-aquae was analyzed. The Dunaliella salina powders were characterized by a high content of carbohydrates, saturated fatty acids (SFAs), omega-6-polyunsaturated fatty acids (n6-PUFAs), heavy metals, and α-tocopherol, whereas the protein amounts, essential amino acids (EAAs), omega-3-PUFAs (n3-PUFAs), vitamins, and minerals were low. In the powder of Haematococcus pluvialis, ten times higher amounts of carotenoids compared to all other analyzed powders were determined, yet it was low in vitamins D and E, protein, and EAAs, and the n6/n3-PUFAs ratio was comparably high. Vitamin B12, quantified as cobalamin, was below 0.02 mg/100 g dry weight (d.w.) in all studied powders. Based on our analysis, microalgae such as Aphanizomenon and Chlorella may contribute to an adequate intake of critical nutrients such as protein with a high content of EAAs, dietary fibers, n3-PUFAs, Ca, Fe, Mg, and Zn, as well as vitamin D and E. Yet, the nutritional value of Aphanizomenon flos-aquae was slightly decreased by high contents of SFAs. The present data show that microalgae are rich in valuable nutrients, but the macro- and micronutrient profiles differ strongly between and within species.

scholarly journals Solvent-Induced Hysteresis Loop in Anionic Spin Crossover (SCO) Isomorph Complexes

2021 ◽  
Vol 7 (6) ◽  
pp. 75
Author(s):  
Emmelyne Cuza ◽  
Samia Benmansour ◽  
Nathalie Cosquer ◽  
Françoise Conan ◽  
Carlos J. Gómez-García ◽  
...  
Keyword(s):  
Metal Ion ◽  
Spin Crossover ◽  
Magnetic Behaviour ◽  
Magnetic Studies ◽  
Tridentate Ligands ◽  
Tripodal Ligand ◽  
Single Crystal Structures ◽  
One Step ◽  
Lower Temperature ◽  
Step Transition

Reaction of Fe(II) with the tris-(pyridin-2-yl)ethoxymethane (py3C-OEt) tripodal ligand in the presence of the pseudohalide ancillary NCSe- (E = S, Se, BH3) ligand leads to the mononuclear complex [Fe(py3C-OEt)2][Fe(py3C-OEt)(NCSe)3]2·2CH3CN (3), which has been characterised as an isomorph of the two previously reported complexes, Fe(py3C-OEt)2][Fe(py3C-OEt)(NCE)3]2·2CH3CN, with E = S (1), BH3 (2). X-ray powder diffraction of the three complexes (1–3), associated with the previously reported single crystal structures of 1–2, revealed a monomeric isomorph structure for 3, formed by the spin crossover (SCO) anionic [Fe(py3C-OEt)(NCSe)3]− complex, associated with the low spin (LS) [Fe(py3C-OEt)2]2+ cationic complex and two solvent acetonitrile molecules. In the [Fe(py3C-OEt)2]2+ complex, the metal ion environment involves two py3C-OEt tridentate ligands, while the [Fe(py3C-OEt)(NCSe)3]− anion displays a hexacoordinated environment involving three N-donor atoms of one py3C-OEt ligand and three nitrogen atoms arising from the three (NCSe)− coligands. The magnetic studies for 3 performed in the temperature range 300-5-400 K, indicated the presence of a two-step SCO transition centred around 170 and 298 K, while when the sample was heated at 400 K until its complete desolvation, the magnetic behaviour of the high temperature transition (T1/2 = 298 K) shifted to a lower temperature until the two-step behaviour merged with a gradual one-step transition at ca. 216 K.

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