极端嗜盐菌色素的研究

嗜盐菌色素是一种从微生物（嗜盐菌）中提取精制成的天然红色素（菌红素）。我们对新疆发现的wy－2a极端嗜盐菌所产生的色素进行了分离、提纯、理化性质、结构和分子量的测试．主要色素成份色素甲分子量为572．次要组分色素已分子量为407，是属类胡萝卜素化合物．该类胡萝卜素与文献报道有所差异[1]

套袋时间对梨果皮色素和果实品质的影响

以南果梨为试材 ,研究了不同时期套袋对梨果皮色素的影响。试验结果表明 :套袋后叶绿素、类葫萝卜素的含量明显下降 ,而且套袋越早下降越多。套袋后叶绿素总的趋势虽和对照非常相似 ,但果皮中类葫萝卜素含量的趋势却发生了变化。套袋对花青素的合成有影响 ,有使花青素的合成减少的趋势 ,但这种影响程度受套袋时期决定。同时 ,套袋使果实的含糖量、含酸量增加。

Responses of Chlorophyll Fluorescence and Carotenoids Biosynthesis to High Light Stress in Rice Seedling Leaves at Different Leaf Position

In the present study, we investigated the changes of photosynthesis, chlorophyll fluorescence and the content of carotenoid pigments in rice (Oryza sativa L.) seedling leaves and their responses to high light. The results showed that the rate of photosynthesis, the contents of individual and total carotenoids and the pool size of xanthophyll cycle decreased with age increasing of the leaf. When the leaves were exposed to high light for 2 h, the qN of mature leaf (5th leaf) increased more significantly than that of younger (6th leaf) and older leaves (3rd and 4th leaf). Comparing with the leaves before exposure to high light, the excitation pressure on PSⅡ (1- qP ) increased by 44%, 57%, 19% and 45% in the 3rd, 4th, 5th and 6th leaf under high light, respectively. The highest content of carotenoids and the greatest conversion of violaxanthin to zeaxanthin were found in the 5th leaf, and it was consistent with the 5th leaf exhibiting the strongest resistance to high light. Our results suggested that the ability of rice leaf to resist photoinhibition is related to the level of carotenoids and the ability of carotenoids biosynthesis.

Correlation between Carotenoids Content and Several Quality Traits of Wheat Varieties

A total of 31 wheat varieties（lines） released in different years in Huanghuai Area were selected as materials so as to study the carotenoids content,lipoxygenase activity, and some other quality traits of wholemeal. Results showed that carotenoid content and other quality traits had highly significant differences among varieties. Carotenoids content was significantly positive correlated with watersoluble pentosan and yellowness. Carotenoids content was significantly negative correlated with peak viscosity, hold through, breakdown, final viscosity, unit weight,formation time, and was negative correlated with peak time, protein content and stability time. According to cluster analysis, carotenoid contents in 31 varieties were divided into three major groups： one group had common carotenoid content, which included 19 varieties such as Meng 0318; one group had relatively low carotenoid content, which included 10 varieties such as Luomai23; and the last group had relatively high carotenoid content, which included 2 varieties such as Huaimai22. The average carotenoid contents of the three groups were 1.93, 1.07 and 2.99 mg/kg respectively.

Determination and Comparison of Pigment Contents in Leaves of Punica granatum L. Hybrids with Different Leaf Colors

[Objective] This study aimed to investigate the reason for the different leaf colors of pomegranate hybrid progeny. [Method] Spectrophotometry was used to determine the contents of three pigments, including chlorophyll, carotenoid and anthocyanin, in the leaves of eight pomegranate individuals and their parents at growth stage. [Result] The results showed that during the early growth stage, the anthocyanin contents of four pomegranate individuals with red leaves were higher than the control, to be specific, the anthocyanin content of No.5 pomegranate individual reached the highest of 4.12 mg/g; the chlorophyll and carotenoid contents of four pomegranate individuals with yellow-green leaves showed consistent dynamic trends with the control, to be specific, the chlorophyll content and chlorophyll/carotenoid ratio of No.4 pomegranate individual reached the highest, while the chlorophyll a/carotenoid b ratio of No.3 pomegranate individual was the lowest. During vigorous growth stage, the contents of chlorophyll, carotenoid and anthocyanin of eight pomegranate individuals showed consistent dynamic trends, with no significant difference with the control. Analysis of variance indicated that there were significant differences in the contents of chlorophyll and carotenoid among different pomegranate individuals at different growth stages and in the content of anthocyanin among different pomegranate individuals, while no significant difference was observed in the chlorophyll/carotenoid ratio among different pomegranate individuals at different growth stages. [Conclusion] The differences in leaf colors among pomegranate hybrid progeny are caused by different contents and ratios of anthocyanin and chlorophyll at growth stage.

Effects of Different Baking Processes on Carotenoid Content in Upper Leaves of Fluecured Tobacco

[Objective] We aimed to improve the quality of flue-cured tobacco with K326 upper leaves and explore the optimal tobacco baking process in Chongqing tobacco-producing region. [Method] Four different baking processes （endogenetic force moisture-removing flue-curing technique, exogenetic force moisture-removing flue-curing technique, three-stage flue-curing process, three-stage and six-step flue- curing process） were adopted in this research to investigate the effects of different baking processes on carotenoid content of same-maturity degree upper leaves of the flue-cured tobacco K326. [Result] The results showed at the yellowing and color fixing stages, the carotenoids were most fully decomposed in endogenetic force moisture-removing flue-curing technique. The decomposed carotenoid content was lowest in exogenetic force moisture-removing flue-curing technique, for which the carotenoid content was highest （50.53 mg/g）. [Conclusion] At the yellowing and color fixing stages, exogenetic force moisture-removing flue-curing technique was most conducive to the carotenoid accumulation in tobacco baking process.

Kinetic Fluorescence Spectral Analysis of Core Antennas CP43 and CP47 of Photosystem Ⅱ with Ultrafast Time-resolved Technology

Ultrafast time_resolved fluorescence experiments have been performed with core antennas CP43 and CP47 of PS Ⅱ. Their dynamic fluorescence spectra were obtained with excitation wavelength 514.5 nm. For CP43, the emission spectrum was found to be from 640 to 780 nm with a peak at ～680 nm and the lifetime of fluorescence was 3.54 ns. For CP47, the emission spectrum was from 630 to 775 nm with a peak at ～691 nm and the fluorescence lifetime was 3.22 ns. The fluorescence emission efficiencies of Chl a in CP43 and CP47 were calculated to be approximately 38.3% and 40.6%, respectively. The energy transfer from β_Car to Chl a in CP43 and CP47 was discussed. The rates of energy transfer from β_Car to Chl a were measured to be about 9.6×10 11 s -1 and 1.3×10 12 s -1 and energy transfer efficiencies 47.5% and 66.5% respectively. The edge_edge distances between β_Car and Chl a in CP43 and CP47 were estimated to be ～0.110 nm and ～0.085 nm respectively.

Lipoxygenase Activity and Its Relationship with Traits of Whole-mill Color in Wheat

130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.

雄性孔雀华丽的尾屏

与孔雀浮华艳丽的尾屏一样,雄性斑马雀艳丽的嘴喙也帮助它们吸引异性。英国生物学家布罗特研究了英国的斑马雀和法国燕八哥,发现那些拥有亮红色喙的斑马雀和橙色喙的燕八哥吸引雌性能力最强,因为这表示最亮丽的喙的雄性主人拥有一级棒的身体状况,具有最强的免疫功能。 科学家发现不同动物具有的从亮红色到黄色色彩的关键物质都是类胡萝卜素。

Disruption of phytoene desaturase gene results in albino and dwarf phenotypes in Arabidopsis by impairing chlorophyll, carotenoid, and gibberellin biosynthesis

Carotenoids play an important role in many physiological processes in plants and the phytoene desaturase gene （PDS3） encodes one of the important enzymes in the carotenoid biosynthesis pathway. Here we report the identification and analysis of a T-DNA insertion mutant of PDS3 gene. Functional complementation confirmed that both the albino and dwarfphenotypes ofthepds3 mutant resulted from functional disruption of the PDS3 gene. Chloroplast development was arrested at the proplastid stage in thepds3 mutant. Further analysis showed that high level ofphytoene was accumulated in the pds3 mutant. Addition of exogenous GA3 could partially rescue the dwarf phenotype, suggesting that the dwarf phenotype ofthepds3 mutant might be due to GA deficiency. Microarray and RT-PCR analysis showed that disrupting PDS3 gene resulted in gene expression changes involved in at least 20 metabolic pathways, including the inhibition of many genes in carotenoid, chlorophyll, and GA biosynthesis pathways. Our data suggest that the accumulated phytoene in the pds3 mutant might play an important role in certain negative feedbacks to affect gene expression of diverse cellular pathways.

Nutrient Application Model Affects the Contents of Chlorophyll and Carotenoid in Functional Leaves of Early Rice

The objective of this study was to investigate the effects of different nutri-ent application models on the contents of chlorophyl and carotenoid in the functional leaves of early rice. Using rice cultivar Xiangzaoxian45 as experimental materials, the experiment was performed by designing 6 treatments, i.e., T1 （fertilization without nitrogen）, T2（local conventional fertilization）, T3（fertilization for high yield and high effi-ciency）, T4 （fertilization for super high yield）, T5 （fertilization application for super high yield and high efficiency A） and T6 （fertilization application for super high yield and high efficiency B） in two experimental plots Yiyang and Xiangyin. The results showed that T3 respectively increased the contents of chlorophyl and carotenoid at fil ing stage by 29.27%, 38.20% and 13.16%, 30.12% in Yiyang and Xiangyin, as wel as yield of early rice by 4.20%, 4.80% to T2 on the condition of saving 20% ni-trogen fertilizer. Additional y, T5 and T6 on the condition of saving 16.7% nitrogen fertilizer by T4 increased the contents of chlorophyl and carotenoid of fil ing stage by 53.91%, 53.73% and 35.95%, 37.47% in Yiyang and Xiangyin, as wel as yield of early rice by 16.60%, 18.75% to T2 in Yiyang; increased the contents of chlorophyl and carotenoid at fil ing stage by 57.82%, 56.80% and 54.88%, 57.03% in Yiyang and Xiangyin, as wel as yield of early rice 10.10%, 6.75% to T2 in Xiangyin. More-over, there was a significant correlation or an extremely significant correlation be-tween yield and the contents of chlorophyl and carotenoid at different soil fertility level （P〈0.05 or P〈0.01）. Therefore, nutrient application plays an important role in the contents of chlorophyl and carotenoid in the functional leaves of early rice.

PHYSIOLOGICAL INHIBITORY EFFECT OF OCS IN ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA (TREBOUXIOPHYCEAE, CHLOROPHYTA)

Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.

Neurospora lca-1 Regulates Conidiation and Carotenoid Production

[Objective] This study aimed to investigate the regulatory mechanisms of carotenoid biosynthesis in Neurospora crassa. [Method] Gene knockout mutants pro- ducing less carotenoid were screened from 6 087 mutants; the yield of carotenoid and asexual spore was measured; finally fluorescent quantitative real-time PCR was adopted to analyze the transcription of genes related to carotenoid synthesis and asexual sporulation, [Result] Six knockout mutants produced less carotenoid. In one of them, the yield of both carotenoid and asexual spore reduced, because the gene which encodes an ATP-dependent chromatin remodelling complex ATPase chain ISW1 was knocked out. This gene was named /ca-1 in this study. And the /ca-1 deletion result- ed in a reduction of 88% in conidial production and a decrease of 81% in carotenoid production. [Conclusion] The Ica-1 positively regulates the carotenoid syn- thesis and asexual sporulation in N. crassa.

Carotenoids Particle Formation by Supercritical Fluid Technologies

Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed that micronized quercetine particles with mean particle size of 1.0-1.5 μm can be made via solution enhanced dispersion by supercritical fluids(SEDS) process,in which CO2 worked as turbulent anti-solvent;while for astaxanthin,micronized particles with mean particle size of 0.3-0.8 μm were also made successfully by rapid expansion supercritical solution(RESS) process.

Survival,recovery and microcystin release of Microcystis aeruginosa in cold or dark condition

Microcystis often dominates phytoplankton in eutrophic lakes and must survive a long period of cold or dark conditions. However, the survival strategies of Microcystis to withstand cold or dark stress are less well known. In this study, we conducted experiments on the responses of two toxic Microcystis aeruginosa strains （FACHB-905 and FACHB-915） and their microcystin release in conditions of low temperature （15℃ or 4℃, with illumination） or darkness, and subsequent recovery in standard conditions （25℃ with illumination）. On exposure to 15℃, a small decrease in cell viability was observed, but the cell number increased gradually, suggesting that M. aeruginosa FACHB-905 and FACHB-915 cells seem in general tolerant in 15℃. Interestingly, our results show that a higher carotenoid content and microcystin release potentially enhance the fitness of surviving cells at 15℃. M. aeruginosa cells exposed to lower temperature light stress （4℃） did not completely lose viability and retained the ability to reinitiate growth. In darkness, the maximum quantum yield （Fv/Fm） and the maximum electron transport rate （ETRmax） values and cell viability of M. aeruginosa cells gradually decreased with time. During the recovery period, the photosynthetic efficiency of M. aeruginosa reverted to the normal level. Additionally, M. aeruginosa FACHB-905 and FACHB-915 exposed to low temperature had increased caspase-3-1ike activity and DNA fragmentation, which suggests the occurrence of a type of cell death in M. aeruginosa cells under cold stress similar to programmed cell death. Overall, our findings could confer certain advantages on the Microcystis for surviving cold or dark conditions encountered in the annual cycle, and help explain its repeated occurrence in water blooms in large and shallow lakes.

Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically

The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematocoecus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba＇s method, alkali treatment destroys chlorophyll. However, we found that： 1） carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2） dimethyl sulfoxide （DMSO）-extracted chlorophyll of green Haematococeus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract.

Responses of antioxidant defense system of epilithic mosses to drought stress in karst rock desertified areas

Barbula fallax Hedw., Erythrodontium julaceum(Schwaegr.) Par., and Bryum argenteum Hedw. are typical rock mosses growing on rocks in different terrestrial habitats. In this study, B. fallax and E. julaceum, which are epilithic mosses growing in rock desertification in Guizhou, China, were used as ecophysiological mosses in a combination of field investigations and laboratory experiments. We also investigated the reference moss B. argenteum, which is a widely distributed moss in habitats with soil as substrate. Our research focused on the response of the antioxidant defense system of epilithic mosses to drought stress. Most antioxidant defense indicators increased initially, then declined at later stages of drought stress. In contrast, the carotenoid content increased constantly. In addition, there was an initial increase(albeit variable) in relative membrane permeability, with this parameter showing a parabolic trend in all of the epilithic mosses. Among the three species, E. julaceum demonstrated the strongest resistance followed by B. fallax and then by B. argenteum. The epilithic mosses displayed stronger resistance compared to the native mosses; the increase in O_2 content and other reactive oxygen species(ROS) at the early stage of drought stress induced the enzymatic and non-enzymatic scavenging systems tosequester ROS. Moreover, the radical scavenging ability and strong drought tolerance was maintained. The longterm growth of bryophyte under drought conditions in a karst environment can help eliminate the intense response of mosses to drought stress as they adapt.

Study on Extraction Method of Carotenoids from Citrus Leaves

In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experiment and orthogonal experiment.The results showed that the optimum extraction condition was:the ration of ethanol and acetone 1∶1(v/v,containing 0.1%BHT),solid-liquid ratio 1∶30(g/mL),extraction time 7 min,ultrasonic power 240 W,extraction frequency 3 times.Under the above condition,the extraction rate of carotenoids was 85.98%.

Isolation and optimization of production of Astaxanthin from Antarctic yeast Rhodotorula sp. NJ298

Rhodotorula sp. NJ298 which could produce carotenoids was isolated from Antarctic sea ice. The major carotenoid was identified as astaxanthin by Liquid Chromatography/Mass Spectrometry （LC/MS）, and its content accounted for 87.62% of total carotenoids （1,786 μg/g）. High Performance Liquid Chromatogrephy （HPLC） analysis showed that the purity of the astaxanthin reached about 96. 16% through a simple purification. Maximum astaxanthin production （1,908μg/g） was obtained when the yeast was grown at 10 ℃ in seawater medium containing 5 g/L sodium acetate, 5 g/L peptone, 0.5 g/L NaC1, 0.01 g/L KH2PO4; 0.01 g/L MgSO4·7H20 and 0.001 g/L FeSO4·7H20 at pH 7.5.