Fatty Acid Methyl Ester Composition Research Articles

Production of Biodiesel from Caster Oil: Experimental and Optimization Study

Biodiesel production provides a diversified and renewable energy source offering lower greenhouse gas emissions than traditional diesel. It also offers economic benefits by reducing dependence on imported fossil fuels. Castor oil transesterification is an essential process in the creation of biodiesel. In this experimental study, castor oil transesterified using methanol, and potassium hydroxide was the catalyst. The effects of various reaction parameters, including temperature, the molar ratio of methanol to oil, and catalyst concentration, on the biodiesel yield were studied and optimized by the conventional method followed by the statistically based Box-Behnken design method. The maximum yield was reached at a temperature of 65°C, a molar ratio of 12:1 methanol to oil, and a catalyst concentration of 1.5% by weight. The yield of biodiesel under these conditions was 93%. The optimized results of experiments showed increases in yield to 93.36% at 65°C temperature, 14.12:1 a molar ratio methanol to oil, and a 1.12% by weight catalyst concentration; hence, the optimal temperature was the highest achieved value. The fatty acid methyl ester composition analysis revealed that the major constituents of the biodiesel were ricinoleic acid methyl ester, linoleic acid methyl ester, and oleic acid methyl ester. The findings of this research highlight the significance of selecting the appropriate reaction conditions to maximize biodiesel yield. Also, it was found that castor oil had the potential to be an essential feedstock for biodiesel production.

Effect of citric acid on cell membrane structure and function of Issatchenkia terricola WJL-G4.

This study aimed to investigate the changes of cell membrane structure and function of Issatchenkia terricola under citric acid by performing physiological analysis. The membrane integrity, surface hydrophobicity, structure, fluidity, apoptosis, and fatty acid methyl esters composition of I. terricola WJL-G4 cells were determined by propidium iodide staining, microbial adhesion to hydrocarbon test, transmission electron microscopy analysis, fluorescence anisotropy, flow cytometry, and gas chromatography-mass, respectively. The results showed that with the increasing of citric acid concentrations, the cell vitality, membrane integrity, and fluidity of I. terricola reduced; meanwhile, apoptosis rate, membrane permeable, hydrophobicity, and ergosterol contents augmented significantly. Compared to control, the activities of Na+, K+-ATPase, and Ca2+, Mg2+-ATPase increased by 3.73-fold and 6.70-fold, respectively, when citric acid concentration increased to 20g l-1. The cells cracked and their cytoplasm effused when the citric acid concentration reached 80g l-1. I. terricola could successfully adjust its membrane structure and function below 60g l-1 of citric acid. However, for citric acid concentrations above 80g l-1, its structure and function were dramatically changed, which might result in reduced functionality.

Enhanced carotenoid production, biodiesel quality, and harvesting efficiency in microalga Graesiella emersonii via heterotrophic cultivation strategy

The aim of this study was to evaluate the potential industrial applicability of the green microalga Graesiella emersonii GEGS21 by comparing its biomass, photosynthetic pigments, and biodiesel properties under photoautotrophic (PA) and heterotrophic (HT) cultivation. Four agricultural soluble fertilizers (SFs) were tested as substitute medium for algal growth. Of these, three were not only cost-effective but also more efficient in promoting growth compared to the BG-11 algal medium. Supplementing the SF medium with 12 g/L of glucose significantly improved algal biomass productivity under HT condition, and the optimal conditions were identified as 0 M NaCl, a temperature of 30 °C, and a pH of 8. Subsequent supplementation with yeast extract led to a notable enhancement in algal growth, resulting in approximately 18.6-times higher biomass productivity compared to the PA condition. Under HT cultivation, the productivities of the photosynthetic pigments including lutein and zeaxanthin were significantly increased approximately by 3.6-fold and 3.5-fold, respectively compared to the PA condition (p < 0.05). Moreover, HT cultivation led to improved biodiesel properties, such as iodine value, cetane number, oxidative stability, and kinematic viscosity. These enhancements, achieved through altered fatty acid methyl ester composition, align with the ASTM D6751 and EN14214 biodiesel standards. Interestingly, when cultivated under HT conditions, algal strain exhibited higher sedimentation efficiency, accompanied by an enhanced cellular starch content, compared to both PA and mixotrophic conditions. This suggests a promising strategy for economically viable harvesting by altering the specific gravity of algal cells. In conclusion, our findings suggest that HT cultivation of Graesiella emersonii GEGS21 may serve as an effective approach to produce value-added compounds and bioenergy, offering potential for economical harvesting.

Total Lipid Content and Fatty Acid Composition of Two Morphologically Distinct Chlorella spp. for Biodiesel Production

This study investigated the potential of two morphologically distinct Chlorella spp. to assess the total lipid content and fatty acid composition targeting biodiesel production. Due to their rapid growth, less space requirement, and zero-conflict with current food demand, green microalgae-led biodiesel production has gained a key attention as an alternative, sustainable and eco-friendly substitute for fossil fuels diminishing the increased demand for fossil fuels, fuel prices and excessive release of greenhouse gases to the atmosphere. The Chlorella spp. were isolated from Beire Lake, Colombo (Wet Zone) and Kiriibban Lake, Monaragala (Dry Zone) of Sri Lanka. They were named as BCS1 and RCS2, respectively. Semi-mass culturing of Chlorella spp. in BG-11 medium (pH=7.5-8.5) was carried out in a greenhouse providing aeration and a 12:12 light: dark photoperiod. After 4 weeks, Chlorella spp. were harvested using aluminium sulphate, employing flocculation method. Harvested biomass was oven-dried and made into a fine powder for analysis. The total lipid content (TLC) of Chlorella spp. was determined using n-hexane as the extraction solvent in a soxhlet extractor maintaining three replicates for each. Extracted lipids were dried in a rotary evaporator and TLC was calculated gravimetrically. The total lipid content of BCS1 and RCS2 was recorded as 15.67% and 18.33%, respectively. After quantification, lipids were resuspended and concentrated in 1 mL of n-hexane to convert into fatty acid methyl esters (FAMEs)/ biodiesel via a transesterification reaction. The trans-esterified lipids (FAMEs) were analysed via Gas Chromatography. The most dominant FAMEs of BCS1 were palmitic acid (C16:0), oleic acid [C18:1 cis (n9)], stearic acid (C18:0), lignoceric acid (C24:0), lauric acid (C12:0) and myristic acid (C14:0). The most dominant FAMEs of RCS2 were cis-10-pentadecenoic acid (C15:1), elaidic acid [C18:1 trans (n9)], linolelaidic acid [C18:2 trans (n6)], cis-11-eicosenoic acid [C20:1 (n9)], lignoceric acid (C24:0) and oleic acid [C18:1 cis (n9)]. A well-balanced saturated and unsaturated FAME composition is essential for the optimal biodiesel quality, herein it was found in BCS1 with 41.62% of palmitic acid and 33.38% of oleic acid. Higher percentage of oleic acid exhibits a combination of oxidative stability and low temperature properties determining the suitability of BCS1 as a biodiesel feedstock compared to RCS2. In conclusion, even though RCS2 has a higher total lipid content, BCS1 exhibits more favourable characteristics in its FAME composition as a promising feedstock for biodiesel production.&#x0D; &#x0D; Keywords: Green microalgae, Chlorella spp., Total lipid content, Lipid composition, Biodiesel

Catalytic Upgrading of Biodiesel by Partial Hydrogenation of Its FAME Composition: A Systematic Review

Biodiesel is one of the most popular biofuels as it is a promising substitute for conventional diesel fuel, but for now, it cannot be used as a stand-alone fuel due to its low oxidative stability. For this reason, there have been efforts to upgrade biodiesel in the last few years through the partial hydrogenation of its fatty acid methyl esters (FAMEs). This procedure succeeds in resolving the problem of low oxidative stability, but in some cases, a new issue arises as non-selective hydrogenation deteriorates the fuel’s cold flow properties, which are crucial for vehicle’s operation without damaging the vehicle’s engine. More specifically, the problem of deteriorated cold flow properties is caused by the formation of trans-monounsaturated and fully saturated FAMEs during the hydrogenation reaction. Hydrogenated biodiesels are preferred to contain more cis-monounsaturated FAMEs because these are considered to have the best combination of high oxidative stability and good cold flow properties. As a result, various systems and methods have been tested to achieve selective partial hydrogenation of biodiesel FAMEs. In this review article, the catalytic systems and processes that stood out in various research studies are presented, and the factors that lead to the best possible outcome are investigated and discussed.

Waste orange seeds (Citrus sinensis seed) transformation, a viable industrial bio-oil: Oil extraction, physicochemical characterization and vital instrumental analyses studies

The processing of Petroleum-based oil has contributed to environmental challenges such as climate change. Recently, research attention has been shifted to oil extraction from different non-edible seeds as a suitable substitute. Accordingly, this study examines the physiochemical characterization, and the effect of extraction temperature on the yield of waste Citrus sinensis seed [orange seed (OS)] bio oil. Studies on the prevalent functional group, fatty acid methyl ester compositions and thermal oxidative stability were carried out using the Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectroscopy (GCMS) and differential scanning calorimetry (DSC), respectively. The oil content of the OS bio oil was 46.26%w/w. The high iodine number (31.47 mg/100 g) and low pour point (4.50 °C) of the OS bio oil showed its high content of unsaturated fatty acid. The FTIR functional group of the OS bio oil showed predominantly alkane of CH stretching, aldehydes, esters, and carboxylic acid. The chemical composition of the OS bio oil as determined by GCMS (massHunter/library/NIST 14.1) showed the occurrence of octadecadienoic and oleic acids as poly-saturated and saturated fat found in plant glycosides and vegetable fats and oil. The DSC thermal stability analysis showed the possible existence of mixed triglycerides. Finally, the result from the physiochemical characterization compositions, and functional group the OS bio oil indicated its potential as a suitable substitute for petroleum-based oil.

The Role of Fatty Acids from Plant Surfaces in the Infectivity of Colletotrichum fioriniae.

Aqueous extracts derived from flowers stimulate germination, secondary conidiation, and appressorial formation of various latent fruit rotting fungi. Even raindrops passing over flowers accumulate sufficient activity to influence the infectivity of fruit rotting fungi. Using a spore germination bioassay, high levels of bioactivity were found in chloroform extracts from plant tissues, implicating the nonpolar components of the cuticle. The fatty acid (FA) and fatty acid methyl ester (FAME) composition (C9-C20) of blueberry and cranberry tissues as well as aqueous flower extracts were characterized using a gas chromatography-mass spectrometry (GC-MS) method. The FAs and FAMEs found in the plant extracts were then tested for bioactivity using a spore germination bioassay. The C16:0 and C18:2 FAs and FAMEs, as well as the C18:0 FAME and the C20:0 FA, all stimulated appressorial formation while the C10:0 FA stimulated secondary conidiation. The C10:0 and C16:0 FAs were the only two bioactive components also identified from the aqueous floral extracts of both blueberry and cranberry and are therefore considered as contributors to the bioactivity observed in these extracts. The aqueous extracts from surfaces other than flowers showed little or no activity, and it is speculated that the movement of FAs may be related to the level of polymerization and cutin polyester development in flowers versus other plant organs. This study highlights the importance of the bloom period for infection and that the apparent effects on host susceptibility may therefore depend on the availability of specific FAs or combinations thereof.

Assessment of a green zeolite/bacterial cellulose nanocomposite membrane as a catalyst to produce biodiesel from waste cooking oil

ABSTRACT Zeolite-bacterial cellulose nanocomposite membrane (ZBCN) has been prepared and evaluated as a catalyst in the transesterification of waste cooking oil (WCO) to give biodiesel. Bacterial cellulose membrane was obtained during cultivation of Komagataeibacter as a bacterial isolate; meanwhile, zeolite A (ZA) was prepared from Egyptian ores. The results confirmed that, the amount of triglyceride (TG) converted into fatty acid methyl ester (FAME) was ≥77%, while the total conversion of TG and the conversion to other compounds were 84.4% and 7.4%, respectively, during 9 h and methanol to TG 40:1 molar ratio. XRD, SEM, EDX, and zeta potential measurements were utilized to characterize the prepared catalyst. TLC and HPTLC were employed to prove biodiesel successful synthesis and quantify its percentage in the product, respectively. The composition of FAMEs was determined by GC-MS. It revealed that the major components in the synthesized FAMEs were palmitic acid methyl ester (40.2%), oleic acid methyl ester (53%), and linoleic acid methyl ester (5.4%). The saponification number, iodine value, cetane number, and higher heating values of the synthesized biodiesel were 193.3 mg KOH/g, 54.6 g I/100 g, 62.26, and 42.3 MJ/kg, respectively, which meet the qualification of international standards. The acidity (1.68 mg KOH/g) and the viscosity (10 cSt) of the synthesized biodiesel by ZBCN showed superiority over their counterparts of WCO, but they still need further improvement.

Investigation on the Microbiological Quality and Fatty Acid Methyl Esters Composition of Commercially Available Cold-pressed Nigella sativa L. Oil

Background:: Nigella sativa is a traditional plant with several ethno-medicinal activities. There have been several health advantages associated with Nigella sativa (Ns) L. oil, which has a high concentration of bioactive compounds. Method:: This research aimed to examine the fatty acid methyl ester profiles, microbiological profiles, and aflatoxin profiles of cold-pressed Ns oils acquired from Turkish herbalists. For this, the fatty acids methyl esters (FAMEs) content and microbiological purity of 10 different Ns oils were examined. Results:: The principal FAME components in Ns seed oils were linoleic (C18:2), oleic (C18:1), and palmitic acid (C16:0), with relative percentages of 34.17-57.54%, 19.41-30.52%, and 7.05-12.54%, respectively. The quantity of total saturated fatty acids (SFA) in all investigated oils ranged from 11.47 to 18.69%, while the amount of total unsaturated fatty acids ranged from 80.94 to 88.53%. Six of ten products (0.35-1.49%) were found to contain cis-11 eicosenoic acid, a chemical unique to Ns oil. Conclusion:: Although no Aflatoxin was found in any of the samples, Enterobacteriaceae levels were exceptionally low, and yeast mold concentrations surpassed the Turkish Food Codex's permissible limit values.

Fatty Acid Methyl Ester Composition of Prominent Animal Milks Consumed within the Middle East: A Comparative Analysis

Fatty Acid Methyl Ester Composition of Prominent Animal Milks Consumed within the Middle East: A Comparative Analysis

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.

Composition of fatty acid methyl ester in microalgae Chlorella vulgaris: Comparison between various methods of harvesting, extraction and transesterification

The aim of the study was to identify which of methods produces the highest yield of fatty acid methyl ester (FAME) from microalgae. Different methods of harvesting (centrifugation, Cen & coagulation, Co), extraction (Test Tube, TT & Soxhlet, Sox) and transesterification (direct transesterification, d-trans & extraction transesterification, ext-trans) were considered. The procedures of this research consists of microalgae cultivation, harvesting of biomass and extraction of oil to obtain the lipid. The further process of converting lipid into FAME is followed by transesterification process. The FAME compositions of Chlorella vulgaris were analyzed using Gas chromatography mass spectrometry (GC–MS). The main components were consists of palmitic, stearic and oleic acids for both transesterification methods. However, FAME extracted from d-trans contained more components (linoleic and linolenic acid) than ext-trans. Furthermore, the highest amount of FAME gained by ext-trans was produced by the method of centrifugation-test tube (Cen-TT). Although Cen-TT produced the highest amount of FAME for ext-trans, it still cannot meet the highest amount of FAME produced by d-trans. Therefore, the Cen-TT method was selected to be the best microalgae harvesting and extraction method in ext-trans meanwhile the most efficient transesterification method was d-trans.

Doped Ruthenium/Hypercrosslinked Polystyrene (HPS) Catalysts in the Modification of Fatty Acid Methyl Esters

The modification of fatty substrates using heterogeneous catalysts have extensive industrial application and has an emphatic position in a sustainable context. Herein ruthenium, nickel, cobalt and copper-doped ruthenium, supported on hypercrosslinked polystyrene (HPS) catalysts were prepared by wet impregnation, characterized and applied on the modification of canola fatty acid methyl esters (FAME). The characterization showed a dispersive effect of doping metals over the ruthenium particles, the presence of acid sites and overall surface morphology, which allows targeting potential applications. The chosen modifications consisted of hydrogenation, hydroformylation, oxidative cleavage and deoxygenation, resulting in superb catalytic activities of over 99% conversions for hydrogenation and deoxygenation. The simplicity of the canola FAME composition allows the understanding of the catalytic processes and allows the upscale of more complex FAME matrixes. Finally, the obtained data stimulates further optimization studies for each application with a variation on the catalysts and the usage of residual fatty substrates, greatly enhancing the sustainability profile of the systems.

Transesterification method of microalgae biomass to produce fatty acid methyl esters

AbstractBACKGROUNDThis study investigated the effect of different solvents on the production of fatty acid methyl esters (FAMEs) from Chlorella vulgaris using two different methods of transesterification: direct transesterification (d‐trans) and extraction transesterification (ext‐trans). Different solvents were expected to lead to different amounts of FAMEs. Two solvents (methanol and ethanol) with volumes of each of 10, 12 and 14 mL were selected to produce higher amounts of FAMEs.RESULTSThe findings indicate that the highest amounts of palmitic and palmitoleic acids were extracted in 12 mL of methanol, but none of the components of FAMEs was discovered in ethanol when FAMEs were produced using d‐trans. It is shown that FAMEs that are extracted by methanol contain more components as compared to FAMEs extracted by ethanol based on gas chromatography–mass spectrometry analysis. Overall, the highest amount of FAMEs was produced when extracted using 12 mL of methanol for both methods. For ext‐trans, palmitic acid was found in all components of FAMEs that were extracted using both solvents.CONCLUSIONSThe results indicate that d‐trans showed a higher FAME amount than ext‐trans which is explained by the presence of free fatty acids and glycerides that resulted in higher yield of FAMEs in the d‐trans process. Overall, dry biomass is the best substrate for the d‐trans process to produce a higher amount of FAMEs than wet biomass because directly transesterified algal biomass, including water, resulted in losses of FAME composition. © 2023 Society of Chemical Industry (SCI).

Chicken tallow, a low-cost feedstock for the two-step lipase-catalysed synthesis of biolubricant

Biolubricants are oleochemical esters that are non-toxic to the environment, and they are preferred because of their high-performance activities in various automobile and industrial fields. In this study, chicken tallow has been explored as an alternative to a non-renewable source, which acts as a low-cost feedstock for synthesizing biolubricants in a two-step hydro esterification process catalysed by Candida rugosa lipase (CRL). The enzymatic hydrolysis of chicken tallow is optimized at different time intervals at 40 °C, and the maximum release of 160.2 µmol min−1 free fatty acids (FFAs) is observed at 100 min. The hydrolysed FFAs are characterized by the gas chromatography-mass spectrometry (GC-MS) analysis that has depicted the fatty acid methyl esters (FAMEs) composition of the tallow oil. The recovered FFA is then enzymatically esterified with trimethylolpropane (TMP) to produce TMP esters. Optimization studies are performed to explore the effect of factors such as time, temperature, amount of the enzyme, and TMP: FFA molar ratio for the esterification process. Thus, the optimal conditions for achieving a maximal hydroxyl group conversion of 60% during TMP ester production include incubation time (120 min), temperature (35 °C), lipase concentration (3% w/w), and TMP: FFA molar ratio (1:4). Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) studies confirm the synthesized TMP esters. Moreover, physicochemical properties such as viscosity, cloud point (CP), and calorific value (CV) are found to be 36 mm2/s, 7159.14 cal/g, and 20 °C, respectively.

Biodiesel production from edible and non-edible biomasses and its characterization

Biodiesel is considered one of the most viable renewable alternatives to its petroleum-derived counterpart. It can be produced from various sources, mainly via homogeneously alkali-catalyzed transesterification. Nevertheless, as the demand for edible oils grew for food and fuel, non-edible oils emerged as a more appealing choice for producing biodiesel. Waste cooking oils (WCOs) comprise an alternative and low-cost feedstock that are produced in vast quantities and can be used for biodiesel production. This study compares biodiesel properties produced by an uncooked sunflower oil obtained from a local bio-industry and a WCO sample collected from a fast food shop. Results showed that most biodiesel samples’ properties in both cases met the EN 14214 specifications. GC-MS chromatographs were similar in terms of fatty acid methyl esters (FAMEs) composition. However, oxidation stability for both biodiesel samples and viscosity for the WCO biodiesel sample were out of specifications. Further investigation is required to improve biodiesel properties and optimize production conditions.

Comparison of Various Prediction Model for Biodiesel Cetane Number using Cascade-Forward Neural Network

Cetane number (CN) is one of the important fuel properties of diesel fuels. It is a measurement of the ignition quality of diesel fuel. Numerous studies have been published to predict the CN of biodiesels. More recently, the utilization of soft computing methods such as artificial neural networks (ANN) has received considerable attention as a prediction tool. However, most studies in the use of ANN for estimating the CN of biodiesels have only used one algorithm to train a small number of datasets. This study aims to predict the CN of 63 biodiesels based on the fatty acid methyl esters (FAME) composition by developing an ANN model that was trained with 10 different algorithms. To the best of our knowledge, this is the first study to predict the CN of biodiesels using numerous ANN training algorithms utilizing sizeable datasets. Results revealed that the ANN model trained with Levenberg-Marquardt gave the highest prediction accuracy. LM algorithm successfully predicted the CN of biodiesels with the highest correlation and determination coefficient (R = 0.9615, R2 = 0.9245) as well as the lowest errors (MAD = 2.0804, RMSE = 3.1541, and MAPE = 4.2971). Hence, the Cascade neural network trained with the LM algorithm could be considered a promising alternative to the empirical correlations for predicting biodiesel’s CN.

Coupling phenol bioremediation and biodiesel production by Tetradesmus obliquus: Optimization of phenol removal, biomass productivity and lipid content

There is a growing interest for the utilization of microalgae in the bioremediation of organic pollutants and the use of biomass as a biofuel feedstock. This study investigated the influence of phenol exposure and culture conditions on the phenol removal efficiency, biomass productivity and lipid contents of Tetradesmus obliquus. Plackett-Burman design identified CaCl2, NaNO3, and initial phenol concentration as the most important variables affecting on phenol removal. The optimum conditions to maximize biomass productivity, phenol removal and lipid content were determined using the Box-Behnken experimental design as 150.1 mg L−1 phenol, 0.1 g L−1 NaNO3, and 0.03 g L−1 CaCl2. Under these conditions, phenol was completely removed from the optimized medium after 3 days and the biomass productivity and lipid content were 19.53 mg L−1 day−1 and 27.85% (w/w) after 10 days, respectively. Phenol treatment promoted algal biomass productivity to ∼1.3-folds and lipid productivity to ∼ 1.6-folds higher than the control treatment without adding phenol (negative control). Additionally, phenol altered the fatty acid methyl ester composition and increased the saturated and polyunsaturated fatty acid contents with concomitant decrease in the monounsaturated fatty acids. The predicted biodiesel characteristics viz. iodine value, cetane number, oxidation stability, kinematic viscosity, and flash point, in the presence of phenol were in accordance with the international standards. Accordingly, the present study indicated that phenol could be effectively bioremediated by T. obliquus with simultaneous promotion of the algal biomass and lipid productivity for biofuel production.

Pseudomonas californiensis sp. nov. and Pseudomonas quasicaspiana sp. nov., isolated from ornamental crops in California.

Five bacterial strains were isolated from symptomatic leaves of Achillea millefolium, Delphinium sp. and Hydrangea sp. in California. Colonies isolated on King's medium B (KMB) appeared white, mucoid and round, similar to Pseudomonas species. Phylogenetic analyses based on 16S rRNA, rpoB, rpoD and gyrB genes placed the bacteria into three distinct groups within Pseudomonas that were most closely related to Pseudomonas viridiflava, Pseudomonas cichorii or Pseudomonas caspiana. To further characterize the strains, phenotypic analyses and the following tests were performed: fatty acid methyl ester composition, LOPAT, fluorescence on KMB, Biolog assay, and transmission electron microscopy. Finally, whole genome sequencing of the strains was conducted, and the sequences were compared with reference genomes of Pseudomonas species based on average nucleotide identity (ANI). The first group, which consists of three strains isolated from delphinium, hydrangea and achillea, had 95.6-96.9 % pairwise ANI between each other; the second group consists of two strains isolated from delphinium that had 100 % pairwise ANI. Although comparisons of the two groups with publicly available genomes revealed closest relationships with P. viridiflava (91.6 %), P. caspiana (88.3 %) and P. asturiensis (86.7 %), ANI values were less than 95 % compared to all validly published pseudomonads. Combining genomic and phenotypic data, we conclude that these strains represent two new species and the names proposed are Pseudomonas quasicaspiana sp. nov. (type strain DSMZ 11 30 42T=LMG 32 434T) for the strains isolated from delphinium, achillea and hydrangea and Pseudomonas californiensis sp. nov. (DSMZ 11 30 43T=LMG 32 432T) for the two strains isolated from delphinium. The specific epithets quasicaspiana and californiensis were selected based on the close phylogenetic relationship of strains with P. caspiana and on the geographic location of isolation, respectively.

Selective catalytic transfer hydrogenation of polyunsaturated fatty acid methyl esters using Pd/organobentonite as catalyst under microwave heating

In this study, the catalytic transfer hydrogenation (CTH) of polyunsaturated fatty acid methyl esters (FAMEs) was carried out using ammonium formate as hydrogen donor and Pd/organobentonite (Pd/OB) as catalyst under the assistance of microwave. The effects of different technology parameters on the content of each FAME composition were investigated during the CTH reaction, and the optimal reaction conditions for the hydrogenation of FAMEs were determined. Under the optimal CTH conditions (40 g as the amount of ammonium formate, 60 g as the water amount, 8 wt.% as the catalyst dosage, 80 °C as the reaction temperature, 140 min as the reaction time and 350 rpm as the agitation speed), methyl linoleate (C18:2) was successfully hydrogenated into methyl oleate (C18:1) with high C18:2 conversion ratio (CRC182) of 78.56% and high C18:1 yield of 72.22%, and high selectivity for cis-C18:1 of 70.29%. Compared with conventional heating, microwave heating used in the CTH could enhance the CRC182 from 60.27% to 78.56% and reduce hydrogenation time. Moreover, the reaction of microwave-assisted CTH accorded with pseudo-first-order dynamic model through analyzing the obtained experimental data. In general, the effective hydrogenation of polyunsaturated FAMEs could be achieved under the microwave-assisted CTH reaction.