Screening and identification of Pseudomonas aeruginosa AB4 for improved production,characterization and application of a glycolipid biosurfactant using low‐cost agro‐based raw materials

BACKGROUND: The study is focused on (i) screening and taxonomic identity of a bacterial strain for biosurfactant production, and (ii) evaluation of its potential for production of a biosurfactant using agro‐based feedstock(s) and characterization of it for application in the removal of heavy metals. RESULTS: The production of biosurfactant by an isolate Pseudomonas aeruginosa AB4 (identified on the basis of 16S rRNA analysis) using various cost‐effective substrates were examined at conditions 40 °C, 120 rpm for 7 days. It revealed maximum (40 gL^?1) rhamnolipids production and 46% reduction of initial surface tension. Its optimum production was achieved at (i) C:N ratio 10:0.6, (ii) pH 8.5 and (iii) 40 °C. The cell–free supernatant examined for biosurfactant activity by (i) haemolytic assay, (ii) CTAB‐ methylene blue assay, (iii) drop collapse test, (iv) oil spreading technique and (v) EI 24 assay showed its glycolipid nature and stable emulsification. Analysis of partially purified rhamnolipids by (i) thin layer chromatography (TLC), (ii) high performance thin layer chromatography (HPTLC), (iii) high performance liquid chromatography (HPLC), (iv) Fourier transform infrared (FT‐IR) and (v) gas chromatography–mass spectrometry (GC‐MS) confirmed its structure as methyl ester of 3‐hydroxy decanoic acid (a glycolipid) with two major structural congeners (Rha‐C₁₀‐C₁₀ and Rha‐C₁₀‐C₈) of mono‐rhamnolipids. Finally, it showed sequestration of Cd and Pb, suggesting its application in biosurfactant‐assisted heavy metal bioremediation. CONCLUSION: This work has screened and identified a bacterium with superior biosurfactant production capabilities, characterized the glycolipidic biosurfactants as rhamnolipid and indicated the feasibility of biosurfactant production using novel renewable, relatively inexpensive and easily available resources such as non‐edible vegetable de‐oiled seed cakes and showed its utility in remediation of heavy metals. Copyright © 2010 Society of Chemical Industry     

Determination of seed oil content and fatty acid composition in sunflower through the analysis of intact seeds, husked seeds, meal and oil by near-infrared reflectance spectroscopy

A methodological study was conducted to test the potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oil content and fatty acid composition of sunflower seeds. A set of 387 intact-seed samples, each from a single plant, were scanned by NIRS, and 120 of them were selected and further scanned as husked seed, meal, and oil. All samples were analyzed for oil content (nuclear magnetic resonance) and fatty acid composition (gas chromatography), and calibration equations for oil content and individual fatty acids (C_16:0, C_16:1, C_18:0, C_18:1, and C_18:2) were developed for intact seed, husked seed, meal, and oil. For intact seed, the performance of the calibration equations was evaluated through both cross- and external validation, while cross-validation was used in the rest. The results showed that NIRS is a reliable and accurate technique to estimate these traits in sunflower oil (validation r ² ranged from 0.97 to 0.99), meal (r ² from 0.92 to 0.98), and husked seeds (r ² from 0.90 to 0.97). According to these results, there is no need to grind the seeds to scan the meal; similarly accurate results are obtained by analyzing husked seeds. The analysis of intact seeds was less accurate (r ² from 0.76 to 0.85), although it is reliable enough to use for pre-screening purposes to identify variants with significantly different fatty acid compositions from standard phenotypes. Screening of intact sunflower seeds by NIRS represents a rapid, simple, and cost-effective alternative that may be of great utility for users who need to analyze a large number of samples.     

The effect of lyophilization on the solvent extraction of lipid classes,fatty acids and sterols from the oysterCrassostrea gigas

The lipid class compositions of adult Pacific oysters [Crassostrea gigas (Thunberg)] were examined using latroscan thin-layer chromatography/flame-ionization detection (TLC/FID), and fatty acid compositions determined by capillary gas chromatography and gas chromatography/mass spectrometry (GC/MS). The fatty acid methyl esters were separated using argentation TLC and also analyzed as their 4,4-dimethyloxazoline derivatives using GC/MS. Major esterified fatty acids inC. gigas were 16∶0, 20∶5n−3, and 22∶6n−3. C₂₀ and C₂₂ nonmethylene interrupted (NMI) fatty acids comprised 4.5 to 5.9% of the total fatty acids. The NMI trienoic fatty acid 22∶3(7,13,16) was also identified. Very little difference was found in the proportions of the various lipid classes, fatty acids or sterols between samples of adult oysters of two different sizes. However, significant differences in some of the lipid components were evident according to the method of sample preparation used prior to lipid extraction with solvents. Lyophilization (freeze drying) of samples led to a significant reduction in the amounts of triacylglycerols (TG) extracted by solvents in two separate experiments (7.0 and 52.5% extracted). Extracts from lyophilized samples had less 16∶0, C₁₈ unsaturated fatty acids, and 24-ethylcholest-5-en-3β-ol, while C₂₀ and C₂₂ unsaturated fatty acids comprised a higher proportion of the total fatty acids. There was no significant change in the amounts of polar lipids, total sterols, free fatty acids or hydrocarbons observed in extracts from lyophilized samples relative to extracts from nonlyophilized samples. Addition of water to the freezedried samples prior to lipid extraction greatly improved lipid yields and resulted in most of the TG being extracted.     

Exploration of Staphylococcus nepalensis (KY024500) Biosurfactant towards Microbial Enhanced Oil Recovery

Oleochemicals have long been used as biolubricants, biopolymers, and biosurfactants; an effective alternative to petroleum-based products. The present study explores the biosurfactant potential of a novel strain, isolated from rocks of earthquake-prone area. On the basis of morphological, biochemical and 16S rRNA sequencing analysis, the isolate was identified as Staphylococcus nepalensis (KY024500). A biosurfactant yield 2.39, 1.39, and 0.9 g L⁻¹ was obtained using glycerol, waste orange peel, and diesel as a sole carbon source, respectively. Based on oil recovery experimental findings through sand pack column, the obtained biosurfactant from waste orange peels as a sole carbon source was carried forward for further analysis. Thus, obtained biosurfactant from waste orange peels were subjected to solvent extraction and purified by column chromatography. The purified biosurfactant thus obtained was characterized with the help of fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), gas chromatography-mass spectroscopy (GC–MS), and MALDI TOF MS/mass spectroscopy (MS) analysis. FTIR spectroscopic analysis revealed the presence of a carbonyl, amine, hydroxyl, and methyl as functional groups. The GC–MS analysis showed the presence of benzene dicarboxylic acid diethyl ester and pthalic acid as fatty acids while MALDI TOF MS/MS analysis shows lysin-glycin as a hydrophilic dipeptide moiety. This study also demonstrates Microbial Enhanced Oil Recovery (MEOR) potential of the biosurfactant as more efficient than commercial ones. The biosurfactant obtained from waste orange peel as carbon source was able to facilitate a 20% higher recovery of diesel from sand pack recovery column.     

Molecular analysis of intact preen waxes of Calidris canutus (Aves: Scolopacidae) by gas chromatography/mass spectrometry

The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additional resolution to the analysis of wax esters. The C₂₁−C₃₂ wax esters are composed of complex mixtures of hundreds of individual isomers. The odd carbon-numbered wax esters are predominantly composed of even carbon-numbered n-alcohols (C₁₄, C₁₆, and C₁₈) esterified predominantly with odd carbon-numbered 2-methyl fatty acids (C₇, C₉, C₁₁, and C₁₃), resulting in relatively simple distributions. The even carbon-numbered wax esters show a far more complex distribution due to a number of factors: (i) Their n-alcohol moieties are not dominated by even carbon-numbered n-alcohol moieties are not dominated by even carbon-numbered n-alcohols esterified with odd carbon-numbered 2-methyl fatty acids, but odd and even carbon-numbered n-alcohols participate in approximately equal amounts; (ii) odd carbon-numbered methyl-branched alcohols participate abundantly in these wax ester clusters; and (iii) with increasing molecular weight, various isomers of the 2,6-, 2,8-, and 2,10-dimethyl branched fatty acids also participate in the even carbon-numbered wax esters. The data demonstrate that there is a clear biosynthetic control on the wax ester composition although the reasons for the complex chemistry of the waxes are not yet understood.     

Linear, steroidal, and triterpene esters, and steryl glycosides from Festuca argentina

Ester waxes and steryl glycosides of the grass Festuca argentina were studied. Saponification of the waxes from the petroleum ether extract led to n-hexacosanol as the major single linear alcohol, along with pentacyclic triterpenols, such as β-amyrin, germanicol, isobaurenol, lupeol, hopenol-a and hopeol, and low amounts of sterols, such as cholesterol, campesterol, stigmasterol, sitosterol and dihydrositosterol, identified by gas chromatography/mass spectrometry (GC/MS). Fatty acids were identified as methyl esters as C_12∶0, C_14∶0, C_16∶0, C_18∶0, C_18∶2, and C_20∶0. The occurrence of a wide chainlength range of fatty acids and a single linear alcohol closely matched for other reports on the tribe Festuceae. On the contrary, pentacyclic triterpenols with a variety of skeletons, especially isobauerenol, are not usual as esters of fatty acids in the Gramineae. Low amounts of steryl glycosides were also obtained from the methylene chloride percolate of the methanol extract. Upon acetylation followed by hydrolysis, aglycones were identified by capillary gas-liquid chromatography (GLC) and GC/MS. As Δ⁷-cholesterol, campesterol, stigmasterol, sitosterol, dihydrositosterol, and the sugars as glucose, xylose, and arabinose by GLC of the respective alditol acetates. This is the first report on the linear, steryl, and triterpenyl esters of F. argentina. It is noteworthy that Δ⁷-steryl glycosides are rare, and steryl monoarabinosides have not been proviously reported on the family Gramineae.     

Characterization and Authentication of Significant Chinese Edible Oilseed Oils by Stable Carbon Isotope Analysis

The ratios of stable carbon isotopes (δ¹³C) of 12 oils extracted from Chinese edible oilseed samples and their individual fatty acids were determined by elemental analysis-isotope ratio mass spectrometry (EA-IRMS) and gas chromatography-isotope ratio mass spectrometry (GC-IRMS). The results have demonstrated that the δ¹³C ratios of the oils from C3-plant seeds range from ?26.8 to ?30.7‰, while the δ¹³C ratios of C4-plant maize oil are in the interval of ?14.1 to ?16.2‰. Eighteen fatty acids were identified and their abundances were measured by gas chromatography–mass spectrometry (GC–MS) in these oils with C_16:0, C_18:0, C_18:1 and C_18:2 as the major constituents. From the data on fatty acids and stable carbon isotopes, several sensitive markers were developed to detect the adulteration of Chinese edible oilseed oils. Examples are provided with pre-blended samples to illustrate the discrimination procedures and corresponding sensitive markers with emphasis on camellia seed oil, flax seed oil and perilla seed oil.     

Utilization of acid oils in making valuable fatty products by microbial lipase technology

Microbial lipase-catalyzed hydrolysis, esterification, and alcoholysis reactions were carried out on acid oils of commerce such as coconut, soybean, mustard, sunflower, and rice bran for the purpose of making fatty acids and various monohydric alcohol esters of fatty acids of the acid oils. Neutral glycerides of the acid oils were hydrolyzed byCanadida cylindracea lipase almost completely within 48 h. Acid oils were converted into fatty acid esters of short- and long-chain alcohols like C₄, C₈, C₁₀, C₁₂, C₁₆, and C₁₈ in high yields by simultaneous esterification and alcoholysis reactions withMucor miehei lipase as catalyst. Acid oils of commerce can be utilized as raw materials in making fatty acids and fatty acid esters using lipase-catalyzed methodologies.     

Fatty acid composition of oil in snow crab (Chionoecetes opilio) by gas chromatography/mass spectrometry

The hepatopancreatic fatty acid extract of the snow crab contains a high percentage (26%) of odd-carbon-numbered fatty acids and a substantial quantity (29%) of methyl-branched fatty acids, as indicated by gas chromatography/mass spectrometry (GC/MS) and gas liquid chromatography (GLC). A wide distribution in chain length of the fatty acids (C₁₀ to C₂₆) and in positional isomers of the linear monoenes are also indicated by GC/MS.     

Production and characterization of glycolipid biosurfactant from Streptomyces enissocaesilis HRB1 and its evaluation for biomedical and bioremediation applications

The aim of this investigation is to produce and characterize biosurfactant from Streptomyces sp. HRB1 and to evaluate its biomedical and bioremediation potential. Biosurfactant producing property of Streptomyces sp. HRB1 isolated from petroleum contaminated soil was confirmed by hemolytic and oil spread assays. Based on the results of FT-IR spectral and GC–MS analysis, the biosurfactant was confirmed as glycolipid type. Biosurfactant from Streptomyces sp. HRB1 exhibited 71% inhibition against Pseudomonas aeruginosa biofilm formation, 77.33% quorum sensing inhibition property against Chromobacterium violeceum MTCC 2656, more than 80% inhibition in antioxidant assays namely, DPPH, ABTS, and metal chelation, promising anti-proliferative activity against leukemia and myeloma cells with low IC₅₀ values, 96% decolorization of malachite green within 48 h of reaction time, and minimal toxicity against normal cell lines in dose-dependent manner. The taxonomic position of the potential strain HRB1 was further confirmed as Streptomyces enissocaesilis HRB1 based on their phenotypic and molecular characteristics. To conclude, Streptomyces enissocaesilis HRB1 isolated from petroleum-contaminated soil is a promising source for low-cost production of glycolipid biosurfactant with potential biomedical and environmental applications such as antiphytofungal, antibiofilm, anti-quorum sensing, antioxidant, anticancer, and dye degradation properties.     

Modifications of butter stearin by blending and interesterification for better utilization in edible fat products

This work primarily aims to further modify the stearin fractions, obtained from anhydrous milk fat, after fractionation by dry process and by solvent process using isopropanol, for extending their scope of utilization in edible fat products. Butter stearin fractions, on blending with liquid oils like sunflower oil and soybean oil in different proportions, offer nutritionally important fat products with enriched content of essential fatty acids like C_18∶2 and C_18∶3. The butter stearin fraction from isopropanol fractionation, when interesterified with individual liquid oils by Mucor miehei lipase as a catalyst, yields fat products having desirable properties in making melange spread fat products with reasonable content of polyunsaturated fatty acids and almost zero trans fatty acid content.     

Characterization of skin-surface lipids from the monkey (Macaca fascicularis)

Skin-surface lipids from the monkeyMacaca fascicularis are composed of sterol esters (38%), cholesterol (4%) and two types of wax diesters, identified as Type II (IIa and IIb, 17% and 40%, respectively). Type IIa contained diesters of 1,2-alkanediols esterified with two molecules of long-chain (C₁₄−C₃₄) fatty acids having straight and branched chains. In the diesters IIa, fatty acids shorter than C₁₉ predominated in position 1, and fatty acids longer than C₂₀ predominated in position 2. Type IIb contained diesters of 1,2-alkanediols esterified with C₄ and C₅ branched-chain fatty acids (predominantly isovaleric acid) at position 1 and long-chain (C₁₄−C₂₇) acids, having straight and branched chains, at position 2. The shortchain acids were converted to 2-nitrophenylhydrazides and analyzed by high-performance liquid chromatography (HPLC). Ammonia chemical ionization (CI)-gas chromatography (GC)-mass spectrometry (MS) resolved the intact diesters IIb into 12 peaks corresponding to molecular weights ranging from 597 to 748, and showed that the molecular species, such as C₂₁−C₁₆−C₅ (diol, fatty acid in position 2, fatty acid in position 1), C₂₂−C₁₆−C₅ and C₂₃−C₁₆−C₅, were prevalent. The fatty acids from both diesters were mostly (>98%) saturated. The 1,2-alkanediols from both diesters consisted of C₁₆−C₂₆ saturated straight- and branched-chain components. The acyl groups of sterol esters contained 86% C₁₄−C₃₄ branched-chain acids. The unsaturated fatty acids (5.4%) belonged to a straight-chain monoenoic series having extremely long chains (C₁₈−C₃₄). The branched-chain structures in the fatty acids and diols were iso and anteiso. These results show the species-specific profile for the skin-surface lipid synthesis.     

Sustainable Production of Biosurfactant from Agro-Industrial Oil Wastes by Bacillus subtilis and Its Potential Application as Antioxidant and ACE Inhibitor

The microbial conversion of agro-industrial oil wastes into biosurfactants shows promise as a biomass refinery approach. In this study, Bacillus subtilis #309 was applied to produce surfactin using rapeseed and sunflower cakes, the most common oil processing side products in Europe. Studies of the chemical composition of the substrates were performed, to determine the feasibility of oil cakes for surfactin production. Initially, screening of proteolytic and lipolytic activity was performed to establish the capability of B. subtilis #309 for substrate utilization and hence effective surfactin production. B. subtilis #309 showed both proteolytic and lipolytic activity. The process of surfactin production was carefully analyzed by measurement of the surfactin concentration, pH, surface tension (ST) and emulsification index (E₂₄). The maximal surfactin concentration in the sunflower and rapeseed cake medium reached 1.19 ± 0.03 and 1.45 ± 0.09 g/L, respectively. At the same time, a progressive decrease in the surface tension and increase in emulsification activity were observed. The results confirmed the occurrence of various surfactin homologues, while the surfactin C₁₅ was the dominant one. Finally, the analysis of surfactin biological function exhibited antioxidant activity and significant angiotensin-converting enzyme (ACE)-inhibitory activity. The half-maximal inhibitory concentration (IC₅₀) value for ACE inhibition was found to be 0.62 mg/mL for surfactin. Molecular docking of the surfactin molecule to the ACE domains confirmed its inhibitory activity against ACE. Several interactions, such as hydrophobic terms, hydrogen bonds and van der Waals interactions, were involved in the complex stabilization. To the best of our knowledge, this is the first report describing the effect of a lipopeptide biosurfactant, surfactin, produced by B. subtilis for multifunctional properties in vitro, namely the ACE-inhibitory activity and the antioxidant properties, using different assays, such as 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). Thus, the ACE-inhibitory lipopeptide biosurfactant shows promise to be used as a natural antihypertensive agent.     

Monoethylenic fatty acids of a partially hydrogenated herring oil

A Canadian Atlantic herring oil hydrogenated for margarine use to an iodine value of 76 and melting point of 32.5 C was found to have 30% saturated acids and 66% monounsaturated fatty acids. The monounsaturated fatty acids could be analytically determined ascis andtrans isomers by open tubular gas liquid chromatography.Trans acids were 33% of the C₁₆ and C₁₈ monounsaturated acids, and 32 and 28%, respectively, of the C₂₀ and C₂₂ monounsaturated acids. After separation of geometric isomers by Florisil-silver nitrate chromatography the positional isomers in each class were determined by oxidative fission. The double bond positions of the originalcis fatty acids were largely retained in bothcis andtrans isomers, but additional isomers were observed, especially in thetrans fatty acids.     

Fatty Acids from a Glass Sponge <Emphasis Type="Italic">Aulosaccus</Emphasis> sp. Occurrence of New Cyclopropane-Containing and Methyl-Branched Acids

In order to identify new structures, the free fatty acids from an extract of a glass sponge Aulosaccus sp. (from the north‐west Pacific) belonging to one of the least chemically investigated classes (Hexactinellida), were fractionated by RP‐HPLC and analyzed by NMR spectroscopy and GC–MS of their pyrrolidine derivatives, methyl(ethyl) esters and their dimethyl disulfide adducts. One hundred and twenty‐three C₁₂–C₃₁ acids (including nine new compounds) were detected, one hundred and ten of these compounds have not been found previously in glass sponges. The levels of common methylene‐interrupted polyenes, monoenes of the (n–7) family and less common branched‐chain components proved to be high. New acids were shown to be 5,13‐dimethyl‐tetradec‐4‐enoic, cis‐10,11‐methylene‐heptadecanoic, 10,12‐dimethyl‐octadecanoic, cis‐12,13‐methylene‐nonadecanoic, (14E)‐13‐methyl‐eicos‐14‐enoic, 19‐methyl‐eicos‐13‐enoic, cis‐20,21‐methylene‐heptacosanoic, 27‐methyl‐octacos‐21‐enoic and (22Z)‐nonacos‐22‐enoic. Some important mass spectrometric characteristics of pyrrolidides of homologous cyclopropane fatty acids are reported and discussed.     

Characterization of chilean hazelnut (Gevuina avellana mol) seed oil

The fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene-extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography-electron impact mass spectrometry after 2-alkenyl-4,4-dimethyloxazoline derivatization. This stable oil (Rancimat induction period at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated (principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C_16:1 Δ¹¹, C_18:1 Δ¹², C_20:1 Δ¹¹, C_20:1 Δ¹⁵, C_22:1 Δ¹⁷, and presumably C_22:1 Δ¹⁹ were identified. The C_18:1 Δ¹² and C_22:1 Δ¹⁹ fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α-, γ-tocopherols and β-, γ- and δ-tocotrienols were found, the oil contained a substantial amount of α-tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition.     

Chemical Composition and Fatty Acid Profile of Khat (Catha edulis) Seed Oil

The proximate, physicochemical, and fatty acid compositions of seed oil extracted from khat (Catha edulis) were determined. The oil, moisture, crude protein, crude fiber, crude carbohydrate, and ash content in seeds were 35.54, 6.63, 24, 1.01, 30.4 %, and 1.32 g/100 g DW respectively. The free fatty acids, peroxide value, saponification value, and iodine value were 2.98 %, 12.65 meq O₂/kg, 190.60 mg KOH/g, and 145 g/100 g oil, respectively. Linolenic acid (C_18:3, 50.80 %) and oleic (C_18:1, 16.96 %) along with palmitic acid (C_16:0, 14.60 %) were the dominant fatty acids. The seed oil of khat can be used in industry for the preparation of liquid soaps and shampoos. Furthermore, high levels of unsaturated fatty acids make it an important source of nutrition especially as an animal product substitute for omega‐3 fatty acids owing to the high content of linolenic acid.     

Identification of Unique Aldehyde Dimers in Sorghum Wax Recovered after Fermentation in a Commercial Fuel Ethanol Plant

Sorghum wax can be extracted from the surface of sorghum (Sorghum bicolor) kernels. It is composed mostly of a mixture of unsaturated C₂₈ and C₃₀ alkanes, fatty acids, fatty alcohols, and fatty aldehydes. Like carnauba wax, sorghum wax is a hard wax with a high melting point and it has potential edible and industrial applications. The yield of sorghum wax from the surface of sorghum kernels is 0.2–0.5 g of wax per 100 g of kernels. Sorghum wax can also be recovered from the “distillers oil” which is obtained after fermentation of sorghum (milo) or sorghum/corn blends in dry grind fuel ethanol plants. This distillers sorghum wax can potentially be obtained in yields of up to 10% by chilling the distillers oil to precipitate the wax and then recovering it via centrifugation or filtration. Like sorghum kernel wax, distillers sorghum wax is mainly composed of C₂₈ and C₃₀ alkanes, alcohols, and aldehydes in the molecular weight (MW) range of 350–450. However, we found that 7–49% w/w of distillers sorghum wax is composed of larger wax components with MW of 799–912. Analysis via high-resolution atmospheric pressure chemical ionization mass spectrometry (APCI) and gas chromatography with electron ionization mass spectrometry (GC/MS-EI) resulted in exact mass data and fragmentation patterns that suggested that these high MW compounds are monounsaturated fatty aldehyde dimers, likely formed by aldol condensation. Further confirmation supporting the GC/MS data for the aldol reaction was obtained by comparison with similar aldol products.     

Chemical survey and erucic acid content of commercial varieties of nasturtium,Tropaeolum majus L.

Nasturtium (Tropaeolum majus L.) oil contains the highest levels of erucic acid of known seed oils (75–80%). A significant portion of the acid is attached to the 2-position of the glycerol, and trierucin is a major component (ca. 50%) of the oil. Seeds from eleven varieties of commercially available garden nasturtium (T. majus) were screened for oil content, erucic acid levels and fatty acid distribution. Oil contents ranged fromca. 6 to 11%, and erucic acid levels in the oils ranged from 62 to 80%. One sample ofT. speciosum was also analyzed, and contained 28% oil, fatty acids from C₁₆ to C₂₈ and triglycerides up to C₇₂.     

Effects of Different Oil Sources and Residues on Biomass and Metabolite Production by Yarrowia lipolytica YB 423-12

Yarrowia lipolytica is known to have the ability to assimilate hydrophobic substrates like triglycerides, fats, and oils, and to produce single-cell oils, lipases, and organic acids. The aim of the present study was to investigate the effects of different oil sources (borage, canola, sesame, Echium, and trout oils) and oil industry residues (olive pomace oil, hazelnut oil press cake, and sunflower seed oil cake) on the growth, lipid accumulation, and lipase and citric acid production by Y. lipolytica YB 423-12. The maximum biomass and lipid accumulation were observed with linseed oil. Among the tested oil sources and oil industry residues, hazelnut oil press cake was the best medium for lipase production. The Y. lipolytica YB 423-12 strain produced 12.32 ± 1.54 U/mL (lipase activity) of lipase on hazelnut oil press cake medium supplemented with glucose. The best substrate for citric acid production was found to be borage oil, with an output of 5.34 ± 0.94 g/L. The biotechnological production of valuable metabolites such as single-cell oil, lipase, and citric acid could be achieved by using these wastes and low-cost substrates with this strain. Furthermore, the cost of the bio-process could also be significantly reduced by the utilization of various low-cost raw materials, residues, wastes, and renewable resources as substrates for this yeast.