Total Fatty Acid Methyl Esters Research Articles

Possibilities of Utilising Biomass Collected from Road Verges to Produce Biogas and Biodiesel

Grass collected as part of roadside maintenance is conventionally subjected to composting, which has the disadvantage of generating significant CO2 emissions. Thus, it is crucial to find an alternative method for the utilisation of grass waste. The aim of this study was to determine the specific biogas yield (SBY) from the anaerobic mono-digestion of grass from road verges and to assess the content of Fatty Acid Methyl Esters (FAMEs) in grass in relation to the time of cutting and the preservation method of the studied material. The biochemical biogas potential (BBP) test and the FAMEs content were performed on fresh and ensiled grass collected in spring, summer, and autumn. The highest biogas production was obtained from fresh grass cut in spring (715.05 ± 26.43 NL kgVS−1), while the minimum SBY was observed for fresh grass cut in summer (540.19 ± 24.32 NL kgVS−1). The methane (CH4) content in the biogas ranged between 55.0 ± 2.0% and 60.0 ± 1.0%. The contents of ammonia (NH3) and hydrogen sulphide (H2S) in biogas remained below the threshold values for these inhibitors. The highest level of total FAMEs was determined in fresh grass cut in autumn (98.08 ± 19.25 mg gDM−1), while the lowest level was detected in fresh grass cut in spring (56.37 ± 7.03 mg gDM−1). C16:0 and C18:0, which are ideal for biofuel production, were present in the largest amount (66.87 ± 15.56 mg gDM−1) in fresh grass cut in autumn. The ensiling process significantly impacted the content of total FAMEs in spring grass, leading to a reduction in total saturated fatty acids (SFAs) and an increase in total unsaturated fatty acids (USFAs). We conclude that grass biomass collected during the maintenance of road verges is a valuable feedstock for the production of both liquid and gaseous biofuels; however, generating energy from biogas appears to be more efficient than producing biodiesel.

Stearidonic acid improves eicosapentaenoic acid status: studies in humans and cultured hepatocytes

BackgroundAhiflower oil from the seeds of Buglossoides arvensis is rich in α-linolenic acid (ALA) and stearidonic acid (SDA). ALA and SDA are potential precursor fatty acids for the endogenous synthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are n3-long chain polyunsaturated fatty acids (n3-LC-PUFAS), in humans. Since taurine, an amino sulfonic acid, is often associated with tissues rich in n3-LC-PUFAS (e.g., in fatty fish, human retina), taurine may play a role in EPA- and DHA-metabolism.ObjectiveTo examine the capacity of the plant-derived precursor fatty acids (ALA and SDA) and of the potential fatty acid metabolism modulator taurine to increase n3-LC-PUFAS and their respective oxylipins in human plasma and cultivated hepatocytes (HepG2 cells).MethodsIn a monocentric, randomized crossover study 29 healthy male volunteers received three sequential interventions, namely ahiflower oil (9 g/day), taurine (1.5 g/day) and ahiflower oil (9 g/day) + taurine (1.5 g/day) for 20 days. In addition, cultivated HepG2 cells were treated with isolated fatty acids ALA, SDA, EPA, DHA as well as taurine alone or together with SDA.ResultsOral ahiflower oil intake significantly improved plasma EPA levels (0.2 vs. 0.6% of total fatty acid methyl esters (FAMES)) in humans, whereas DHA levels were unaffected by treatments. EPA-levels in SDA-treated HepG2 cells were 65% higher (5.1 vs. 3.0% of total FAMES) than those in ALA-treated cells. Taurine did not affect fatty acid profiles in human plasma in vivo or in HepG2 cells in vitro. SDA-rich ahiflower oil and isolated SDA led to an increase in EPA-derived oxylipins in humans and in HepG2 cells, respectively.ConclusionThe consumption of ahiflower oil improves the circulating levels of EPA and EPA-derived oxylipins in humans. In cultivated hepatocytes, EPA and EPA-derived oxylipins are more effectively increased by SDA than ALA.

Utilization of microalgae for agricultural runoff remediation and sustainable biofuel production through an integrated biorefinery approach

Generally wastewater such agricultural runoff is considered a nuisance; however, it could be harnessed as a potential source of nutrients like nitrates and phosphates in integrated biorefinery context. In the current study, microalgae Chlorella sp. S5 was used for bioremediation of agricultural runoff and the leftover algal biomass was used as a potential source for production of biofuels in an integrated biorefinery context. The microalgae Chlorella sp. S5 was cultivated on Blue Green (BG 11) medium and a comprehensive optimization of different parameters including phosphates, nitrates, and pH was carried out to acquire maximum algal biomass enriched with high lipids content. Dry biomass was quantified using the solvent extraction technique, while the identification of nitrates and phosphates in agricultural runoff was carried out using commercial kits. The algal extracted lipids (oils) were employed in enzymatic trans-esterification for biodiesel production using whole-cell biomass of Bacillus subtilis Q4 MZ841642. The resultant fatty acid methyl esters (FAMEs) were analyzed using Fourier transform infrared (FTIR) spectroscopy and gas chromatography coupled with mass spectrometry (GC–MS). Subsequently, both the intact algal biomass and its lipid-depleted algal biomass were used for biogas production within a batch anaerobic digestion setup. Interestingly, Chlorella sp. S5 demonstrated a substantial reduction of 95% in nitrate and 91% in phosphate from agricultural runoff. The biodiesel derived from algal biomass exhibited a noteworthy total FAME content of 98.2%, meeting the quality standards set by American Society for Testing and Materials (ASTM) and European union (EU) standards. Furthermore, the biomethane yields obtained from whole biomass and lipid-depleted biomass were 330.34 NmL/g VSadded and 364.34 NmL/g VSadded, respectively. In conclusion, the findings underscore the potent utility of Chlorella sp. S5 as a multi-faceted resource, proficiently employed in a sequential cascade for treating agricultural runoff, producing biodiesel, and generating biogas within the integrated biorefinery concept.Graphical

Development of a fast GC-response factor method to quantify total FAMEs in biodiesel from various fatty acid sources

Biodiesel is a renewable energy source that can be employed as an alternative fuel to fossil diesel. Monitoring samples in terms of fatty acid methyl esters (FAMEs) content using gas chromatography (GC) is a useful way to evaluate the quality of biodiesel produced. Fast GC can be used to reduce the time of analysis and consequently the costs, even though the equipment required for this may be expensive. Therefore, we developed and validated a Fast GC-response factor (Fast-GCRF) methodology using a low-priced nonpolar column, flame ionization detection (FID) and a standard chromatograph usually destined for conventional GC separations. The method was validated and applied to the quantification of FAMEs produced from various raw materials (soybean, cottonseed, canola, coconut, palm, sesame, sunflower, castor, corn, macauba, almond, peanut, chia seeds, residual frying oils, and chicken fat), being both selective and robust even when subjected to changes in sample preparation. The Fast GCRF method presented respective maximum relative standard deviation (RSD) values for instrumental precision, repeatability, and intermediate precision of 2.3 %, 3.6 %, and 2.8 %. When compared to conventional GC methodologies, accurate results with high degrees of agreement were obtained using the Fast-GCRF method, within an at least four times shorter analysis time.

Caprine milk fatty acid responses to dietary dried grape pomace

Including grape pomace in goat diets presents a potentially valuable strategy for enhancing the sustainability of goat farming and mitigating environmental risks. This work aimed to investigate the impact of dietary dried grape pomace (DGP) on milk yield, milk composition and milk fatty acid (FA) profile in goats. Gas chromatography was utilised to obtain an extensive profile of FA in milk fat. Dry matter intake, as well as milk yield and composition were not altered by dietary DGP. Despite the predominance of linoleic acid (LA, 18:2 cis-9,cis-12) in the lipids of DGP and the presence of phenolic compounds, its inclusion in the diet did not negatively affect the quantitatively main groups of FA. Furthermore, there was no significant impact on butyric, caproic, caprylic, and capric acids, the major 18:1 trans isomers, including vaccenic acid (18:1 trans-11), LA, α-linolenic acid (18:3 n-3), and the long chain polyunsaturated n-6 and n-3 FA. However, rumenic acid in milk fat was significantly reduced from 0.36 to 0.30 g/100 g of total fatty acid methyl esters. This study supports that up to 6%, DGP can be safely included in conventional dairy goat diets without compromising the production results or altering to great extent the milk FA profile.

A liquefied ammonia method for extracting lipids from Nannochloropsis oculata without drying and cell disruption

Lipid extraction technology that avoids energy-consuming processes, such as drying and cell disruption, is needed for efficient biofuel production. Here, we propose a novel technique for lipid extraction directly from wet Nannochloropsis oculata using liquefied NH3, eliminating energy-consuming drying and cell-disruption steps. An experimental apparatus to distribute liquefied NH3 to the sample at 20 °C and 0.85 MPa was developed. At an NH3/sample ratio of 45 (wt./wt.), approximately 48.5 wt% of the sample was separated as a crude extract, with the removal of over 99 wt% of the water content. The elemental composition of the feedstock and crude extract did not indicate any increase in N levels. The total fatty acid methyl ester yields (10.5 % of dry-weight biomass) were comparable to those obtained using conventional methods. The crude extract contained valuable C12–C20 fatty acids, indicating that liquefied NH3 extraction is attractive for producing bioproducts from wet microalgae.

Enhancing Lipid Production of Chlorella sp. by Mixotrophic Cultivation Optimization

Mixotrophic microalgal cultivation can utilize CO2 and organic carbon sources. This study optimized the cultivation nitrogen source (peptone, urea, yeast extract, NH4Cl, (NH4)2SO4, NH4NO3, NaNO3 and KNO3), carbon combination (glucose, glycerol, sucrose), (NH4)2SO4 nitrogen source and pH (6–11) in a local microalgae species with three characteristics (high pH-resistant, high growth rate and high lipid content). Chlorella sp. G3H3-1-2 biomass production and lipid accumulation were estimated using the fatty acid methyl esters (FAMEs) concentration. The Chlorella sp. G3H3-1-2 FAME content was strongly influenced by the carbon, nitrogen sources and pH variations. The pH ranged from 6.0 to 8.0, which produced the highest specific growth rate of 1.22 day−1 for Chlorella sp. G3H3-1-2 while using glucose as the single carbon source. However, the highest total FAMEs content of 59% in the Chlorella sp. G3H3-1-2 biomass of 1.75 g/L was obtained while using the combination of 1 g-glucose/L as the carbon source and 0.2 g-(NH4)2SO4/L as the nitrogen source at the high pH value of 10.

Lipid production and cellular changes in Fremyella diplosiphon exposed to nanoscale zerovalent iron nanoparticles and ampicillin

With the dramatic decrease in fossil fuel stocks and their detrimental effects on the environment, renewable energy sources have gained imminent importance in the mitigation of emissions. As lipid-enriched energy stocks, cyanobacteria are the leading group of microorganisms contributing to the advent of a new energy era. In the present study, the impact of Nanofer 25 s nanoscale zero-valent iron nanoparticles (nZVIs) and ampicillin on lipid production and cellular structural changes in Fremyella diplosiphon strain B481-SD were investigated. Total lipid abundance, fatty acid methyl ester (FAME) compositions, and alkene production as detected by high-resolution two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC/TOF–MS) was significantly higher (p < 0.05) in the individual application of 0.8 mg/L ampicillin, 3.2 mg/L nZVIs, and a combined regimen of 0.8 mg/L ampicillin and 3.2 mg/L nZVIs compared to the untreated control. In addition, we identified significant increases (p < 0.05) in monounsaturated fatty acids (MUFAs) in F. diplosiphon treated with the combination regimen compared to the untreated control, 0.8 mg/L of ampicillin, and 3.2 mg/L of nZVIs. Furthermore, individual treatment with 0.8 mg/L ampicillin and the combination regimen (0.8 mg/L ampicillin + 3.2 mg/L nZVIs) significantly increased (p < 0.05) Nile red fluorescence compared to the untreated control, indicating neutral membrane lipids to be the main target of ampicillin added treatments. Transmission electron microscopy studies revealed the presence of single-layered thylakoid membranes in the untreated control, while complex stacked membranes of 5–8 layers were visualized in ampicillin and nZVI-treated F. diplosiphon. Our results indicate that nZVIs in combination with ampicillin significantly enhanced total lipids, essential FAMEs, and alkenes in F. diplosiphon. These findings offer a promising approach to augment the potential of using the strain as a large-scale biofuel agent.

Sterols, free fatty acids, and total fatty acid content in the massive Porites spp. corals cultured under different pCO2 and temperature treatments

Lipids may serve as energy reserves to support coral calcification, allow acclimation to higher temperatures, and are implicated in the control of CaCO3 precipitation. Here, we report the lipid composition of the soft tissues (including host and symbionts) of 7 massive Porites spp. coral colonies (4 × P. lutea and 3 × P. murrayensis), which were cultured under different pCO2 concentrations (180, 260, 400 and 750 µatm) and at two temperatures (25 ℃ and 28 ℃), below the thermal stress threshold. We report the fatty acid methyl esters (FAME), free fatty acid (FFA) to total fatty acid content, sterol and wax ester profiles, and identify two ketones (n-alkanone) and three long chain aldehyde (n-alkanal) derivatives. Increasing seawater temperature significantly increases the contributions of FFAs to the total lipids, of C18:2 and C20:0 to the total FFA pool, of C14:0 to total FAME, and of campesterol to total sterol. The temperature increase also reduces the contributions of unusual fatty acid derivatives to total lipids, of C14:0, C15:0, C16:0 and C17:0 saturated free fatty acids to total FFAs, and of C16:0 FA to total FAME. Fatty acids are implicated in the control of membrane structure fluidity and the observed changes may promote acclimation and thermostability as temperature varies. Seawater pCO2 has no significant effect on the composition of tissue lipids with the exception that the contribution of C14:0 FA to total lipid content is significantly lower at 180 µatm compared to 260 and 750 µatm. Decreased contribution of total sterols and unusual fatty acid derivatives and increased contribution of total FFAs to total lipids are observed in the fastest calcifying coral (a P. lutea specimen) compared to the other corals, under all pCO2 and temperature conditions. Although a rapid calcifier this genotype has been shown previously to exhibit pronounced abnormal changes in skeletal morphology in response to decreased seawater pCO2. Variations in tissue lipid composition between coral genotypes may influence their resilience to future climate change.

Lipid quantity and composition vary between three European house fly strains

AbstractLipids are an important class of nutrients for insects, as they are the main energy source during metamorphosis and crucial for survival and reproduction. Lipid reserves in insects are mostly accumulated during larval development and can be influenced by environmental factors such as diet and temperature. Genetic factors can also affect larval lipid content and composition. Larvae of the house fly, Musca domestica L. (Diptera: Muscidae), are a valuable emerging resource for the insect feed sector, fueling a growing interest in the factors regulating larval lipid content. We investigated whether strains of three geographical origins vary in ontogeny, quantity, and composition of stored lipids in response to temperature. Italian, Spanish, and Dutch house fly larvae were reared on a similar diet at 25 and 35 °C. Larval dry weight and total lipid content were determined in early‐, mid‐, and late‐third instars by extraction of soluble lipids. The fatty acid composition was analyzed in late‐third instars using an improved extraction and derivatization protocol. We found that strain, larval stage, and temperature affected larval dry weight and absolute and relative lipid content, with significant interaction effects between these three factors. All flies were reared in a common environment, indicating a genetic component to lipid storage. Analysis of lipid composition identified 11 fatty acids, including some rarely reported in the literature. Five fatty acids accounted for 80 and 81% of the total fatty acid methyl esters detected at 25 and 35 °C, respectively. An effect of temperature but not strain was evident on the composition of the fatty acids. The observed differences in lipid content among strains and temperature conditions could be of interest for commercial rearing of the house fly.

Dual-mode cultivation of the mixed microalgal culture to induce lipid synthesis using anaerobic digestate as an ammonia source

Anaerobic Digestate (AD) is a desirable and significant nutrient source for microalgal growth. It can be utilized as a part of the circular economy in the generation of high-value-added products. Dual-mode cultivation with AD as a substrate can be an efficient strategy to enhance the algal biomass and produce high-quality biodiesel. As dilution is required to prevent growth inhibition, in this study, growth optimization was initially carried out to figure out the best dilution ratio of AD, which corresponded to a wide range of 0 to 2,000 mg NH4-N/L concentrations. The Bold’s basal medium with triple nitrate (3NBBM) that supplemented AD at 4 % dilution resulted in the highest biomass (2290 mg·L−1). After maintaining the highest biomass-producing condition, stressors such as sodium chloride (NaCl) and ferric chloride (FeCl3) have also been searched to increase lipid production. The lipid content has increased by 1.8-fold as a result of the stress (at 20 g·L−1 NaCl and 0.1 mg·L−1 FeCl3). At those stress conditions, the saturated fatty acid concentrations were around 33 % of the total fatty acid methyl esters (FAME). In addition, compliance with the biodiesel standards has also been ensured at 0.1 mg·L−1 FeCl3. The combination of AD with nutrients and salt stressors, like NaCl and FeCl3, within the concept of dual-mode cultivation, could be a viable strategy to produce sustainable, high-quality biodiesel with a high proportion of algal biomass and could be integrated into microalgae production facilities.

Direct transesterification of microalgae after pulsed electric field treatment

AbstractBACKGROUNDLipid extraction is a major bottleneck for the commercialization of microalgae due to energy costs involved during solvent recycling. Direct transesterification offers the possibility to bypass the extraction step by immediately converting the lipids to fatty acid methyl esters (FAMEs). In this study, the efficiency of direct transesterification after pulsed electric field (PEF) treatment was evaluated. Freshly harvested Auxenochlorella protothecoides (A. protothecoides), cultivated either autotrophically or mixotrophically, was subjected to PEF. Two treatment energies were tested, 0.25 and 1.5 MJ kgdw−1, and results were compared with those for conventional two‐step transesterification.RESULTSFor autotrophically grown A. protothecoides, the percentage of the total FAMEs recovered from untreated biomass and microalgae treated with 0.25 MJ kgdw−1 was 30% for both cases, while for 1.5 MJ kgdw−1 it was 65%. A 24 h incubation step between PEF treatment and direct transesterification significantly improved the results. Untreated biomass remained stable with 30% of FAMEs, while with both treatment energies a 97% FAME recovery was achieved. However, for mixotrophic A. protothecoides the process was not as effective. Approximately 30% of FAMEs were recovered for all three conditions immediately after PEF with only a marginal increase after incubation. The reason for this different behavior of the two cultivation modes is unknown and under investigation.CONCLUSIONSOverall, the synergy between PEF and direct transesterification was proven to have potential, in particular for autotrophic microalgae. Its implementation and further optimization in a biorefinery therefore merit further attention. © 2022 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry (SCI).

Carbon quantum dots (CQD) fabricated from Exiguobacterium sp. VK2 exopolysaccharide (EPS) using hydrothermal reaction and its biodiesel applications

The bacterial exopolysaccharides (EPS) enticed the researchers because of its natural protection against predators, and adhesion to the surface. Thus, this study was conducted for the EPS production from Exiguobacteriumsp. VK2, the synthesis of Carbon Quantum Dot (CQD) from EPS and it was further used for bioenergy production. The CQD was synthesized and characterized using hydrothermal reaction and its structure was elucidated by several methods like Fourier transform infrared (FT-IR) spectrum, UV–visible spectroscopy, Gas chromatography-Mass spectroscopy (GC-MS), X-ray diffraction (XRD), HR-TEM, SAED (Selected Area Electron Diffraction) spectrum, Atomic Force Microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Brunaur-Emmett-Teller (BET) analysis. Further, the synthesized CQD from EPS of Exiguobacterium sp.VK2 was tested for its catalytic activity in biodiesel production from waste cooking oil (WCO) along with two different conventional catalysts and more than 90% of total fatty acid methyl ester (FAME) was achieved by CQD than the control.

Cold stress stimulates algae to produce value-added compounds

Two cold-tolerant microalgae, Chlorella vulgaris and Scenedesmus sp., were grown at 22 and 5 °C. At the lower temperature, the microalgae showed substantial biochemical and morphological changes. The soluble sugar profile in response to low-temperature cultivation was very different in the two strains. C. vulgaris increased both the sucrose and raffinose family oligosaccharides (RFOs) content at 5 °C while Scenedesmus sp. drastically reduced the sucrose content. Both strains increased the total fatty acid methyl ester (FAME) content when grown at 5 °C. However, the FAME profiles were very different: C. vulgaris mainly increased C18:1 and less so C18:3, while Scenedesmus sp. decreased C18:1 but greatly increased C18:3. The morphology of C. vulgaris changed slightly at the lower temperature, while Scenedesmus sp. showed substantial changes in the size and shape. Low temperature triggered the synthesis of unsaturated fatty acids that are essential for human nutrition.

Assessment of Commercially Safflower Oils (Carthami Oleum Raffinatum) in Terms of European Pharmacopoeia Criteria and Their Weight Control Potentials.

Safflower oils, which are sold commercially, are in demand with food, cosmetics, and health-promoting claims. In this study, safflower oil samples belonging to 11 different brands were evaluated in terms of European Pharmacopoeia Criteria 7.0. Additionally, in vitro weight control potential of all samples was investigated. Samples to be analyzed were purchased from pharmacies, herbal, online, and cosmetics stores. Acid and peroxide values of 11 safflower samples and analysis of their fatty acids by gas chromatography-mass spectrometry (GC-MS) were carried out according to the "Carthami oleum raffinatum" monograph registered in the European Pharmacopeia 7.0. To test the effects of all samples on weight control, their inhibitory effects on carbohydrate-digesting enzymes (α-glucosidase and α-amylase) were evaluated using spectrophotometric methods. Out of 11 oil samples, only two of them had acid and peroxide values below the reference value. According to GC analysis, safflower oil samples are rich in monounsaturated fatty acids (oleic acid) and polyunsaturated fatty acids (linoleic acid) (67.10-99.53%) of total fatty acids in its content are oleic, linoleic, palmitic, and stearic acids. Saturated fatty acids were 0.58 to 12.18% of the total fatty acid methyl esters in oils. When evaluated in terms of the inhibition of α-amylase and α-glucosidase enzymes that hydrolyze carbohydrates, the results showed that safflower oil samples had no inhibitory activity on these enzymes. It has been determined in this report that many safflower oil samples on the market do not meet the quality criteria recommended in European Pharmacopoeia 7.0. It was observed that safflower oil did not show any inhibitory effect on these two enzymes, which is considered a rational approach for weight control.

Residual palm kernel expeller as the support material and alimentation provider in enhancing attached microalgal growth for quality biodiesel production

Albeit the biodiesel production from suspended microalgal system has gained immense interests in recent years, the domineering limitation of being economically infeasible has hindered this technology from partaking into a large-scale operation. To curtail this issue, attached growth system had been introduced by various studies; however, those were still unable to alleviate the socio-economic challenges faced in commercializing the microalgal biomass production. Thus, this study had developed a novel approach in cultivating-cum-harvesting attached Chlorella vulgaris sp. microalgae, whilst using solid organic waste of palm kernel expeller (PKE) as the supporting and alimentation material for microalgal biofilm formation. The effects of three variables, namely, PKE dosage, light intensity, and photoperiod, were initially modelled and later optimized using Response Surface Methodology tool. The derived statistical models could predict the growth performances of attached microalgal biomass and lipid productivity. The optimum growing condition was attained at PKE dosage of 5.67 g/L, light intensity of 197 μmol/m2 s and photoperiod of 8 light and 16 dark hours/cycle, achieving the microalgal density and lipid content of 9.87 ± 0.05 g/g and 3.39 ± 0.28 g/g, respectively, with lipid productivity of 29.6 mg/L day. This optimum condition had led to the intensification of biodiesel quality with a high percentage of monounsaturated fatty acid, i.e., oleic acid (C18:1), encompassing 81.86% of total fatty acid methyl ester components. Given that the positive acquisition of PKE as an excellent supporting material in enhancing the microalgal density and lipid productivity that had resulted in the commercially viable biodiesel quality, this study served as a novel revolution in augmenting the microalgae and solid waste utilities for sustainable energy generation.

Uso de harina de semilla de uva como antioxidante natural en dietas de pollos de engorda Hubbard de crecimiento lento enriquecidas con ácidos grasos poliinsaturados

The purpose of the study was to assess the effect of the grapeseed meal, added to slow-growing Hubbard broilers diet high in polyunsaturated fatty acids (PUFA) due to the dietary flaxseed meal. The 7-wk feeding trial used 80 broiler chicks (14 d), assigned to two groups: control (C) and E, with 4 replicates of 10 chicks/group. The basal diet was similar for both groups during both feeding stages. The diet for group E was supplemented with 3% grapeseed meal. Six broilers from each group were slaughtered in the end of the feeding trial, and blood, breast and leg meat samples were collected. Serum cholesterol was significantly lower in group E (110.85 mg/dL), than in group C (146.82 mg/dL). The PUFA concentration was significantly higher in group E, than in group C, both in the breast (31.34 %, compared to 27.73 % total fatty acid methyl ester - FAME) and in the leg (32.44 %, compared to 30.06 % total FAME). The cholesterol concentration was significantly lower in group E (42.52 mg), than in group C (60.91 mg/100 g fresh sample) in the leg. After 7 d of refrigeration, the peroxide value was significantly lower in group E (8.11 meq), than in group C (8.79 meq/kg fat) in the breast meat, while fat acidity was significantly lower in group E (40.82 mg KOH), than in group C (43.99 mg KOH / g fat) in the leg. The dietary 3 % grapeseed meal, used as natural antioxidant, in PUFA-enriched broiler diets, had positive effects on the blood parameters and meat quality.

Establishment of an efficient tray-drying process for qualitative biodiesel production from a locally isolated microalga Tetradesmus obliquus cultivated in polyhouse raceway ponds

In this present investigation, a locally isolated green alga, Tetradesmus obliquus (Turp.) Kütz., grown in 16,000 L optimized culture volume in raceway ponds, was explored for the development of a rapid algal drying protocol using a self-designed tray-dryer. The biphasic nitrogen starved cultures were subjected to drying with 5, 7.5, and 10 mm algal slurry thickness at three different temperatures viz. 60, 80, and 100 °C. The wet algal slurry with ~90% initial moisture content (MC) required 12, and 15 h of drying period at 80 °C to achieve maximum lipid yield (~425 mg/g dry algal weight) for 5, and 7.5 mm initial slurry thickness, respectively. Newton's model constant (k) was calculated from the available datasets which showed that the increase in slurry thickness resulted in lower k values indicating a slower drying process with higher thickness. Partial drying up to 10% residual MC at 80 °C showed 93% lipid recovery in comparison to complete drying at the same temperature. The drying period was significantly reduced to only 6–8.5 h in comparison to complete drying. The energy consumption of this tray-drying technique at 80 °C with 10% residual MC was calculated to be 10.81, and 9.93 kWh/ kg dry biomass, for 5, and 7.5 mm initial algal slurry thickness, respectively. The lipid produced from the tray-dried biomass after conversion to biodiesel, was further analyzed in GC–MS. It was found that the saturated and mono-unsaturated fatty acids constituted 90% of the total fatty acid methyl ester (FAME) yield in the obtained algal biodiesel. Furthermore, the characterization of various fuel properties of the produced biodiesel revealed the values were within the definite limits of Indian and international biodiesel standards, thus, demonstrating the bright possibility of producing qualitative biodiesel from T. obliquus using this rapid tray-drying technique.

Multi-objective tailored optimization deciphering carbon partitioning and metabolomic tuning in response to elevated CO2 levels, organic carbon and sparging period.

Microalgae have garnered much contemplation as candidates to fix CO2 into valuable compounds. Although microalgae have been studied to produce various metabolites, they have not yet proved successful for commercialization. Since, handling such problems practically requires satisfying multiple parameters simultaneously, we put forth a multi-parameter optimization strategy to manipulate the carbon metabolism of Scenedesmus sp. to improve biomass production and enhance CO2 fixation to increase the production of fuel-related metabolites. The Box-Behnken design method was applied with CO2 concentration, CO2 sparging time and glucose concentration as independent variables; biomass and total fatty acid methyl ester (total FAME) content were analyzed as response variables. The strain is supplemented with both CO2 and glucose with an aim to enhance carbon flux and rechannel it towards carbon fixation. As per the results obtained in this study, Scenedesmus sp. could effectively exploit high CO2 concentration (15%) for longer duration under high concentration of glucose supplementation (9g/L) producing a biomass of 635.24±39.9μg/mL with a high total fatty acid methyl ester (FAME) content of 71.29±4.2μg/mg, significant acetyl-CoA carboxylase enzyme activity and a favorable fatty acid profile: 35.8% palmitic acid, 10.5% linoleic acid and 30.6% linolenic acid. The carbohydrate content was maximum at 10% CO2 sparged for the longest duration of 90min under glucose concentration of 9g/L. This study puts forth an optimal design that can provide evidence on comprehending the carbon assimilation mechanism to enhance production of biomass and biofuels and provide conditions to microalgal species to tolerate CO2 rich flue gas.

Growth Performance and Biochemical Composition of Tetradesmus obliquus in Media with Different Phosphorus Concentrations

In this study, the effects of phosphorus on culture growth and biochemical composition of Tetradesmus obliquus were investigated. T. obliquus was cultivated in medium with different P concentrations. Cell number, optical density and dry weight values were measured every other day and total protein and lipid content, amino acid and fatty acids profiles were detected. The highest cell number (2905x104), optical density (1.07) and dry weight (0.04 mgL-1) were observed in 75% P+ medium. 50% P- medium has the highest (47.7% of dry weight) protein amount and the maximum of total lipid content (17.08% of dry weight) was determined in 75% P- medium. 75% P+ medium has the highest total amino acid value (64.37 mgg-1 dry weight) and 75% P- medium has the lowest (55.22 mgg-1dry weight). The highest saturated fatty acids (23.57%) and mono-unsaturated fatty acids (19.97%) were observed in 50% P- medium. The second highest percentages of polyunsaturated fatty acids values were in the 75% P- medium (48.63 %). These results show that phosphorus limitation increases the total protein, lipid and fatty acid methyl esters amounts and restricts the cell division and anabolic reaction. An excess in phosphorus has an enhancing effect on amino acid synthesis.