红曲色素发酵流加补料研究

以CG-1红曲霉菌为研究对象,研究了红曲霉菌液态发酵延长代谢稳定期的措施.实验表明:在发酵稳定期以流速为1 g·L-1·h-1葡萄糖进行流加补料能够延长代谢稳定期,发酵水平可达321 u/mL.     

外源甜菜碱对盐胁迫下枸杞光合功能的改善

研究了外源甜菜碱对盐胁迫下枸杞扦插苗叶片光合功能的影响。结果表明,外源甜菜碱能使盐胁迫下的枸杞叶片叶绿素荧光动力学参数Fo、Fm、Fv、Fv／Fm、Fm／Fo和Fv／Fo增高,使光合色素叶绿素a(Chla)、叶绿素b(Chlb)和类胡萝卜素(Car)含量明显增加,叶绿素a与b的比值(Chla／Chlb)升高,类胡萝卜素与叶绿素的比值(Car／Chl)降低,说明外源甜菜碱有利于植物对光能的捕获、吸收、传递和转换,提高叶片的光合活性,降低盐胁迫对植物的抑制作用。     

高产红曲黄色素菌株的选育

利用紫外、硫酸二乙酯、氯化锂和亚硝基胍复合诱变的方法,选育到一株高产黄色素的红曲霉突变株MYM2.经过稳定性实验证明,诱变得到的菌株稳定性较好,液态发酵试验黄色素色价达到100U/mL以上,黄色素色调达到3.5左右.此黄色素在300nm～600nm波长之间只有一个在410 nm附近的最大吸收峰,在pH 3～8之间稳定性较好.当pH小于3时,红曲黄色素不稳定,黄色素溶液变混浊,放置后有沉淀产生.     

海洋细菌E18菌株的生物学特性及其蓝紫色素稳定性的研究

从海泥中分离获得一株海洋细菌E18菌株,发现其具有稳定产生蓝紫色素的特性。对该菌的形态特征、培养特征及生理生化特征进行了研究。对该菌的分子鉴定结果表明,该菌为假交替单胞菌属细菌。萃取该菌的色素,并试验光、紫外线、热、pH、氧化剂及还原剂对该色素的影响,结果表明:该色素的最大吸收峰为579nm,紫外光对其稳定性无影响,但自然光对其有一定的消色作用。60℃~80℃温度范围对色素有一定的增色作用,而90℃以上高温可使色素消色。色素在pH3~9区域内稳定。色素对还原剂Na2SO3较为稳定,而高浓度的氧化剂H2O2可使色素改变颜色。     

Development of internal standard for lipoprotein subclass analysis using dual detection gel-permeation high-performance liquid chromatography system

The LipoSEARCH® System is an innovative lipoprotein class analysis method based on gel-permeation high-performance liquid chromatography (HPLC). This system uses a gel permeation column to separate the major lipoprotein subclasses (chylomicron, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein) in serum according to particle size and splits them into two pathways to measure total cholesterol (TC; esterified + unesterified cholesterol) and triglyceride (TG) concentrations simultaneously to obtain chromatograms for each.These chromatograms were analyzed based on the results of the calibration serum by fitting Gaussian curves to profile the 20 lipoprotein subclasses defined in detail. An important assumption of this HPLC system is its simultaneous detection of two pathways to guarantee the accuracy of each analysis. Therefore, in the present study, we investigated the development of an internal standard that can guarantee the simultaneous detection of this system by adding a pigment to the serum. We focused on quinone pigments with absorption at 550 nm, which is the wavelength used for the enzymatic assay of TC and TG concentrations in the system. As a result, we succeeded in producing overlapping pigment peaks that appeared after the analytical chromatograms in two pathways. It is also suggested that the pigment solution as an internal standard is stable in freezing storage and has little effect on the analysis. The developed internal standard is expected to contribute to the accuracy assurance of lipoprotein analysis by this dual-detection HPLC system.     

Ex-vivo models of the Retinal Pigment Epithelium (RPE) in long-term culture faithfully recapitulate key structural and physiological features of native RPE

The Retinal Pigment Epithelium (RPE) forms the primary site of pathology in several blinding retinopathies. RPE cultures are being continuously refined so that dynamic disease processes in this important monolayer can be faithfully studied outside the eye over longer periods. The RPE substrate, which mimics the supportive Bruch’s membrane (BrM), plays a key role in determining how well in-vitro cultures recapitulate native RPE cells. Here, we evaluate how two different types of BrM substrates; (1) a commercially-available polyester transwell membrane, and (2) a novel electrospun scaffold developed in our laboratory, could support the generation of realistic RPE tissues in culture. Our findings reveal that both substrates were capable of supporting long-lasting RPE monolayers with structural and functional specialisations of in-situ RPE cells. These cultures were used to study autofluorescence and barrier formation, as well as activities such as outer-segment internalisation/trafficking and directional secretion of key proteins; the impairment of which underlies retinal disease. Hence, both substrates fulfilled important criteria for generating authentic in-vitro cultures and act as powerful tools to study RPE pathophysiology. However, RPE grown on electrospun scaffolds may be better suited to studying complex RPE-BrM interactions such as the formation of drusen-like deposits associated with early retinal disease.     

Shaping the eye from embryonic stem cells: Biological and medical implications

Organogenesis is regulated by a complex network of intrinsic cues, diffusible signals and cell/cell or cell/matrix interactions that drive the cells of a prospective organ to differentiate and collectively organize in three dimensions. Generating organs in vitro from embryonic stem (ES) cells may provide a simplified system to decipher how these processes are orchestrated in time and space within particular and between neighboring tissues. Recently, this field of stem cell research has also gained considerable interest for its potential applications in regenerative medicine. Among human pathologies for which stem cell-based therapy is foreseen as a promising therapeutic strategy are many retinal degenerative diseases, like retinitis pigmentosa and age-related macular degeneration. Over the last decade, progress has been made in producing ES-derived retinal cells in vitro, but engineering entire synthetic retinas was considered beyond reach. Recently however, major breakthroughs have been achieved with pioneer works describing the extraordinary self-organization of murine and human ES cells into a three dimensional structure highly resembling a retina. ES-derived retinal cells indeed assemble to form a cohesive neuroepithelial sheet that is endowed with the intrinsic capacity to recapitulate, outside an embryonic environment, the main steps of retinal morphogenesis as observed in vivo. This represents a tremendous advance that should help resolving fundamental questions related to retinogenesis. Here, we will discuss these studies, and the potential applications of such stem cell-based systems for regenerative medicine.     

The Physiological Response of Phyllostachys edulis under the Elevated Atmospheric Ozone

In order to provide theoretical evidences for bamboo cultivation under the background of climate change, the method of open top chambers (OTCs) was employed to approach the effects of elevated ozone on photosynthetic pigments content, lipid peroxidation and anti oxidation enzymes in the leaves of Phyllostachys edulis. The result indicated that with the increasing of ozone concentration, the content of the chlorophyll, carotenoid and SOD activity decreased, while the content of souble protein, relative electrical conductivity, contents of MDA, O2- and the activity of POD increased.Correlation analyses showed that there was significant negative correlation between O2- content and SOD activity as well as photosynthetic pigment,whereas significant positive correlation between O2- and relative electeical conductivity, MDA, POD as well as soluble protein. It was summarried that, on one hand, long time exposure to high ozone concentration exposure, accelerated the aging of leaves, intensified the damage to membrane lipid, and destroyed the structure of cell membrane and the function of anti oxidation system as well. It affected the regular growth of P.edulis. This research was conducted to provide theoretical evidence for bamboo cultivation during this time of possible climate change.     

Chloroplast Composition and Structural Differences in a Chlorophyll-reduced Mutant of Oilseed Rape Seedlings

缺乏叶绿素的油菜突变体的叶绿体组成和结构变化 赵云 杜林方* 杨胜洪 李世崇 张义正 （四川大学生命科学学院,成都610064）     

高产大豆品种的高光效特性

利用荧光射光谱技术及荧光诱导动力学技术,研究了不同基因型大豆,高产大豆黑农４０和黑农４１及你燕大豆黑农３７的光能吸收,传递和转化等特性。结果表明,高产大豆的叶绿素（Ｃｈｌ）和类胡萝卜素（Ｃａｒ）的含量增高于黑农３７,但不同的品种种差异幅度有所不同。吸收光谱表明高产大豆叶经体对光能有更强的吸收能力;Ｍｇ＾２＋对高产大豆叶绿体ＰＳＩ和ＰＳⅡ之间激发能分配的有力均高于低产品种;高产大豆叶片ＰＳⅡ原初光能