Fatty acid composition of the lipids in fungi of the genus Aspergillus developing on mineral media with different carbon sources

This work was aimed at studying the effect of different carbon sources in the composition of mineral media on the growth of fungi belonging to the Aspergillus genus and on the fatty acid composition of their lipids. A chemically-defined medium with glucose was shown to be optimal for the growth of 18 Aspergillus strains and for the synthesis of lipids by them. The fatty acid composition of lipids was studied when the fungi grew in media with different carbon sources. The lipids were shown to contain saturated and unsaturated fatty acids with the prevalence of oleic, linoleic and linolenic acids.     

Dependence of the fatty acid composition of the lipids in fungi of the genus Penicillium on their natural habitat conditions

The fatty acid composition of lipids was studied in Penicillium fungi growing in different habitats. Saturated fatty acids were represented by lauric, margaric, stearic and palmitic acids (the latter prevailed-- 18%-26%). Unsaturated monoene fatty acids were represented by acids from C16:1 to C18:1, diene and triene fatty acids by linoleic and linolenic acids. The predominance of linoleic acid was not found in all cultures of the genus. Changes in the fatty acid composition of lipids may be attributed to different ecological habitats of the Penicillium genus species.     

The effect of the preservative sorbic acid on the lipid composition of the ascomycete fungus <Emphasis Type="Italic">Penicillium roqueforti</Emphasis> Thom

The mechanism of action of potassium sorbate, a widely used food preservative on the lipid composition of the Ascomycete fungus Penicillium roqueforti, the main contaminant of cheese, was investigated. The inhibition of fungal growth by potassium sorbate was found to be associated with a change in the composition of phospholipids (a decrease in phosphatidylcholine content and an increase in phosphatidylethanolamine and phosphatidic acid content) and of neutral lipids (a decrease in the triacylglycerol and sterol content and an increase in the free fatty acid content). The fatty acid composition of fungal lipids also changed. A drastic decrease in the linoleic acid content occurred both in the total lipid fraction and in the triacylglycerol and total phospholipid fractions, whereas the oleic acid content increased correspondingly. This suggests that sorbic acid (SA) affects Δ12 desaturase activity, which controls the adaptive response of mycelial fungi to deleterious environmental factors.     

The lipids of mycelial fungi and the prospects for the development of microbial oleo-biotechnology. I. The lipids of mycelial fungi

The importance of mycelial fungi as a source of lipids for development of modern oleo biotechnology is considered. For this purpose the data on fungal lipid composition and the main enzymes of fatty acid synthesis in fungi as compared with procaryotes and higher eucaryotes as well the data on the effect of a number of physicochemical factors on the yield and composition of the lipids of the micromycetes are presented. The information on the fungi producers according to the lipid composition able to substitute the vegetable oil and be the source of linolic, linolenic and arachidonic acids is put forward.     

Effect of the exogenous lipids of complex media on the fatty acid composition of mycelial microorganisms

The effect of exogenous lipid sources on the composition of fatty acids was studied in actinomycetes of the Streptomyces genus and in fungi belonging to the genera Blakeslea, Cunninghamella and Penicillium. The following sources of exogenous lipids were used: soybean and maize flour, sunflower by-products, chicken droppings, maize extract, yeast extract, peptone, sperm whale fat, sunflower and palm oil. The composition of fatty acids in total extracted lipids of the studied mycelial microorganisms was shown to reflect two processes: lipid synthesis de novo and assimilation of exogenous fatty acids. This fact ought to be taken into account both in the chemotaxonomic interpretation of fatty acid composition and in practical recommendations for the utilization of microbial lipids. It is of particular interest to study the physiological role of exogenous lipid metabolism in the cells of microorganisms.     

Effect of growth temperature on lipid composition of Streptococcus faecium

The effect of growth temperature on the lipid and fatty acid composition of Streptococcus faecium has been studied. No differences in the qualitative composition of S. faecium lipids were observed. In all isolated fractions (neutral lipids, glycolipids, and phospholipids plus other polar lipids), the major fatty acids were palmitic (C-16:0), palmitoleic (C-16:1), octadecenoic (C-18:1), and cyclopropane (C-19:0). Changes in the fatty acid composition of the different fractions were observed which depended on growth temperature; the most significant one was the decrease of octadecenoic acid and the increase of palmitic acid in glycolipids and polar lipids as the temperature increased. The level of cyclopropane C-19:0 was approximately eightfold lower at 8 degrees C than at the other temperatures tested (20, 30, and 45 degrees C).     

Fatty acids in the species of several zygomycete taxa

The composition of fatty acids synthesized de novo by thirty strains of zygomycetes from various taxa was studied. The qualitative fatty acid compositions of the fungal lipids were found to be virtually identical, but there were significant differences in the contents of individual acids. Highly active producers of essential C18 fatty acids, with their content exceeding 30-40% of total fatty acids, were discovered among the fungi of the families Mucoraceae, Pilobolaceae, and Radiomycetaceae. Linoleic acid was found to predominate in the fungi of the genera Radiomyces, Mycotypha, and Circinella, and linolenic acid (identified as its gamma-isomer by gas-liquid chromatography), in the fungi of the genera Absidia, Circinella, Pilaira, and Hesseltinella. The total yield (mg/l) of bioactive acids (C18:3, C18:2, C18:1) varied from 761.4 in Pilaira anomala to 3477.9 in Syncephalastrum racemosum; the total yield of essential acids, from 520.7 in Pilaira anomala to 1154.5 in Hesseltinella vesiculosa; of linoleic acid, from 279.7 in Pilaira anomala to 836.3 in Mycotypha indica; and of linolenic acid, from 120.8 in Mycotypha indica to 708.0 in Hesseltinella vesiculosa. The data on the efficient synthesis of these acids make the actively producing strains promising for biotechnological synthesis of commercially valuable lipids. Linderina pennispora VKM F-1219, a zygomycete of the family Kickxellaceae, which was earlier singled out into the order Kickxellales [12], was shown to differ from zygomycetes of the order Mucorales in having a high content of cis-9-hexadecenoic (palmitoleic) acid, reaching 37.0% of the fatty acid total.     

Studies on methanol-oxidizing yeast

The yeast strain 11Bh was studied from the aspect of qualitative and qunatitative composition of lipids formed in cells during growth on methanol, synthetic ethanol and glucose. The strain was found to form some 3% free fatty acids toward the end of the growth phase. More esterified fatty acids are formed on ethanol and glucose (2.75 and 2.86%, respectively) than on methanol (1.6%). The composition of lipids and representation of the various fatty acids in the lipids is similar on all three substrates. The cell lipids contain over 40 rel.% oleic and about 16 rel.% each of palmitoleic, palmitio and linolenic acid. Odd-numbered fatty acids are present after growth on any of the three substrates, amounting to at most 4 rel.%. Of the extracellular fatty acids formed toward the end of growth of cells on methanol, propionic and acetic acid occurred in largest amounts in the medium. An erratum to this article is available at .     

About different mechanisms of the biochemical adaptation of mycelial fungi to temperature stress: changes in lipids composition

A comparative study was conducted concerning the effect of temperature stress on the lipid composition of representatives of the subkingdoms Eomycota and Neomycota. Changes in the composition of lipid acyl chains (such as saturation and desaturation, isomerization, and changes in the length of fatty acid carbon chains), in the phospholipid composition, and in the contents of sterols and other neutral lipids were revealed. Hyperthermia resulted in (i) an increase in the phosphatidylcholine level; (ii) a decrease in the phosphatidylethanolamine level; (iii) a rise in the content of reserve lipids (triacylglycerols); and (iv) a decline in the free fatty acid level in the neutral lipids. An inverse pattern occurred under hypothermic conditions. The peculiarities in the patterns of the temperature adaptation-related changes in the lipid bilayer composition are considered in terms of the systematic position of the fungi.     

The effects of temperature and growth rate on the proportion of unsaturated fatty acids in bacterial lipids

The effects of temperature and growth rate on the fatty acid composition of the extractable lipids of four mesophilic and three psychotrophic bacteria were examined. Two of the mesophiles (Escherichia coli and Pseudomonas aeruginosa) increased the proportion of unsaturated fatty acids in their lipids with decreasing temperature over their whole growth temperature range. The other mesophiles (Enterobacter aerogenes and Lactobacillus casei) increased the proportion of unsaturated fatty acids with decreasing temperature only over the lower half of their growth temperature ranges. The psychrotrophs Pseudomonas fluorescens and Enterobacter sp. had a constant proportion of unsaturated acids over the lower half of their growth temperature range, while the psychotrophic Lactobacillus sp. showed no consistent change in its unsaturated fatty acid composition with temperature. All species showed some variation of unsaturated fatty acid composition with growth rate at the highest and lowest growth temperatures, although such variations were small in some species (Ent. aerogenes and Lactobacillus sp.).     

Wool-colonizing micro-organisms capable of utilizing wool-lipids and fatty acids as sole sources of carbon and energy

Two keratinolytic fungi, Chrysosporium keratinophilum and Malbranchea anamorph of Uncinocarpus reesii, and another three wool-colonizing fungi not previously reported to be keratinolytic, Aspergillus fumigatus, A. Flavus and Scopulariopsis candida, were isolated from soil samples baited with animal wool. These fungi were tested for their ability to utilize wool-lipids as sole source of carbon and energy. The lipid contents of wool of various animals ranged between 2 and 5%. The different lipid extracts were similar in composition; they contained steryl esters, sterols, fatty acids, fatty alcohols and monoacylglycerols. The predominant acyl moiety in wool-lipids of different animals was linolenic acid (18:2). The five fungi tested grew well on an inorganic medium supplemented with total wool-lipids as sole sources of carbon and energy. Individual lipid classes fractionated by preparative thin layer chromatography and suspended into inorganic medium were able to support fungal growth as sole carbon sources. These fungi and another eight wool-colonizing strains, C. tropicum, C. zonatrum, C. anamorph of Arthroderma curryei, Microsporum canis, M. distortum, Trichophyton interdigitale, Emmonsia parva and Myceliophthora vellerae could also utilize standard lipids and fatty acids (cholesterol and palmitic and linoleic acids). Evidence fo the uptake and degradation of cholesterol by C. keratinophilum is presented.     

Analysis of Lipids of Citrullus lanatus (cv. Sugar baby) During Seed Germination and Seedling Growth

Changes in the dry weight (dry wt.), total and neutral lipids,and fatty acid composition were determined in the cotyledonsand axis of Citrullus lanatus cv. Sugar baby seedlings duringtheir first 12 d growth in the dark, at 25 ? 1 ?C. The major stored reserves were mobilized between days 3 and8. The lipid concentration after day 4 decreased rapidly inthe cotyledons. On the first day the lipid concentration inthe axis was higher than in the cotyledons but decreased rapidlyand from day 5 up to the end of the experiments it remainedat very low values. In the cotyledons, the change in the fattyacid composition was relatively small compared to the significantchange observed in the axis. The neutral lipids of the cotyledonsdecreased sharply between days 2 and 6 while their fatty acidcomposition suffered no significant change. The axis, comparedto the cotyledons, contained a small but concentrated amountof neutral lipids, which decreased up to day 6. Thereafter,an increase was observed. The fatty acid composition of theaxis neutral lipids changed significantly, linoleic and oleicacid decreased while palmitic and linolenic acid increased. Key words: Citrullus lanatus, seed germination, seedling growth, lipids, fatty acids     

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.     

Growth of three fungi on poultry fat or beef tallow

Aspergillus niger, Geotrichum candidum and Mucor miehei, when grown on a medium containing beef tallow or poultry fat for 5 days at 28°C, in Roux bottles, shake-flasks or fermenters, synthesized from 0.4 to 3.2 g lipids/I. The degree of fat utilization varied from 15 to 70%. The type of fat in the medium, the species of fungi and its cultivation method all influenced the fatty acid composition of fats remaining in the medium, as well as the intracellular lipids of the fungi.     

Different mechanisms of the biochemical adaptation of mycelial fungi to temperature stress: Changes in the lipid composition

A comparative study was conducted concerning the effect of temperature stress on the lipid composition of representatives of the subkingdomsEomycota andNeomycota. Changes in the composition of lipid acyl chains (such as saturation and desaturation, isomerization, and changes in the length of fatty acid carbon chains), in the phospholipid composition, and in the contents of sterols and other neutral lipids were revealed. Hyperthermia resulted in (i) an increase in the phosphatidylcholine level, (ii) a decrease in the phosphatidylethanolamine level, (iii) a rise in the content of reserve lipids (triacylglycerols), and (iv) a decline in the free fatty acid level in the neutral lipids. An inverse pattern occurred under hypothermic conditions. The peculiarities in the patterns of the temperature adaptation-related changes in the lipid bilayer composition are considered in terms of the systematic position of the fungi.     

Characterization and Differentiation of Filamentous Fungi Based on Fatty Acid Composition

Cellular fatty acid composition of 100 different filamentous fungi, including oomycetes, zygomycetes, ascomycetes, basidiomycetes, and sterile mycelia, was analyzed to determine if they can be differentiated from one another on this basis and how minor variations in culture temperature and age affect this characteristic. Many fungi were found to possess the same fatty acids but produced different relative concentrations of each. Some fungi differed in both the fatty acids produced and in the relative concentrations of others. Multivariate discriminant analysis demonstrated that all of the species included in this study had significantly different (P < 0.001) fatty acid profiles. Each of the three phyla from which representative species were analyzed and the sterile forms had distinctive fatty acid profiles. Significant differences in fatty acid composition were also found at the intraspecific level. Both culture temperature and age affected fatty acid composition in the fungi examined, but when these factors were held constant, variance in fatty acid composition was not a problem and fungal fatty acid profiles could be differentiated statistically.     

Effects of temperature and nutritional changes on the fatty acids of agmenellum quadruplicatum.

The fatty acid composition of the blue-green bacterium Agmenellum quadruplicatum was examined under a wide variety of growth conditions. The fatty acid composition was found to undergo significant changes with variations in temperature, media composition, and growth phase (log versus stationary). With increasing growth temperature (20 to 43 C) log-phase cells exhibited an increase in saturated fatty acids (38.4% at 20 C to 63.6% at 43 C). Striking changes were seen with some of the individual fatty acids such as 18.3, which made up 16.0% of the total fatty acid at 20 C but was not neasurable at 43 C. Fatty acid 12:0 was not measurable at 20 C but made up 16.3% of the total fatty acids at 43 C. Cell lipids were separated into neutral lipid, glycolipid, and very polar liquid fractions. The neutral lipid fraction was composed almost entirely of 12 carbon fatty acids (12:0, 12:1). Glycolipid and very polar lipids were more similar in their fatty acid composition when compared to the total cellular fatty acids, although they did lack 12 carbon fatty acids. The total of 12 carbon fatty acids in the cell can be used as an indicator of the amount of neutral lipid present.     

Effects of hydrostatic pressure and temperature on growth and lipid composition of the inner membrane of barotolerant Pseudomonas sp. BT1 isolated from the deep-sea

A barotolerant member of the genus Pseudomonas was isolated from deep-sea sediment obtained from the Japan Trench, at a depth of 4418 m. The growth temperature was found to affect the hydrostatic pressure range in which the bacterium could grow; the optimum hydrostatic pressure for growth shifted to a higher pressure with increasing temperature. We examined the lipid composition of the inner membrane of cells grown at various hydrostatic pressures and temperatures. The fatty acid components of the inner membrane lipids were C16:0, C16:1, C18:0, and C18:1. The phospholipid components of the inner membrane were phosphatidylethanolamine, cardiolipin, phosphatidylglycerol, and phosphatidylserine. It is evident that the effects of elevated hydrostatic pressure are comparable to the effects of low temperature on both the fatty acid composition of the inner membrane lipids and the phospholipid composition of the inner membrane of this bacterium.     

Alanine transport by Chinese hamster ovary cells with altered phospholipid acyl chain composition

The Na+-dependent transport of alanine has been examined in Chinese hamster ovary (CHO) cells as a function of the fatty acid composition of their membrane lipids. Significant changes in the fatty acid composition of the CHO cell phospholipids were achieved by supplementation of the growth medium with specific saturated (palmitate) or monoenoic (oleate) free fatty acids. Arrhenius plots of the temperature-dependent uptake of alanine were constructed for cells of altered fatty acid composition. Alanine uptake was characterized by a single discontinuity in the Arrhenius plot. The temperature of this break was observed to be dependent upon the fatty acid composition of the cell phospholipids, ranging from 16 degrees C for cells enriched with oleate to 32 degrees C for cells enriched in palmitate. Calculation of the Km value for the uptake process showed no significant change with temperature or fatty acid supplementation. Correlations are made between the physical state of the membrane lipids and the temperature-dependence for alanine transport. The results are discussed in terms of membrane fatty acid composition, ordered in equilibrium fluid phase transitions and amino acid transport.     

Functional compatibility in cucumber mycorrhizas in terms of plant growth performance and foliar nutrient composition

Functional compatibility in cucumber mycorrhizas in terms of plant and fungal growth, and foliar nutrient composition from all possible combinations of six cucumber varieties and three species of arbuscular mycorrhizal (AM) fungi was evaluated. Measurements of foliar nutrient composition included N, P, K, Mg, Ca, Na, Fe, Zn, Mn and Cu. Growth of AM fungi was measured in terms of root colonisation, as examined with microscopy and the AM fungus biomarker fatty acid 16:1ω5 from both phospholipids and neutral lipids. Different responses of plant growth and foliar nutrient profiles were observed for the different AM symbioses examined. The AM fungus Claroideoglomus claroideum caused growth depression in association with four out of six cucumber varieties; Rhizophagus irregularis caused growth promotion in one of six cucumber varieties; whereas Funneliformis mosseae had no effect on the growth performance of any of the cucumber varieties examined. All three AM fungi markedly altered host plant shoot nutrient composition, with the strongest contrast observed between cucumber–R. irregularis symbioses and non‐mycorrhizal cucumber plants, independent of cucumber variety. On the other hand, AM fungal growth in roots differed between the three AM fungi, but was unaffected by host genotype. Strong build‐up of storage lipids was observed for R. irregularis, which was more moderate in the two other AM fungi. In conclusion, strong differential responses of cucumber varieties to inoculation with different AM fungi in terms of growth and shoot nutrient composition revealed high functional diversity in AM symbioses in cucumber plants.