三角褐指藻岩藻黄素-叶绿素蛋白复合体的分离纯化和功能研究

通过改进硅藻主要捕光天线(FCP)的分离和提取方法, 得到高纯度、高均一性的三角褐指藻FCP蛋白,并通过电泳、液相色谱、质谱和吸收荧光光谱学等手段研究三角褐指藻FCP的氨基酸序列、色素组成和捕光特点等, 初步预测三角褐指藻的结构和功能特点。结果表明三角褐指藻FCP含有198个氨基酸, 与高等植物LHCII的序列Identity约为24%。三维结构预测显示FCP具有与LHCII相似的三次跨膜螺旋框架结构, 但跨膜螺旋较短, 且无膜表面螺旋结构。FCP中主要结合了叶绿素a、叶绿素c、岩藻黄素, 不含叶绿素b, Chl. a/c为3.0。光谱学分析表明岩藻黄素可以在水下弱光环境中有效地捕获绿光, 并高效地传递至叶绿素。而岩藻黄素在400-500 nm区域吸收的光能, 向叶绿素传递效率较低, 预示着岩藻黄素在强光下也有一定的光保护功能。FCP中有4个叶绿素结合的保守氨基酸位点, 可能是其叶绿素结合位置, 但岩藻黄素的结合位置因其结构和结合位点的变化而无法预测。研究为进一步探索FCP的结构和功能特性奠定了基础。     

硅藻岩藻黄素特性与其生物合成的研究进展

为探究棕鞭金藻生产岩藻黄素的综合性能, 以期建立高效合成岩藻黄素的发酵工艺, 研究首先对金藻发酵培养基中的碳氮比、维生素添加量进行优化。结果表明, 当碳氮比为24、维生素添加量为3.75 mg/L维生素B₁和1.25 mg/L维生素B₁₂时, 有利于金藻细胞内的岩藻黄素高效合成。此外, 通过调控金藻光/暗培养模式, 对其在不同条件下的细胞生长、最大光合效率和岩藻黄素积累情况进行比较研究, 结果显示从种子培养到上罐发酵全过程进行光诱导后, 胞内岩藻黄素含量显著提升。通过系统优化, 金藻发酵后的胞内岩藻黄素含量和产量分别达到1.79 mg/g和33.6 mg/L, 比优化前的发酵水平提高33.6%和31.2%。研究利用发酵优化技术强化了棕鞭金藻的岩藻黄素积累, 为后续进一步进行大规模过程放大奠定了前期基础, 也为其他微藻生产岩藻黄素提供了借鉴和参考。

     

高产岩藻黄素的海洋硅藻筛选及光照条件优化

为提高岩藻黄素（Fucoxanthin）提取效率,对16株海洋硅藻岩藻黄素的检测含量和实际含量进行了分析,并以一株牟氏角刺藻（Chaetoceros muelleri）为对象,研究了岩藻黄素与另外两种关键光合色素（即叶绿素a和β-胡萝卜素）的含量及其消长受光强和光质影响的特征。研究结果显示,不同种或同种不同株的海洋硅藻,在相同的培养条件、收获时期、提取方法下,其提取率差异大,可从不足1%到89.78%;岩藻黄素的检出含量各异,从0.03到5.02 mg/g。受不同光照强度[低:50μmol/（m²·s）;中:100μmol/（m²·s）;高:200μmol/（m²·s）和光质（红光、蓝光）]的影响,岩藻黄素产量呈现不同特征。在低光照强度下,单位细胞岩藻黄素的含量相对较高。在红光条件下,岩藻黄素的产量高于蓝光。在相同光强条件下,岩藻黄素含量随增殖周期变化;在单色光质条件下,几种光合色素均在生长平台期后期含量增加。岩藻黄素的含量变化与叶绿素a和β-胡萝卜素的含量及其消长关系密切。研究为筛选藻株、优化硅藻培养条件以累积岩藻黄素提供了参考。     

基于WGCNA发掘缺磷、红光和黄光处理下三角褐指藻岩藻黄素合成关键基因

加权基因共表达网络分析(weighted gene co-expression network analysis,WGCNA)是一种分析多个样本间基因表达模式的方法,可将表达模式相近的基因聚类并发掘与特定的性状或表型相关的关键基因。本研究采用转录组测序和WGCNA方法,分析了三角褐指藻(Phaeodactylum tricornutum)在缺磷、红光和黄光等非生物胁迫下对岩藻黄素积累的影响。结果表明,与对照组相比,岩藻黄素含量在缺磷和红光处理后显著提高(P<0.05),但是在黄光处理后显著降低(P<0.05)。利用转录组测序得到的10,392个基因构建加权基因共表达网络,为了确保无标度网络,选择β=18(R²>0.8)作为软阈值。通过对岩藻黄素含量进行关联分析,共鉴定了10个共表达模块,其中purple模块与岩藻黄素含量呈正相关(r=0.9,P=1E–200),并确定了9个关键基因,包括5个岩藻黄素合成通路上的基因(DXR、PSY、PDS1、ZEP2、VDL2)和4个转录因子基因(bHLH5、HOX2、CCHH13、HSF1b)。进一步利用qRT...     

不同干燥方式对当归性状、显微形态、活性成分含量和抗氧化物酶活性的影响

以当归“岷归1号”为研究对象,探究平衡脱水干燥(P)、阴干(Y)、晒干(S)及熏干(X)4种干燥方式对药材性状、显微结构、活性成分和抗氧化物酶活性的影响.结果 表明:P和Y的当归色泽均匀鲜亮、表面皱纹疏松,外观品相较好;P与X当归的油室平均直径和淀粉粒密度均高于X与Y的;P当归的阿魏酸、多糖、挥发油提取率、浸出物、洋川...     

不同干燥方法对蝇蛆蛋白粉营养价值的影响

采用化学分析和动物实验的方法对冷冻干燥、微波干燥和低温干燥的蝇蛆粉进行了营养评价。结果表明,3种干燥方法不影响蝇蛆粉的粗蛋白和灰分含量,但微波干燥蝇蛆粉的脂肪含量显著降低;氨基酸分析显示,冷冻干燥蝇蛆粉的氨基酸总含量>微波干燥的蝇蛆粉>低温干燥的蝇蛆粉,而3种方法干燥的蝇蛆粉EAA/TAA均等于或大于41%,说明干燥所得的蝇蛆粉均属优质蛋白。另外,与FAO/WHO参考模式值相比,冷冻干燥蝇蛆粉的必需和半必需氨基酸总量明显高于FAO/WHO参考模式值,微波干燥的蝇蛆粉与FAO/WHO参考模式值相当,而低温干燥的蝇蛆粉中必需与半必需氨基酸含量显著低于FAO/WHO参考模式值,说明微波干燥及低温干燥会破坏蝇蛆中的某些必需或半必需氨基酸。动物实验结果表明,冷冻干燥的蝇蛆粉在动物体内被吸收利用的程度最高,其次是酪蛋白,再次是低温干燥的蝇蛆粉,而微波干燥的蝇蛆粉被动物吸收利用的程度最低。     

青蒿不同组织采集时期和干燥方式对青蒿素含量影响研究

实验研究了不同采收时期、不同组织、不同干燥方式对青蒿中青蒿素含量的影响.结果表明,山西忻州7月初到8月中旬为青蒿生长盛期,这一段时间内阳光充足、空气湿度适宜,温度成为青蒿素累积的主要因素.最佳采收时期生长盛期至花期之前,在青篙植株及叶片中青蒿素含量均呈现茎、根、老叶、新叶依次递增的规律,晒干的样品青蒿素平均含量比烘干的样品含量高.     

不同干燥方式对青花椒精油品质的影响

不同的干燥方式对青花椒精油品质的影响有着较大的差异。本文采用自然干燥、热风干燥、真空冷冻干燥、冷冻—微波联合干燥等四种不同的干燥工艺对辛香料进行干燥处理。从含水率、精油含量、能耗和精油组分等方面对干燥方式进行比较评价,并通过GC-MS分析鉴定出青花椒精油的主要组分为烯类和醇类。由结果可知,联合干燥所用时间短,能耗少,所得精油含量最多,含水率低,品质也更好,因此联合干燥工艺更适合干燥青花椒。     

不同干燥方法对冬瓜片品质的影响

以冬瓜为试材,研究自然干燥、普通热风干燥和微波干燥 3 种不同干燥方法对冬瓜品质的影响,通过测定冬瓜片的复水性、维生素C和酸度等,探求冬瓜长久储藏的方法。结果表明,微波干燥法在以上各质量参数方面均为最优。     

多指标评价干燥温度对党参药材质量的影响

目的：考察不同干燥温度对党参药材质量的影响,筛选最佳的干燥温度,为党参药材的干燥加工工艺研究以及党参药材质量控制提供理论依据。方法：采用鼓风干燥的方法,以外观性状质量、醇浸出物、党参多糖、党参炔苷和党参苷Ⅰ的含量为党参药材质量的评价指标,考察不同干燥温度（40℃、50℃、60℃和105℃）对新鲜采收的党参药材质量的影响。结果：不同鼓风干燥温度对党参的醇浸出物和党参多糖的含量无显著影响,但60℃和105℃干燥的党参中党参苷Ⅰ和党参炔苷的含量显著低于40℃和50℃,说明高温对于党参炔苷和党参苷I的含量影响较大。结论：综合考虑干燥时间、药材外观形状的影响,优选50℃为鲜党参热风干燥法的最佳干燥温度。     

通过加速贮存试验估算u-PA产品在不同温度时的贮存寿命

通过在 6 0℃、70℃、80℃的加速贮存试验 (MIS)观察了 u- PA冻干产品的热稳定性 ,并对其活性的热降解速度和不同温度时贮存寿命进行了估算。在 3 7℃ ,2 5℃ ,4℃ ,0℃贮存时 ,活性单位损失 5 0 %所需的时间为 1 73 d、2 .78a,70 .8a,1 1 8a:活性单位损失 1 0 %需的时间分别为 2 0 d、1 0 0 d、7.6 4 a、1 1 a。     

Microsatellite loci from the trematode Lecithochirium fusiforme,a parasite of the European conger eel

Seven polymorphic loci containing dinucleotide repeats and one trinucleotide microsatellite were developed for the hemiurid fluke Lecithochirium fusiforme, a parasite of the European conger eel Conger conger. All parasites that were collected from a single individual host (a total of 54 specimens) were genotyped. The number of alleles ranged from two to eight. The observed and expected heterozygosities ranged from 0.057 to 0.736 and from 0.091 to 0.794, respectively. Hardy–Weinberg deviations were statistically significant for two loci. These markers will be useful for study of parasite transmission patterns and population genetic structure.     

不同溶剂和保存条件对尾叶悬钩子花色素苷提取及稳定性的影响

对尾叶悬钩子(Rubus caudifolius Wuzhi)鲜果中花色素苷的提取条件、主要化学组分及pH值、温度、没食子酸和Al^3 对其颜色及稳定性的影响进行了分析探讨。结果表明,尾叶悬钩子花色素苷的主要组分可能为矢车菊素-3-葡萄糖苷;pH值和温度影响该花色素苷的色泽及其稳定性,随着pH值和温度的增加,其分解加剧,且花色素苷的分解均遵循动力学一级反应规律;添加不同浓度的Al^3 ,色素溶液的吸光值有所升高,显示出有一定的增色效应,但Al^3 和没食子酸对贮藏期间花色素苷的稳定性及色泽均无明显效果。     

Fluidized-bed drying and storage stability of Cryptococcus flavescens OH 182.9, a biocontrol agent of Fusarium head blight

A method to produce dried granules of Cryptococcus flavescens (formerly Cryptococcus nodaensis) OH 182.9 was developed and the granules evaluated for storage stability. Small spherical granules were produced and dried using a fluidized-bed dryer. A drying and survival curve was produced for the process of fluidized-bed drying at 30°C. The granules were dried to different moisture contents (4, 7, 9 and 12%) and evaluated for storage stability at 4°C for up to a year. These different moisture contents granules had the following respective water activities (0.22, 0.38, 0.47 and 0.57 a _w). The results show the storage stability varied significantly across this moisture content range. The 9% moisture content sample had the best short-term stability (up to 4 months), while 4% moisture content had the best long-term survival (1 year). A desorption isotherm of C. flavescens was determined and modeled. The results of the storage stability and drying studies are interpreted in context of the desorption isotherm.     

Effect of storage temperatures on the stability of cytokines in cervical mucous

Cytokines have progressively come to serve as indicators for the presence or severity of a disease. But accurate measurement of cytokine levels can be deterred by lack of proper handling and storage of the samples. In this study, we attempted to measure the effect of snap-freezing and refrigeration at the time of collection on cervical mucous. Luminex analyses of the frozen and refrigerated pairs exhibited no significant differences in levels for 7 out of the 10 cytokines measured simultaneously. The cytokines TNF-alpha, IFN-gamma and IL-1beta, were significantly different between the pairs with the refrigerated samples showing higher levels for each of these cytokines. The results suggest that refrigeration of mucous samples immediately after collection would allow for better conservation of the cytokines in cervical mucous.     

Effects of particle size and drying methods of corn on growth performance,digestibility and haematological and immunological characteristics of weaned piglets

The objective of this study was to evaluate the effects of particle size and drying methods of corn on growth performance of weaned piglets. Crossbreed weaned piglets (n = 192; Duroc × Landrace × Large White) were assigned to one of four treatments (2 × 2 factorial arrangement). All piglets were fed corn–soybean meal diets and treatments were (1) hot air-dried and coarsely ground corn, (2) hot air-dried and finely ground corn, (3) sun-dried and coarsely ground corn and (4) sun-dried and finely ground corn. The results showed that finely ground corn (FGC) improved the performance of piglets. Additionally, the apparent total tract digestibility (ATTD) of gross energy (GE) and ether extract (EE) were increased by FGC, but the drying methods did not affect the performance of piglets or ATTD. Furthermore, smaller particle size significantly decreased the intestinal permeability, which was also not influenced by drying methods. FGC increased the total number of white blood cells, but not other blood parameters. Finally, the level of serum interleukin-1 was decreased by fine grinding and that of serum tumour necrosis factor α was decreased by sun drying. Conversely, these characteristics of weaned piglets can hardly have been affected either by the corn drying method or its interaction with grinding methods.     

海蒿子多糖DEⅠ、DEⅡ组分分离纯化、结构及抗癌活性研究

海蒿子干粉经热水抽提、乙醇沉淀、DEAE-Sephadex A-25柱层析分离,得到多糖DEⅠ、DEⅡ,总糖含量分别为52.40%、38.8%.经酸降解、薄层层析、气相色谱-质谱分析,证明其单糖组成均为木糖、岩藻糖、半乳糖、果糖、甘露糖、葡萄糖.其中岩藻糖含量最高.多糖DEⅠ、DEⅡ对P388肿瘤具有抑制活性.     

Survivability and storage stability of Trichoderma atroviride TRS40 preserved by fluidised bed drying on various agriculture by-products

Agriculture by-products were applied to proliferate biomass of Trichoderma atroviride TRS40 in solid state fermentation (SSF) cultures. The culture media overgrown with mycelium together with conidia were preserved by fluidised bed drying at various temperatures (50°C, 60°C and 70°C) and the received biopreparations were stored for 12 months. In order to determine the suitability of TRS40 in the production of biopreparations, the influence of preservation process and storage time on their survivability was examined. The three-component mixture proved more effective in the SSF cultures, ensuring TRS40 count at 6.07?×?10^9?CFU/g?dm, which was ca. 6 times higher than in the mono-component medium. TRS40 survivability after preservation at various temperatures ranged from 40.4% to 100%, regardless of carrier type. In turn, after 12-month storage of the biopreparations produced on the three-component medium, regardless of drying temperature, the number of viable cells ranged from 2.43?×?10⁸ to 2.49?×?10^8?CFU/g?dm. Furthermore, selected parameters of growth kinetics in the Bioscreen C system were determined. The storage time of biopreparations had various effects on growth kinetic parameters. In addition, the preserved preparations based on the TRS40 retained their capability for biosynthesis of hydrolases, even after 12 months of storage.