干旱对棉花根和下胚轴质膜脂肪酸组分及其相关酶活性的影响(简报)

棉花根和下胚轴质膜（PM）脂肪酸主要由棕榈酸（16：0）、硬脂酸（18：0）、亚油酸（18：2）和亚麻酸（18：3）组成。干旱胁迫后,PM脂肪酸论和度增加,不饱和脂肪酸和不饱和指数（IUFA）降低。其中棕榈酸含量上升和亚麻酸含量下降较大,膜透性增高,质膜H －ATPase和Ca2 －ATPase活力降低,脂氧合酶（LOX）活性增强。     

缅甸蟒脂肪酸分析

用气相色谱法测定了缅甸蟒油20种脂肪酸,其中不饱和脂肪酸含量达67.5%,多不饱和脂肪酸含量达10.3%.含量较高的脂肪酸有油酸、棕榈酸、亚油酸、棕榈油酸,特有脂肪酸DHA、α-亚麻酸,并且明显不同于其他蟒和蛇的脂肪酸含量.缅甸蟒油具有重要的药用和保健品开发利用价值.     

不同种源山桐子果实脂肪酸组成变异分析

以采自11个种源的山桐子为材料,测定其果实脂肪酸的组成及其变异情况,结果表明：山桐子果实中不饱和脂肪酸含量较高,尤以亚油酸含量最高,11个种源的平均值为63．58％,且种源间差异显著,分宜、宜昌种源亚油酸相对含量明显高于其他9个种源;饱和脂肪酸以棕榈酸为主,11个种源山桐子果实棕榈酸差异显著,且以平武种源最高;其余脂肪酸含量均较低,变异幅度较大;种子中棕榈酸和棕榈烯酸含量明显高于果肉,而亚油酸、亚麻酸及硬脂酸含量明显低于果肉,油酸含量相近：果实不饱和脂肪酸含量依次为果肉〉全果〉种子,且变异系数及相对极差均较小,尤以果肉中最小;除硬脂酸外,山桐子果实中其他4种主要脂肪酸组分受海拔等地理环境的影响均较小。     

外源脂肪酸对酒精诱导自絮凝颗粒酵母细胞膜磷脂脂肪酸组成变化的影响

实验将自絮凝颗粒酵母培养于同时添加脂肪酸 (0.6mmol/L)和酒精 (6 %～ 9% ,V/V)条件下以考察其细胞膜磷脂脂肪酸组成的变化。与单独添加棕榈酸相比 ,同时添加酒精引起细胞膜磷脂棕榈酸含量明显增加 ,伴随 9十四碳烯酸、棕榈油酸和油酸含量明显减少 ;与单独添加亚油酸相比 ,同时添加酒精未引起细胞膜磷脂亚油酸含量明显变化 ,但引起油酸含量明显增加 ,伴随 9 十四碳烯酸、棕榈油酸和棕榈酸含量减少 ;与单独添加亚麻酸相比 ,同时添加酒精引起细胞膜磷脂亚麻酸含量减少 ,伴随油酸含量显著增加 ,同时 9 十四碳烯酸、棕榈油酸和棕榈酸含量减少。存活率实验证实 ,上述变化是菌体对酒精刺激的适应性响应 ,因为 ,与培养于仅添加脂肪酸条件下的菌体相比 ,培养于同时添加酒精条件下的菌体耐酒精能力明显提高。研究表明 ,棕榈酸和油酸都可通过加强细胞膜渗透屏障而提高菌体的耐酒精能力 ,这是饱和脂肪酸 (SFA)与不饱和脂肪酸 (UFA)可提高同一菌株耐酒精能力的新的实验现象 ,揭示UFA与SFA在影响酵母菌耐酒精能力的机制上存在共同的作用方式     

樱桃李核仁油脂肪酸组成分析

采用气相色谱法及气相色谱-质谱联机技术,对樱桃李Prunus divaricata Ldb.核仁油中的脂肪酸进行了定量、定性分析.其脂肪酸组成为油酸66.3%、亚油酸25.6%、棕榈酸5.6%、硬脂酸1.4%,不饱和脂肪酸油酸和亚油酸的总量占91.9%,该油有较高的营养价值.     

菌草灵芝孢子油与段木灵芝孢子油中脂肪酸组成的比较研究

利用气相色谱法,对菌草灵芝孢子油与段木灵芝孢子油中脂肪酸组成、不饱和脂肪酸含量等进行了比较研究。结果发现两者脂肪酸GC指纹图谱极为相似(脂肪酸组成基本相同),说明了菌草灵芝孢子油与段木灵芝孢子油一样有同样的开发价值,但是脂肪酸含量不同,菌草灵芝孢子油中亚油酸和油酸占55.61%,不饱和脂肪酸占61.15%;段木灵芝孢子油中亚油酸和油酸占49.87%,不饱和脂肪酸占54.88%。而且两者的外观、气味略不同。     

油茶CoSAD基因载体的构建、鉴定及功能分析

为揭示油茶( Camellia oleifera Abel)硬脂酰-ACP脱饱和酶( SAD)基因(即CoSAD基因)的功能,构建了该基因的原核表达载体pET28b-CoSAD、植物表达载体pBI121-CoSAD和RNA干扰载体pBI121-CoSAD RNAi,并采用PCR扩增及双酶切方法对3类载体进行鉴定;在此基础上,对原核表达载体中的CoSAD基因进行诱导表达分析,并对pBI121-CoSAD转化的拟南芥〔Arabidopsis thaliana ( Linn.) Heynh.〕sad突变体植株和pBI121-CoSAD RNAi转化的拟南芥野生型植株进行转基因鉴定和主要脂肪酸成分含量分析。 PCR扩增和双酶切结果显示：从 pET28b-CoSAD、pBI121-CoSAD和pBI121-CoSAD RNAi 载体的阳性克隆中均可获得目的条带,表明这3类载体均构建成功;用1 mmol·L-1 IPTG分别诱导0.5、1.0、2.0、3.0、4.0和5.0 h,CoSAD基因均能够在pET28b-CoSAD转化的大肠杆菌BL21感受态细胞中正常表达,能够获得与预测结果相符的相对分子质量约47000的特异目的蛋白条带,且蛋白活性随诱导时间的延长而升高。从pBI121-CoSAD转化的拟南芥突变体植株和pBI121-CoSAD RNAi转化的拟南芥野生型植株中也均可扩增出目的条带。 GC-MS分析结果显示：与拟南芥野生型植株相比,其突变体植株的硬脂酸和棕榈酸含量较高、油酸和棕榈油酸含量较低;但突变体植株经pBI121-CoSAD转化后,硬脂酸和棕榈酸含量降低而油酸和棕榈油酸含量提高;野生型植株经过pBI121-CoSAD RNAi转化后,硬脂酸和棕榈酸含量提高、油酸和棕榈油酸含量降低,表明pBI121-CoSAD转化能够促进拟南芥sad突变体植株体内饱和脂肪酸向不饱和脂肪酸转化,而pBI121-CoSAD RNAi转化对拟南芥SAD基因的表达有明显的抑制作用,这2种重组质粒均可影响拟南芥植株的脂肪酸含量。研究结果表明：油茶CoSAD基因具有调控饱和脂肪酸(硬脂酸和棕榈酸)向不饱和脂肪酸(油酸和棕榈油酸)转化的功能,对茶油的脂肪酸组成具有关键的调控作用。     

渗透胁迫对棉花根和下胚轴PM脂肪酸组分和ATPase的影响

实验结果表明：棉花根和下胚轴ＰＭ脂肪酸主要由棕榈酸（１６：０）,硬脂酸（１８：０）,亚油酸（１８：２）和亚麻酸（１８：３）组成。用－０．３ＭＰａ和－１．１ＭＰａ根际胁迫,棉花根和下胚轴ＰＭ饱和脂肪酸含量增加,不饱和脂肪酸和不饱和指数（ＩＵＦＡ）降低,这几种组分中棕榈酸含量上升较大,亚麻酸含量下降较大。胁迫处理使膜透性增高,脂肪酸组分发生变化,致使ＰＭ Ｈ＾＋－ＡＴＰａｓｅ,Ｃａ＾＋＋－ＡＴＰ－ａｓ     

华南主要野生蔬菜的脂肪酸成分分析

本实验以华南主要野生蔬菜守宫木、土人参、一点红、白仔菜、紫背菜、鳄嘴花、藤三七、塘葛菜为材料,并以华南特产蔬菜菜心为对照,对8种野生蔬菜的脂肪酸成分进行了分析.结果表明:8种野菜共检出十四酸、软脂酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻酸、二十二酸和二十四酸共9种脂肪酸,但不同野菜之间的脂肪酸组成与含量差异极大.8种野菜的饱和脂肪酸的总量都高于菜心,饱和脂肪酸种类最多的是藤三七,含4种.不饱和脂肪酸的变化与饱和脂肪酸相反,8种野菜都低于菜心,但其油酸、亚油酸远高过菜心.菜心富含亚麻酸,但不含亚油酸.可见8种野菜油营养价值较高.     

花椒籽油的提取和组分分析

选用石油醚、无水乙醇、正己烷三种溶剂对花椒籽油进行索氏提取,结果青花椒籽油的得率分别为:5.34%、5.49%、4.80%;红花椒籽油的得率分别为:18.69%、24.41%、17.20%;红花椒籽油得率是青花椒籽油得率的3~4倍。花椒籽油经皂化后采用气相色谱-质谱联用法(GC-MS)分析不同溶剂提取的花椒籽油脂肪酸组分,并用峰面积归一化法测定各种组分相对含量。结果鉴定的主要组分为棕榈酸、棕榈油酸、油酸和亚油酸,这四种组分占95%以上;青花椒籽油中不饱和脂肪酸含量在83.43%以上;其中棕榈油酸占60%以上,油酸占20%左右,亚油酸占5%左右。红花椒籽油中不饱和脂肪酸含量在69%以下;其中棕榈油酸占12%余,油酸占40%左右,亚油酸占10%左右。而红花椒籽油中棕榈酸含量在30%左右,约是青花椒籽油中棕榈酸含量(11%左右)的3倍。     

森林群落物种组成对凋落物组成的影响

在海南铜鼓岭山麓灌木林和季雨矮林固定大样地的基础上,通过收集凋落物,比较两林型的凋落物数量及其器官组成、凋落叶物种组成,探讨森林群落物种组成与凋落物组成的关系。结果表明:(1)两林型的凋落物总量及其器官组成不同,山麓灌木林(6.227 t/hm~2)比季雨矮林的年凋落量大(5.636 t/hm~2);凋落叶是凋落物的主要组成部分,能反映凋落物的凋落情况。(2)山麓灌木林凋落物优势种和主要物种为贡甲、林仔竹、橄树等15个物种,凋落叶总量占77.72%;季雨矮林的凋落物优势种和主要物种为方枝蒲桃、肖蒲桃、贡甲等17个物种,凋落叶总量占71.84%;山麓灌木林中凋落物优势种和主要物种的叶凋落量与其组成物种的株数、总断面积、树冠面积极显著正相关而季雨矮林的凋落物优势种和主要物种的叶凋落量与其组成物种的株数极显著正相关。山麓灌木林中两者的Jaccard相似性系数为20%,季雨矮林为25.93%,两林型的群落物种组成与凋落叶物种组成不一致,热带森林群落优势种不一定是凋落物优势种。     

Macromolecular composition of bacteria

Equations are presented that describe the macromolecular composition in exponential bacterial cultures as functions of five parameters: doubling time of the culture (τ), protein per origin of replication (P₀), chromosome replication time (C-period), peptide chain elongation rate (c_p), and the time between termination of replication and cell division (D-period). Implicit in the value for some of these parameters is a specific macromolecular control system: the control of the growth rate (τ), the timing of initiation of rounds of chromosome replication (P₀), and the regulation of cell division (D). The utility of these relations is illustrated by using updated measurements of the macromolecular composition of E. coli B/r to calculate values for the fundamental parameters and to predict the composition of a mutant which has a defect in the control of DNA replication. Furthermore, the meaning of several often-cited physiological parameters (RNA/protein, RNA/cell and RNA/genome) is examined. The relations presented here show that these parameters and their variation with growth rate are not directly relevant to arguments about control of ribosome synthesis or culture growth.     

Biochemical composition of ctenophores

The biochemical composition of three species of North Sea ctenophores, the beroid Beroe gracilis (Künne), the tentaculate Pleurobrachia pileus (Fabricius) and the lobate Bolinopsis infundibulum (Müller), was analysed in terms of total fractions of protein, lipid, ninhydrin-positive substances (NFS), polysaccharides (PS), and low molecular-weight carbohydrates (LMC). The sum of these biochemical fractions was highest in Beroe (128 mg/g dry wt) and much lower in Pleurobrachia (61 mg/g dry wt) and Bolinopsis (27 mg/g dry wt). Beroe shows higher ratios of NPS/protein and LMC/PS than either of the other species. These findings are explained by differences in the morphology and metabolism of the species.In a 3-wk starvation experiment, Pleurobrachia lost ≈65% of its body mass and ≈80% of its organic content after 14 days at 15°C. However, after 10 days, the biochemical composition of the body tissue changed only slightly indicating that all components of body tissue are consumed without any preference for a specific storage material. Therefore the biochemical composition does not necessarily reflect differences in the nutritional conditions of the ctenophores the field.     

Lipid composition of cyanidium

The major lipids in Cyanidium caldarium Geitler are monogalactosyl diglyceride, digalactosyl diglyceride, plant sulfolipid, lecithin, phosphatidyl glycerol, phosphatidyl inositol, and phosphatidyl ethanolamine. Fatty acid composition varies appreciably among the lipids, but the major ones are palmitic acid, oleic acid, linoleic acid, and moderate amounts of stearic acid. Trace amounts of other acids in the C₁₄ to C₂₀ range were also present. Moderate amounts of linolenic acid were found in two strains, but not in a third. The proportion of saturated acid is relatively high in all lipids ranging from about a third in monogalactosyl diglyceride to three-fourths in sulfolipid. This may be a result of the high growth temperature. Lipases forming lysosulfolipid, and lysophosphatidyl glycerol are active in ruptured cells; galactolipid is degraded with loss of both acyl residues. Thus the lipid and fatty acid composition of Cyanidium more closely resembles that of green algae than that of the blue-green algae, although there are differences of possible phylogenetic interest.     

Ganglioside composition of astrocytes

Short-term and long-term (greater than 7 months) cultured astrocytes from 14-day-old rat brain were analyzed for ganglioside content. Analysis of the extracted gangliosides by HPTLC revealed that ganglioside GM1 was absent in 35 days and 235 days cultured astrocytes, and that the predominant ganglioside was GM3, showing a double band in both cases. A small amount of the disialogangliosides (GD3, GD1a) was also detected. More than 70% of radioactivities into ganglioside fractions by cultured astrocytes, in the presence of N-[3H]-acetylmannosamine, appeared in ganglioside GM3. The upper band component of GM3 increased 60% in long-term astrocyte cultures compared to 35-day-old cultures. Also, an increased GD3 content in long-term astrocyte cultures was detected. These results suggest that the increase of GD3 and upper band GM3 in long-term cultured astrocytes might be related to the appearance of small processes showing strong reactivity against GFAP and vimentin during astrocyte-subculture.