Lipids of the Green Alga BotryococcusCultured in a Batch Mode

The lipid fraction of the green alga Botryococcuscultured in a batch mode was found to contain polar lipids (more than 50% of the total lipids), di- and triacylglycerols, sterols and their esters, free fatty acids, and hydrocarbons. In aging culture, the content of polar lipids somewhat decreased and that of triacylglycerols increased by more than four times. The content of hydrocarbons in the algal biomass did not exceed 0.9% and depended little on the culture age. Intracellular lipids contained saturated and unsaturated (mono-, di-, and trienoic) fatty acids. The maximum content of C_{16 : 3}and -C_{18 : 3}fatty acids (up to 35% of the total fatty acids) was detected in the phase of active growth. The extracellular and intracellular lipids of the alga differed in the proportion of particular lipids and in the fatty acid pattern.     

Lipids from the green algae Botryococcus during staged growth in batch mode]

The lipid fraction of the green alga Botryococcus cultured in a batch mode was found to contain polar lipids (more than 50% of the total lipids), di- and triacylglycerides, steroids and their esters, free fatty acids, and hydrocarbons. In senescent culture, the content of polar lipids somewhat decreased and that of triacylglycerides increased by more than four times. The content of hydrocarbons in the algal biomass did not exceed 0.9% and depended little on the culture age. Intracellular lipids contained saturated and unsaturated (mono-, di-, and trienoic) fatty acids. The maximum content of C16:3 and alpha-C18:3 fatty acids (up to 35% of the total fatty acids) was detected in the phase of active growth. The extracellular and intracellular lipids of the alga differed in the proportion of particular lipids and in the fatty acid pattern.     

The Fatty Acid Composition of Paramecium aurelia Cells and Cilia: Changes with Culture Age

SYNOPSIS.
The fatty acids of whole cells and cilia from Paramecium tetraurelia strains 51s and d,95 and from Paramecium octaurelia strain 299s were identified. Ciliates were grown axenically in 3 types of culture media. More than 30 fatty acid species were identified and their structures determined by gas chromatography, mass spectrometry, argentation chromatography, hydro-genation, and fragmentation technics. The major fatty acids were hexadecanoic, octadecanoic, 9-octadecenoic, 9,12-octadecadi-enoic, 6,9,12-octadecatrienoic, and 5,8,11,14-eicosatetraenoic acids. Minor variations in fatty acid compositions were observed in cells grown in the different culture media as well as among the 3 strains. Major changes in fatty acid compositions occurred with culture age and cell density. The cells accumulated exogenous lipids in cytoplasmic vesicles. These lipids were utilized as culture age progressed. Both cellular volume and lipid content were greater in young than in older cultures. Fatty acid compositions of both whole cells and cilia changed with age and had a relative decrease in saturated, short-chained and odd-numbered carbon acids. Cilia lipids were enriched in long-chained, polyunsaturated acids as compared to lipids in whole cell extracts. Eicosatetra-enoic acid (arachidonic acid) increased to the greatest extent with age in both cellular and ciliary lipids, accounting for 20–60% of the total fatty acids in cilia. The age-related change in fatty acid composition in Paramecium is among the largest observed in eukaryotic organisms. It was concluded that some minor fatty acids found in Paramecium lipids were incorporated directly from certain culture media and that Paramecium had w 3, 6, and 9 pathways for polyunsaturated fatty acid biosynthesis.     

Nutritional content of Liometopum apiculatum Mayr larvae (“escamoles”) by vegetation type in north-central Mexico

In Mexico the ant Liometopum apiculatum is an important insect nutritionally, economically and ecologically. Their larvae (“escamoles”) contain proteins, lipids, vitamins and minerals, the concentrations of which may be related with the type of vegetation where the ant forages. The objective of this study was to evaluate the content of macro and micro nutrients of L. apiculatum larvae collected in three types of vegetation in north-central Mexico. We determined content of moisture, crude protein, total lipids, crude fiber, ash, and nitrogen-free extract. The amino acids were analyzed by cationic Exchange chromatography with acid hydrolysis and fatty acids by gas chromatography and solvent extraction with sodium methoxide. The effect of vegetation type on nutrient content was determined with an ANOVA and Sheffé comparison of means (P?<?.05). The concentration of amino acids and fatty acids (FA) was analyzed with a Kruskall-Wallis test (P?<?.05). Significant differences were found in protein, lipids and ash (P?<?.0001) and moisture content (P?<?.0036). We identified 17 amino acids, which concentration differed by type of vegetation. There were no significant differences in fatty acids. It is likely that the differences in the concentrations of macronutrients are due to the diversity and differential density of the food components available in each type of vegetation for L. apiculatum, and that the number of types and quantity of amino acids and fatty acids depend on the chemical properties of the liquid secretions the ants obtain by trophobiosis.     

Lipase-mediated production of specific lipids with improved biological and physicochemical properties

The use of lipases in the modification of lipids has grown significantly in recent years. This increased interest is mainly due to the ability of these enzymes to catalyze the production of lipids with specific distributions of fatty acids that better fit the current needs of consumers, who are looking for healthier foods that are manufactured with the highest quality. The successful use of lipases to obtain modified lipids with low caloric content, high concentrations of n?3 fatty acids or high amounts of phenolic compounds demonstrate the great potential of these enzymes. The lipase-catalyzed production of lipids with reduced caloric content is made possible by the addition of a medium or a very long chain fatty acid to the triacylglyceride. Diacylglicerols with low caloric content can also be produced using lipases. Due to the deficiency of n?3 fatty acids in the current diet, strategies for the lipase-mediated incorporation of these acids in the TAG have shown promising results. Finally, studies have successfully used lipases for the incorporation of phenolic compounds in the lipid structure, which produce compounds with improved oxidative stability and more beneficial health effects.     

Characterizations of Phospholipids from Paramecium tetraurelia Cells and Cilia*,†

Phospholipids from Paramecium tetraurelia strains 51s and d,95 cultures and isolated cilia were characterized. The following classes of phospholipids were identified in whole cell lipids: the 1-alkyl-2–acylglyceryl and the 1,2–diacylglyceryl forms of phosphonylethanolamine, phosphorylethanolamine. and phosphorylcholine; cardiolipin: ceramide aminoethylphosphonate and 5 other sphingolipids: phosphatidylserine; phosphatidylinositol; and lyso derivatives of the major glycerophospholipids. Cilia lipids were rich in ether lipids, phosphonolipids. and sphingolipids. Net lipid biosynthesis did not occur, as determined by the weight of lipids extracted from culture medium compared with the weight of lipids extracted from culture medium and ciliates after 7 days of growth. Total lipids/cell decreased with culture age. changes in the neutral lipid fraction accounting for the major decrease. Phospholipid class distributions changed with culture age—the glyceryl phosphorylethanolamine and choline content of cells decreased, while the glyceryl ohosphonylethanolamine content remained relatively constant: hence, the ratio of phosphonolipids to total phospholipids increased. All fatty acids observed in total lipids from cells and cilia were also present in the glycerophospholipids. Total lipids from cilia contained a greater percent of polyunsaturated fatty acid than those of whole cells. Whole cells and cilia glyceryl phosphonolipids contained up to 93% eicosatetraenoic plus eicosapentaenoic fatty acids. The enrichment of phosphonolipids in cilia accounted for most of the polyunsaturated fatty acid enrichment observed in cilia total lipids. The fatty acid composition of all major whole cell glycerophospholipid classes changed dramatically with culture age, while only small changes occurred in cilia glycerophospholipid fatty acids.     

Fatty acid composition of <Emphasis Type="Italic">Wautersia eutropha</Emphasis> lipids under conditions of active polyhydroxyalkanoates synthesis

The fatty acid composition of the lipids of a Wautersia eutropha polyhydroxyalkanoate-producing strain was studied by chromato-mass spectrometry. A total of 27 fatty acids were identified; their distribution in the cell fractions was determined. In the cytoplasmic membrane, palmitic, palmitoleic, and cis-vaccenic acids were the major components. Long-chain β-hydroxy acids and myristic acids (components of the lipopolysaccharides of the cell envelope) predominated in the fraction of strongly bound lipids. When the polymer was actively synthesized, the content of cyclopropane acids in the easily extracted lipids increased and the content of the corresponding monoenoic acids decreased. The strongly bound lipids had a high content of long-chain β-hydroxy acids (more than 50% of the total fatty acids). These results made it possible to determine the source of polyhydroxyalkanoate (PHA) contamination and to choose the strategy for their purification.     

Lipids in plant tissue cultures. II. Unusual fatty acids in lipids of Hydnocarpus anthelminthica cultures

The lipids in callus cultures of Hydnocarpus anthelminthica were studied after 60, 160 and 460 days of growth. In each of the cultures the lipid classes usually found in plant tissue cultures were detected. With increasing age of the cultures the total lipid content as well as the proportions of triglycerides decreased. The major constituent fatty acids of the total lipids were palmitic and linoleic acids. Small amounts of cyclopentenyl fatty acids were also present. The proportions of saturated straight-chain fatty acids increased with the age of the cultures whereas the proportions of monounsaturated straight-chain fatty acids decreased. Only small changes were observed with polyunsaturated fatty acids. The content of cyclopentenyl fatty acids rose with the age of the cultures. The monounsaturated straight-chain fatty acids consisted of mixtures of isomers whose composition changed with the age of the cultures. In contrast, the polyunsaturated straight-chain fatty acids belonged exclusively to the Δ9 series, regardless of the age of the cultures.     

Effect of amylose content on the lipids of mature rice grain

Most of the nonstarch lipids in brown rice (Oryza sativa) of three rices differing in amylose content were contributed by bran, germ, polish and subaleurone layer. Nonstarch lipids consisted of 82–91% neutral lipids (of which 73–82% were triglycerides), 7–10% phospholipids and 2–8% glycolipids. Linoleic, oleic and palmitic acids were the major fatty acids. Nonwaxy (24 and 29% amylose) milled rice had proportionally more starch lipids and less nonstarch lipids than waxy (2% amylose) milled rice. Starch lipids were mainly lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids. The major fatty acids were palmitic and linoleic acids, followed by oleic acid.     

Combining metabolic engineering and process optimization to improve production and secretion of fatty acids

Microbial oils are sustainable alternatives to petroleum for the production of chemicals and fuels. Oleaginous yeasts are promising source of oils and Yarrowia lipolytica is the most studied and engineered one. Nonetheless the commercial production of biolipids is so far limited to high value products due to the elevated production and extraction costs. In order to contribute to overcoming these limitations we exploited the possibility of secreting lipids to the culture broth, uncoupling production and biomass formation and facilitating the extraction. We therefore considered two synthetic approaches, Strategy I where fatty acids are produced by enhancing the flux through neutral lipid formation, as typically occurs in eukaryotic systems and Strategy II where the bacterial system to produce free fatty acids is mimicked. The engineered strains, in a coupled fermentation and extraction process using alkanes, secreted the highest titer of lipids described so far, with a content of 120% of DCW.     

Scenedesmus sp. NJ-1 isolated from Antarctica: a suitable renewable lipid source for biodiesel production

Microalgal lipids are promising alternative feedstocks for biodiesel production. Scenedesmus sp. NJ-1, an oil-rich freshwater microalga isolated from Antarctica, was identified to be a suitable candidate to produce biodiesel in this study. This strain could grow at temperatures ranging from 4 to 35?°C. With regular decrease in nitrate concentration in the medium, large quantities of triacylglycerols accumulated under batch culture conditions detected by thin layer chromatography and BODIPY 505/515 fluorescent staining. Scenedesmus sp. NJ-1 achieved the average biomass productivity of 0.105?g?l^?1?d^?1 (dry weight) and nearly the highest lipid content (35?% of dry cell weight) was reached at day 28 in the batch culture. Neutral lipids accounted for 78?% of total lipids, and C18:1 (n-9), C16:0 were the major fatty acids in total lipids, composing 37 and 20?% of total fatty acids of Scenedesmus sp. NJ-1 grown for 36?days, respectively. These results suggested that Scenedesmus sp. NJ-1 was a good source of microalgal oils for biodiesel production.     

The role of exogenous lipids in lycopene synthesis in the mucoraceous fungus Blakeslea trispora

The addition of plant oils to the growth medium stimulated growth and lipid synthesis in the fungus Blakeslea trispora. However, only oils with high content of linoleic and especially linolenic acid enhanced lycopene formation. The increase in lycopene formation was accompanied by accumulation in the neutral lipid fraction of the fatty acids prevailing in plant oils. In contrast, the influence of exogenous lipids on the fatty acid composition of bulk fungal phospholipids was insignificant. Nonetheless, a marked increase in the content of membrane lipids and of their phosphatidylethanolamine content was revealed. Presumably, the main mechanism of stimulation of lycopene formation by the oils involves an increase in the solubility of lycopene in the triacylglycerols of the lipid bodies, which is due to an increase in the desaturation degree of their fatty acids. The predominance of linoleic and especially of linolenic fatty acid in plant oils is regarded as a criterion for selecting the oil species for the purpose of intensifying lycopene synthesis.     

The Neutral Lipids of Paramecium tetraurelia: Changes with Culture Age and the Detection of Steryl Esters in Ciliary Membranes1

Neutral lipids, particularly triglycerides, accounted for the major decrease in the total lipid content in Paramecium cells that occurs with culture age. Sterols, triglycerides, and steryl esters were the major classes of neutral lipids in cells and isolated cilia. Free as well as high concentrations of esterified sterols were detected in purified ciliary membrane preparations. Stigmasterol and 7-dehydrostigmasterol were the major components of both free and esterified sterols of cells and cilia; however, when cholesterol was present in the growth medium, it was desaturated to 7-dehydrocholesterol and incorporated into cellular and ciliary lipids. Free fatty acids from cells and triglycerides from cells and cilia were low in polyunsaturated fatty acids and reflected the composition of fatty acids in the culture medium. An exception was the reduced concentration of stearate in triglycerides from whole cells. Greater than 50% of triglyceride fatty acids from cilia were saturated. The fatty acid compositions of cellular triglycerides and ciliary steryl esters did not change with culture age, but those of cellular steryl esters and ciliary triglycerides did change. In comparison with phospholipids, these neutral lipid fatty acid compositional changes were smaller. The sensitivity of these stigmasterol-containing cells to polyene antibiotics indicated that they were killed by nystatin > filipin > amphotericin B. The unexpected finding of high concentrations of steryl esters in ciliary membrane preparations is discussed.     

Photosynthesis,lipids and proteins in the cyanobacteriumSynechocystis PCC 6803 as affected by temperature

The cyanobacteriumSynechocystis PCC 6803 was grown photoautotrophically in an inorganic medium at constant growth temperatures of 20, 38 (control) or 43°C for 9 h. The up and down-shift of cultivation temperature decreased the growth as measured by culture absorbance and chlorophylla content. However, high temperature slightly increased the oxygen evolution while temperature lower than control inhibited oxygen evolution during the whole incubation period. The protein synthesis studied by¹⁴C-labeled protein declined under low temperature by about 50%. The fatty acid pattern is characterized as lacking in C₂₀/C₂₂ acids but containing large amounts of C₁₆ and C₁₈ polyunsaturated fatty acids, 16:2 and 18:3 in particular. The lower temperature increased the percentage of monounsaturated fatty acids while higher temperature increased the saturated fatty acid content in total lipids and lipid classes studied.     

A system for manipulating the membrane Fatty Acid composition of soybean cell cultures by adding tween-Fatty Acid esters to their growth medium : basic parameters and effects on cell growth

The development of a system for modifying the membrane fatty acid composition of cultured soybean cells (Glycine max [L.] Merr.) is described. Tween-fatty acid esters carrying specific fatty acids were synthesized and added to the medium of suspension cultures. Cells transferred large quantities of exogenous fatty acids from Tweens to all acylated membrane lipids; up to 50% of membrane fatty acids were exogenously derived. C15 to C20 saturated fatty acids and C16, C18, and C20 unsaturated fatty acids with either cis or trans double bonds were incorporated into lipids. Cells elongated saturated fatty acids of C16 or less, and unsaturated fatty acids with cis double bonds were further desaturated. No other types of modifications were observed. Growth ceased in cells treated with excessive concentrations of Tween-fatty acid esters, but frequently not for several days. Cessation of cell growth was correlated with changes in membrane fatty acid composition resulting from incorporation of large amounts of exogenous fatty acids into membrane lipids, although cells tolerated large variations in fatty acid composition. Maximum tolerable Tween concentrations varied widely according to the fatty acid supplied. Potential uses of this system and implications of the observed modifications on the pathway of incorporation are discussed.     

The utilization of sterols and other lipids by insect cells grown in vitro

Cells derived from Antheraea eucalypti were grown in vitro in a medium containing triglycerides, diglycerides, free fatty acids, and sterols as the main ‘neutral’ lipids. The sterol content of the medium was derived chiefly from the haemolymph component. The ‘neutral’ lipids in the cells were triglycerides, free fatty acids, and sterols. During growth over 6 days there was a quantitative balance between cholesterol and β-sitosterol gained by the cells and those sterols removed from the medium when allowance was made for losses from sterile medium. Cells metabolized more triglycerides and free fatty acids than they incorporated.     

Biomass productivity and productivity of fatty acids and amino acids of microalgae strains as key characteristics of suitability for biodiesel production

Microalgae are discussed as an alternative source for the production of biofuels. The lipid content compared to cultivation time of used species is the main reason for any choice of a special strain. This paper reviews more analytical data of 38 screened microalgae strains. After the cultivation period, total content of lipids was analysed. The extracted fatty acids were quantified as fatty acid methyl esters by GC analysis. The amino acids were analysed by HPLC. Chlorella sp., Chlorella saccharophila, Chlorella minutissima and Chlorella vulgaris were identified as species with the highest productivity of fatty acids relevant to transesterification reactions. The components were mainly linoleic acid, palmitic acid and oleic acid. To increase productivity of highly saturated fatty acids, cultivation parameters light intensity and temperature were varied. In this manner, the ideal conditions for biodiesel production were defined in this publication.     

Heat shock response in the thermophilic fungus Rhizomucor miehei

Changes in the composition of the membrane lipids and cytosol carbohydrates of the thermophilic fungus Rhizomucor miehei in response to heat shock were studied. Under optimal conditions (41–43°C), high trehalose content (8–11%) was found at all stages of growth of submerged culture. Heat shock (51–53°C) for 1 h did not result in enhanced trehalose synthesis, while increase in shock duration to 3 h resulted in a significant increase in trehalose content. The share of sterols and phosphatidic acids in the membrane lipids increased, while the share of phosphatidylcholines and phosphatidylethanolamines decreased. These processes resulted in increased content of non-bilayer lipids, while the unsaturation degree of the fatty acids of the major phospholipids did not decrease. Comparison of resistance to lethal heat shock in the control and experimental variants of R. miehei revealed that this thermophilic fungus exhibited no acquired heat resistance.     

Kefir Grains Change Fatty Acid Profile of Milk during Fermentation and Storage

Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR), Viçosa (AV) e Lavras (AD)], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when p<0.05. The highest palmitic acid content, which is antimutagenic compost, was seen in AV grain (36.6g/100g fatty acids), which may have contributed to increasing the antimutagenic potential in fermented milk. Higher monounsaturated fatty acid (25.8g/100g fatty acids) and lower saturated fatty acid (72.7g/100g fatty acids) contents were observed in AV, when compared to other grains, due to higher Δ9-desaturase activity (0.31) that improves the nutritional quality of lipids. Higher oleic acid (25.0g/100g fatty acids) and monounsaturated fatty acid (28.2g/100g fatty acids) and lower saturated fatty acid (67.2g/100g fatty acids) contents were found in stored kefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality.     

The influence of branched-chain and ω-alicyclic fatty acids on the transition temperature of bacillus subtilis lipids

The influence of branched-chain and ω-alicyclic fatty acids on the transition temperature of Bacillus subtilis lipids was studied by measuring the fluorescence depolarisation of the probe 1,6-diphenyl-1,3,5-hexatriene incorporated into lipid bilayers. Only anteiso-C₁₅ and C₁₇ fatty acid-enriched lipids showed no transition in the observed temperature range. Compared to the transition of normal lipids iso-fatty acid-enriched lipids have a slightly higher transition temperature. The incorporation of ω-alicyclic fatty acids with increasing size of the alicycle leads to a decrease in the transition temperature. A possible role of ω-cyclohexane fatty acids in Bacillus acidocaldarius is proposed.