不同生态条件对绿色巴夫藻生长与脂肪酸组成的影响

研究不同温度、盐度、光照条件对绿色巴夫藻生长和脂肪酸组成的影响。实验结果表明:绿色巴夫藻的适温范围在5—30℃之间,最适为25℃;该藻为低盐度种类,在试验范围内都能生长,其最适盐度为6‰;生长较适宜的光照强度为3000—5000lx。巴夫藻的主要脂肪酸为C14∶0、C16∶0、C16∶1(n-7)、C18∶1(n-9)、C18∶3(n-3)、C18∶4(n-3)、C22∶6(n-3),其中在20℃时C22∶6(n-3)的含量达到最高,且PUFA(n-3)的含量也较高;在低盐度条件下有利于PUFA(n-3)的合成,盐度为6‰时C20∶5(n-3)的含量最高为总脂的6.02%,在盐度为15‰时C22∶6(n-3)的含量达到最高(总脂的17.79%);光照强度对C22∶6(n-3)的影响不大,在3000lx时C20∶5(n-3)的含量较高。结果表明低光照强度下利于PUFA(n-3)的合成,且C22∶6(n-3)的含量较高。     

盐度对哈氏仿对虾肌肉一般营养成分和氨基酸组成及含量的影响

通过调查不同盐度(12～36)环境下养殖的哈氏仿对虾(Parapenaeopsis hardwickii)肌肉一般营养成分和氨基酸组成及含量,研究了盐度对该虾肌肉营养品质的影响。结果显示,肌肉的水分随环境盐度升高出现显著的直线下降,而粗蛋白含量随环境盐度升高而直线升高;各盐度组的粗脂肪含量虽然没有明显差异,但其含量随盐度升高有一定的线性下降趋势;36盐度组的粗灰分含量比12、16、20和28盐度组的明显高,32盐度组的灰分含量比20和24盐度组的也明显高;所检测的肌肉干样16种氨基酸中,只有3种氨基酸的含量随盐度升高而升高,而其他13种氨基酸的含量随盐度升高明显降低,其中有10种氨基酸的含量在盐度12～24条件下的比盐度28～36条件下的明显高,而这些氨基酸含量在盐度12～24之间没有明显差异。各盐度组间氨基酸总量和鲜味氨基酸含量均没有明显差异;必需氨基酸和半必需氨基酸含量在盐度12～24条件下的均比盐度28～36条件下的明显高,而在12～24盐度组之间以及28～36盐度组之间均没有明显差异。必需氨基酸/氨基酸总量的比值和必需氨基酸/非必需氨基酸比值随盐度升高均明显线性降低;盐度12～24组的必需氨基酸指数(66.13～67.42)高于盐度28～36组的(62.56～64.46)。综上所述,盐度12～24环境下养殖的哈氏仿对虾肌肉营养价值相对较高,表现为低盐趋向,考虑到肌肉的水分含量和生长性能,哈氏仿对虾在养殖期间选择16～24盐度范围比较合适,同时也说明哈氏仿对虾适合大多数沿海地区环境的盐度条件。     

Lipid and Fatty Acid Composition of Brain Tissue from Adrenoleukodystrophy Patients

Abstract: White matter and active plaque tissue from adrenoleukodystrophy (ALD) patients were analysed for lipid class and fatty acid compositions and the results compared with white matter from normal brain. ALD white matter was characterized by increased levels of cholesteryl esters and decreased levels of phosphatidylethanola- mine, including phosphatidylethanolamine plasmalogen, in comparison with normal brain white matter. In addition to even higher levels of cholesteryl esters, ALD plaque tissue had reduced levels of cerebrosides as well as phosphati-dylethanolamines. The loss of phosphatidylethanolamine plasmalogen is indicative of early demyelination. Total lipid from ALD white matter and ALD plaque tissue contained nearly five times and seven times, respectively, more 26:0 than total lipid from normal brain white matter. The 26:0 in ALD white matter was elevated in all lipid classes except phosphatidylinositol, but was located mainly in cerebrosides, phosphatidylcholine, sphingomyelin, and sulfatides. Most of the 26:0 in ALD plaque tissue was present in cholesteryl esters, followed by phosphatidylcholine and sphingomyelin, with reduced amounts in cerebrosides as compared with ALD white matter. The results are consistent with an initial accumulation of very-long-chain fatty acids in ALD white matter, primarily in sphingolipids and phosphatidylcholine, and subsequent accumulation of very-long- chain fatty acids in cholesteryl esters during demyelination. In addition, it was notable that the sphingolipids, especially sphingomyelin in ALD brain, had decreased levels of 24:1 and increased levels of 18:0, as well as increased levels of very-long-chain fatty acids. The extent to which the data shed light on mechanisms of demyelination in ALD is discussed.     

Effect of growth phase on the fatty acid composition of Thermus spp.

Two yellow and two red pigmented strains of Thermus were monitored for changes in fatty acid content and composition with reference to growth phase at the optimum temperature. Fatty acid content per mg of dry weight increased as the cultures aged. In addition the quantities of iso C 15:0, iso C 17:0 and iso C 16:0 increased in yellow pigmented strains, but in red pigmented strains, an increase was seen in iso C 15:0, but C 16:0 and iso C 16:0 levels decreased. Thus the fatty acid composition of these organisms varies with growth phase, and shows also strain specific variability.     

Accumulation of docosahexaenoic acid-rich lipid in thraustochytrid <Emphasis Type="Italic">Aurantiochytrium</Emphasis> sp. strain T66: effects of N and P starvation and O<Subscript>2</Subscript> limitation

Aurantiochytrium sp. strain T66 was grown in batch bioreactor cultures in a defined glutamate- and glycerol-containing growth medium. Exponentially growing cells had a lipid content of 13% (w/w) of dry weight. A fattening of cells fed excess glycerol occurred in the post-exponential growth phase, after the medium was depleted of N or P. Lipid accumulation was also initiated by O(2) limitation (below 1% of saturation). N starvation per se, or in combination with O(2) limitation, gave the highest lipid content, i.e., 54% to 63% (w/w) of dry weight. The corresponding maximum culture density was 90 to 100 g/l dry biomass. The content of docosahexaenoic acid (22:6n-3) in N starved, well-oxygenated cells reached 29% (w/w) of total fatty acids but increased to 36% to 52% in O(2)-limited cells, depending on the time span of the limitation. O(2)-limited cells did not accumulate the monounsaturated fatty acids that were normally present. We inferred that the biological explanation is that O(2) limitation hindered the O(2)-dependent desaturase(s) and favored the O(2)-independent polyunsaturated fatty acid synthase. The highest overall volumetric productivity of docosahexaenoic acid observed was 93 mg/l/h. Additionally, we present a protocol for quantitative lipid extraction, involving heat and protease treatment of freeze-dried thraustochytrids.     

Effects of Fatty Acids on Lipid Composition and Function of Tonoplast Vesicles in Barley Seedlings Under Salt Stress

When barley ( Hordeum vulgare L. ) seedlings were treated with 100 mmol/L NaC1 for 2 d, the index of unsaturated fatty acid (IUFA) increased in the tonoplast vesicles that were isolated from the seedlings mots of two barley cultivars with different salt tolerance, whereas no change were observed when the seedlings were treated with exogenous fatty acids with different satumbility. Exogenous stearic acid and linoleic acid decreased Na + absorption and transportation to the shoots, increased K + absorption and transportation, decreased the leakage of electrolytes, and increased the phospholipid and galactose contents of lipids in tonoplast, enhanced the activities of tonoplast H+ -ATPase and H+ -PPase. This is consistent with the results that the two fatty acids, linoleic acid and stearic acid, regulate ion absorption and distribution, mitigate salt stress to some extent, the effects of linoleic acid being more the latter.     

Effects of Culture Method and Growth Phase on Free Lipid Composition of Yersinia pseudotuberculosis

The influence of culture method (free-floating cells in liquid nutrient broth or bacteria attached to agar surface on solid agarized medium of the same formulation) and bacterial age on the composition of free lipids in Yersinia pseudotuber-culosis (O:Ib serovar, strain KS 3058) grown in the cold (5°C) has been investigated. The specific growth rate of the bacteria on solid medium was about threefold less than that in liquid medium. The qualitative composition of phospholipids and fatty acids only slightly depended on the bacterial culture method. At the same time, the colonially growing cultures contained somewhat more total lipids, they synthesized more phospholipids, in the linear growth phase they contained more lysophosphatides, and they had higher fatty acid unsaturation index and higher pathogenic potential than their planktonic counterparts grown in otherwise identical conditions. The bacterial growth phase influenced the amount of 3-hydroxytetrade-canoic acid and, indirectly, that of lipopolysaccharide. The dynamics of changes in the amount of this acid with bacterial age was opposite in the surface and broth cultures.     

Fatty acid and glycerolipid synthesis in abscised daffodil flowers after acetate feeding

The coronae of Narcissus pseudonarcissus flowers incorporated [1-¹⁴C]acetate almost exclusively into the fatty acid moieties of glycerolipids. After a 4 h incubation, the newly synthesized acids were: stearate plus palmitate (50%); oleate (17%); linoleate (32%); and linolenate (0.5%). Phosphatidylcholine and diacylglycerol were the principal labelled lipids. In pulse experiments these acids were further desaturated, with time, to an appreciable extent and, concurrently, transferred essentially from phosphatidylcholine to diacylglycerol, diacylgalactosylglycerol, and diacylgalabiosylglycerol. The labelling of diacylgalactosylglycerol and diacylgalabiosylglycerol paralleled the appearance of linolenate. The distribution of labelled acids in phosphatidylcholine, diacylgalactosylglycerol, and diacylgalabiosylglycerol was very different. The results were compared with those obtained in vitro with isolated coronae chromoplasts and discussed in relation to current schemes of fatty acid and glycerolipid synthesis in plant cells.     

Fatty acid compositions of arthropod and cephalopod photoreceptors: interspecific,seasonal and developmental studies

Fatty acid compositions of the compound eyes of insects (soldier-bug, Hemiptera, and silk moth, Lepidoptera), crustaceans (crayfish and grapsid crab, Decapoda) and inner and outer segments of visual cells of a squid (Cephalopoda, Mollusca) were analyzed by gaschromatography for interspecific comparison. Fatty acid compositions showed great variation among species. In insect compound eyes, 16:0 and 18:0 were the main saturated fatty acids, and 18:1 was the dominant unsaturated fatty acid. Silk moth eyes contained, in addition, considerable amounts of 18:2 and 20:5. In crustacean compound eyes, the main saturated fatty acids were 16:0 and 18:0, and 14:0 (5.0%) was only detected in grapsid crabs; the main unsaturated fatty acids were 20:4, 20:5 and 22:6. Both whole eyes and rhabdom fraction of crayfish showed similar profiles of fatty acid compositions. Both inner and outer segments of squid retinae were characterized by high amounts of unsaturated fatty acids, especially 22:6. Compound eyes of grapsid crabs were used for the experiments on seasonal changes of fatty acid compositions. UFA/SFA ratios (weight in % of unsaturated fatty acids saturated fatty acids) were lowest (1.0) in July and highest (2.5) in March, and unsaturation indexes (average number of double bonds per molecule) were lowest (1.5) in July and highest (2.3) in March. Fatty acids 18:0 and 20:1 showed a significant correlation with the changes of seasonal temperature. Fatty acid analysis of the developing compound eyes of silk moths during the pupal stage revealed that eicosapentanoic acid (20:5) increased remarkably in parallel with the development of photoreceptive membranes, the rhabdoms. This suggests that eicosapentaenoic acid may play an important role in formation and function of rhabdoms.     

Influence of Host Diet on the Fatty Acid Composition and Content of Rumen Protozoa in Cattle

The fatty acid profiles and contents of protozoa from the rumen fluid of cattle varied according to the type of diet consumed by their host. Changing from a high-quality hay diet to a low-quality hay diet (DA) decreased the proportions of saturated acids and increased the proportions of the unsaturated acids 18:1 cis-9, 18:2 and 18:3 in neutral lipids (NL) and phospholipids (PL). Adding sucrose, urea and sulphur (SUS) to DA increased the proportions of branched chain acids in PL while addition of safflower oil increased polyunsaturated acids in PL and 18:1 trans-11 in NL. Diet did not alter the PL fatty acid content of protozoa but oil supplement of DA resulted in a 10-fold increase in the content of free fatty acids. The defaunating effect of oil supplement was partly reversed by SUS suggesting that factors other than the fatty acid content of cells are important in determining the toxicity of oil to rumen protozoa. The results indicate that the amounts of individual long-chain fatty acids taken up by rumen ciliates are largely determined by their concentrations in rumen digesta.     

培养基组分及培养条件对蜡梅花粉萌发及花粉管生长的影响

采用液体培养法研究不同培养基组分和培养条件对蜡梅花粉萌发和花粉管生长的影响。结果表明:(1)PEG-4000是蜡梅花粉离体培养所必需的培养基成分,当培养基中无PEG-4000时,花粉不能正常萌发。(2)培养基内低浓度蔗糖对花粉萌发和花粉管的生长无显著影响,但随着蔗糖浓度的升高,则对花粉萌发和花粉管生长表现出强烈的抑制作用,且浓度越高,抑制效应越强。(3)培养基内其它组分分别在一定浓度范围(0～250g/L PEG-4000、0～50mg/L硼酸、0～30mg/L硝酸钙)内对花粉萌发及花粉管生长有促进作用,但超过上述高限值时则起抑制作用。(4)培养基内镁和钾的浓度对花粉萌发及花粉管生长影响不显著。研究表明,蜡梅最适花粉液体培养基组分为250g/L PEG-4000+50mg/L H3BO3+30mg/L Ca(NO3)2.4H2O,且在pH 5.5、温度15℃和600lx的光照培养条件下蜡梅花粉萌发和花粉管生长最佳。     

Effect of Growth Temperature on Phospholipid and Fatty Acid Compositions in a Psychrotrophic Bacterium, Pseudomonas sp. Strain E-3

The effect of growth temperature on the compositions of phospholipidsand fatty acids of the psychrotrophic bacterium Pseudomonassp. strain E-3 was studied. The composition of phospholipids(phosphatidylethanolamine, phosphatidylglycerol and cardiolipin)did not differ significantly in cells grown at 5?, 15?, and30?C. Phosphatidylethanolamine (PE) was the most abundant, amountingto over 70% of total phospholipids. When the growth temperaturewas lowered, palmitoleic [16:1(9)] and cis-vaccenic [18:1(11)]acids increased at the expense of palmitic (16:0) acid, especiallyin PE. In vivo experiments using [l-¹⁴C]16:0 showed that incorporationof radioactivity into 16:1(9) was oxygen-dependent and cerulenin-insensitive,and incorporation into 18:1(11) was cerulenin-sensitive. Theseresults suggest that 16:0 was aerobically desaturated to 16:1(9)and subsequently elongated to 18:1(11). Desaturation activityof 16:0 in the cells grown at 25?C was enhanced by loweringthe assay temperature. (Received February 12, 1987; Accepted July 10, 1987)     

Fatty acid composition of Simonsiella strains

Gas-liquid chromatography of methyl esters of bound fatty acids extracted from the cells of 48 Simonsiella strains showed that these aerobic, gliding, multicellular-filamentous bacteria have fatty acid profiles of the pattern considered typical of Gramnegative eubacteria. All strains contained predominantly tetradecanoic acid (29.5%), 9-hexadecenoic acid (22.2%), an unidentified acid with an equivalent chain length of approximately 20 carbon atoms (15.8%), and dodecanoic acid (11.4%).Discriminant analysis of the mean relative percentages of 12 fatty acids correctly assigned 94% of the strains to groups based on their source of origin (i.e., the oral cavities of sheep, cat, human or dog); the relative amounts of only 3 of the fatty acids (9-octadecenoic acid, hexadecanoic acid, and tetradecanoic acid) provided most of this discrimination.     

Transient Accumulation of Metabolic Intermediates of p-Cresol in the Culture Medium by a Pseudomonas sp. Strain A Isolated from a Sewage Treatment Plant

Summary Activated sludge from a sewage treatment plant in Kanpur, India, was screened for bacterial strains metabolizing p-cresol exclusively under aerobic conditions. One such isolate was identified to be belonging to the genus Pseudomonas based on morphological and physiological criteria as well as 16S ribosomal RNA gene sequence analysis. Two intermediates were identified from the culture medium during the growth phase of Pseudomonas sp. strain A that indicated that the strain degraded p-cresol via the protocatechuate (PCA) pathway. p-Cresol was rapidly converted into p-hydroxybenzaldehyde (PHB) during early growth phase, which was later utilized after p-cresol depletion. p-Hydroxybenzoate (PHBA) accumulation was observed during the later stages of exponential growth phase. Kinetic constants for the degradation of p-cresol were determined using Haldane’s model. High μ_max and inhibitory constant (K_I) values along with the observed accumulation of significant amounts of PHB in culture filtrates seem to indicate that the isolated Pseudomonas sp. strain A may be of potential use in biotransformations.     

The effect of low oxygen concentration on the acyl-lipid and fatty-acid composition of the C4 plant Amaranthus paniculatus L.

Acyl lipids and their constituent fatty acids were studied in leaves, chloroplasts and bundle-sheath strands of the C₄ plant Amaranthus paniculatus L. grown under normal and 4%-oxygen-containing atmospheres. In all fractions the major lipids were found to be monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sulphoquinovo-syldiacylglycerol and phosphatidylglycerol. Significant quantities of phosphatidylcholine and phosphatidylethanolamine were restricted to leaves and bundle-sheath strands. All lipids, except phosphatidylglycerol where 3-trans-hexadecenoic acid was also present, contained palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. On a chlorophyll basis and compared with whole leaves, the amounts of phosphatidylcholine and phosphatidylethanolamine in bundle-sheath strands were considerably reduced. Three weeks after the change from a normal to a 4% atmospheric O₂ level, the galactolipid content, particularly in the bundlesheath strands, was enhanced. There were no significant differences in the degrees of saturationunsaturation of total acyl lipid for the plants grown in the low oxygen and normal atmospheres, although under 4% O₂ the phosphatidylglycerol contained an increased proportion of 3-trans-hexadecenoic acid at the expense of palmitic acid.Abbreviations DGDG digalactosyldiacylglycerol - MGDG monogalactosyldiacylglycerol - PC phosphatidylcholine - PE phosphatidylethanolamine - PG phosphatidylglycerol - SQDG sulphquinovosyldiacylglycerol     

Growth promotion of Chlorella ellipsoidea by co-inoculation with Brevundimonas sp. isolated from the microalga

Eight bacterial strains identified as P1, P2, Y1, Y2, W1, W2, G, and R were isolated from a long-term laboratory culture of the green alga Chlorella ellipsoidea. Although it is unknown how these bacterial strains have been maintained with the C. ellipsoidea culture, all appeared to promote the growth of C. ellipsoidea. Co-inoculation of each bacterial strain with C. ellipsoidea resulted in 0.5–3 times greater algal growth than that of C. ellipsoidea alone. The most effective bacterium (i.e., strain P1) was selected and further characterized. Biochemical analysis and transmission electron microscopy revealed that strain P1 is closely related to the genus Brevundimonas. Sequence analysis of the 16S rRNA of strain P1 showed 99.9 and 99.4% nucleotide sequence identity to that of B. nasdae and B. vesicularis, respectively. In addition to the growth promotion of C. ellipsoidea by strain P1, the growth of strain P1 was also significantly enhanced by co-culturing with C. ellipsoidea, indicating a symbiotic relationship between the bacterium and alga. Scanning electron microscopy showed the direct adhesion of strain P1 cells to the surface of C. ellipsoidea cells, as well as the development of abundant crinkles on the surface of co-cultured C. ellipsoidea cells. Handling editor: J. Padisak     

Growth responses of the mixotrophic dinoflagellates, Cryptoperidiniopsis sp. and Pfiesteria piscicida, to light under prey-saturated conditions

Recent research emphasis on the ecology of Pfiesteria spp. (Dinophyceae) has led to recognition of several morphologically similar heterotrophic dinoflagellates that often co-occur with Pfiesteria spp. in estuaries along the United States Atlantic coast. These include cryptoperidiniopsoid dinoflagellates, which resemble Pfiesteria spp. in having complex life cycles that include zoospores capable of kleptoplastidy. To examine and compare the role of kleptoplastidy in Cryptoperidiniopsis sp. and Pfiesteria piscicida, we tested the effects of irradiance on growth under prey-saturated (Storeatula major, Cryptophyceae) conditions. Growth of Cryptoperidiniopsis was strongly influenced by light intensity while no major effects were observed in P. piscicida. In Cryptoperidiniopsis, highest cell numbers and specific growth rates, but lowest specific cryptophyte consumption rates, were found at the highest light intensity tested (100 μmol photons m⁻² s⁻¹). A growth model was developed and used to estimate that the average half-life of chloroplasts ingested by Cryptoperidiniopsis decreased 3.4-fold from 12.6 h at high light to 3.7 h in the dark. These results show that light strongly enhances specific growth rate and growth efficiency of Cryptoperidiniopsis feeding on cryptophytes, and suggest that retained kleptochloroplasts may play a quantitatively significant role in carbon and energy metabolism of this organism. Differences in the effects of light between Cryptoperidiniopsis and P. piscicida may reflect different nutritional strategies, and allow these closely related dinoflagellates to occupy different niches and co-exist.     

高纬度地区大豆蛋白含量及氨基酸组分的表型鉴定与聚类分析

对国内外高纬度地区的240份大豆种质资源的蛋白及16个氨基酸组分进行测定,通过遗传多样性、因子和聚类分析,进行了表型鉴定及基因型分类。结果表明,供试大豆种质蛋白及氨基酸组分变异较丰富,遗传多样性程度较高。根据因子分析,将筛选到的3个公因子进行聚类分析,可将供试种质资源分为7类。蛋白含量从高到低的顺序为类群Ⅶ>类群Ⅵ>类群Ⅴ>类群Ⅱ>类群Ⅰ>类群Ⅲ>类群Ⅳ。12个氨基酸组分的变化趋势与蛋白一致。类群Ⅶ和类群Ⅵ为高蛋白遗传群体,可作为高蛋白基因聚合育种的亲本材料。通过前期分析,筛选到24份高蛋氨酸资源,包括有公野04L-141、龙品03-311、Proto、和龙油太、猫眼豆、茶色豆、紫花2号、东农48等,可为高蛋氨酸种质创新提供材料基础。