四种松针粉中β－胡萝卜素含量的分析

本文用分光光度──多波长线性回归──计算机联用的方法,处理二组份体系,不经物理或化学分离,直接测出杜松、油松、云杉、樟子松针叶中β－胡萝卜素的含量,结果表明,这四种松针粉β－胡萝卜素含量较高,是一种值得推广应用的植物资源。     

四种松针粉中β—胡萝卜素含量的分析

本文用分光光度－－多波长线性回归－－计算机联用的方法,处理二组份体系,不经物理或化学分离,直接测出杜松、油松、云彬、樟子松针叶中β－胡萝卜素的含量,结果表明,这四种松针粉β－胡萝卜素含量较高,是一种值得推广应用的植物资源。     

β-胡萝卜素的生物合成与发酵促进剂

本文论述了β－胡萝卜素的生物合成途径及某些发酵助剂对微生物产β－胡萝卜素的影响。据对甘些植物和真菌产生β－胡萝卜素的研究,认为β－胡萝卜素及相关类胡萝卜素是一类自己酰ＣＯＡ开始的次生代谢产物。通过大量的研究实例表明,添加合适的发酵促进剂是提高β－胡萝卜素产量和降低生产成本非常有效的工艺学途径。     

紫花芒果后熟过程中主要类胡萝卜素含量的变化

紫花芒果后熟过程中主要类胡萝卜素含量的变化周玉蝉,唐友林,谭兴杰（中国科学院华南植物研究所广州５１０６５０）关键词：总类胡萝卜素;α－胡萝卜素;β－胡萝卜素;叶黄素;芒果芒果以富含维生素Ａ原——卜胡萝卜素而著称,而果实中类胡萝卜素含量的变化与芒果后熟...     

紫苏化学成分分析

对紫苏（Ｐｅｒｉｌｌａｆｒｕｔｅｓｃｅｎｓｖａｒ．ａｒｇｕｔａ）植物叶片及种子进行了化学成分分析,结果表明,紫苏叶片中粗蛋白含量较高,为２８％,β－胡萝卜素含量为２４．７ｍｇ／ｋｇ,全株挥发油含量为０．２２％～２．７０％;紫苏种子油脂肪酸中α－亚麻酸含量为６２．９％,研究结果为合理开发利用我国野生紫苏植物资源提供了重要依据。     

丝状真菌SC－2产β－胡萝卜素的研究

利用改良的ＳＭＡ培养基富集培养从植物的落花上分离筛选出的产β─胡萝卜素的菌株ＳＣ—２。该菌株在以棉籽饼粉为主要原料的培养基上生长良好。最高生物量达５４ｍｇ干菌体／ｍｌ培养液。胡萝卜素含量１．８５ｍｇ／ｇ干菌体。ＨＰＬＣ测定β─胡萝卜素占总胡萝卜素的９０．５％。     

三孢布拉霉JM9207合成油脂的研究

STUDIESONSYNTllliSISOFLIPIDS！NBLAKESEAIRliyl,nnxJIANGWen－HouSHANZhi-PingMENGYu（JangsuInstituteofMicrobiology．Wuxi214063）用三抱布拉霉发酵生产卜胡萝卜素需要在培养基中加入植物油,它能显著提高胡萝卜素产量,该菌在吸收利用植物油脂合成胡萝卜素过程中也在细胞内积累丰富的油脂。本文研究了该菌的油脂合成,结果表明,三抱布拉霉菌有较强的吸收同化培养基中添加的植物油并合成菌体自身油脂的能力。菌体油脂脂肪酸组分中C;。和C;。酸含量占绝大多数,其中亚油酸和油酸占62～84％。菌体油脂脂肪酸…     

胡萝卜(Daucus carota L.)中主要胡萝卜素和番茄红素含量的QTL分析

以高胡萝卜素自交系P50006和HCM A.C.为亲本构建的F2群体为作图群体,对胡萝卜中α-胡萝卜素、α-胡萝卜素、总胡萝卜素和番茄红素含量进行QTL定位及遗传分析。结果表明,α、β-胡萝卜素、总胡萝卜素和番茄红素含量的广义遗传力分别为0.75、0.50、0.31和0.93。遗传图谱包含91个SRAP(Sequence-related amplified polymorphism)标记,分布于9个连锁群,总长度502.9cM,标记间平均距离5.5cM。除α-胡萝卜素含量外,α-胡萝卜素、总胡萝卜素和番茄红素含量分别检测到1个主效QTL,均为加性遗传效应,分别解释表型变异为12.79%、12.87%和14.61%。此外,α-胡萝卜素和番茄红素含量还分别检测到1对上位性QTL,最大遗传效应分别为显性×加性互作和显性×显性互作,分别解释表型变异为15.1%和6.5%。文章中与QTL连锁的分子标记可用于高胡萝卜素、番茄红素的种质筛选和聚合育种。     

外源MeJA胁迫对盐生杜氏藻生理生化特性的影响

研究外源茉莉酸甲酯(MeJA)对盐生杜氏藻细胞β-胡萝卜素含量、叶绿素含量、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性的影响。结果表明,当外源MeJA浓度为0～100μmol/L时,随着MeJA浓度的升高,β-胡萝卜素和叶绿素含量呈上升趋势,当MeJA浓度为100μmol/L时,盐生杜氏藻β-胡萝卜素和叶绿素含量最高,当MeJA处理浓度大于100μmol/L时,盐生杜氏藻β-胡萝卜素和叶绿素含量逐渐降低。生理生化结果分析表明,外源MeJA处理可提高盐生杜氏藻POD酶和SOD酶活性,随着MeJA浓度的增加,SOD酶活性呈逐渐上升的趋势,POD酶活性呈先上升后下降的趋势,与β-胡萝卜素含量、叶绿素含量的变化趋势基本一致,说明外源MeJA处理可诱导盐生杜氏藻β-胡萝卜素积累可能与叶绿素含量、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性有关。     

丝状真菌SC—2产β—胡萝卜素的研究

利用改良的ＳＭＡ培养基富集培养从植物的落花上分离筛选出的产β－胡萝卜素的菌株ＳＣ－２。该菌株在以棉籽饼粉为主要原料的培养基上生长良好。最高生物量达５４ｍｇ干菌体／ｍｌ培养液。胡萝卜素含量１．８５ｍｇ／ｇ干菌体。ＨＰＬＣ测定β－胡萝卜素占总胡萝卜素的９０．５％。     

Effects of soil fertilization and covering of the culture with plastic film on the provitamin A content of early lettuces

Summary Different growing conditions of early lettuces were assayed. Some plots of lettuces were grown covered with a perforated plastic sheet, and other plots were not covered. The soil of some plots was fertilized with a usual N+P+K+S fertilizer used at a normal rate, and the soil of other plots with a fertilizer containing only nitrogen at a rate about 40 times lower than the normal one for N. The total carotenes (provitamin A) contents of the ripe lettuces were measured. Covering with a plastic sheet always decreased the total carotenes contents. The N+P+K+S fertilizer used at normal rate increased, relatively to the nitrogen fertilizer lacking of P+K+S and used at low rate, the total carotenes contents of the non-covered lettuces, but had no or low effect on the total carotenes contents of the covered lettuces.     

β-Carotene biosynthesis by extracts of the C115 mutant of Phycomyces blakesleeanus

A cell extract of the yellow C115 car-42 mad-107(?) mutant of Phycomyces blakesleeanus, capable of converting MVA-[2-¹⁴C] into isoprenoids, was used to investigate the formation of β-carotene. The incorporation of radioactivity into β-carotene was reduced by the addition of unlabelled carotenes, solubilised using detergent, to the incubation mixtures. On reisolation of these carotenes after anaerobic incubations, they were found to carry radioactivity. The relative efficiencies of these carotenes as trapping agents are discussed in relation to the pathways of carotene cyclisation and to the apparent operation of a system for the negative feedback control of carotene biosynthesis.     

Characterization of carotenes in a combination of a C18 HPLC column with isocratic elution and absorption spectra with a photodiode-array detector

Carotenes have attracted much attention in recent years for their biological function in processes such as photosynthesis. The characterization of carotenes is difficult, however, because they consist of only carbon and hydrogen atoms, without oxygen. In the present study, we systematically examined the chemical structures of more than 30 carotenes, including most of the carotenes found in phototrophic organisms, and observed their elution order using a Novapak C₁₈ HPLC column with simple isocratic elution. The elution order of the carotenes was C₃₀, C₄₀,C₄₅ then C₅₀. The C₄₀ carotenes with fewer conjugated double bonds (N) had longer retention times. With respect to the end groups, the carotenes eluted in the following order: φ, Ψ, ∈ then β end groups. Furthermore, absorption spectra in the HPLC eluent used were recorded with a photodiode-array detector. A greater N value was associated with a longer absorption maximum wavelength. Since the conjugated end groups (φ and β) influenced the absorption spectra and the non-conjugated end groups (Ψ and ∈) did not, the number of conjugated end groups (zero, one and two) was clearly distinguishable. Therefore, the chemical structures of carotenes can be easily determined by a combination of the HPLC retention times and the absorption spectra. This revised version was published online in June 2006 with corrections to the Cover Date.     

鹿蹄草植物的研究与应用

对鹿蹄草植物的自然资源分布、化学成分、药理作用、及其应用的相关研究做了综述。该植物在世界各地广泛分布、含有鹿蹄草素等多种化学成分,药理研究证明其具有抗菌、抗病毒、消炎、镇痛作用、对心脑血管系统等作用,主要应用在医药工业、食品工业和园林绿化面。最后对该属植物的研究前景做了展望。     

Identification of a gene required for cis-to-trans carotene isomerization in carotenogenesis of the cyanobacterium Synechocystis sp. PCC 6803.

A disruptive mutant of the sll0033 gene of the cyanobacterium Synechocystis sp. PCC 6803 produced primarily cis carotenes and small amounts of all-trans carotenes, but no xanthophylls, under dark conditions. Under light conditions, however, it produced normal carotenoids, that were the same as those produced by wild-type cells grown under both light and dark conditions. When the mutant cells cultured under dark conditions were irradiated, cis-isomers of carotenes were converted to all-trans lycopene. These findings demonstrate that this gene, designated crtH, is involved in the isomerization of cis-carotenes to all-trans forms in dark conditions, and that cis-carotenes were also converted to all-trans forms under light conditions by photoisomerization.     

药用植物灯盏花的研究进展

对药用植物灯盏花的特征特性、化学成分、药理作用及栽培技术,以及灯盏花的研究进展进行了综述,为进一步研究该植物提供参考．     

Survey of Thermal Energy Dissipation and Pigment Composition in Sun and Shade Leaves

A survey was conducted of the magnitude of energy dissipationin photosystem II (expressed as nonphotochemi-cal quenchingof chlorophyll fluorescence, NPQ) as well as leaf carotenoidcomposition of a wide range of different plant species growingin deep shade and/or full sun. Consistently higher levels ofthe reversible component of NPQ as well as higher degrees ofrapidly attainable de-epoxida-tion of the xanthophyll cycle(VAZ) pool were observed in sun leaves compared to deep shadeleaves. It is concluded that these altered features of the xanthophyllcycle allowed sun leaves to dissipate excess energy more effectivelyover the short term. In addition to the rapid increase in reversibleNPQ, shade leaves exhibited a slow further, and sustained, increasein NPQ. In contrast to these deep shade leaves experimentallyexposed to high PFDs, understory leaves experiencing highlyvariable PFD in their natural environment appeared to be ableto dissipate excess excitation energy adequately via xanthophyllcycle-dependent thermal dissipation. Furthermore, very consistenttrends across plant species were observed for changes in carotenoidcomposition (pools of carotenes, VAZ, and other xantho-phylls)in response to light environment, as long as it is assumed thatin some species rß-carotene can be replaced by     

Relation Between the Chlorophyll Content and Paleness of Gibberellic Acid-Treated Leaves

The rate of chlorophyll synthesis as a function of lime was examined in plants of Hordeum vitlgare L. cultivated in Knop solution containing 1 mg/1 GA₃. The action of concentration on the relations of chlorophyll components was investigated in GA₃ solutions of five different concentrations. The relations of total chlorophyll contents, including those of the a and b components, were determined from ethanol and aqueous acetone extract at various periods of treatment, at the same moment but with different concentrations of GA₃. A significant difference is noted between the chlorophyll contents of the GA₃ treated plants and those of the control. The chlorophyll contents of treated plants are decreasing. The difference increases with raising GA₃ concentration. The components were separated on thin layer with the partition method, and the spots were eluted. The density was measured with a spectrophotometer. Among the yellow components in the treated plants, the carotenes (α and β carotenes) increase as compared with the control plants. The total quantity of xanthophylls (lutein, zeaxanthine, lutein-5, 6-epoxide, violaxanthine and neoxanthine) almost equals the xanthophyll amount in the control plants; there is no significant difference. The paleness of leaves treated with GA₃ is provoked by the quantitative change of pigment components; the chlorophylls o and b decrease, the xanthophylls remain unchanged and the carotenes increase.     

The enzymatic conversion of cis-(14C)phytofluene, trans-(14C)phytofluene, and trans-zeta-(14C)carotene to more unsaturated acyclic, monocyclic, and dicyclic carotenes by a cell-free preparation of red tomato fruits

This paper reports the conversion of cis-[¹⁴C]phytofluene to trans-[¹⁴C|phytofluene and the conversion of the latter compound to trans-ζ-[¹⁴C]carotene by a soluble enzyme system obtained from the plastids of red tomato fruits. Each of these radioactive compounds was also converted to labeled neurosporene, lycopenc, α-carotene, and β-carotene by the same enzyme system. The incorporation of each substrate into more unsaturated carotenes was carried out under nitrogen at pH 7.5–8.2 (borate buffer), at 25 °C in the dark.Proof of the formation of the above carotenes from each of the three radioactive substrates was demonstrated by cochromatography with authentic nonradioactive carotenes on an alumina chromatographic column. A close correspondence between radioactivity and light absorbance for each carotene was observed. Confirmation of these conversions was achieved by cochromatography with authentic samples on thinlayer plates. Final proof for the formation of the acyclic and cyclic carotenes from the above radioactive substrates was obtained by gas-liquid chromatography of the hydrogenated products. Coincidence between mass and radioactivity was observed.Maximum conversion of cis- and trans-phytofluenes to more unsaturated carotenes by the red tomato fruit enzyme system appears to be dependent upon the presence of NADP⁺, FAD, and Tween 80. The formation of the carotenes is also increased in the presence of Mg²⁺ or Mn²⁺ ions.     

The role of oxidative stress on carotene production by Blakeslea trispora in submerged fermentation

In aerobic metabolism, reactive oxygen species (ROS) are formed during the fermentation that can cause oxidative stress in microorganisms. Microbial cells possess both enzymatic and non-enzymatic defensive systems that may protect cells from oxidative damage. The antioxidant enzymes superoxide dismutase and catalase are the two key defensive enzymes to oxidative stress. The factors that induce oxidative stress in microorganisms include butylated hydroxytoluene (BHT), hydrogen peroxide, metal ions, dissolved oxygen tension, elevated temperature, menadione, junglone, paraquat, liquid paraffin, introduction to bioreactors of shake flask inocula and synthetic medium sterilized at initial pH 11.0. Carotenes are highly unsaturated isoprene derivatives. They are used as antioxidants and as coloring agents for food products. In fungi, carotenes are derived via the mevalonate biosynthesis pathway. The key genes in carotene biosynthesis are hmgR, ipi, isoA, carG, carRA and carB. Among microorganisms, Βlakeslea trispora is the main microorganism used for the production of carotenes on the industrial scale. Currently, the synthetic medium is considered the superior substrate for the production of carotenes in a pilot plant scale. The fermentation systems used for the production of carotenes include shake flasks, stirred tank fermentor, bubble column reactor and flat panel photobioreactor. This review summarizes the oxidative stresses in microorganisms and it is focused on the current status of carotene production by B. trispora including oxidative stress induced by BHT, enhanced dissolved oxygen levels, iron ions, liquid paraffin and synthetic medium sterilized at an initial pH 11.0. The oxidative stress induced by the above factors increases significantly the production of carotenes. However, to further reduce the cost of carotene production, new biotechnological methods with higher productivity still need to be explored.