Dyer Method Research Articles

Effects of Boiling and Smoking on the Proximate Composition and Oil Quality of a Commercially Important Freshwater Fish (Chrysichthys nigrodigitatus) from Nkam River in Cameroon

The effects of boiling and smoking on the proximate composition and lipids quality of a freshwater fish (Chrysichthys nigrodigitatus) collected from Nkam River in Cameroon were investigated. Fresh fish was filled, boiled or smoked and then, aliquoted for analyses. One portion was dried at 50 °C and ground into flour for the proximate composition determination. The other portion was served for lipids extraction using the Bligh and Dyer method. The extracted oil was characterized physico-chemically using chemical indexes and GC/FID. Moisture, protein, ash and lipid contents of raw fish were 80.67±4.18, 64.42±1.51, 10.90±0.42 and 22.06±5.40 % dm respectively. The changes in dry matter, protein and ash contents were found to be statistically significant (P<0.05) after smoking. The most important mineral of this fish was the Potassium (7017.54-8771.93 mg/kg). Except the calcium and phosphorus contents which decreased with the treatments, the amount of the other detected minerals was significantly increased. It was also found that these technological treatments significantly increased (P<0.05) the free fatty acids and hydroperoxides formation in oil, while it decreased its iodine value. The fatty acid profile of untreated and treated fish revealed her richness in Palmitic (22.91-34.76%), Oleic (12.83-23.55%), Stearic (11.29-14.81%), Linoleic (LA) (ω6) (2.83-6.75%), Arachidonic (ω6) (2.50-6.64%) and Docosahexaenoic (DHA) (ω3) (1.56-12.31%) acids. The ratio PUFA/SFA of raw fish (0.47) was severely reduced by the smoking (0.26) while it increases after boiling (0.61). This fish contain appreciable levels of Omega-6 PUFA, suggesting that it could be used as a source of healthy diet for human beings. These findings may also be beneficial for the fish industry, nutritionists and researchers who were striving to improve the nutritive value, processing and marketing of selected fish species.

Laboratory extraction of microalgal lipids using sugarcane bagasse derived green solvents

Three green solvents were tested for lipid extraction based on the Bligh and Dyer method. Lipids from the microalgae Chlorella pyrenoidosa were extracted through the tertiary systems 2-methyltetrahydrofuran:isoamylalcohol:water (1:3, 1:2, 1:1, 2:1, 3:1 v/v) and 2-methyltetrahydrofuran:ethanol:water (3:1 v/v). For comparative effect, extractions with chloroform:methanol:water (3:1, 2:1, 1:1, 1:2, 1:3 v/v), with binary systems 2-methyltetrahydrofuran:water, isoamyl alcohol:water, chloroform:water, n-hexane:water, and monophasic systems 2-methyltetrahydrofuran (2-MeTHF), isoamyl alcohol, chloroform and n-hexane were used. The Bligh and Dyer method using green solvents was highly efficient, although some undesirable components were extracted, especially when larger volumes of isoamyl alcohol were used. System 2-MeTHF:ethanol:water formed only a biphasic system when it was used in a 3:1 (v/v) proportion, obtaining 64% of fatty acids. The chloroform:methanol (1:2 v/v) system extracted 122.2 ± 1.9 mg g−1, in which 92.4% consisted of fatty acids. In systems using green solvents, the extractions with the system 2-MeTHF:isoamyl alcohol (2:1 v/v) achieved a 78% selectivity (99.6 ± 7.6 mg g−1of fatty acids) and an 88.2% efficiency when compared with the reference system chloroform:methanol 1:2 (v/v).The fatty acids profile showed that extractions with 2-MeTHF:isoamyl alcohol had higher percentages of fatty acids with low degree of unsaturation, which is ideal for the production of better quality biodiesel. The results obtained suggest that2-MeTHF:isoamyl alcohol (2:1 v/v) can replace the chloroform:methanol system currently used. At an industrial level, this system still requires some technical improvements related to the energy expenditure for solvent evaporation, and at an economic level, the high price of the 2-MeTHF makes the process impracticable compared with hexane.

Optimization of lipid extraction from the oleaginous yeasts Rhodotorula glutinis and Lipomyces kononenkoae

The constant growing demand for vegetable oil for biodiesel and food is raising many environmental concerns about the sustainability of its production based on crops. Oleaginous yeasts show great potential to end with those concerns due to their high lipid productivity in small areas. To evaluate their productivity in lipids, an efficient and reproducible extraction process should be used. As no standard extraction process is available for the extraction of yeast lipids, an optimized extraction process is presented. In this work, the lipids extraction process for the yeasts Rhodotorula glutinis and Lipomyces kononenkoae is optimized using bead beating for cell rupture and introducing adaptations of the two most used extraction methods (Bligh and Dyer and Folch). For Rhodotorula g. the optimum extraction conditions are obtained by the Bligh and Dyer method applying 4.8 cycles of 47 s with 0.7 g of glass beads. For Lipomyces k. the optimum extraction conditions make use of the Folch method applying seven cycles of 42 s with 0.54 g of glass beads. These results reinforce the idea that, for each yeast, different extraction processes may be needed to correctly determine the lipid yield. The extraction procedure was further evaluated with less harmful solvents. Toluene was tested as a possible substitute of chloroform, and ethanol as a possible substitute of methanol. With the optimized extraction process, better results for Lipomyces k. were obtained using toluene and ethanol, while for Rhodotorula g. toluene proved to be a valid substitute of chloroform but ethanol is far less effective than methanol.

Investigation on the Effect of Microalgae Chlorella sp. and Spirulina on Biodiesel Production

The aim of this study is to investigate the production of biodiesel from two kinds of microalgae Chlorella sp. and Spirulina platensis. Various items such as culture, lipid extraction and the production of biodiesel have been studied. The results showed that the rapid growth of Chlorella sp. from 0.2 to 0.5 gr per liter productivity biomass of cultivation is more suitable than Spirulina microalgae with slow growth of 0.1 to 0.3 gr per liter for the productivity biomass of culture. In comparison to 26.2% lipid content of microalgae Chlorella sp., Spirulina microalgae lipid content and the amount of 14.3 indicate a significant difference. Biodiesel output value was 28.2% by direct transesterification method. According to the results, it could be argued that microalgae Chlorella sp. features make the most suitable microalgae species for biodiesel production. These features include: rapid growth and high productivity, biomass and suitable lipid contents, environmentally easier cultivation rather than other species, suitable fatty acid profiles, having the most common fatty acids compounds (as C14:0, C16:0 and C18:0) in biodiesel. Extraction method had the best performance of extraction by the biomass Bligh and Dyer method.

Qualitative and quantitative comparison of cyclic phosphatidic acid and its related lipid species in rat serum using hydrophilic interaction liquid chromatography with tandem-mass spectrometry

Cyclic phosphatidic acid (cPA) is a simple lipid containing a fatty acid attached at the sn-1 position and a cyclic phosphate ring structure at the sn-2 and sn-3 positions of the glycerol backbone. The pharmacological effects of cPA have been demonstrated in several diseases such as cancer and neuropathic pain; however, the composition of the molecular species of cPA in relative to other lipid species in biological samples is still unclear. Recently, hydrophilic interaction liquid chromatography (HILIC) has demonstrated the ability to perform lipidomic analyses of biological samples. In the present study, we developed the quantitative measurement of cPA and its related lipid species, such as lysophosphatidic acid (LPA) and lysophosphatidylcholine (LPC), in rat serum using HILIC equipped with tandem-mass spectrometry (MS/MS). The lipid analysis using HILIC-MS/MS system demonstrated high linearity and reproducibility. The modified Bligh and Dyer method using citric acid was showed high efficiency on the extraction of cPA and LPA without contamination of artificial products. In rat serum, cPA and LPC contained more saturated fatty acids such as palmitic acid and stearic acid than unsaturated fatty acids, whereas LPA and phosphatidylcholine more contained unsaturated fatty acids than saturated fatty acids. The analytical methods for measuring cPA and its related lipid species in the present study will aid the analysis of their metabolism.

Triglyceride profiling in adipose tissues from obese insulin sensitive, insulin resistant and type 2 diabetes mellitus individuals

BackgroundLipid intermediates produced during triacylglycerols (TAGs) synthesis and lipolysis in adipocytes interfere with the intracellular insulin signaling pathway and development of insulin resistance. This study aims to compare TAG species and their fatty acid composition in adipose tissues from insulin sensitive (IS), insulin resistant (IR) and type 2 diabetes mellitus (T2DM) obese individuals.MethodsHuman subcutaneous and omental adipose tissue biopsies were obtained from 64 clinically characterized obese individuals during weight reduction surgery. TAGs were extracted from the adipose tissues using the Bligh and Dyer method, then were subjected to non-aqueous reverse phase ultra-high performance liquid chromatography and full scan mass spectrometry acquisition and data dependent MS/MS on LTQ dual cell linear ion trap. TAGs and their fatty acid contents were identified and compared between IS, IR and T2DM individuals and their levels were correlated with metabolic traits of participants and the adipogenic potential of preadipocyte cultures established from their adipose tissues.ResultsData revealed 76 unique TAG species in adipose tissues identified based on their exact mass. Analysis of TAG levels revealed a number of TAGs that were significantly altered with disease progression including C46:4, C48:5, C48:4, C38:1, C50:3, C40:2, C56:3, C56:4, C56:7 and C58:7. Enrichment analysis revealed C12:0 fatty acid to be associated with TAGs least abundant in T2DM whereas C18:3 was found in both depleted and enriched TAGs in T2DM. Significant correlations of various adipose tissue-derived TAG species and metabolic traits were observed, including age and body mass index, systemic total cholesterol, TAGs, and interleukin-6 in addition to adipogenic potential of preadipocytes derived from the same adipose tissues.ConclusionPilot data suggest that adipose tissues from obese IR and T2DM individuals exhibit TAG-specific signatures that may contribute to their increased risk compared to their IS counterparts. Future experiments are warranted to investigate the functional relevance of these specific lipidomic profiles.

PH-Dependent exhibition of hemolytic activity by an extract of Hypsizygus marmoreus fruiting bodies.

The current study found that an extract from the fruiting bodies of the edible mushroom Hypsizygus marmoreus exhibited hemolytic activity against sheep red blood cells when its pH was lowered. Although hemolytic activity was not detected when an extract had a neutral pH, an extract with a low pH exhibited potent hemolytic activity. The maximal hemolytic activity was exhibited by an extract with a pH of 5.5. A heat-treated extract did not exhibit hemolytic activity before its pH was lowered, and that activity was inhibited in the presence of PMSF and EDTA. The turbidity of the extract increased during lowering of its pH, and the precipitate fraction exhibited hemolytic activity. Fractionation by a modified Bligh and Dyer method and TLC analyses suggested that a hemolytic compound in the extract might be a type of lipid. These results suggest that a hemolytic lipid-like compound in an extract of H. marmoreus fruiting bodies may be released by a non-active precursor substance(s) through metalloenzyme(s) while the extract has a low pH.

Central composite design parameterization of microalgae/cyanobacteria co-culture pretreatment for enhanced lipid extraction using an external clamp-on ultrasonic transducer

Lipids extracted from algal biomass could provide an abundant, rapidly growing, high yield feedstock for bio-diesel and other green fuels to supplement current fossil-based sources. Ultrasound pretreatment is a mechanical cell disruption method that has been shown to enhance lipid recovery from algae due to cavitation effects that disrupt algae cell walls. In this study, a locally grown mixture of Chlorella vulgaris/Cyanobacteria leptolyngbya was sonicated in an ultrasonic reactor with a clamp-on transducer prior to solvent lipid extraction. This configuration allows for a non-contact delivery method of ultrasonic energy with improved operational advantages (no fouling of transducer, continuous operation, and fully scalable design). A central composite design (CCD) was implemented to statistically analyze and evaluate the effect of ultrasonic power (350–750 W) and treatment time (5–30 min) on lipid yield. Lipid recovery was found to increase with both ultrasonic power and treatment time. Total lipid yields (on dry biomass basis) extracted via the Bligh and Dyer method from Chlorella vulgaris/cyanobacteria co-culture ranged from 8.3% for untreated algae to 16.9% for algae sonicated with 750 W power for 30 min, which corresponds to more than a doubling of lipid recovery due to ultrasound pretreatment. Increased power and treatment times were found to increase the degree of cell disruption as observed in the SEM and TEM images after ultrasonic pretreatment. Additionally, hexane (1:1 v/v) was evaluated as an alternative to the standard Bligh & Dyer (2:2:1.8 v/v/v chloroform/methanol/cell suspension) lipid extraction solvent system. On average, the Bligh and Dyer method extracted on average over twice the amount of lipids compared to hexane extraction. The lipid profile of the algae extracts indicates high concentrations of lauric acid (12:0), palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), and linoleic acid (18:2). This particular configuration of an ultrasonic system proved to be a viable method for the pretreatment of algae for enhanced lipid yields. Future research should focus on identifying alternative extraction solvents and expanding the range of treatment conditions to optimize the ultrasonic power and treatment times for maximum lipid recovery.

Crosslink between lipids and acute uveitis: a lipidomic analysis.

To explore the roles of phospholipids and sphingolipids in the inflammatory process of uveitis. Aqueous humor (AH) and the retina were obtained from endotoxin-induced uveitis (EIU) rats during the acute inflammation stage (24h after endotoxin injection). Lipids were extracted using a modified Bligh and Dyer method and subjected to mass spectrometric identification using class-specific lipid standards and ratiometric quantification. Relative intensity analysis was performed to evaluate the amount change of common lipids between the EIU and control groups. Unique lipid species encompassing all five phospholipid classes were found in both control and the EIU AH and retina. Commensurate with the significantly increased level of lysophospholipids in the EIU AH and retina, we found that the ratio of lysophospholipids to total phospholipids was significantly increased too. We also detected a significant increase in 18:0 lysophosphatidylcholine levels in the EIU group (fold change =6.4 in AH and 3.8 in retina). Cer240, Cer241, and SM240 levels remarkably increased in the EIU AH. Enhanced C12 ceramide-1-phosphate (C12 C-1-P), C16 C-1-P, C24 C-1-P, and upregulated Cer160, Cer240, SM120, and SM240 were found in EIU retina. C-1-P was believed to restore homeostasis by inhibiting nuclear factor kappa B (NF-κB) activation. However, we still found elevated NF-κB levels in the EIU retina. A variety of lipids might have played a critical role in EIU inflammation. Exogenous topical application of these protective lipids or inhibition of these pro-inflammatory lipids may be useful therapeutic strategies for the resolution of EIU.

A novel rapid ultrasonication-microwave treatment for total lipid extraction from wet oleaginous yeast biomass for sustainable biodiesel production

Oleaginous yeasts have emerged as a sustainable source of renewable oils for liquid biofuels. However, biodiesel production from them has a few constraints with respect to their cell disruption and lipid extraction techniques. The lipid extraction from oleaginous yeasts commonly includes dewatering and drying of cell biomass, which requires energy and time. The aim of this work was to establish a process for the lipid extraction from wet biomass applying acid catalyzed hot water, as well as microwave, and rapid ultrasonication-microwave treatment together with the conventional Bligh and Dyer method. In the wake of testing all procedures, it was revealed that rapid ultrasonication-microwave treatment has great potential to give high lipid content (70.86% w/w) on the cell dry weight basis. The lipid profile after treatment showed the presence of appropriate quantities of saturated (10.39 ± 0.15%), monounsaturated (76.55 ± 0.19%) and polyunsaturated fatty acids (11.49 ± 0.23%) which further improves biodiesel quality compared to the other methods. To the best of our knowledge, this is the first report of using rapid ultrasonication-microwave treatment for the lipid extraction from wet oleaginous yeast biomass in the literature.

Comparison of modified Matyash method to conventional solvent systems for polar metabolite and lipid extractions

In the last decade, metabolomics has experienced significant advances in the throughput and robustness of analytical methodologies. Yet the preparation of biofluids and low-mass tissue samples remains a laborious and potentially inconsistent manual process, and a significant bottleneck for high-throughput metabolomics. To address this, we have compared three different sample extraction solvent systems in three diverse sample types with the purpose of selecting an optimum protocol for subsequent automation of sample preparation. We have investigated and re-optimised the solvent ratios in the recently introduced methyl tert-butyl ether (MTBE)/methanol/water solvent system (here termed modified Matyash; 2.6/2.0/2.4, v/v/v) and compared it to the original Matyash method (10/3/2.5, v/v/v) and the conventional chloroform/methanol/water (stepwise Bligh and Dyer, 2.0/2.0/1.8, v/v/v) using two biofluids (human serum and urine) and one tissue (whole Daphnia magna). This is the first report of the use of the Matyash method for extracting metabolites from the US National Institutes of Health (NIH) model organism D. magna. Extracted samples were analysed by non-targeted direct infusion mass spectrometry metabolomics or LC-MS metabolomics. Overall, the modified Matyash method yielded a higher number of peaks and putatively annotated metabolites compared to the original Matyash method (1–29% more peaks and 1–30% more metabolites) and the Bligh and Dyer method (4–20% more peaks and 1–41% more metabolites). Additionally the modified Matyash method was superior when considering metabolite intensities. The reproducibility of the modified Matyash method was higher than other methods (in 10 out of 12 datasets, compared to the original Matyash method; and in 8 out of 12 datasets, compared to the Bligh and Dyer method), based upon the observation of a lower mRSD of peak intensities. In conclusion, the modified Matyash method tended to provide a higher yield and reproducibility for most sample types in this study compared to two widely used methods.

Triglycerides analysis in adipose tissue from insulin sensitive and insulin resistance obese patients

IntroductionObesity triggers changes in adipose tissue composition and functionality that contribute to the progression of obesity‐associated metabolic diseases such as insulin resistance and type 2 diabetes mellitus (T2DM). However, some obese individuals maintain insulin sensitivity and show better adipose tissue functions compared to their equally obese insulin resistance counterparts. Lipid intermediates produced during triaclyglycerols (TAG) synthesis and lipolysis interfere with the intracellular insulin signaling pathway and development of insulin resistance. This study aims to compare TAG species and their fatty acid composition in adipose tissues from insulin sensitive (IS) and insulin resistant (IR) individuals.MethodsHuman subcutaneous and Omental adipose tissue biopsies were obtained from 64 clinically characterized obese individuals during weight reduction surgery. TAG were extracted from the adipose tissues using the Bligh& Dyer method then subjected to non‐aqueous revers phase UHPLC and full scan mass spectrometry acquisition and data dependent MS/MS on the Thermo LTQ dual cell linear ion trap. TAG and their fatty acid contents were compared between IS and IR individuals and their levels were correlated with metabolic traits of participants and the adipogenesis potential of preadipocyte cultures established from their adipose tissues.ResultsData revealed over 120 unique TAG species identified based on their exact mass in adipose tissues. Analysis of TAG levels suggested a number of depot‐specific TAG species irrespective of insulin sensitivity status as well as specific TAG that decreased or increased with disease progression. Significant correlations between TAG species and metabolic traits were observed including age, body mass index, total cholesterol, interleukin‐6, C‐reactive protein, alkaline phosphatase and adipogenic potential.ConclusionPilot data suggest that adipose tissues from obese individuals exhibit depot and insulin response‐specific lipid signatures that may contribute to the increased risk of IR and T2DM. Future experiments will investigate the functional relevance of these specific lipidomic profiles.Support or Funding InformationAnti‐Doping Lab Qatar Result 2 General characteristics of participants Variables IS (N=18) IR (N=35) T2DM (N=11) p value Age (year) 30.9 (8.5) 32.1 (8.7) 42.7 (11.0) 0.002 BMI (kg.m−2) 41.6 (7.6) 42.4 (6.8) 44 (8.1) 0.71 SBP (mmHg) 122 (17.6) 35 (127.08) 132 (5.4) 0.27 DBP (mmHg) 71.9 (12.5) 35 (72.2) 79.2 (6.2) 0.25 MAP 86.4 (8.2) 90.4 (13.6) 97.4 (6.1) 0.06 Cholesterol (mmol/L) 4.4 (0.81) 4.6 (0.69) 4.8 (0.64) 0.25 LDL (mmol/L) 2.6 (0.72) 2.92 (0.71) 2.6 (0.69) 0.33 HDLC (mmol/L) 1.3 (0.3) 1.19 (0.28) 1.15 (0.26) 0.16 Triglyceride (mmol/L) 1.14 (0.74) 1.29 (0.59) 2.35 (1.16) 0.00 Leptin (ng/ml) 68.07 (30.5) 62.09 (25.1) 39.8 (31.5) 0.04 Adiponectin (ng/ml) 5.6 (4.9) 3.7 (2.2) 3.05(1.09) 0.12 IL‐6 (pg/ml) 3.8 (2.04) 4.3 (2.4) 4.4 (2.3) 0.70 FBG (mmol/L) 4.9 (0.7) 5.8 (1.06) 9.5 (5.8) 0.00 Insulin (mIU/L) 7.07 (2.2) 18.3 (9.05) 16.6 (7.1) 0.00 HOMA‐IR 1.4 (0.4) 5.2 (3.2) 6.6(3.9) 0.00 Compared to BMI‐matched IS subjects, IR and T2DM individuals had higher circulating levels of TAG and lower leptin

Reproducibility of Phosphoinositide Lipid Extraction & Presentation in Bioanalytical Assays

Phosphatidylinositol 4‐phosphate (PI4P) produced by Phosphatidylinositol 4‐Phosphate kinases is an abundant Golgi phosphoinositide functioning in lipid exchange and vesicle transport within mammalian cells. Researchers wanting to quantify PI4P use the Bligh and Dyer method for extracting and separating phospholipids in cells and biological tissues. This common lipid extraction procedure is known to have inherent variation. Using a human promyelocytic leukemia cell line and an ELISA that is sensitive and specific for PI4P, we examine sources of variation in bioassays including sample (HL‐60 cells), the extraction procedure, and lipid detection. We determined a PI4P Mass ELISA has low coefficient of variation (<10%) if the extracted sample volume is held constant and samples are prepped and lipids presented with standardized procedures. Thus, the organic solvent extraction process is the major source of variation in typical Bligh‐Dyer preparations.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Growth of locally isolated microalga in POME to produce lipid as alternative energy sources

Purpose of this study was to find the best growth of locally isolated microalgae that produce lipids from Palm Oil Mill Effluent (POME) as an alternative energy source. Microalgae was cultivated in POME in glass vessel at room temperature using a lighting intensity of 13,000 lux and continuously aeration for 24 and 12 hours, respectively. Biomass of microalgae were analyzed daily to get their growth by spectrophotometry at 624 nm wavelength, whereas Modified Bligh and Dyer method determined lipid content. Results show that the best growth occurred at 10% inoculum with lighting cycle and aeration of 24 hours (on/off) and resulting highest biomass content of 0.99 g dry weight/L followed by the decrease of organic substances in POME. The percentage reduction of COD, BOD, TSS, and oil at POME reached above 92%, while phosphate concentration reached 89.2%. Cultivation of microalgae in POME for 12 days showed its ability to reduce organic substances and nutrients in POME and produced biomass with lipid content of 35%. These results reached to the conclusion that locally isolated microalgae has an ability to treat POME safely for environment and POME can be used as a growing medium of microalgae that produces lipids.

Nutritional Value of Pseudodiaptomus annandalie (Copepoda: Calanoida) and its Suitability as Feed to Milkfish Larvae

The nutritional value of Pseudodiaptomus annandalie and its suitability as feed to milkfish larvae were determined. Pure isolates of P. annandalie was subjected to feeding in four different microalgal species (Chlorella sp., Chaetoceros calcitrans, Isochrysis galbana and Tetraselmis chuii) for 15 days of culture. Lipid extraction was done using Bligh and Dyer method and analyzed in a gas chromatograph for fatty acid profile. Results were analyzed using univariate ANOVA (p.0.05) and subsequent Tukey tests. Results of the first experiment showed that the number of fatty acids in P. annandalie varied significantly at different microalgal diets. DHA/EPA ratio was highest in Chaetoceros calcitrans (4.91%). This suggest that Chaetoceros calcitrans is the best microalgal food for P. annandalie because it promotes high DHA/EPA ratio in its fatty acid profile which is an important requirement for fish larvae. When live P. annandalie together with other natural foods were tested, results showed that treatment fed live copepods had significantly (p<0.05) higher average length after day 24 (14.86+0.78 mm) over other treatments. Survival rate was significantly highest in treatment fed live P. annandalie (65.58+0.65%) compared with other treatments. Live copepod therefore is a suitable feed for milkfish larvae because it contains a high fatty acid profile.

Extracción de aceite a partir de microalgas obtenidas de la laguna El Estanco, en San Andrés de sotavento - Colombia

The objective of this research is to extract oil from the microalgae obtained in the lagoon El Estanco, located in San Andrés de Sotavento, Colombia, using the modified Bligh & Dyer method, with two types of solvents For chloroform + methanol and hexane. The results obtained with solvent extraction chloroform + methanol provided the largest volume of extracted oil, a comparison with hexane.Keywords: Oil, Extraction, Microalgae.

Metabolomic analysis of low and high biofilm-forming Helicobacter pylori strains

The biofilm-forming-capability of Helicobacter pylori has been suggested to be among factors influencing treatment outcome. However, H. pylori exhibit strain-to-strain differences in biofilm-forming-capability. Metabolomics enables the inference of spatial and temporal changes of metabolic activities during biofilm formation. Our study seeks to examine the differences in metabolome of low and high biofilm-formers using the metabolomic approach. Eight H. pylori clinical strains with different biofilm-forming-capability were chosen for metabolomic analysis. Bacterial metabolites were extracted using Bligh and Dyer method and analyzed by Liquid Chromatography/Quadrupole Time-of-Flight mass spectrometry. The data was processed and analyzed using the MassHunter Qualitative Analysis and the Mass Profiler Professional programs. Based on global metabolomic profiles, low and high biofilm-formers presented as two distinctly different groups. Interestingly, low-biofilm-formers produced more metabolites than high-biofilm-formers. Further analysis was performed to identify metabolites that differed significantly (p-value < 0.005) between low and high biofilm-formers. These metabolites include major categories of lipids and metabolites involve in prostaglandin and folate metabolism. Our findings suggest that biofilm formation in H. pylori is complex and probably driven by the bacterium’ endogenous metabolism. Understanding the underlying metabolic differences between low and high biofilm-formers may enhance our current understanding of pathogenesis, extragastric survival and transmission of H. pylori infections.

Gas chromatography–mass spectrometry analysis on effects of thermal shock on the fatty acid composition of the gills of the Antarctic teleost, Trematomus bernacchii

Environmental contextGlobal warming is an important problem for life on Earth, and there is an increasing need to understand how organisms respond to rising temperatures. We show that an Antarctic fish, the emerald rockcod, can acclimate to thermal shock by modifying the fatty acid composition and total lipid content in its gills. This study contributes to our understanding of how the physiology of Antarctic life could be influenced by climate change. AbstractAs a result of rising temperatures in the Antarctic seawater, there is an increasing interest to investigate the capacities for inducing a temperature acclimation response in Antarctic organisms. We analysed the effect of a thermal shock on the fatty acid (FA) composition of gills of the Antarctic notothenioid Trematomus bernacchii. To perform the quantification of fatty acids in gills, we applied an analytical method based on a fast microwave-assisted extraction (MAE) of lipids from a lyophilised sample, a base-catalysed trans-esterification of lipid extract to obtain fatty acid methyl esters (FAMEs), and their separation and identification by gas chromatography–mass spectrometry. The percentage of lipids extracted with MAE preceded by sample lyophilisation, 0.6 ± 0.3 % ww (wet weight), was consistent with the lipids obtained by the official Bligh and Dyer method, 0.8 ± 0.3 % ww. These data are among the first ever published for T. bernacchii. Specimens, caught in Terra Nova Bay (Ross Sea), were held in different tanks at 0, +1 and +2 °C, for 1, 5 and 10 days. In general, thermal shock produced an alteration in total lipid content, an increase in the percentage of saturated FAs, a decrease in mono-unsaturated FAs, and a variable response of poly-unsaturated FAs (an increase in specimens exposed to 0 and +1 °C, a decrease in those exposed to +2 °C). A chemometric approach based on principal component analysis indicated that temperature and exposure time influenced the composition of FAs in the gills, probably through an alteration of the metabolic pathways of FAs. This is the first study ever published on the FA composition of total lipids in gills of T. bernacchii exposed to high temperatures. This study demonstrates that T. bernacchii is capable of rapidly acclimating to a thermal shock, and contributes to increasing the knowledge on the effect of temperature on Antarctic notothenioids.

Increasing content of lipid in tropical microalgae Chlorella sorokiniana and Closterium sp. with variation of nitrogen content and extraction temperature

This research was aimed to obtain algae biofuels as an alternative energy which comes from tropical microalgae biomass Chlorella sorokiniana and Closterium sp. The cultivation was performed at a controlled room in batch culture photobioreactor, temperature 27°C, pH 6, aeration with air flow rate of 150 mL/sec, and light intensity at 2400 lux. These nutrient sources used artificial PHM with KNO3 variation as a nitrogen source of 0 grams; 0.25 grams; 0.5 grams; 1 gram. The research involved microalgae lipid extraction with Blight &amp; Dyer method and also carried out support of alcohol, chloroform and distilled water (1:1:1) with optimum temperature 30oC. Oil yields that obtained were analyzed with Gas Chromatography Mass Spectrometry (GC-MS) method, dry weight with a gravimetric method and cell density with spectrophotometry. The result showed that the reduction of KNO3 materials (0,25 gr) can produce biomass and highest total lipid content at 0,41 g/L and 20,31 %/(w/w). The results showed that KNO3 decreased the amount of biomass which was not significant but the total lipid content of microalgae was increased. Lipid content and fatty acids extracted from Blight &amp; Dyer showed oil content that could potentially be the raw material of biodiesel.

Hydroxyapatite chromatographic procedures for phospholipids: Endotoxin purification methods

ABSTRACTWe studied the one-step purification of endotoxin by hydroxyapatite chromatography using total lipids extracted from Escherichia coli by the Bligh and Dyer method. High endotoxic activity was detected in a fraction eluted from 0.5 mg total lipids using an isopropanol gradient under salt-free buffer conditions. The fraction contained at least 7,000 endotoxin units and was completely free from other phospholipids. Notably, the running time of the chromatographic separation was approximately 4 h, whereas purification by the conventional hot phenol–water procedure requires ≥60 h. The procedure developed here is a simple, scalable, and rapid method for the purification of endotoxin.