超声波提取番茄果实中类胡萝卜素条件的优化

比较不同方法提取番茄冻干粉中类胡萝卜素的结果表明,超声波提取效率最高,以丙酮/石油醚(2:1)作提取剂,在超声波功率为100W,水浴温度30℃下提取30min能充分提取类胡萝卜素.     

香蕉皮类胡萝卜素提取工艺条件的研究

为探究香蕉皮类胡萝卜素提取及综合利用的可能性,采用单因素试验与正交试验相结合的方法优化香蕉皮类胡萝卜素的提取工艺条件。结果表明：其最佳提取工艺条件为：以丙酮为提取溶剂、料液比1∶25、提取温度45℃、提取时间75min,在此工艺条件下可获得最佳提取效果,类胡萝卜素提取量平均值为12.541 mg/g。另用超声波辅助提取法,得到香蕉皮中类胡萝卜素提取量平均值为13.740mg/g,在提取时间仅为20min的情况下,比普通浸提法的提取量增加了9.56%,提取效率大大提高。     

西兰花类胡萝卜素的提取及其抗氧化活性研究

在单因素试验基础上,通过正交试验初步优化确定了西兰花中类胡萝卜素提取的最佳工艺条件为：用无水乙醇作为提取液、料液比1∶60、提取时间180min、提取温度55℃,提取率可达268.26mg/100g。同时通过水杨酸法测定类胡萝卜素粗提物清除羟基自由基的能力,证实西兰花类胡萝卜素具有较强的抗氧化能力。     

蓝光诱导蛹虫草菌丝类胡萝卜素的积累

蛹虫草(Cordyceps militaris L.)在培养时受蓝光诱导,其菌丝体中有高产量的类胡萝卜素积累.当温度为25℃且蓝光光照强度为6.5μmol·m-2·S-1时,菌丝体的类胡萝卜素含量在含蚕蛹粉的培养基上24h达到最高峰的495.5μg/g FW;而在不含蚕蛹粉的培养基上72h才达最高峰414.1μg/g FW.蛹虫草菌丝类胡萝卜素的积累也受蓝光光照强度的影响,最适光照强度可随培养时间的不同而有所变化.此外,黑暗培养时间的长短和温度也可共同影响蛹虫草菌丝产类胡萝卜素时对蓝光的敏感性.     

优美红游动菌类胡萝卜素的提取条件研究

研究了优美红游动菌(Rhodoplanes elegans)的生长以及类胡萝卜素的产生,通过比较4种广泛采用的细胞破碎方法,对优美红游动菌(Rhodoplanes elegans)类胡萝卜素的提取条件进行了研究,结果表明:类胡萝卜素的产生与菌种的生长曲线相符合,菌种活化后培养45h,类胡萝卜素的含量趋于稳定;取此时培养液,采用超声波法破碎细胞(破碎功率640W,时间10min),类胡萝卜素提取效果最好,初提液类胡萝卜素的提取率约为7.62mg·(g干菌体)^-1;酸热法对色素的破坏严重。这为进一步开发利用天然色素资源提供了一定的理论依据。     

植物类胡萝卜素提取与分析技术研究进展

类胡萝卜素是所有光合生物及一些非光合原核生物和真菌合成的亲脂性天然色素, 对植物、动物和人都具有广泛的生物学作用。随着现代分析技术的快速发展, 越来越多的类胡萝卜素得以发现和利用。该文通过对植物类胡萝卜素的提取、分离纯化、含量测定和结构鉴定等方面的最新研究进展进行系统阐述, 以期为植物类胡萝卜素的有效开发利用提供技术支撑。     

红酵母超高压突变体的类胡萝卜素提取及特性研究

采用酸-热法破壁和丙酮为提取溶剂,在所优化的最佳组合条件下,从红酵母超高压突变株提取类胡萝卜素,平均提取率可达718.1μg/g干细胞。色素粗提物采用柱色谱分离纯化后,通过薄层色谱（TLC）、紫外光谱和HPLC进行分析,发现该酵母突变体的发酵产物至少含β-胡萝卜素、园酵母素和红酵母红素等3种色素,其中β-胡萝卜素含量最多,超过50%的比例。该色素提取物的光热稳定性好于先前报道的同类色素;体外清除自由基实验也表明该类胡萝卜素提取物具有良好的抗氧化活性。因此,利用该突变株发酵生产类胡萝卜素值得进一步研究和开发。     

红酵母产类胡萝卜素提取工艺的优化研究

目的:从提取溶剂及提取条件等方面对红酵母产类胡萝卜素提取工艺进行了优化研究。方法:用单因子实验对提取溶剂进行了筛选;用析因试验对提取条件进行了分析研究;通过最陡爬坡实验和中心组合设计实验,优化得到了最佳的类胡萝卜素提取条件。结果:结果表明丙酮和二甲亚砜组成的复合体系是理想的提取溶剂。溶剂添加量、提取温度、提取时间、丙酮与二甲亚砜组分比例都对红酵母产类胡萝卜素提取产生一定影响,其中溶剂添加量和丙酮与二甲亚砜组成比例的影响最为显著(P<0.001)。最佳优化提取条件为:溶剂添加量为42.66%(V/V),丙酮与二甲亚砜组成比例为62.47%(V/V),温度为20℃,提取时间为90min,在此条件下红酵母产类胡萝卜素的最大提取量为5.51μg/ml。结论:实验得到了红酵母发酵产类胡萝卜素溶剂提取条件的一个非常合适的模型。     

丝状真菌深黄被孢霉RNA的提取方法

本文在一步法的基础上,提出了一种适合于富ＲＮａｓｅ和多糖的丝状真菌的ＲＮＡ提取方法,该方法可得到完整,均一的ＲＮＡ样品,且简化了操作,同时建立起一套快速有效的ＲＮＡ样品质量检验的方法。     

常用萃取剂提取福寿螺卵中类胡萝卜素的初步研究

【背景】福寿螺为世界性恶性入侵水生动物,也是我国公布的第一批外来人侵物种之一。福寿螺大量啃食为害水稻、茭白、白莲等重要农作物,对我国南方各省农业生产造成了巨大威胁,因此,预防和控制福寿螺灾害显得尤为重要。合理利用福寿螺能有效控制福寿螺的数量和危害,是生物防治的一个重要部分。福寿螺卵中含丰富的类胡萝卜素,充分利用螺卵中的类胡萝卜素能拓展福寿螺的利用途径和方法。【方法】为探寻福寿螺卵中类胡萝卜素的提取方法,本研究采用甲醇、无水乙醇、丙酮、乙酸乙酯、二氯甲烷、石油醚等6种常用萃取剂提取福寿螺卵中类胡萝卜素,用紫外可见光分光光度计测定其含量。【结果】结果显示,不同萃取剂中类胡萝卜素的提取量不同,醇类为较适合的提取液（甲醇〉无水乙醇〉丙酮）。【结论与意义】本研究对福寿螺卵中类胡萝卜素的提取方法进行了探索和研究,找出了合适的提取液,为拓展福寿螺的利用途径,以及福寿螺的综合防治提供了参考。     

A nondestructive method for extracting maternally derived egg yolk carotenoids

ABSTRACT.   Maternally deposited carotenoids are a prominent component of egg yolk and are vital for the development and growth of the embryo. In most studies of avian yolk carotenoids, eggs are destructively sampled and this may limit both the number of clutches studied and the research questions addressed. We describe an empirical field trial for a nondestructive biopsy method to extract small samples (0.05 ml) of egg yolk for high-performance liquid chromatography (HPLC) analysis of yolk carotenoid concentrations. We sampled 180 clutches ( N = 44 biopsies) of two species of introduced thrushes (genus Turdus ) from agricultural habitats in central North Island, New Zealand. Once the protocol was established, all biopsied eggs from clutches that were not depredated or deserted before candling were found to be developing normally after 3–5 d of incubation ( N = 28) and all hatched. Biopsy samples (>0.02 g) produced concentrations of yolk carotenoids (and variances) that were statistically indistinguishable from whole yolk destructive samples. In addition, our samples (>0.02 g) confirmed previously reported differences in yolk carotenoid concentrations between the two thrush species and revealed a significant decline in yolk carotenoid concentration with laying order. Further examination of how variability in yolk carotenoid concentration and identity influences offspring sex, success, and survival or, later in life, reproductive success and ability to efficiently incorporate dietary carotenoids into both integument and immune tissues will require larger sample sizes. Studies to date have been restricted by the number of destructive samples that investigators are willing (or permitted) to obtain from wild species. Thus, we hope that our nondestructive method of sampling yolk will promote further examination of the links between carotenoid uptake from the environment and maternal investment in the avian yolk.     

Cellophane based mini-prep method for DNA extraction from the filamentous fungus Trichoderma reesei

Background  

Methods for the extraction of DNA from filamentous fungi are frequently laborious and time consuming because most of the available protocols include maceration in liquid nitrogen after the mycelium has been grown in a liquid culture. This paper describes a new method to replace those steps, which involves the growth of the mycelium on cellophane disks overlaid on solid medium and the use of glass beads for cell wall disruption.     

A rapid method for efficient gene replacement in the filamentous fungus Aspergillus nidulans

The construction of mutant fungal strains is often limited by the poor efficiency of homologous recombination in these organisms. Higher recombination efficiencies can be obtained by increasing the length of homologous DNA flanking the transformation marker, although this is a tedious process when standard molecular biology techniques are used for the construction of gene replacement cassettes. Here, we present a two-step technology which takes advantage of an Escherichia coli strain expressing the phage λ Red(gam, bet, exo) functions and involves (i) the construction in this strain of a recombinant cosmid by in vivo recombination between a cosmid carrying a genomic region of interest and a PCR-generated transformation marker flanked by 50 bp regions of homology with the target DNA and (ii) genetic exchange in the fungus itself between the chromosomal locus and the circular or linearized recombinant cosmid. This strategy enables the rapid establishment of mutant strains carrying gene knock-outs with efficiencies >50%. It should also be appropriate for the construction of fungal strains with gene fusions or promoter replacements.     

丝状真菌糖生物学

蛋白质的糖基化修饰是一种保守的真核生物蛋白质翻译后修饰,存在于从酵母到人的所有真核生物中,赋予了蛋白质功能的多样性。目前对蛋白质糖基化修饰的了解主要来源于对酵母和哺乳动物细胞的研究,但单细胞真核生物或动物细胞水平的研究,很难反映糖基化修饰在多细胞真核生物的发育分化过程中的复杂功能。由于丝状真菌是多细胞真核生物,有相对简单的发育分化过程,因而是研究多细胞真核生物糖基化功能的理想模型之一,在过去10年中,丝状真菌的糖生物学研究开始受到重视,目前的研究结果表明糖基化修饰与丝状真菌的生长、发育密切相关。     

中华稻蝗脂肪提取方法

以丙酮和石油醚的混合液为提取液,通过正交试验,对中华稻蝗Oxyachinensis(Thunberg)成虫体脂肪进行溶剂提取条件的优化研究,并分别讨论了各因素对中华稻蝗成虫体脂肪提取率的影响。结果表明:料液比4/25、溶剂混比1/1(丙酮:石油醚)、提取时间8h、水浴温度85℃为中华稻蝗脂肪提取的最佳工艺条件,在此条件下,脂肪得率可达5.875%。     

A rapid method for chromatin structure analysis in the filamentous fungus Aspergillus nidulans.

A rapid method for nuclease digestion of Aspergillus nidulans chromatin is described. It overcomes the need for nuclear purification or protoplast preparation. The method is valid for the analysis of the nucleosomal repeat length in bulk chromatin, and allows the analysis of nucleosome phasing at a specific locus.     

Rapid purification method for the 26S proteasome from the filamentous fungus Trichoderma reesei

We have developed a fast and simple two column chromatographic method for the purification of the 26S proteasome from the filamentous fungus Trichoderma reesei that simplifies the overall procedure and reduces the purification time from 5 to 2.5 days. The combination of only the anionic exchange POROS^® HQ column (Applied Biosystems) together with a size exclusion column has not been used previously for proteasome purification. The purified complex was analysed further by two-dimensional electrophoresis (2DE) and examined by transmission electron microscopy (TEM). A total of 102 spots separated by 2DE were identified by mass spectrometry using cross-species identification (CSI) or an in-house custom-made protein database derived from the T. reesei sequencing project. Fifty-one spots out of 102 represented unique proteins. Among them, 30 were from the 20S particle and eight were from the 19S particle. In addition, seven proteasome-interacting proteins as well as several non-proteasome related proteins were identified. Co-purification of the 19S regulatory particle was confirmed by TEM and Western blotting. The rapidity of the purification procedure and largely intact nature of the complex suggest that similar procedure may be applicable to the isolation and purification of the other protein complexes.     

Two unusual glycerophospholipids from a filamentous fungus, Absidia corymbifera

The chloroform-methanol extractable lipids of the soil filamentous fungus Absidia corymbifera VKMF-965 account for about 20% by weight of dry cells and are composed of low-polarity constituents (about 75% of the total lipids), such as triacylglycerols (mainly), diacylglycerols, sterols and free fatty acids, as well as of glycolipids (about 3%) and phospholipids. The last consist largely of components common to the fungal lipids, namely, phosphatidylethanolamine (38% of the total phospholipids), phosphatidyl-myo-inositol (16%), diphosphatidylglycerol (12%), phosphatidylcholine (7%), phosphatidic acid (6%) and phosphatidylglycerol (3%), and two unusual phospholipids, PL1 (6%) and PL2 (9%). Based on the infrared (IR), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectra along with the results of degradation experiment, these two phospholipids have been established to be 1,2-diacyl-sn-glycero-3-phospho(N-acetylethanolamine), or N-acetyl phosphatidylethanolamine, and 1,2-diacyl-sn-glycero-3-phospho(N-ethoxycarbonyl-ethanolamine), respectively. These structures have been confirmed by preparing similar phospholipids from the phosphatidylethanolamine isolated from the same fungus and correlating their chromatographic behaviour, IR and (1)H-NMR spectra with those of PL1 and PL2. So far N-acetyl phosphatidylethanolamine has been detected only in cattle and human brains and a human placenta but its structure was not rigorously proved. PL2 is a novel lipid; to our knowledge no natural phospholipid with an urethane group has yet been found. The main fatty acids of both the phospholipids are n-hexadecanoic, octadecanoic and octadecadienoic ones; PL2 contains in addition a considerable amount of octadecatrienoic acid with its greater portion located at the sn-1 position.     

Pluripotency of 17beta-hydroxysteroid dehydrogenase from the filamentous fungus Cochliobolus lunatus

Cochliobolus lunatus 17beta-hydroxysteroid dehydrogenase (17beta-HSD) is pluripotent for several steroidal and nonsteroidal substrates. In the presence of NADPH the enzyme was found to reduce 3-keto groups of 4,5-dihydro steroids, 20-keto groups, and most efficiently, 17-keto groups of steroidal substrates. In addition, several quinones were accepted and found to be even better substrates as steroids due to their higher affinity for the enzyme-coenzyme complex and faster conversion of the enzyme-coenzyme-substrate complex into the corresponding products. As suggested by the competition studies quinones and 17-ketosteroids are converted by the same active center of the enzyme. For all tested substrates, the equilibrium ordered mechanism was established with NADPH binding first to the enzyme. According to our knowledge, the investigated 17beta-HSD is the first known fungal pluripotent enzyme of this type.