Coenzyme Q systems in ascomycetous black yeasts

72 Strains belonging to 44 species of ascomycetous black yeasts were analyzed for their coenzyme Q systems. Prevalent were Q-10 and dihydrogenated Q-10 systems. Members of the Dothidealean suborder Dothideineae have Q-10 (H₂), while those belonging to the suborder Pseudosphaeriineae mostly have Q-10. The anamorph genus Exophiala Carmichael and the teleomorph genus Capronia Sacc. seem to be heterogenous.     

古尼虫草无性型的分子鉴别

采用PCR技术,以rDNA的ITS区为分子指标,对古尼虫草Cordycepsgunnii的有性和无性阶段进行比较分析,从分子水平上证明古尼虫草的无性阶段是古尼拟青霉Paecilomycesgunnii。     

Hypocrea voglmayrii sp. nov. from the Austrian Alps represents a new phylogenetic clade in Hypocrea/Trichoderma

The holomorph of the new species Hypocrea voglmayrii (Hypocreales, Ascomycota, Fungi) is described by a combined approach, using morphology of the teleomorph, morphology of the anamorph, culture studies and phylogenetic analyses of ITS1 and 2, ech42 and rpb2 gene sequences. Its anamorph Trichoderma voglmayrii is described as a new anamorph species. Unlike most other species of Hypocrea the teleomorph of H. voglmayrii occurs on dry standing trunks and exhibits well defined black ostioles. Although exclusively collected at higher altitudes, this species grows at 35 C in culture. Hypocrea voglmayrii develops pale yellowish to greenish conidia, a yellowish pigment and a coconut-like odor on CMD. Phylogenetically, H. voglmayrii forms a distinct, isolated branch between the section Trichoderma and the H. pachybasioides clade but does not associate with any of these clades in different gene trees.     

Fatty acid composition and antioxidant activity of Antarctic marine sponges of the genus <Emphasis Type="Italic">Latrunculia</Emphasis>

The fatty acid composition of marine cold-water sponges of genus Latrunculia, namely Latrunculia bocagei Ridley and Dendy, 1886, and Latrunculia biformis Kirkpatrick, 1907, for which no fatty acid data had been previously reported, has been examined. High levels of long-chain fatty acids (C_24–30) with high unsaturation levels (mainly polyunsaturation), and high incidence of branched- and odd-chain fatty acids in sponges are suggested to be partially connected with their specific cell membrane requirements to surmount the negative effects of low temperatures and to enable growth in extreme environments. Furthermore, variations in the fatty acid profile at the species level may reflect variations in compositions or quantities of symbiotic microorganisms that commonly represent up to 60 % of the sponge wet weight. The fatty acid compositions of lipid-rich sponge extracts from five Latrunculia specimens dredged from the Bransfield Strait near the Antarctic Peninsula, were obtained using supercritical carbon dioxide and analyzed using gas chromatography–mass spectrometry–flame ionization detection. Furthermore, the antioxidant activities of these extracts were determined using the photochemiluminescent method. Along with common fatty acids, the chemical analyses revealed very long-chain fatty acids (C22, C24). Differences were seen for the fatty acid levels between both species and different specimens of the same species. The observed differences do not seem connected to the habitat depth of the specimen, but rather indicate the variations within the associated microbiome. Furthermore, these sponge extracts showed antioxidant activities, confirming that they contain lipidic compounds that strongly scavenge free radicals.     

The teleomorph state of Candida deformans Langeron & Guerra and description of Yarrowia yakushimensis comb. nov.

Yarrowia lipolytica is the only known species in the teleomorph (i.e. sexual) genus Yarrowia and has its anamorph (i.e. asexual state) classified in the genus Candida Berkhout as Candida lipolytica. This species can be found readily in nature, has significant industrial value and is important to the food and medical fields. Candida deformans was first considered a variety of C. lipolytica and was later listed as a synonym of this species. More recent studies based on sequence variation in the nuclear rRNA gene sequences suggested C. deformans to be a separate species with no known teleomorph linked to it. In this study we show that C. deformans strains, obtained from South Africa, can mate with strains present in the CBS yeast collection and produce a Yarrowia teleomorph, described here as Yarrowia deformans. Strains of Candida yakushimensis nom. inval., a species also belonging to the Yarrowia phylogenetic clade, were also studied and described as a novel species of Yarrowia.     

深红酵母相关菌株全细胞长链脂肪酸的分析及其数值分类

从黄海和渤海海水中分离到15株红酵母,初步定名为深红酵母(Rhodotorula rubraLodder)对这些菌株及另外8株红酵母属对照种的形态、生理生化性状以及全细胞长链脂肪酸的组成进行了测定,并用多元统计方法对菌株间的相似性进行了计算,对菌株分群。结果表明,15株酵母之间性状存在许多差异,这些差异不能完全被鉴定性状所反映,在多元分析中15株菌不能形成紧密的聚类群。研究结果对利用个别形态和生理生化性状确定的深红酵母种的范围提出了异议。     

Lipid content and fatty acid composition of seeds of Capsella species from different geographical locations

Seeds of natural populations of Capsella bursa-pastoris, collected from temperate regions, weighed less and had a higher lipid content than those from colder regions. The long-chain (16:0, 18:0, 18:1, 18:2 and 18:3) and very long-chain (20:0, 20:1, 20:2 and 20:3) fatty acid compositions were, however, quite similar in the lipids of all the seed samples which indicates a rigid genetic, rather than environmental, control of fatty acid biosynthesis. Characteristics of the seeds of the diploid species C. rubella and C. grandiflora were similar to those of the tetraploid C. bursa-pastoris, with the exception of the distinctly lower lipid content in C. grandiflora seeds.     

Comparison of long term lipogenic effects of two different medium-chain triglycerides (tri C8: O and tri C12 : O) in the growing rat.

During the growth (35 g-340 g), and as compared to results obtained with a lipid-free diet or a diet containing long-chain fatty acids, high levels of Tri C8 : O or Tri C12 : O did not change the quantitative aspects of proteinogenesis and lipogenesis balances. The incorporation of Tri C8 : O into the diet did not change the fatty acid composition of body lipid stores while the incorporation of Tri C12 : O induced a lipogenesis characterized by the disappearance of about 50% of the n-9 and n-7 unsaturated fatty acids, the emergence of an equivalent amount of saturated fatty acids in C12 and C14, and the decrease of hexadecanoic or palmitic acid concentration. Titers of saturated fatty acids with a melting point higher than 40 degrees C increased from 34% to 64%. Results suggested an efficient inhibition of fatty acid biosynthesis de novo by C12 : O, associated with an impossibility for microsomal enzymes to assume the elongation of a sufficient amount of C12 : O to maintain C16 : O concentration and to furnish an important amount of substrate (C18 : O) to delta-9-stearoyl coenzyme A desaturase for oleic acid synthesis. Introducing dodecanoic acid into the diet of growing animals appears to be the most efficient method for increasing the degree of saturation of body lipids without changing the concentrations of long-chain saturated fatty acids.     

Brain Gangliosides of Quaking and Shiverer Mutants: Qualitative and Quantitative Changes of Monosialogangliosides in the Quaking Brain

Ganglioside compositions in the brains of the mutant mice quaking and shiverer were compared with those of their littermate controls, C57BL/6 and C3HSWV. Neither ganglioside content nor composition of shiverer brains differed from those of the control brains. Change in the ganglioside composition of the mutant brain from that of the control was observed only in the quaking mutant brain, in which monosialoganglioside GM1 was significantly reduced and GM4 was completely absent. The structures of the gangliosides were determined by negative ion fast atom bombardment mass spectrometry, and the GM3 and GM4 gangliosides in the quaking brain were found to be altered in regard to their long-chain base and fatty acid compositions when compared to the normal C57BL/6 brain.     

Activation of branched and other long-chain fatty acids by rat liver microsomes

Acyl coenzyme A synthetase (EC 6.2.1.3) of rat liver microsomes activates iso- and anteiso-branched long-chain fatty acids containing 12 to 20 carbon atoms. Fatty acid chain length appears to be the major determinant of the maximum rate of acyl CoA biosynthesis of branched, or saturated, or cis monounsaturated long-chain fatty acids. Based on activation studies conducted at 22-45 degrees C, it is concluded that the rate of activation is a function of long-chain fatty acid solubility. The shape of the in vitro activation curve with respect to fatty acid concentration appears to be determined by fatty acid melting point as well as by the presence and position of double bonds. Differently shaped activation curves were observed for cis or trans Delta(6) to Delta(12) central positional isomers of octadecenoic acid and for Delta(3), Delta(4), Delta(13) to Delta(15) terminal isomers of octadecenoic acid. The relationships between fatty acid structure, melting point, solubility, and shape of the activation curve observed during in vitro measurement of acyl CoA formation are discussed.     

Orbilia blumenaviensis and its Arthrobotrys anamorph

A member of the nematophagous anamorph genus Arthrobotrys was isolated from its teleomorph Orbilia blumenaviensis comb. nov. (= Orbilia fici), a species closely related to O. auricolor but deviating in having lanceolate paraphyses. In the presence of nematodes, the anamorph forms three-dimensional adhesive networks. A trimorphism in its conidia was observed which vary in shape and number of septa. In the first isolate, two types of heteropolar conidia were obtained. These differ markedly from the type strain of A. vermicola, which forms mainly homopolar (fusoid) conidia. In a further ascospore isolate of O. blumenaviensis, however, mainly fusoid conidia referable to A. vermicola occurred. Combining morphological and phylogenetic analysis, we conclude that these isolates with differently shaped conidia and/or differences in the ITS rDNA (ca. 2–4%) belong to a single anamorph species, A. vermicola. Both teleomorph and anamorph are illustrated and described.     

Inhibition of fatty acid synthesis in Escherichia coli in the absence of phospholipid synthesis and release of inhibition by thioesterase action.

The effects of inhibition of Escherichia coli phospholipid synthesis on the accumulation of intermediates of the fatty acid synthetic pathway have been previously investigated with conflicting results. We report construction of an E. coli strain that allows valid [14C]acetate labeling of fatty acids under these conditions. In this strain, acetate is a specific precursor of fatty acid synthesis and the intracellular acetate pools are not altered by blockage of phospholipid synthesis. By use of this strain, we show that significant pools of fatty acid synthetic intermediates and free fatty acids accumulate during inhibition of phospholipid synthesis and that the rate of synthesis of these intermediates is 10 to 20% of the rate at which fatty acids are synthesized during normal growth. Free fatty acids of abnormal chain length (e.g., cis-13-eicosenoic acid) were found to accumulate in glycerol-starved cultures. Analysis of extracts of [35S]methionine-labeled cells showed that glycerol starvation resulted in the accumulation of several long-chain acyl-acyl carrier protein (ACP) species, with the major species being ACP acylated with cis-13-eicosenoic acid. Upon the restoration of phospholipid biosynthesis, the abnormally long-chain acyl-ACPs decreased, consistent with transfer of the acyl groups to phospholipid. The introduction of multicopy plasmids that greatly overproduced either E. coli thioesterase I or E. coli thioesterase II fully relieved the inhibition of fatty acid synthesis seen upon glycerol starvation, whereas overexpression of ACP had no effect. Thioesterase I overproduction also resulted in disappearance of the long-chain acyl-ACP species. The release of inhibition by thiosterase overproduction, together with the correlation between the inhibition of fatty acid synthesis and the presence of abnormally long-chain acyl-ACPs, suggests with that these acyl-ACP species may act as feedback inhibitors of a key fatty acid synthetic enzyme(s).     

Heat stress deteriorates mitochondrial β-oxidation of long-chain fatty acids in cultured fibroblasts with fatty acid β-oxidation disorders

Mitochondrial fatty acids β-oxidation disorder (FAOD) has become popular with development of tandem mass spectrometry (MS/MS) and enzymatic evaluation techniques. FAOD occasionally causes acute encephalopathy or even sudden death in children. On the other hand, hyperpyrexia may also trigger severe seizures or encephalopathy, which might be caused by the defects of fatty acid β-oxidation (FAO). We investigated the effect of heat stress on FAO to determine the relationship between serious febrile episodes and defect in β-oxidation of fatty acid in children. Fibroblasts from healthy control and children with various FAODs, were cultured in the medium loaded with unlabelled palmitic acid for 96 h at 37 °C or 41 °C. Acylcarnitine (AC) profiles in the medium were determined by MS/MS, and specific ratios of ACs were calculated. Under heat stress (at 41 °C), long-chain ACs (C12, C14, or C16) were increased, while medium-chain ACs (C6, C8, or C10) were decreased in cells with carnitine palmitoyl transferase II deficiency, very-long-chain acyl-CoA dehydrogenase deficiency and mitochondrial trifunctional protein deficiency, whereas AC species from short-chain (C4) to long-chain (C16) were barely affected in medium-chain acyl-CoA dehydrogenase and control. While long-chain ACs (C12–C16) were significantly elevated, short to medium-chain ACs (C4–C10) were reduced in multiple acyl-CoA dehydrogenase deficiency. These data suggest that patients with long-chain FAODs may be more susceptible to heat stress compared to medium-chain FAOD or healthy control and that serious febrile episodes may deteriorate long-chain FAO in patients with long-chain FAODs.     

Structure and composition of sulfatides isolated from livers of patients with metachromatic leukodystrophy: galactosyl sulfatide and lactosyl sulfatide

The livers of four patients with metachromatic leukodystrophy contained galactosyl sulfatide and lactosyl sulfatide, whereas these substances were undetectable in normal human liver. On the basis of methanolysis and permethylation studies, both sulfatides were shown to be substituted with sulfate at the C-3 position of the galactose moiety. Examination of the fatty acid compositions of these sulfatides showed that C(22:0) and higher 2-hydroxy and nonhydroxy fatty acids predominated in both. Both sulfatides contained the same long-chain bases, predominantly sphingosine, dihydrosphingosine, and phytosphingosine. Using as criteria the proportion of lactosyl sulfatide to galactosyl sulfatide, and the fatty acid and long-chain base compositions, the liver sulfatides from subjects with metachromatic leukodystrophy closely resemble those in the kidney and differ from those in brain and peripheral nerve.     

Cationic amphiphilic drugs inhibit the synthesis of long-chain fatty acyl coenzyme A in rat brain microsomes

The effect of cationic amphiphilic drugs (CAD) on the synthesis of thiol esters of coenzyme A with long-chain fatty acids was studied in microsomes of rat brain in vitro. The results indicate that propranolol, tetracaine and to a lesser extent, chloroquine, inhibit enzyme activity. Procaine and lidocaine did not inhibit enzyme activity in concentrations up to 0.8 mM. This inhibition seems to be directed primarily to the synthesis of polyunsaturated fatty acyl coenzyme A. The results also suggest that this inhibition may be due to the action of CAD on the microsomal membrane and not to an interaction of these drugs with the fatty acid substrates.     

Beta-oxidation of very-long-chain fatty acids and their coenzyme A derivatives by human skin fibroblasts

The beta-oxidation of lignoceric acid (C24:0), hexacosanoic acid (C26:0), and their coenzyme A derivatives was investigated in human skin fibroblast homogenates. The cofactor requirements for oxidation of lignoceric acid and hexacosanoic acid were identical but were different from their coenzyme A derivatives. For example, lignoceric acid and hexacosanoic acid oxidation was strictly ATP dependent whereas the oxidation of the corresponding coenzyme A derivatives was ATP independent. Also the rate of oxidation of coenzyme A derivatives of lignoceric acid or hexacosanoic acid was much higher compared to the free fatty acids. In patients with Zellweger's syndrome, X-linked adrenoleukodystrophy and infantile Refsum's disease, the beta-oxidation of lignoceric and hexacosanoic acids was defective whereas the oxidation of their corresponding coenzyme A derivatives was nearly normal. The results presented in this communication suggest strongly that the beta-oxidation of very-long-chain fatty acids occurs exclusively in peroxisomes. However, the coenzyme A derivatives of very-long-chain fatty acids can be oxidized in mitochondria as well as in peroxisomes. The inability of the mitochondrial system to oxidize free fatty acids may be due to its inability to convert them to their corresponding coenzyme A derivatives. Our results suggest that a specific very-long-chain fatty acyl CoA synthetase may be required for the activation of the free fatty acids and that this synthetase may be deficient in patients with Zellweger's syndrome and possibly X-linked adrenoleukodystrophy, as well. The results presented suggest that substrate specificity and the subcellular localization of the synthetase may regulate the beta-oxidation of very-long-chain fatty acids in the cell.     

Ceratorhiza oryzae-sativae,a new combination for the anamorph of Cerabasidium setariae

Rhizoctonia oryzae-sativae, the anamorph of Ceratobasidium setariae, is transferred to Ceratorhiza. A discussion of teleomorph and anamorph taxonomy and nomenclature is also given and it is concluded that, for the present, there is only one holomorph species.     

Use of holomorph characters to delimit Microascus nidicola and M. soppii sp. nov., with notes on the genus Pithoascus

Several isolates of a perithecial microascaceous ascomycete having falcate ascospores and a Scopulariopsis anamorph were obtained from rotting wood in the boreal forest of Alberta, Canada. Additional isolates appeared conspecific based on anamorphic characters, but failed to produce a teleomorph. These isolates showed similarities to Microascus nidicola (type species of the genus Pithoascus) and Scopulariopsis flava. Sexual compatibility systems were investigated to establish holomorph concepts for these taxa. The teleomorph obtained in mating trials among anamorphic isolates was identical to that of self-fertile isolates. The new heterothallic species M. soppii is described. The anamorph is S. soppii. Single ascospore isolates derived from M. nidicola demonstrated homothallism and lacked an anamorph. Scopulariopsis flava (basionym Acaulium flavum) is considered a nomen dubium. Generic concepts of Pithoascus are evaluated and the genus is treated as a synonym of Microascus. Pithoascus stoveri is transferred as M. stoveri comb. nov.     

The influence of endogenous acyl-acyl carrier protein concentrations on fatty acid compositions of chloroplast glycerolipids.

The concentrations of long-chain acyl-acyl carrier proteins (acyl-ACP) occurring during fatty acid synthesis from [1-14C]acetate within chloroplasts isolated from spinach, pea, and amaranthus leaves were manipulated by making minor changes to a basal incubation medium containing sn-glycerol 3-phosphate (G3P). Pools of oleoyl-, stearoyl-, and palmitoyl-ACP were compared with those of the corresponding 1-acyl glycerol 3-phosphates to determine how endogenous acyl-ACP concentrations affected the fatty acid compositions of chloroplast glycerolipids. The 1-acyl G3P synthesized by isolated chloroplasts contained more palmitate than would be expected for the precursor of thylakoid phosphatidylglycerol in the different plant species. However, treatments which increased ratios of oleoyl- to palmitoyl-ACP by about 50% increased synthesis of sn-1-oleoyl G3P to the extent anticipated from known fatty acid compositions of the different phosphatidylglycerols. Since stearate constituted 70-73% of the acyl-ACP and 48-51% of the 1-acyl-G3P pool of spinach and pea chloroplasts incubated in the presence of cyanide, it is transferred to G3P much more efficiently in situ than would be predicted from competition studies using mixtures of acyl donors and purified acyltransferases. Increasing concentrations of G3P in incubation media from 0.1 to 2 mM had relatively little effect on the amounts and proportions of acyl-ACPs but forced the synthesis of palmitoyl-G3P and, ultimately, disaturated glycerolipid. It is concluded that the chloroplast G3P acyltransferases are primarily responsible for determining the fatty acid compositions of procaryotic glycerolipids in plants, but that acyl-ACP concentrations may play a more important role than would be anticipated from the kinetics of the purified enzyme. However, those kinetics may be quite complex; allosteric effectors may influence the affinities of the enzyme for oleoyl-ACP and for G3P.     

Hypocrea atroviridis sp. nov., the teleomorph of Trichoderma atroviride

A new species, Hypocrea atroviridis, is described for the teleomorph of Trichoderma atroviride. Based on sequences of ITS-1, 5.8S, and ITS-2 regions of the rDNA complex and translation-elongation factor (EF-1α), T. atroviride and H. atroviridis form a well-supported clade within Trichoderma sect. Trichoderma. The conserved anamorphic phenotype of T. atroviride, observed for both conidial and ascospore derived cultures, was only found within that clade. In contrast, the teleomorph phenotype of H. atroviridis was morphologically indistinguishable from H. rufa, the teleomorph of T. viride. This Hypocrea phenotype may, therefore, be considered to be plesiomorphic within Trichoderma sect. Trichoderma, suggesting that genes controlling the expression of the teleomorph and anamorph evolve at different rates and that the genes controlling expression of the teleomorph are more conserved than are those controlling the expression of the anamorph.