Methyl Palmitate Research Articles

The Role of Honey Bee Derived Aliphatic Esters in the Host-Finding Behavior of Varroa destructor

Varroa destructor is an obligate ectoparasite of honey bees and shifted from its original host Apis cerana to the new host Apis mellifera in the first half of the twentieth century. The host shift has resulted in a great threat to the health and survival of A. mellifera colonies worldwide. Chemical signals play a crucial role in all aspects of the Varroa life cycle, including host finding. However, the chemical cues that affect the host finding behavior of Varroa mites are still not fully understood. In this study, we systematically profiled the headspace volatiles of both worker and drone larvae of the two honey bee species by using solid phase micro-extraction coupled to gas chromatography-mass spectrometry (SPME-GC-MS), and then used electrophysiological recording and Y-tube olfactometer bioassay to study the potential roles of the selected compounds. The chemical profiling showed that there were four aliphatic esters, ethyl myristate (EM), methyl palmitate (MP), ethyl palmitate (EP), and ethyl oleate (EO) commonly detected from all four types of larval hosts. Among them, EM was a new substance identified from honey bee headspace volatiles. Results from electrophysiological recordings indicated that all the aliphatic esters could elicit significant responses of Varroa pit organs on its forelegs. Moreover, behavioral analyses revealed that EM could significantly attract V. destructor at a medium dosage (10 µg), while MP had no observable effect on the mites and both EP and EO were able to repel the parasites. Our findings suggest an important role of host-derived aliphatic esters in Varroa host finding, and provide new chemicals for Varroa monitoring and control.

Comparative metabolomics of the different fractions of two saltwort (Salsola L.) species in relation to their anti-inflammatory activity

Many of the plants of genus Salsola are edible halophytes which are known for their use in treatment of inflammation as well as their nutritional content. This study aims at comprehensive chemical profiling of two Salsola species that are widely distributed in arid areas; S. imbricata and S. jordanicola, using UHPLC-QqQ-MS in an attempt to decipher the bioactive constituents of the aerial parts of the selected plants and their ex-vivo anti-inflammatory activity. 73 chromatographic peaks were annotated where phytosterols dominated the metabolites in S. imbracta while phenylalkylamines were the major constituents detected in S. jordanicola. OPLS-DA model coefficients plot indicated that tetradecanoic acid, beta sitosterol and pentacosane were positively correlated to discrimination of S. imbricata species while N-feruloyloctopamine, N-feruloyltyramine, and ferulic acid, were positively correlated to discrimination of S. jordanicola species. Meanwhile, fractions of S. imbracta, reduced the 5 upregulation of TNF-α caused by LPS to levels lower than those produced by piroxicam while the petroleum ether and n-butanol fraction of S. jordanicola were more effective than piroxicam in reducing IL-6 gene expression. The coefficients plot depicted that methyl palmitate, aegicin, cleomiscoside, beta sitosterol and sitostanol possessed strong positive correlation to the down regulation of the pro-inflammatory marker TNF-α, IL-1β and IFN-γ while only norepinephrine derivatives were the major metabolites that showed strong positive correlation to the inhibition of IL-6 pro-inflammatory marker. The results obtained may help to explain chemically, the potential anti-inflammatory effect of the various Salsola species fractions increasing the value of the Salsola species as a putative functional foods.

Direct production of isomerized biodiesel over MoS2/ZrPOx under solvent-free conditions

The catalytic deoxygenation and isomerization of biolipids in one pot is a challenge in the production of high-quality biodiesel. Herein, series of bifunctional catalysts, combining with in-situ sulfided MoO3 and phosphoric acid modified-ZrO2, were fabricated for upgrading of biolipid under solvent-free conditions. It is demonstrated that the bifunctional catalysts exhibit great performance for the hydrotreating of methyl palmitate and raw biolipid, affording up to 90% of total hydrocarbons with 20.3% and 18.7% of isomerized alkanes in diesel range. Among several studied ratios, the catalyst with Mo loading of 12.5% and P/Zr ratio of 1/7 achieves the highest yield of i-alkanes due to a coeffect of MoS2 and acid sites on the surface based on characterizations. The regenerated catalyst also shows excellent performance with no significant change in the structure. Moreover, a synergy between MoS2 and phosphoric acid is discussed to elucidate the high activity of biolipid conversion.

Efficient hydrothermal deoxygenation of methyl palmitate to diesel-like hydrocarbons on carbon encapsulated Ni−Sn intermetallic compounds with methanol as hydrogen donor

Efficient hydrothermal deoxygenation of methyl palmitate to diesel-like hydrocarbons on carbon encapsulated Ni−Sn intermetallic compounds with methanol as hydrogen donor

In Situ Fabrication of the Al2O3@NiMo Core–Shell Catalyst from LDH for Low-Pressure Hydrodeoxygenation of Fatty Acid Methyl Ester

The hydrothermal stability of supported metal catalysts is one of the greatest challenges in the development of biomass conversion to chemicals and fuels. Herein, a hydrotalcite-based core–shell catalyst (Al2O3@NiMo-LDO) was synthesized by urea precipitation and ion-exchange methods, which could selectively convert bio-oil model compounds to liquid alkanes with high activity and selectivity and excellent hydrothermal stability at low pressure. In the hydrogenation of methyl palmitate, the catalyst afforded 81% conversion and 99% selectivity of n-pentadecane and n-hexadecane under low pressure, with excellent hydrothermal stability. The excellent catalytic performance of Al2O3@NiMo-LDO was attributed to the strong hydrogen activation ability, improvement of the utilization of active components under low pressure, and the increase in the number of active Mo5+ species. The superior hydrothermal stability was attributed to the core–shell structure, which avoided the influence of the specific surface area of Al2O3 that is reduced by the hydration reaction between Al2O3 and H2O at high temperature.

Experimental Investigations and Numerical Modelling of Compression Ignition Engine Fuelled With Diesel and Biodiesel Blend

In this study, diesel fuel and two hundredth by volume of synthesised biodiesel from waste coconut oil (WB20) were used as fuel in unmodified, naturally aspirated, single cylinder compression ignition engine to study their performance and combustion characteristics at full load condition. Numerical studies were carried out with the use of CFD and compiled with the experimental results. FORTE software was used for CFD simulation. Methyl-palmitate (MPA) and Dodecane (C12H26) were used as surrogate fuels for biodiesel and diesel fuel respectively. The variation of special parts for diesel fuel and WB20 with CI engine in-cylinder pressure, in- cylinder temperature and mass fraction of O2, CO and NO emission at 10p and 20p ATDC were analysed. The mass fraction contours of in-cylinder temperature, O2, CO and NO for diesel fuel and WB20 were found to be decreased with increase in crank angle from 10o to 20° ATDC. The maximum BTE, in-cylinder pressure, in-cylinder temperature, O2, CO2 and NO were obtained for WB20 at 10° ATDC.

The Synergistic Effect of Polyphosphates Acid and Different Compounds of Waste Cooking Oil on Conventional and Rheological Properties of Modified Bitumen

In order to conserve non-renewable natural resources, waste cooking oil (WCO) in bitumen can help lower CO2 emissions and advance the environmental economy. In this study, three different components of WCO were isolated and then, together with polyphosphoric acid (PPA), used separately as bitumen modifiers to determine the suitability of various substances in WCO with PPA. Conventional tests, including penetration, softening point temperature, and ductility, and the dynamic shear rheology (DSR) test, including temperature sweep and frequency sweep, were used to evaluate the influence of WCO/PPA on the traditional performance and rheological properties at high and low temperatures. The results indicate that WCO reduced the ductility and penetration value, when the use of PPA increased the softening point temperature and high-temperature performance. Compared to reference bitumen, the rutting factor and viscous activation energy (Ea) of bitumen modified with 4% WCO and 2% PPA has the most significant increase by 18.6% and 31.5, respectively. All components of WCO have a significant impact on improving the low-temperature performance of PPA-modified bitumen. The performance of the composite-modified bitumen at low temperatures is negatively affected by some waxy compounds in WCO, such as methyl palmitate, which tends to undergo a solid-liquid phase change as the temperature decreases. In conclusion, the inclusion of WCO/PPA in bitumen offers a fresh approach to developing sustainable pavement materials.

Thermodynamic Modeling of Liquid-Liquid Equilibrium in Ternary Systems with Biodiesel and Isolated Ester (Methyl Palmitate)

Liquid-liquid equilibrium data were measured and analyzed for two ternary systems (biodiesel + methanol + glycerol and methyl palmitate + methanol + glycerol). Biodiesel, produced by the conventional chemical route at 60 °C for 60 min, using methanol and soybean oil at a molar rate of 10:1 and potassium hydroxide concentration (KOH) of 1 wt% exhibited thermal decomposition at temperatures between 100 and 250 ºC, reaching mass loss of approximately 98.8%, confirming soybean oil conversion into biodiesel by gas chromatography and thermogravimetry. Tie line composition quality was verified using Othmer-Tobias and Hand correlation equations. The distribution and selectivity coefficients were calculated for the immiscibility regions. The experimental tie line data exhibited good correlation in the UNIQUAC and NRTL thermodynamic models. The biodiesel system displayed deviations of 0.66 and 0.53% for the UNIQUAC and NRTL models, respectively. In addition, the methyl palmitate system showed a 1.23 and 0.48% deviation for the UNIQUAC and NRTL model, respectively. The individual behavior of the main biodiesel esters , based on the UNIQUAC model parameters, demonstrated that the type of fatty acid does not interfere in model correlation, likely due to the similarity between their composition and properties.

GC-MS Analysis and In-vitro Apoptosis Induction and Anticancer Activity of Methanol Extract of Aspergillus terreusagainst Lung Cancer

The present study was focusing on qualitative and quantification of bioactive compounds present in Aspergillus terreus and evaluating its anticancer activity and apoptosis detection against lung cancer. Methods: A. terreus was sequentially extracted using the Soxhlet extraction technique with hexane, ethyl acetate, methanol and distilled water. Detection of bioactive compounds was done using Standard biochemical tests and GC-MS analysis was performed with NIST database to identify the bioactive compounds. The toxicity and anticancer activity of crude extract was investigated using MTT assay on L929 cells and lung cancer A549 cells whereas apoptosis study was conducted through Flowcytometry-based surface marker study on the A549 cancer cell line. Results: secondary metabolites analysis showed the presence of phenols and terpenoids as major constituents in the methanol extract whereas other solvent extracts have shown the absence of major bioactive compounds. Quantification studies showed that methanol extract has shown the phenolic content 179 µg/g of Gallic acid equivalent. The GC-MS analysis showed the presence of 1-Flurodecane, Methyl palmitate, Ethyl palmitate, 9, 12-Octadecanopic acid, 10-Octadecanoic acid, Methyl stearate, Octadecadeoinoate, Ethyl 9-hexadecanoate and 1-Monoarachidin as major bioactive compounds. Further, MTT based toxicity study on the L929 cell line revealed that methanol extract at lower concentrations like 50µg, 100µg and150µg shown more than 50% of cell viability and at higher concentration between 200µg-250 µg it was showing toxic nature with 47.89±0.01% viability. In case of anticancer activity against lung cancer A549 cell line the methanol extract have shown the dose dependent activity i.e the percentage of cell viability was decreased with increase in the concentration of methanol extract at 250µg the cell viability was found to be 35.12±0.005%. Flow cytometry based apoptosis study revealed that methanol extract has shown the inducing apoptosis in treated lung cancer A549 cells with percentage of 10.84. Conclusion: overall the present study shown that A. terreus possess different class of bioactive compounds and it has higher phenolic content. Toxicity study showed that methanol extract exhibited toxic nature at higher concentration on tested cell line and Anticancer and Apoptosis study revealed that methanol extract has shown the prominent with inhibiting the growth of lung cancer A549 cells through inducing apoptosis. Further, A. terreus would be a promising natural microorganism that has to be further researched in order to discover and isolate potent drug to treat cancer. Future studies will be on study of in-vivo animal studies and study of molecular mechanism of drug action on particular with anticancer study.

Monoesters for transformer insulating liquid

The development of low viscosity insulating liquids derived from natural esters is conducted in our laboratory. Nine monoesters, i.e., methyl myristate, ethyl myristate, isopropyl myristate, methyl palmitate, ethyl palmitate, isopropyl palmitate, methyl stearate, ethyl stearate, and isopropyl stearate were synthesized from alcohols and saturated fatty acids. Treatments were performed to reduce water and acid contents and improve the oxidation stability of the monoesters. Some fundamental properties, such as breakdown voltage, kinematic viscosity, density, water content, acidity, and oxidation stability, were tested before and after treatments. The results are evaluated based on the international electrotehnical commission (IEC) standard specifications for low-viscosity monoesters derived from natural esters, IEC 62770. Except for the water content, all other properties have good compliance with the standard. The treatments reduced the water content significantly, but the values are still slightly higher than that specified by the standard.

Production of N‐methyldiethanolamine di‐ester via heterogeneous transesterification of palm methyl ester over modified calcium oxide catalyst by metal oxides

AbstractThe production cycle of the heterogeneous catalyzed‐transesterification of methyl ester and alkanolamine for the production of esterquats precursor can be considered as a cleaner and sustainable process. This process is an important alternative route as opposed to the conventional homogeneous catalysis as it can eliminates the formation of wastewater, consumes less toxic chemical and reduce the production cost through catalyst reuse. Calcium oxide (CaO)‐based catalysts which include pure CaO and modified CaO by other metal oxides were employed in this study for the production of alkanolamine ester, a precursor of esterquats. The basicity and textural properties of these catalysts were characterized using TPD‐CO2 and N2 physisorption, respectively. Transesterification activity of CaO‐based catalysts successfully showed a high di‐ester yield of more than 85% at 160°C, 80 mbar, 4 wt% of catalyst dosage, 6 h reaction time, methyl palmitate to N‐methyldiethanolamine mole ratio of 2:1 and agitation speed of 150 rpm. ZnO/CaO catalyst rendered the best durability characteristic as it exhibited constant activities for three subsequent runs with 85% di‐ester yield. ZnO/CaO showed high catalytic activity similar to pure CaO catalyst with low leaching of Ca active phase and better reusability than that of pure CaO catalyst, that shows loss of its activity after the first cycle.

The Activity of Lipase From Jatropha Seed (Jatropha Curcas L.) And Its Application On Hydrolysis of Castor Oil In Organic Solvent

Jatropha curcas L. is one of the seed plants that have lipase activity and can work well in hydrolysis reactions and chemical synthesis. This study aims to determine lipase activity that reacts with castor oil in organic solvents. In this research, organic solvents, especially hydrophobic solvents, were used in the hydrolysis reaction to increase lipase's catalytic activity. The organic solvent used has a hydrophobicity level between 2 and 4, namely hexane. The research stages consisted of lipase isolation, lipase assay, the effect of adding metal ions assay, and analysis of the compound of castor oil. The results showed that jatropha seeds had lipase activity in crude of 0.603 U/mL and increased to 0.911 U/mL after the addition of K+. The result of hydrolysis and transesterification of castor oil by lipase is ricinoleic acid (4,58%) and methyl ricinoleic (11,67%), and the concentration of ricinoleic acid (17.09%) and methyl ricinoleic (60.83%) were increased after addition of K+. The esterification reaction produces alkyl ester compounds such as methyl palmitate, ethyl pentadecanoate, methyl linoleate, methyl oleate, and methyl stearate. The lipase isolated from jatropha seeds not only catalyzes the hydrolysis reaction but also catalyzes chemical synthesis reactions such as esterification and transesterification.

Hydrodeoxygenation–Isomerization of Methyl Palmitate over SAPO-11-Supported Ni-Phosphide Catalysts

Ni-phosphide catalysts on SAPO-11 were studied in the hydrodeoxygenation–isomerization of methyl palmitate (C15H31COOCH3—MP). The catalysts were synthesized using temperature-programmed reduction (TPR) of a phosphate precursor ((NH4)2HPO4 and Ni(CH3CH2COO)2), TPR of a phosphite precursor (H3PO3 and Ni(OH)2), and using phosphidation of Ni/SAPO-11 by PPh3 in the liquid phase. The samples were characterized by ICP-AES chemical analysis, N2 physisorption, NH3-TPD, XRD, and TEM. First, the screening of the catalysts prepared by the TPR method was carried out in a semi-batch autoclave to determine the influence of the preparation method and conditions on one-pot HDO–isomerization (290–380 °C, 2–3 MPa). The precursor’s nature and the amount of phosphorus strongly influenced the activity of the catalysts and their surface area and acidity. Isomerization occurred only at a low P content (Ni/P = 2/1) and blocking of the SAPO-11 channels by unreduced phosphates at higher P contents did not allow us to obtain iso-alkanes. Experiments with liquid phosphidation samples in a continuous-flow reactor also showed the strong dependence of activity on phosphidation duration as well as on Ni content. The highest yield of isomerized products (66% iso-C15–16 hydrocarbons, at complete conversion of O-containing compounds, 340 °C, 2 MPa, and LHSV = 5.3 h−1) was obtained over 7% Ni2P/SAPO-11 prepared by the liquid phosphidation method.

Investigation of single drop evaporation characteristics of two-component fatty acid methyl esters at high temperature

To investigate the evaporation and micro-explosion characteristics of blended droplets at 773 K and 973 K ambient temperatures, methyl palmitate (MP) and methyl oleate (MO) are selected as typical fuels in this study. The MP concentration ranges from 10 % to 50 % to investigate the micro-explosion characteristics of the blended droplets. No micro-explosion that occurs during its whole lifetime when MP is pure, but the micro-explosion can be observed in all blended droplets. Interestingly, the micro-explosion intensity, average evaporation rate, micro-explosion delay time, and evaporation duration of droplet all reach the optimum value when the MP concentration is 20 % at 773 K and 973 K. The micro-explosion can be divided into three categories by intensity, namely strong micro-explosion, weak micro-explosion, and puffing. The strong micro-explosions occur at 973 K when the concentration is 20 %. It can be inferred that micro-explosion is the critical factor in shortening the evaporation duration. Cleavage reaction that occurs in the MO produced bubbles to increase the micro-exploration intensity. Meanwhile, the polymerization that carried out in the MO inhibits the evaporation with producing solid. It is observed experimentally that the residual volume caused by the polymerization decreases with increasing MP concentration. Furthermore, a new relationship is established in terms of the evaporation rate, micro-explosion intensity and ambient temperature by numerical fitting.

Application of Anoxybacillus gonensins UF7 lipase as a catalyst for biodiesel production from waste frying oils

This study was carried out to purify and characterize the lipase of locally isolated bacterium Anoxybacillus gonensis UF7 (GenBank accession: OM328064), and to investigate its applicability as a catalyst for biodiesel production. After ammonium sulphate precipitation and ion-exchange chromatography steps, the lipase of A. gonensis UF7 was purified with a specific activity of 1370 U/mg protein, a purification fold of 13.1 and a recovery yield of 40.65 %. The molecular weight of the enzyme was determined as 73 kDa by SDS-PAGE. The lipase showed maximum activity and stability at pH 8.0 and 60 °C. Its activity and stability were also high in the presence of methanol, ethanol, SDS, Tween-80, Triton X-100, Tween 80, Ca2+ and Mg2+. To prepare biodiesel from waste frying oils using purified lipase, the optimum reaction conditions were determined as a reaction time of 24 h, an enzyme concentration of 3 mL and an oil:methanol ratio of 3:1 (30 mL:10 mL). Transesterification yield was calculated as 87.7 %. The main fatty acid methyl esters of the biodiesel were methyl oleate (50.8 %), methyl palmitate (20.2 %) and methyl linoleate (16.6 %). The usability of lipases of Anoxybacillus strains including A. gonensins as a catalyst in biodiesel production was investigated for the first time in the present study.

Vapor-liquid equilibrium for the {R-OH + R-palmitate} systems at 50.3 and 101.3 kPa

Fossil sources of energy become focus of many debates due to the pollution caused by them. In this scenario, renewable fuels, as biodiesel, are studied to improve their production efficiency and become more competitive with fossil fuels and even substitute them. Biodiesel, produced by the transesterification reaction, is constituted by a mixture of fatty acid esters and needs to be separated from its reactional solution in order to be commercialized. To improve the separation processes, the thermodynamic behavior of the mixtures involving components of the biodiesel needs to be known. Aiming this, the vapor–liquid equilibrium (VLE) of the methanol + methyl palmitate and ethanol + ethyl palmitate systems was analyzed at 50.3 and 101.3 kPa and the experimental data were submitted to a thermodynamic consistency test and thermodynamic modeling with the Peng-Robinson (PR), Group Contribution Volume Translated Peng-Robinson (GC-VT-PR) and the Perturbed Chain - Statistical Associating Fluid Theory (PC-SAFT) equations of state. Experimental data were considered thermodynamically consistent, and the modeling showed good results in terms of the lowest relative deviations of temperature and vapor mole fraction obtained with the GC-VT-PR and PC-SAFT models.

GC-MS based Phytochemical Profiling and investigation of in vitro pharmacological activity of Croton sparsiflorus

Phytochemicals are major group of compounds responsible for potential pharmacological activity of plant Croton sparsiflorus. It is a herbal plant that belongs to the Euphorbiaceae family and is reported with diverse therapeutic properties. In the current study, different solvent extracts (Chloroform, Ethyl acetate, Ethanol and Distilled water) of Croton sparsiflorus were examined for phytochemical screening based on GC-MS analysis. Antioxidant activity of plant extracts was examined by DPPH, FRAP, H2O2 assay and anti-inflammatory was performed by in vitro protein denaturation assay. Phytochemical screening reported presence of phenols, terpenoids and fats in aqueous leaf extract and saponins were present in chloroform extract. GC-MS analysis reported presence of six compounds namely methyl palmitate, 9-octadecenoic acid (z)-, methyl ester, methyl stearate, methyl lignocerate pentacosane and tetratetracontane. These compounds were reported to have several biological and industrial applications. Overall antioxidant assays showed that aqueous leaf extract has shown significant comparable activity near to the standard drug ascorbic acid. In vitro anti-inflammatory activity results revealed that as compared to the standard aspirin drug, aqueous leaf extract showed less but appreciable activity. In future, Croton sparsiflorus plant can be used for treating oxidative stress and inflammation related disorders as it possesses potential antioxidant and anti-inflammatory activity.

Investigating the Toxicity of Compounds Yielded by Staphylococci on Vero Cells.

Bacterial secondary metabolites play a major role in the alleviation of diseases; however, the cytotoxicity of other metabolites cannot be ignored as such metabolites could be detrimental to human cells. Three Staphylococci strains Staphylococcus aureus, staphylococcus epidermidis and staphylococcus saprophyticus were used in the experiments. These strains are well known to cause hospital and community-acquired infections. Secondary metabolites from S. aureus isolated from milk of cows with clinical features of mastitis (swollen udders and the production of watery clotted milk), S. saprophyticus (ATCC 35552), and S. epidermidis (ATCC 51625) were exposed to a minimal medium then screened using Gas Chromatography High-Resolution Time-of-flight Mass Spectrometry (GC-HRTOF-MS) and identified with Nuclear Magnetic Resonance (NMR). From S. epidermidis, two compounds were isolated: oleamide and methyl palmitate; three from S. aureus, including fluoranthene, 3-methyl-2-phenyl-1H-pyrrole, and cyclo(L-Leu-L-Propyl); while S. saprophyticus yielded succinic acid, 1,2,6-hexantriol, veratramine, and 4-methyl-pentyl-amine. The secondary metabolites were tested for cytotoxicity using the Vero cell line. Fluoranthene exhibited toxicity with an LC50 of 0.0167 mg/mL to Vero cells, while the other metabolites did not. Methyl palmitate was the least toxic of all of the metabolites. The results imply that none of the compounds, except fluoranthene, pose any danger to human cells.

Synthesis of Biodiesel from Feun Kase (Thevetia peruviana) Seed Oil Using NaOH Catalyst

The demand for biodiesel in the renewable energy sector continues to grow yearly. However, the majority of biodiesel sources currently still compete with the food sector. Feun Kase seeds contain high oil and do not compete with food, so they have prospects as a new source of biodiesel. This study aimed to find the optimal conditions for synthesizing biodiesel from Feun Kase seed oil, carried out through transesterification with four reaction variables: catalyst variation, time, temperature, and the molar ratio of oil/methanol. This study was equipped with parameter test data according to SNI (Indonesian National Standard) 7182:2015, also equipped with characterization using FTIR (Fourier Transform Infrared) and GCMS (Gas Chromatography Mass Spectroscopy). The highest biodiesel yield of 84.09% was obtained using optimum conditions of 1% NaOH catalyst, oil/methanol molar ratio of 1:6 at 70°C for 90 minutes of reaction. The test results of biodiesel parameters are density (851 kg/m3), smoke point (6°C), kinematic viscosity (5.35 cSt); acid number (1.08 mg KOH/gr), saponification number (159.32 mg KOH/gr), iodine number (78.62 g I2/100 g sample), flash point (165°C), and cetane number (62.86). FTIR analysis proved the presence of methyl esters with typical absorption at 1743 cm-1, 1195.87 cm-1, and 1436.97 cm-1. GCMS characterization showed that Feun Kase biodiesel was dominated by methyl oleate (53.45%), methyl palmitate (27.05%), methyl stearate (10.96%), and methyl linoleate (6.29%).

Augmentation of the Photoreactivation Gene in Fremyella diplosiphon Confers UV-B Tolerance.

In spite of the enormous potential of cyanobacteria as a renewable energy source, elevated UV exposure is a major impediment to their commercial viability and productivity. Fremyella diplosiphon is a widely explored cyanobacterium with great biofuel capacity due to its high lipid content. To enhance UV stress tolerance in this species, we overexpressed the photoreactivation gene (phr A) that encodes for photolyase DNA repair enzyme in the wild type F. diplosiphon (B481-WT) by genetic transformation. Our efforts resulted in a transformant (B481-ViAnSa) with a 3808-fold increase in the phr A mRNA transcript level and enhanced growth under UV-B stress. Additionally, DNA strand breaks in the transformant were significantly lower after 12 and 16 h of UV radiation, with significantly higher dsDNA recovery in B481-ViAnSa (98.1%) compared to that in B481-WT (81.5%) at 48 h post irradiation. Photosystem II recovery time in the transformant was significantly reduced (48 h) compared to that in the wild type (72 h). Evaluation of high-value fatty acid methyl esters (FAMEs) revealed methyl palmitate, the methyl ester of hexadecenoic acid (C16:0), to be the most dominant component, accounting for 53.43% of the identified FAMEs in the transformant. Results of the study offer a promising approach to enhance UV tolerance in cyanobacteria, thus paving the way to large-scale open or closed pond cultivation for commercial biofuel production.