许氏平鲉发育早期的氨基酸与脂肪酸组成及变化

为了研究许氏平鲉(Sebastes schlegelii)雌鱼体内受精后仔鱼开口前和仔鱼开口后两个阶段氨基酸和脂肪酸的组成变化规律, 采用生化常规方法定量测定并分析了许氏平鲉发育早期的受精卵(FE)、胚胎期(ES)、初产仔鱼(PL₁)、前仔鱼期(PL₂)、后仔鱼期(PL₃)和稚鱼期(J)6个阶段的氨基酸和脂肪酸组成特点及含量变动。结果表明: 总氨基酸含量从FE至PL₁显著下降, 至PL₃显著上升, 至J又显著下降(P<0.05); 游离氨基酸含量以FE最低(12.77 mg/g), 从FE到PL₁显著上升(P<0.05), 并在PL₁含量达到最高值(92.19 mg/g), PL₁发育到J呈现先下降后上升再下降的变化趋势(P<0.05), 游离氨基酸与总氨基酸的比值范围在2.37%—19.66%。在各发育阶段干样中检出碳链长度在C₁₄-C₂₄的29种脂肪酸, 分别为9种饱和脂肪酸(SFA)、9种单不饱和脂肪酸(MUFA)和11种多不饱和脂肪酸为(PUFA), 受精卵中主要脂肪酸依次为C_22:6n-3(DHA)、C_18:ln-9c、C_16:0和C_20:5n-3(EPA)。胚胎期(FE-ES)的脂肪酸利用率顺序为SFA、MUFA、n-6PUFA、n-3PUFA, 主要以C_18:3n-3、C_18:0、C_16:1n-7及C_20:5n-3(EPA)作为胚胎期的能量来源, C_22:6n-3(DHA)的实际利用率最低(9.71%), 被优先保存下来, C_16:0的实际利用量最高(10.94mg/g); 仔鱼内源营养阶段(ES-PL₁)脂肪酸利用率顺序为MUFA、n-6PUFA、SFA、n-3PUFA, 主要以C_16:1n-7、C_18:0、C_20:4n-6(ARA)及C_18:1n-9c作为开口前仔鱼的主要能量来源, 其中仔鱼对DHA实际利用量最高(18.23 mg/g)。PL₁-PL₃阶段DHA相对于EPA和ARA被选择性利用; PL₃至J阶段ARA相对于EPA和DHA被选择性利用。研究表明: 许氏平鲉仔鱼开口前阶段总氨基酸含量与游离氨基酸含量的变化趋势截然相反, 胚胎期与仔鱼内源营养阶段脂肪酸利用率和利用量均有所不同, 仔鱼期DHA优先被利用, 过渡至稚鱼期ARA优先被利用。建议在仔鱼开口后添加富含DHA生物性饵料, 仔鱼过渡到稚鱼期在配合饵料中添加ARA营养物质, 防止苗种营养不足, 保证成活率。     

Assessment of fatty acids in cardiac tissue as 9-anthryldiazomethane esters by high-performance liquid chromatography

A high-performance liquid chromatographic technique for the rapid assessment of fatty acids in cardiac tissue is described. A level of 50.4 ± 14.9 nmol fatty acids per g wet weight of rat myocardial tissue could be monitored. The content of the individual fatty acids C_14:0, C_16:0, C_16:1, C_18:0, C_18:1, C_18:2 and C_20:4 amounted to 1.9, 13.5, 0.6, 14.4, 6.1, 6.5 and 7.2 nmol/g wet weight, respectively. A comparison of this method with a well established gas chromatographic technique yielded good agreement. In contrast with time-consuming gas chromatographic techniques, there is no need to isolate (unesterified) fatty acids from the other lipid classes with column chromatography or thin-layer chromatography, because the derivatizing reagent 9-anthryldiazomethane reacts highly specifically with fatty acids.     

Composition of triglycerides from aphids of six different families and from different seasonal forms of Aphis evonymi

The triglyceride compositions of extracts and cornicle secretions of specimens from a range of aphid families were examined by mass spectrometry and found to support earlier evidence that there is little correlation between taxonomic position and chemical constitution.

Parasites developing within Myzus persicae preferentially consumed the typical aphid triglycerides which contain hexanoic (C₆), sorbic (C_6:2), myristic (C₁₄), and palmitic (C₁₆) acid moieties, so that when parasitism was advanced, only triglycerides with three long-chain fatty acids per molecule remained. The adult parasites themselves contained very little triglyceride.

Triglycerides of Aphis evonymi and Aphis fabae were similar and varied in composition regularly throughout the year. In the apterous and alate (summer) viviparae, there were equal amounts of myristoyl (C₁₄) and palmitoyl (C₁₆) triglycerides, while in fundatrices and fundatrigeniae (spring forms) myristoyl was predominant. Males collected in autumn resembled the spring forms. However, oviparae and eggs of these and other species differed considerably from the other seasonal forms, in having more hexenoic (C_6:1), sorbic (C_6:2), and myristoleic (C_14:1) acid moieties.     

白鱀豚额隆油、下颌油及皮脂油的脂肪酸组成

在齿鲸类的头部,有两个特殊的富含油脂的构造,即额隆和一对下颌脂肪体。在全身的皮下有很厚的皮脂层。Litchfield等(1974,1975)对齿鲸类中近20个属的额隆、下颌脂肪体和皮脂的脂质类型作比较研究,发现不同类群的油脂组分有差别,任何类群的额隆和下颌脂肪体的油脂--头脂的组分,与皮脂油的组分有明显区别,而额隆和下颌脂肪体的油脂组分是相近的。     

Improved method for simultaneous determination of alcohols, volatile fatty acids, lactic acid or 2,3-butanediol in biological samples

A rapid and sample procedure was developed to determine, by gas-liquid chromatography, the concentrations of C₂---C₄ alcohols, C₂---C₆ volatile fatty acids (VFA) and lactic acid or 2,3-butanediol in fermentation liquids. both lactic acid and 2,3-butanediol are oxidized to acetaldehyde by periodic acid and acetaldehyde was eluted before ethanol. A complete separation of the alcohols and acids was performed in <15 min on a column packed with 80/100 Chromosorb WAW, having GP 10% SP-1200/1% H₃PO₄ as the liquid phase. The method was suitable for the analysis of rumen fluid and fermentation products from microbial cultures. The detection limits for all compounds were <0.13 nmol · injection⁻¹.     

Detection of microbial-derived fatty acids in carious dentin by gas chromatography and gas chromatography-mass spectrometry

The aim of the present study was to analyze the fatty acid content of carious and sound human dentin. Gas chromatography and gas chromatography-mass spectrometry revealed the presence of fatty acids of C₁₀-C₁₈ size in the carious dentin, whereas fatty acids of C₁₆ size were present in minute amounts in three samples of the corresponding sound dentine controls. No fatty acids were detected in the other sound dentin control samples. The source of fatty acids was considered to be microorganisms invading the dentin during the progression of the caries lesion. The presence of bacterial fatty acids in carious dentin may serve as a marker for the pathological process and thus contribute to the understanding of the mechanisms involved.     

Effect of non-target cells on the sensitivity of the PCR for Escherichia coli O157 : H7

The fatty acid composition from mycelia of Streptomyces hygroscopicus strains was studied. A significant proportion of C_{18 : 2} was found in cultures. High levels of C_{16 : 0}, iso-C_{16 : 0} and C_{18 : 1} were also detected in all S. hygroscopicus strains. The different representatives of S. hygroscopicus had almost the same proportion of unsaturated fatty acids. Certain shifts in the amount of iso, anteiso and straight-chain fatty acids in some cultures were revealed. This might be explained by the adaptation capability of strains belonging to one species to form a variety of available fatty acids determined by particular cell membrane composition favouring certain antibiotic biosynthesis.     

Effect of the microbial lipopeptide on tumor cell lines: apoptosis induced by disturbing the fatty acid composition of cell membrane

Microbial lipopeptides play an important role in apoptosis induction of tumor cells. However, there is little knowledge about the relationship between apoptosis induction and membrane fatty acids. The present study focused on the effects of lipopeptides produced by Bacillus subtilis HSO121 on Bcap-37 cell lines. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl (MTT) colorimetric assay and surface tension measurements, showed that the critical micelle concentration (CMC) was a critical level for the inhibitory activity of lipopeptides on the growth of Bcap-37 cells. Under the CMC, the order of least to greatest cytotoxicity effect on cancer cell lines by lipopeptides is C₁₃-lipopeptide<C₁₄-lipopepitde<C₁₅-lipopeptide. Above CMC, all lipopeptides directly exert cytolytic activity. The flow cytometric analysis and Hoechst33258 staining experiments confirmed the apoptosis of Bcap-37 cell lines induced by lipopeptides in a dose-dependent manner. This apoptosis was associated with a significant decrease of the unsaturated degree of the cellular fatty acids of Bcap-37 cell lines due to the changes in the cellular fatty acids composition induced by the lipopeptide treatment. These results indicated that disturbance of the cellular fatty acid composition of breast cancer cell lines were related to in the cell apoptosis. Furthermore, significant difference in IC₅₀ values of tumor cells and normal cell showed that the lipopeptide exerted selective cytotoxicity on the cancer cells. Thus HSO121 lipopeptides may have potential applications as an anticancer leads.     

Long-chain and very long-chain fatty acyl-coa synthetase activity in microsomes of jimpy mouse brain

The objective of this study was to determine whether the conversion of free, very long chain fatty acids (C₂₂–C₂₆) to their CoA-esters are involved in cerebroside synthesis, since cerebrosides are uniquely rich in very long chain fatty acids including lignoceric acid (C_24:0). We have studied lignoceroyl-CoA synthetase activity in the microsomes isolated from normal and jimpy mouse brain. The jimpy mouse lacks the ability to make myelin and is deficient in enzyme activities involved in the synthesis of myelin components, including cerebrosides. Unexpectedly, the lignoceroyl-CoA synthetase activity in jimpy brain microsomes was slightly higher than that in control microsomes. The palmitoyl (C_16:0)-CoA synthetase activity in jimpy brain was not different from the control. The level of cerebrosides in microsomes was grossly lower in jimpy brain. The implication of these findings and the involvement of lignoceric acid activation in cerebroside synthesis is discussed.     

Fatty acids of leaf wax esters in Coincya Rouy (Brassicaceae)

A total of 46 populations belonging to the genus Coincya Ruoy (Brassicaceae) from the Iberian Peninsula was examined for their wax ester fatty acids composition. Size of ester fatty acids in the genus Coincya varies between 14 and 28 carbon atoms. This series is dominated by acids with an even number of carbon atoms. The most abundant acids are Ojg, C^y, C^^o and C₂₆ among evens and C₁₇ and C₂₁ among odds. A positive correlation was observed between chemical composition and environmental adaptation, and also with certain morphological characters. Changes relate to low temperatures or to high relative humidity, and there is a positive correlation between chemical composition and leaf glaucousness.     

Changes in soil microbial biomass and community structure with addition of contrasting types of plant litter in a semiarid grassland ecosystem

Aims Elevated atmospheric CO₂ has the potential to enhance the net primary productivity of terrestrial ecosystems. However, the role of soil microorganisms on soil C cycling following this increased available C remains ambiguous. This study was conducted to determine how quality and quantity of plant litter inputs would affect soil microorganisms and consequently C turnover.Methods Soil microbial biomass and community structure, bacterial community-level physiological profile, and CO₂ emission caused by different substrate C decomposition were investigated using techniques of biological measurements, chemical and stable C isotope analysis, and BIOLOG-ECO microplates in a semiarid grassland ecosystem of northern China in 2006 and 2007 by mixing three contrasting types of plant materials, C₃ shoot litter (SC 3), C₃ root litter (RC 3), and C₄ shoot litter (SC 4), into the 10- to 20-cm soil layer at rates equivalent to 0 (C 0), 60 (C 60), 120 (C 120) and 240 g C m ?2 (C 240).Important findings Litter addition significantly enriched soil microbial biomass C and N and resulted in changes in microbial structure. Principal component analysis of microbial structure clearly differentiated among zero addition, C₃ -plant-derived litter, and C₄ -plant-derived litter and among shoot- and root-derived litter of C₃ plants; soil microorganisms mainly utilized carbohydrates without litter addition, carboxylic acids with C₃ -plant-derived litter addition and amino acids with C₄ -plant-derived litter addition. We also detected stimulated decomposition of older substrate with C₄ -plant-derived litter inputs. Our results show that both quality and quantity of belowground litter are involved in affecting soil microbial community structure in semiarid grassland ecosystem.     

Surface lipid composition of C3 and C4 plants

The characteristic surface lipid compositions of several C₃ and C₄ plants are discussed. C₄ plants produce surface lipids (epicuticular waxes) made up of the ubiquitous classes of aliphatic compounds: free fatty acids, aldehydes, primary alcohols, alkanes and aliphatic linear esters. C₃ plants synthesize surface lipids comprising the ubiquitous classes and either of the two following groups of compound: (i) lβ-diketones, hydroxy lβ-diketones, alkan-2-ol esters; (il) ketones and secondary alcohols with the functional group in the middle of the hydrocarbon chain. These features are suggested to represent physioIogical characteristics of the plant and to be related to ecological adaptations. Wax class compositions might also be an ancillary method for defining the C₃ or C₄ mechanism of CO₂ assimilation in cases where uncertainty exists.     

Effect of growth temperature and salt concentration on the fatty acid composition of Flavobacterium halmephilum CCM2831

Abstract In this study the fatty acid composition of Flavobacterium halmephilum CCM2831 grown at different temperatures and salt concentrations is reported. At elevated growth temperatures the amount of cellular saturated long-chain acids (C_18:0 and C_20:0) and the branched-chain acid br-C_17:0 increased, and the concentrations of both cyclic acids and the branched chain acid br-C_15:0 decreased. Increasing the salt concentration in the medium resulted in a gradual increase in cellular cyclopropanoic acids and a concomitant decrease in the monounsaturated fatty acid content.     

Chemical composition, nutritive value, fatty acid and amino acid contents of Galega officinalis L. during its growth stage and in regrowth

The aim of this study was to determine the chemical composition, nutritive value, fatty acid profile and amino acid concentrations of Galega officinalis L. during its first growth cycle and in regrowth. Herbage samples were collected three times at progressive morphological stages from the vegetative to the budding stage, and during regrowth. The dry matter (DM), organic matter (OM), neutral detergent fibre (NDFom), acid detergent fibre (ADFom), lignin (sa) and gross energy (GE) increased during maturation, while the crude protein (CP), ether extract (EE), ash and OM digestibility (OMD) decreased with increasing stage. During the whole growth cycle, and in regrowth, the NE_L was unchanged. Analyses of fatty acids did not reveal differences among plant stages, but did instead between the first cut and regrowth cut. The fatty acid profiles in the plant during growth was characterised by three dominant fatty acids, being -linolenic acid (C_{18:3n − 3}), palmitic acid (C_16:0), and linoleic acid (C_{18:2n − 6}). The -linolenic acid content was instead lower than in the whole plant during growth. The n − 6/n − 3 polyunsaturated fatty acid ratio of the plant was steady at 0.13 during the growth cycle and in regrowth, while it was 0.78 in the seed. The individual amino acid contents of G. officinalis declined with increasing stage of maturity, as the CP declined, but with the exception of the serine content, there was no change in the relative proportions of the individual amino acids due to stage of maturity. Data shows that the nutritive value of G. officinalis forage did not diminish during its growth cycle and that it can improve the self sufficiency of dairy farms. Autumn regrowth was judged to be a good quality forage with a high nutritive value and a higher level of -linolenic acid than during the first growth cycle.     

Alteration of rat adipose tissue lipolytic response to norepinephrine by dietary fatty acid manipulation.

The present study clearly shows that, by feeding rats a semi-synthetic diet of known composition enriched with saturated fatty acids, the epididymal fat pad responsiveness to norepinephrine $\text{in}\text{vitro}$ can be abolished relative to fat pads from animals fed a similar diet but enriched with polyunsaturated fatty acids. Addition of varying concentrations of norepinephrine to the incubation medium produced a clear dose-response relationship in fat pads from animals fed diet enriched with polyunsaturated fatty acids while no effect of norepinephrine was apparent at any dose level in fat tissue from animals fed saturated fatty acids. These changes in lipolytic responsiveness were concurrent with alterations in fatty acid compositions of adipose tissue phospholipids and triglycerides as well as in total tissue contents of phospholipids and cholesterol.     

Deinococcus misasensis and Deinococcus roseus, novel members of the genus Deinococcus, isolated from a radioactive site in Japan

Two gamma- and UV-radiation resistant, Gram-positive, red- or pink-pigmented, rod-shaped, strictly aerobic, oxidase- and catalase-positive bacterial strains, TDMA-25^T and TDMA-uv51^T, were isolated from fresh water collected at Misasa, a radioactive site in Japan. Phylogenetic analysis based on 16S rRNA gene sequences placed both in a distinct lineage in the family Deinococcaceae, and the highest degrees of sequence similarity determined belonged to Deinococcus maricopensis LB-34^T (88.8–89.3%), Deinococcus pimensis KR-235^T (86.4–86.7%) and Deinococcus yavapaiensis KR-236^T (86.1%). The DNA G+C content of the strains was 53–58 mol%. The major respiratory quinone was MK-8. The predominant fatty acids were C_15:0 iso, C_16:0 iso, C_13:0 iso, C_17:0 iso, C_16:0, C_13:0 anteiso, C_15:0 and C_12:0 iso. The strains degraded gelatin, casein, starch and Tween 80. Unique physiological characteristics, differences in their fatty acid profiles, and genotypic and phylogenetic features, differentiated strains TDMA-25^T and TDMA-uv51^T from closely related Deinococcus species. Hence, the two strains are described as novel species of the genus Deinococcus. The names Deinococcus misasensis sp. nov. (type strain TDMA-25^T=JCM 14369=NBRC 102116=CCUG 53610) and Deinococcus roseus sp. nov. (type strain TDMA-uv51^T=JCM 14370=NBRC 102117=CCUG 53611) are proposed.     

Fatty-acid-induced release of manganes from chloroplasts

The effect of both endogenous and exogenous unsaturated free fatty acids on manganese release from chloroplasts of chill-resistant (spinach) and chill-sensitive (tomato, bean) plants was studied. The level of endogenous free fatty acids increased 2–3-fold during cold and dark storage of leaves of chill-sensitive plants and was accompanied by depletion of about 60% of total chloroplast manganese content. Similar effects were observed when accumulation of free fatty acids in chloroplasts was achieved by storage of growing tomato plants for a few days in the dark at room temperature. In contrast, the cold and dark treatment of leaves of chill-resistant plant (spinach) affected neither free fatty acid, manganese levels nor Hill-reaction activity in chloroplasts. Incubation of chloroplasts of both chill-sensitive and chill-resistant plants with bean leaf galactolipase resulted in an accumulation of free fatty acids and a release of approx. 60% of total manganese content. The same amount of total manganese content was released following 3 h incubation of chloroplasts with linolenic acid at fatty acid/chlorophyll ratio (w/w, 2:1–10:1). The efficiency of C₁₈ unsaturated fatty acids/linolenic, linoleic, oleic on manganese release from chloroplasts was established in decreasing order C_18:3 > C_18:2 > C_18:1. The results indicate that the inhibitory effect of both endogenous and exogenous fatty acids on Hill reaction depends on the release from chloroplasts of functionally active, loosely bound manganese. Thus, similarly to both Tris and hydroxylamine treatments of chloroplasts, the incubation of chloroplast preparations with unsaturated fatty acids may be a useful tool for manganese depletion of chloroplasts.     

The outermost cuticle of soybean seeds: chemical composition and function during imbibition

Seeds of different cultivars of Glycine max (L.) Merr. (soybean) have strikingly different rates of water imbibition. Seeds that readily imbibe water are termed 'soft', while those that remain non-permeable, even after several days in water, are referred to as 'hard', 'stone', or 'impermeable' seeds. What prevents soybean hard seeds from taking up water? Previous work established that the initial imbibition of soft soybean seeds correlates with the presence of small cracks in the outermost cuticle that covers the seed coat, prompting a detailed analysis of soybean seed coat cutin. In this paper, it is shown that the outermost cuticle of the seed coat has an unusual chemical composition, lacking typical mid-chain-hydroxylated fatty acids but being relatively rich in other types of hydroxylated fatty acids. The cuticle of the impermeable cultivar studied contained a disproportionately high amount of hydroxylated fatty acids relative to that of the permeable ones. Moreover, a brief treatment with hot alkali released the omega-hydroxy fatty acid component of the outermost cuticle and created holes in it that caused the seeds to become permeable. This demonstrates that the outermost cuticle of the seed is the critical structure that prevents water uptake by hard seeds.     

Arabidopsis CER8 encodes LONG-CHAIN ACYL-COA SYNTHETASE 1 (LACS1) that has overlapping functions with LACS2 in plant wax and cutin synthesis

Plant cuticle is an extracellular lipid-based matrix of cutin and waxes, which covers aerial organs and protects them from many forms of environmental stress. We report here the characterization of CER8 / LACS1 , one of nine Arabidopsis long-chain acyl-CoA synthetases thought to activate acyl chains. Mutations in LACS1 reduced the amount of wax in all chemical classes on the stem and leaf, except in the very long-chain fatty acid (VLCFA) class wherein acids longer than 24 carbons (C₂₄) were elevated more than 155%. The C₁₆ cutin monomers on lacs1 were reduced by 37% and 22%, whereas the C₁₈ monomers were increased by 28% and 20% on stem and leaf, respectively. Amounts of wax and cutin on a lacs1-1 lacs2-3 double mutant were much lower than on either parent, and lacs1-1 lacs2-3 had much higher cuticular permeability than either parent. These additive effects indicate that LACS1 and LACS2 have overlapping functions in both wax and cutin synthesis. We demonstrated that LACS1 has synthetase activity for VLCFAs C₂₀–C₃₀, with highest activity for C₃₀ acids. LACS1 thus appears to function as a very long-chain acyl-CoA synthetase in wax metabolism. Since C₁₆ but not C₁₈ cutin monomers are reduced in lacs1 , and C₁₆ acids are the next most preferred acid (behind C₃₀) by LACS1 in our assays, LACS1 also appears to be important for the incorporation of C₁₆ monomers into cutin polyester. As such, LACS1 defines a functionally novel acyl-CoA synthetase that preferentially modifies both VLCFAs for wax synthesis and long-chain (C₁₆) fatty acids for cutin synthesis.     

Metabolism of CO2 by leaves of different photosynthetic types of Neurachne species

Following a series of continuous exposures to ¹⁴CO₂ for different lengths of time, leaves from Neurachne munroi (C₄), N. minor (C₃-C₄) and N. tenuifolia (C₃| were estimated to assimilate 100%, 9% and 2–4%, respectively, of atmospheric CO₂ by the C₄ pathway. The percentage of ¹⁴C-label appearing in malate and aspartate in leaves of N. minor progressively increased with longer exposure times indicating that a significant proportion of its C₄ acids are formed as secondary products. In ¹⁴CO₂/¹²CO₂ pulse/chase experiments, the ¹⁴C-label in leaves of N. munroi was rapidly transferred from C₄ acids to sugar monophosphates plus sugar diphosphates, and finally to sucrose. In leaves of N. minor, the ¹⁴C-label was slowly metabolized from the C-4 carboxyl of malate and asparate (apparent half-time = 250 s), and the formation of C₄ acids as secondary products was again evident. ¹⁴C-label in serine/glycine accumulated to comparable magnitudes in both N. minor and in N. tenuifolia, but there was an initial lag phase in the accumulation of label in N. minor. C₄ photosynthesis is apparently of minimal importance in reducing photorespiration in N. minor, but leaf anatomical specializations and a possible compartmentation of photorespiratory metabolism may be of considerable importance.