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1.
Hiroko Yokokawa 《Phytochemistry》1980,19(12):2615-2618
The simple lipids present in ten species of Polyporaceae (Piptororus betulinus, Coriolus pargamenus, C. versicolor, C. heteromorphus, Formitopsis cytisina, F. pinicola, Microporus flabelliformis, Gloephyllum saepiarium, Crytoderma citrinum and Grifola frondosa) were investigated. The fatty acids that these species had in common were C16-saturated acids (except in P. betulinus) and C18-unsaturated acids. Ergosterol and ergosta-7,22-dien-3β-ol were isolated from these mushrooms. Lupeol was obtained from G. saepiarium. Ergost-7-en-3β-ol, lanosterol and 24-methylene-24,25-dihydrolanosterol were tentatively identified.  相似文献   

2.
The fatty acid composition of the fruit oils or seed oils of Pittosporaceae (eight genera, 10 species), Araliaceae (two species), Simarubaceae (three species), and of one umbelliferous and one rutaceous species were determined by gas chromatography, argentation TLC and ozonolysis. In the Pittosporaceae, in which the major C18 fatty acid of all species was either oleic acid (18:1, 9c) or linoleic acid (18:2, 9c, 12c), large amounts of C20 and C22 fatty acids seem to occur regularly. Petroselinic (18:1, 6c) and tariric (18:1, 6a) acids were absent. However, petroselinic acid was the major fatty acid in the Araliaceae and Umbelliferae. In these two families only small amounts of C20 and C22 acids were detected and tariric acid was absent. The Rutales contained relatively high amounts of trans-octadecenoic acids (18:1, 9t). Tariric acid was the major fatty acid in the two species of Picramnia (Simarubraceae), which also contained small amounts of petroselinic acid. The major fatty acids in Ailanthus glandulosa (Simarubaceae) and Phellodendron amurense (Rutaceae) were linoleic or linolenic acid (18:3, 9c, 12c, 15c); these species contained neither tariric nor petroselinic acid and the levels of C20 and C22 fatty acids were low. The appearance of schizogenous resin canals and polyacetylenes and the absence of iridoids and petroselinic acid allows the Pittosporaceae to be separated from the Rutales and Araliales and to be placed in an independent order, the Pittosporales. Arguments for a rather close relationship of the Pittosporales to the Araliales and Cornales (including the Escalloniaceae) are presented.  相似文献   

3.
The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology that may be the result of secondary endosymbiosis of a green alga by a nonphotosynthetic amoeba or amoeboflagellate. Whereas much is known about the phylogeny of chlorarachniophytes, little is known about their physiology, particularly that of their lipids. In an initial effort to characterize the lipids of this algal class, four organisms from three genera were examined for their fatty acid and sterol composition. Fatty acids from lipid fractions containing chloroplast‐associated glycolipids, storage triglycerides, and cytoplasmic membrane‐associated polar lipids were characterized. Glycolipid‐associated fatty acids were of limited composition, principally eicosapentaenoic acid [20:5(n‐3)] and hexadecanoic acid (16:0). Triglyceride‐associated fatty acids, although minor, were found to be similar in composition. The polar lipid fraction was dominated by lipids that did not contain phosphorus and had a more variable fatty acid composition with 16:0 and docosapentaenoic acid [22:5(n‐3)] dominant along with a number of minor C18 and C20 fatty acids. Crinosterol and one of the epimeric pair poriferasterol/stigmasterol were the sole sterols. Several genes required for synthesis of these sterols were computationally identified in Bigelowiella natans Moestrup. One sterol biosynthesis gene showed the greatest similarity to SMT1 of the green alga, Chlamydomonas reinhardtii. However, homologues to other species, mostly green plant species, were also found. Further, the method used for identification suggested that the sequences were transferred to a genetic compartment other than the likely original location, the nucleomorph nucleus.  相似文献   

4.
The main glycerolipids (monogalactosyl-, digalactosyl-, sulphoquinovosyl diacylglycerol, phosphatidylglycerol) from five blue-green algae (Microcystis, Anabaena, Nostoc, Oscillatoria, Tolypothrix) were analyzed for fatty acid composition, occurrence of diglyceride species and positional distribution of fatty acids between thesn-1- andsn-2-position of glycerol. In contrast to eucaryotic plants biosynthetically closely related lipids (monogalactosyl-, digalactosyl-, trigalactosyl diacylglycerol) show nearly identical diglyceride moieties, whereas sulphoquinovosyl diacylglycerol and phosphatidylglycerol are separated from galactolipids by composition as well as occurrence of fatty acids. On the other hand the positional distribution of fatty acids in all lipids is controlled exclusively by chain length and not by degree of unsaturation with C18-fatty acids at thesn-1- and C16-fatty acids at thesn-2-position. These results show that in procaryotic organisms the diversity in diglyceride portions of lipids is reduced as compared to eucaryotic organisms, but nevertheless does exist.Abbreviations MGD, DGD, TGD, SQD monogalactosyl-, digalactosyl-, trigalactosyl-, sulphoquinovosyl diacylglycerol - PG phosphatidyl glycerol  相似文献   

5.
Lipid composition and hydrocarbon structure of two colonial green algae of the genus Botryococcus, i.e., a museum strain and a field sample collected for the first time from Lake Shira (Khakasia, Siberia), have been compared. Polar lipids, diacylglycerols, alcohols, triacylglycerols, sterols, sterol esters, free fatty acids and hydrocarbons have been identified among lipids in the laboratory culture. The dominant fraction in the museum strain was formed by polar lipids (up to 50% of the lipids) made up of fatty acids from C12 to C24. Palmitic, oleic, C16 - C18 dienoic and trienoic acids were the main fatty acids of the museum strain. Aliphatic hydrocarbons were found in the lipid of the museum strain. However, these amounted maximally to about 1% of the dry biomass at the end of exponential growth phase. The qualitative and quantitative compositions of FAs and hydrocarbons of the museum strain of Botryococcus, (registered at the Cambridge collection as Botryococcus braunii Kutz No LB 807/1 Droop 1950 H-252) differed from those of the Botryococcus strain described in the literature as Botryococcus braunii. The Botryococcus sp. found in Lake Shira is characterized by a higher lipid content (<40% of the dry weight). Polar lipids, sterols, triacylglycerols, free fatty acids and hydrocarbons have been identified among lipids in the field sample. The main lipids in this sample were dienes and trienes (hydrocarbons <60% of total lipid). Monounsaturated and very long chain monounsaturated fatty acids, including C28:1 and C32:1 acids, were identified in the Botryococcus found in Lake Shira. The chemo-taxonomic criteria allow us to unequivocally characterize the organism collected from Lake Shira as Botryococcus braunii, race A.  相似文献   

6.
Despite their importance in marine and freshwater microalgal assemblages, cold-adapted dinoflagellates have been the subject of few comprehensive lipid studies, particularly with respect to those lipids that comprise plastid membranes. In an effort to understand the differences between warm- and cold-adapted dinoflagellate glycolipid composition, four peridinin-containing, cold-adapted dinoflagellates were surveyed for intact forms of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), two common plastid lipids, using positive-ion electrospray ionization/mass spectrometry (ESI/MS) and electrospray ionization/mass spectrometry/mass spectrometry (ESI/MS/MS). It was determined that the dominant forms of MGDG and DGDG in these cold-adapted, peridinin-containing dinoflagellates possessed C18 fatty acids and did not, with the exception of a 20:5/18:5 form of DGDG in a cold-adapted Gymnodinium sp. from the Baltic Sea, have C20 fatty acids. This finding is in contrast to an earlier study of 35 peridinin-containing, warm-adapted dinoflagellates, which discovered a cluster dominated by C18 fatty acids and a cluster dominated by both C20 and C18 fatty acids. The key difference in MGDG and DGDG production between the former group and the cold-adapted dinoflagellates examined in this study is that the cold-adapted species’ DGDG fatty acids were less saturated. Each cold-adapted dinoflagellate possessed both 18:5/18:5 and 18:5/18:4 DGDG, while most of the warm-adapted dinoflagellates contained only 18:5/18:4 DGDG. This survey also revealed the presence of a putative 18:1/14:0 trigalactosyldiacylglycerol (TGDG) as a dominant glycolipid in Gymnodinium sp. TGDG, previously unreported in dinoflagellates, was also discovered in Gymnodinium sp. in the forms of 18:1/16:0 and 18:1/18:1 TGDG, as minor lipids. Since the fatty acids associated with TGDG are not those found with dominant forms of MGDG or DGDG, TGDG may be produced by a different biosynthetic pathway.  相似文献   

7.
The fatty acid compositions of sterol esters from 4 citrus species, viz, orange. grapefruit, lemon and lime, were determined by GLC. Each species possessed its own intrinsic fatty acid pattern which could be used to differentiate it from the other species. In most cases varieties within a species had fatty acid patterns which could be used for varietal differentiation. In all citrus tested except Columbia lime, the major acid was linoleic acid; this acid varied from 10 to 56% of the total acid content. The ratios of 16/16:1 were distinct for each citrus species. The C22-C29 fatty acids were prevalent in citrus sterol esters ranging from 6·5% for some orange and grapefruit varieties to over 41% for two lime varieties. In all varieties C24 was the most prominent of these longer chain fatty acids. Argentation TLC indicated that these longer chain fatty acids primarily were esterified to dimethyl sterols. ft*|One of the laboratories of the Southern Region, Agricultural Research Service, U.S. Department of Agriculture.  相似文献   

8.
Qualitative and quantitative compositions of esterified fatty acids (FAs) in the total lipids from the leaves, shoots, and roots of halophile plants, such as suaeda (Suaeda altissima), samphire (Salicornia europaea), and wormwood (Artemisia lerchiana), collected in their natural environments were estimated by GLC techniques. It was shown that the vegetative organs of these halophytes contained 24 FA species, and 16 of them were tentatively identified as the very-long-chain FAs (VLCFAs). There were four VLCFA groups, viz. C20, C21, C22, and C23, each including saturated, mono-, and diunsaturated components; C24 and C25 FAs were also present. The concentration of VLCFAs in the total FAs comprised 4–64%. In vegetative organs of higher plants not subjected to genetic transformation, such a high VLCFA content was found for the first time. Saturated and even-numbered components predominated among the VLCFAs, and the roots exceeded severalfold the above-ground organs in the total VLCFA content. Possible pathways of VLCFA biosynthesis in plants, VLCFA content in the vegetative tissues, and the physiological role of membrane lipid FA composition in the plant salt metabolism are discussed.  相似文献   

9.
Fatty acids (FA) of nine fungal species belonging to the subphylumBasidiomycotina were identified by using capillary GC-MS, MS and HPLC. The identified fatty acids included 45 saturated (iso-, anteiso-, and 19 hydroxy acids) and 42 monoenoic acids (including 14 hydroxy acids); dienes and polyenes were represented by 13 fatty acids. The proportion of hydroxy acids in the total fatty acids in the fungal species ranged from 4.3 to 10.2%. Very long-chain fatty acids (C24-C30) were also determined. Four fatty acids 16:0 (8.8–14.3%), 18:1(11) (3.9–14.9%), 18:1(9) (7.7–19.0%) and 18:2(6) (7.6–19.4%), were found as major acids. Of the identified acids, 17 were detected inBasidiomycotina for the first time.  相似文献   

10.
The synthesis of fatty acids and lipids in Nannochloropsis sp. was investigated by labeling cells in vivo with [14C]-bicarbonate or [14C]-acetate. [14C]-bicarbonate was incorporated to the greatest extent into 16:0, 16:1, and 14:0 fatty acids, which are the predominant fatty acids of triacylglycerols. However, more than half of the [14C]-acetate was incorporated into longer and more desaturated fatty acids, which are constituents of membrane lipids. [14C]-acetate was incorporated most strongly into phosphatidylcholine, which rapidly lost label during a 5-h chase period. The label associated with phosphatidylethanolamine also decreased during the chase period, whereas label in other membrane lipids and triacylglycerol increased. The dynamics of labeling, along with information regarding the acyl compositions of various lipids, suggests that 1) the primary products of chloroplast fatty acid synthesis are 14:0, 16:0, and 16:1; 2) C20 fatty acids are formed by an elongation reaction that can utilize externally supplied acetate; 3) phosphatidylcholine is a site for desaturation of C18 fatty acids; and 4) phosphatidylethanolamine may be a site for desaturation of C20 fatty acids.  相似文献   

11.
The lipids of seeds, leaves, and roots of parsley,Petroselinum crispum, and of heterotrophic as well as photomixotrophic cell cultures of this plant were characterized with the aim of finding a system for studying the biosynthesis of unusual fatty acids. It was found that (Z)-6-octadecenoic acid, petroselinic acid, which is the typical constituent fatty acid of triacylglycerols in seeds, occurs only in small proportions, if at all, in leaves, roots, and cell cultures of parsley. In all lipid classes studied petroselinic acid is accompanied by its (Z)-9- and (Z)-11-isomers, oleic and vaccenic acid, respectively. The phosphatidylcholines, phosphatidylethanolamines, and triacylglycerols of both heterotrophic and photomixotrophic callus cultures contain no petroselinic acid but rather oleic and vaccenic acids in equal ratios. Thus, cell cultures of parsley appear to be suitable for studying the biosynthesis of vaccenic acid. The constituent octadecadienoic acids in the lipids of various tissues and cell cultures of parsley consist almost exclusively of the (Z),(Z)-9,12-isomer, linoleic acid, which is derived from oleic acid. (Z),(Z)-6,9- and (Z),(Z)-11,14-Octadecadienoic acids, which could be expected as products of desaturation of petroselinic and vaccenic acids, were not found in any of the lipids of organs and cell cultures investigated.Abbreviations TLC thin-layer chromatography - GLC gas-liquid chromatography  相似文献   

12.
There are three mycolic acid homologues with C22-, C24- and C26-α-units in Mycobacterium. In order to reveal the composition and distribution of these homologues in each subclass and molecular species of mycolic acids and to compare them with the composition of constitutive non-polar fatty acids (free and bound forms), we have separated non-polar fatty acids and each subclass of mycolic acids from 21 mycobacterial species by thin-layer chromatography, and analyzed non-polar fatty acid methyl esters by gas chromatography (GC) and the cleavage products of methyl mycolate by pyrolysis GC. We further performed mass chromatographic analysis of trimethylsilyl (TMS) ether derivatives of mycolic acid methyl esters by monitoring [B-29]+ ions (loss of CHO from the α-branched-chain structure of mycolic acids) of m/z 426, 454 and 482 which are attributed to C22-, C24- and C26-α-units of TMS ether derivatives of methyl mycolates, respectively, (Kaneda, K. et al, J. Clin. Microbiol. 24: 1060-1070, 1986). By pyrolysis GC, C22:0, C24:0 and C26:0 fatty acid methyl esters generated by the C2-C3 cleavage of C22-, C24- and C26-α-unit-containing mycolic acid methyl esters, respectively, were detected. Their proportion was almost the same among subclasses of mycolic acids in every Mycobacterium and also similar to the proportion of constitutive non-polar C22:0, C24:0 and C26:0 fatty acids. By mass chromatography, the composition and distribution of C22- and C24-α-unit-containing homologues were revealed to be similar between α- and α'-mycolic acids in every Mycobacterium. We further analyzed in detail M. vaccae and demonstrated that the mass chromatogram of C22-α-unit-containing homologue was analogous in shape to that of the C24-α-unit-containing one, with the latter mass chromatogram being up-shifted from the former by two carbon numbers, in every subclass of α-, α'-, keto and dicarboxy mycolic acids. The present study suggests that the compositions of three homologues of both mycolic acids and constitutive non-polar fatty acids, which are characteristic to each mycobacterial species, may reflect the proportion of the amount of free C22:0, C24:0 and C26:0 fatty acids synthesized in the cell. It is further demonstrated that intermolecular condensation of two fatty acids which become α- and β-units of mycolic acids will occur independently of the carbon chain length or kinds of polar moieties of fatty acids.  相似文献   

13.
During their rapid maturation period, seeds of Cuphea wrightii A. Gray mainly accumulate medium-chain fatty acids (C8 to C14) in their storage lipids. The rate of lipid deposition (40–50 mg·d–1·(g fresh weight)–1) is fourfold higher than in seeds of Cuphea racemosa (L. f.) Spreng, which accumulate long-chain fatty acids (C16 to C18). Measurements of the key enzymes of fatty-acid synthesis in cell-free extracts of seeds of different maturities from Cuphea wrightii show that malonyl-CoA synthesis may be a triggering factor for the observed high capacity for fatty-acid synthesis. Experiments on the incorporation of [1-14C]acetate into fatty acids by purified plastid preparations from embryos of Cuphea wrightii have demonstrated that the biosynthesis of medium-chain fatty acids (C8 to C14) is localized in the plastid. Thus, in the presence of cofactors for lipid synthesis (ATP, NADPH, NADH, acyl carrier protein, and sn-glycerol-3-phosphate), purified plastid fractions predominantly synthesized free fatty acids, 30% of which were of medium chain length. Transesterification of the freshly synthesized fatty acids to coenzyme A and recombination with the microsomal fraction of the embryo homogenate induced triacylglycerol synthesis. It also stimulated fatty-acid synthesis by a factor 2–3 and increased the relative amount of medium-chain fatty acids bound to triacylglycerols, which corresponded to about 60–80% in this lipid fraction.Abbreviations ACP acyl carrier protein - FW fresh weight This work was supported by the Bundesminister für Forschung und Technologie. The authors thank S. Borchert for her suggestions for plastid preparation.  相似文献   

14.
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 C16 : 3and -C18 : 3fatty 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.  相似文献   

15.
Lipid classes and fatty acid distribution were analysed in the resting sporangium of Synchytrium endobioticum, the causal agent of the potato wart disease. The sporangium contents were shown to have lipid droplets, the major fatty acids there being C16.0, C18.1, and C19.0. The sporangium wall on the other hand was composed of C18.0, C18.1, C18.2, C20.0, and C20.4 fatty acids. A significantly large portion of the sporangium wall lipids contained wax esters with branched chains.  相似文献   

16.
The lipid and fatty acid compositions in two edible subtropical algae (the brown alga Cladosiphon okamuranus Tokida and the green alga Caulerpa lentillifera J. Agardh) were determined to clarify their lipid characteristics and nutritional values. Glycolipids and phospholipids were the major lipid classes, with significant levels of triacylglycerols. Polyunsaturated fatty acids (PUFA) were the major fatty acids of both algae. The lipid class composition and major fatty acids were similar in both the algal species, irrespective of wild and cultured specimens. Typical n‐6 PUFA, such as 18:2n‐6 (linoleic acid) and 20:4n‐6 (arachidonic acid), occurred in characteristically high levels in both of the algae. High levels of n‐3 PUFA were measured in all lipid classes of both species without 22:6n‐3 (docosahexaenoic acid), 18:3n‐3, 18:4n‐3, and 20:5n‐3 (eicosapentaenoic acid) for Cl. okamuranus; and 16:3n‐3, 18:3n‐3, and 20:5n‐3 for Ca. lentillifera. The finding suggests that the green algal species, which mainly biosynthesizes short‐chain (C16 and C18) PUFA, differs from that of the brown alga, which is capable of biosynthesizing high 20:5n‐3 levels. The PUFA levels in glycolipids of the two algal species comprised up to 60%, even though they are subtropical marine species. High n‐6 PUFA levels in the algal lipids probably influence the significant levels of n‐6 PUFA in herbivorous fishes, because the n‐6 PUFA levels in marine fish lipids are generally undetectable or negligible.  相似文献   

17.
We describe a simple tandem mass spectrometric approach toward structural characterization of mycolic acids, the long-chain α-alkyl-β-hydroxy fatty acids unique to mycobacteria and related taxa. On collisionally activated dissociation in a linear ion trap or tandem quadrupole mass spectrometer, the [M−H] ions of mycolic acid generated by electrospray ionization undergo dissociation to eliminate the meroaldehyde residue, leading to formation of carboxylate anions containing α-alkyl chains. The structural information from these fragment ions affords structural assignment of the mycolic acids, including the lengths of the meromycolate chain and the α-branch. This study revealed that the mycolic acids isolated from pathogenic Rhodococcus equi 103 contained a series of homologous ions having C30 to C50 chain with 0–2 double bonds. The α-branch ranged from C10 to C18 with 0 to 1 double bond, in which 16:0 and 14:0 are the most prominent, whereas the meromycolate chain ranged from C14 to C34 with 0 to 2 double bonds. The major molecular species consisted of more than 3 isomers that differ by the lengths of the α-branch or meromycolate chain, and up to 10 isobaric isomers were identified for some minor ions. We also employed tandem quadrupole mass spectrometry with precursor ion and neutral loss scans for profiling mycolic acid with specific structure in mixtures. The tandem spectra obtained from precursor ion scans of m/z 255 (16:0-carboxylate anion) and m/z 227 (14:0-carboxylate anion) may provide a simple specific means for classification of Rhodococci species, whereas tandem spectra from neutral loss of meroaldehyde residue scans provided a simple approach to reveal the mycolic acid molecules with specific meromycolate chain in mixtures.  相似文献   

18.
Konova  I. V.  Galanina  L. A.  Kochkina  G. A.  Pan'kina  O. I. 《Microbiology》2002,71(5):550-557
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 -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, 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.  相似文献   

19.
The antibiotic resistance and lipid composition of rhodococci grown in rich organic media with gaseous or liquidn-alkanes were studied. Hydrocarbon-grown rhodococci exhibited an increased resistance to a wide range of antibiotics (aminoglycosides, linkosamides, macrolides, β-lactams, and aromatic compounds). The enhanced antibiotic resistance of rhodococci grown onn-alkanes correlated with an increased content of total cell lipids (up to 14–28%) and saturated straight-chain fatty acids (C16:0, C18:0, C21:0) and was accompanied by the appearance of cardiolipin and phosphatidylglycerol in cells. These lipid compounds are supposed to promote the formation of nonspecific antibiotic resistance in rhodococci by decreasing the permeability of their cell envelope to antibiotics.  相似文献   

20.
Summary The hydrocarbon composition ofPseudomonas maltophilia was determined by gas chromatography-mass spectrometry. Mono-, di- and tri-unsaturated alkenes were identified with a predominance of polyunsaturated components. The carbon chains of the alkenes contained single methyl branches iniso andanteiso position and double methyl branches in theiso-iso andanteiso-anteiso configurations. The composition of the hydrocarbons from cells grown in synthetic media enriched with amino acids or volatile fatty acids demonstrated that the probable precursors incorporated into individual hydrocarbons were branched and normal fatty acid chains in the range from C3 to C16. The probable fatty acid precursors which were connected together to form the major triunsaturated hydrocarbon chains were two monounsaturated chains, whereas the major liunsaturated chains resulted from condensation of saturated and monounsaturated chains. The probable precursors for the major monounsaturated hydrocarbons were C14 (C15) and C16 (C15) fatty acids. The accumulation of hydrocarbons was not detected until the cells were in the late exponential phase of growth; the maximal levels were reached at the mid-stationary phase of growth.  相似文献   

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