香荚兰细胞悬浮培养产生香兰素条件的研究

该文报道了碳源、氮源及吸附剂对香荚兰细胞悬浮培养产生香兰素的影响,结果表明,蔗糖比葡萄糖及果糖更适合作香荚兰细胞生长及产生香兰素的碳源,最佳蔗糖浓度为５％;当培养基中仅含ＫＮＯ３,则有利于细胞的生长和香兰素的形成,培养液中去掉ＫＮＯ３仅含ＮＨ４ＮＯ３时,细胞生长和香兰素形成均被抑制;培养基添加吸附剂后,香美兰细胞产生的香兰素含量明显增加,活性炭的效果优于ＸＡＤ-２,而且活性炭用量增加,香兰素的产量亦增加。     

诱导物及前体物对香荚兰细胞悬浮培养产生香兰素的影响

未经高温处理的黑曲霉诱导物对香荚兰细胞培养产生香兰素有促进作用;苯丙氨酸有利于香荚兰细胞生长,但对香兰素的合成无影响;阿魏酸则减缓细胞生长,明显促进香兰素的合成,但其浓度不宜高于5mmol/L。     

香荚兰豆提取物

随着香荚兰提取物愈来愈广泛地应用于医药工业和食品工业中,天然香料将成为香料工业的主流,这一事实已愈来愈清楚了。尽管天然香荚兰豆提取物的价格远远高于合成香兰素。香兰素集中体现了天然香荚兰夏与化学合成香兰素之间的明显差别。据分析,用化学方法制造的香兰素所含的香味成份只是天然香荚兰豆提取物的20％。香荚兰豆中含有200多种     

香荚兰提取物掺假的检测方法

以廉价的合成香兰素掺入香荚兰提取物是香荚兰提取业中的严重问题。它涉及每年香荚兰提取物产品的几百万美元交易。香兰素是天然香荚兰豆经熟化后的产物,而合成香兰素通常是用造纸厂的亚硫酸盐废液中的木质素合成的。1唡合成香兰素的香味强度相当于1加仑单倍(Single-fold)香荚兰提取物;前者每唡价格为0.33美元,而后者1加仑价格达40美元,很明显,以合成香兰素进行掺假,在经济效益上十分诱人。 香荚兰豆提取物掺假的检测方法:     

香荚兰酶促生香的研究

采用ＨＰＬＣ分析监测不同生香阶段和陈化期的香荚兰豆荚中香兰素等４个糖甙水解成分的含量变化。用β－葡糖甙酶处理香荚兰青荚,处理后之豆保,香兰素等４个糖甙水解成分的含量均远高于对照。对加酶量,酶促反应时间,反应温度,ｐＨ值４个关键因素进行条件筛选研究,并在所选最佳反应条件下,对不同生香阶段的豆荚进行酶处理。     

不同生香阶段香荚兰豆荚中糖甙水解成份研究

B-葡糖甙酶处理香荚兰青荚,HPLC测定酶处理豆荚和空白对照样中香兰素、香兰酸、对羟基苯甲醛、对羟基苯甲酸4个糖甙水解成份的含量。对不同生香阶段的香荚兰豆荚进行上述水解成份的定性,定量分析度监测其在豆荚完整陈化过程中含量的变化。研究结果可为完善生香加工技术,提高豆荚质量提供依据。     

高效液相色谱法分离测定香兰素

用60％乙醇提取香荚兰豆的香兰素,经高效液相色谱法分离,在紫外波长330nm处测定。选取适当的流动相,能快速、准确地测定出香兰素,最低检测含量可达到0．01μg。     

高效液相色谱法分离测定香兰素

用６０％乙醇提取香荚兰豆的香兰素,经高效液相色谱法分离,在紫外波长３３０ｍｍ处测定,选取适当的流动相,能快速,准确地测定出香兰素,最低检测含量可达到０．０１μｇ．     

诱导物及前体物对香荚兰细胞悬浮培养产生香兰素的影响

未轻高温国处理的黑曲霉诱导物对香英兰细胞培养产生香兰素有促进作用；苯丙氨酸有利于香英兰工，但对香兰素的合成无影响；阿魏酸则减缓细胞生长，明显促进香兰素的合成，但其浓度不宜高于５ｍｍｏｌ／Ｌ。     

芳香植物文摘

香兰素是香荚兰香气的最重要化学物质之一,它是在荚果熟化时由最接近的前驱体--香兰素葡萄糖苷生物合成的。香兰素葡萄糖苷在授粉后大约四个月的正在生长的豆荚里首先被检测出来,以后随着豆荚的成熟逐渐增加,直到豆荚完全成熟达到最高水平。     

THE EFFECT OF CHARCOAL ON THE GROWTH OF LEGUMINOUS PLANTS IN SAND CULTURE

The addition of small proportions (0.5-2.0 %) of activated charcoal to the rooting medium of inoculated peas in nitrogen-free sand culture resulted in marked increases in dry weight of the plants and in nitrogen fixation. Wood charcoal in larger proportions had a similar effect, while animal charcoal severely inhibited growth. The number of nodules was greatly reduced in the presence of activated charcoal, but such nodules as formed were much larger and the nodule tissues per unit weight were more active in nitrogen fixation. Activated charcoal also led to an increase in dry weight of non-inoculated peas supplied with inorganic combined nitrogen. It is tentatively suggested that these favourable effects arise from the adsorption by the charcoal of harmful excretions from roots or micro-organisms or of excess nutrients, and from the maintenance of a more favourable pH in the rooting medium. The examination of barley intersown with the peas, and the results of Kjeldahl analyses on the rooting media, provided no evidence that the enhanced fixation in the presence of activated charcoal was attended by any considerable excretion of fixed nitrogen.     

Enhanced vanillin production from recombinant E. coli using NTG mutagenesis and adsorbent resin

Vanillin production was tested with different concentrations of added ferulic acid in E. coli harboring plasmid pTAHEF containing fcs (feruloyl-CoA synthase) and ech (enoyl-CoA hydratase/aldolase) genes cloned from Amycolatopsis sp. strain HR104. The maximum production of vanillin from E. coli DH5alpha harboring pTAHEF was found to be 1.0 g/L at 2.0 g/L of ferulic acid for 48 h of culture. To improve the vanillin production by reducing its toxicity, two approaches were followed: (1) generation of vanillin-resistant mutant of NTG-VR1 through NTG mutagenesis and (2) removal of toxic vanillin from the medium by XAD-2 resin absorption. The vanillin production of NTG-VR1 increased to three times at 5 g/L of ferulic acid when compared with its wild-type strain. When 50% (w/v) of XAD-2 resin was employed in culture with 10 g/L of ferulic acid, the vanillin production of NTG-VR1 was 2.9 g/L, which was 2-fold higher than that obtained with no use of the resin.     

Post-replication repair and recombination in uvrA umuC strains of Escherichia coli are enhanced by vanillin, an antimutagenic compound

Effects of vanillin on UV killing of umuC mutant strains of E. coli were investigated in order to analyze the antimutagenic role of vanillin in mutagenesis. UV-irradiated uvrA umuC cells showed higher survival when plated on medium containing vanillin rather than medium without vanillin. This increased survival associated with exposure to vanillin was observed more clearly in uvrA umuC lexA(Ind-) and uvrA umuC recF strains. However, the effect was inhibited by additional recB recC mutations and completely blocked by an additional recA mutation. As far as tested the increased survival of UV-treated cells by vanillin was dependent on a capacity for genetic recombination. The effect of vanillin on recombination frequency between 2 plasmid DNA, pATH4 (Cmr Tcs) and pBMX7 (Apr Tcs), in a uvrA umuC background was investigated. A significantly higher frequency of plasmid recombination was observed when vanillin was present in the culture medium. These findings suggest that the antimutagenic effect of vanillin is the result of enhancement of a recA-dependent, error-free, pathway of post-replication repair.     

Histological study of somatic embryogenesis induction on zygotic embryos of macaw palm (<Emphasis Type="Italic">Acrocomia aculeata</Emphasis> (Jacq.) Lodd. ex Martius)

The aim of this paper was to describe the histological events that led to somatic embryogenesis in macaw palm (Acrocomia aculeata (Jacq.) Lodd. ex Martius). Zygotic embryos were inoculated on Y₃ medium containing 9 μM 4-amino-3,5,6-trichloropicolonic acid (picloram). Somatic embryos regenerated from nodular callus on induction medium with activated charcoal under photoperiod or without activated charcoal under dark. Many proembryos originated from the fundamental meristem after 10–20 days of culture. When transferred to medium containing activated charcoal, under photoperiod, calli regenerated into somatic embryos of unicellular origin. These embryos had protoderm, plumule and procambial strands and some of them could germinate. After 30–40 days of culture, meristematic masses grew from procambial cells. The masses generated nodular callus, and after transfer to medium without activated charcoal, under dark, they generated somatic embryos of multicellular origin. Those embryos did not regenerate into plants.     

Influence of form of activated charcoal on embryogenic callus formation in coconut (<Emphasis Type="Italic">Cocos nucifera</Emphasis>)

Development of micropropagation protocols for Cocos nucifera has progressed slowly. Activated charcoal is included in the culture medium of each protocol, mainly to prevent tissue browning. Charcoal production procedures can affect the properties of different brands. In this study, eight types of activated charcoal were evaluated for their effects on free 2,4-dichlorophenoxyacetic acid level, pH, conductivity, and osmolarity of the culture medium and on the frequency of embryogenic callus induction. Moreover, the effect of particle size of the optimum charcoal type on embryogenic callus development was also studied. Charcoal type had a significant effect on (Y3) culture medium properties. Free 2,4-D was highest in Reactivos y Productos Químicos Finos-containing medium and pH was lowest in MERCK-containing medium. Charcoal type also influenced embryogenic callus induction, with acid washed for plant cell and tissue culture-, DARCO- and United States Pharmacopeia-containing media promoting ~60% embryogenic callus, but with different optimal 2,4-D concentrations. Particle size profiles varied among all charcoal types, although small particle fraction (<38 μm) was abundant in all. Use of small particle fractions produced higher frequencies of embryogenic callus (70%) than either large particle or whole charcoal fractions.     

Glucosylation of exogenous vanillin by plant cell cultures

After feeding with vanillin,Vanilla planifolia Andrews cell culture was able to produce the highest amount of glucovanillin compared to Ilex dumosaReissek and Catharanthus roseus (L.) G.Don cell cultures. The optimum yield of glucovanillin was obtained from V. planifolia cells fed with 6.6 mM vanillin and harvested after 12 h. The yield was 3.28 mM glucovanillin (49.7%). This glucoside was stored mainly in the cells.     

Directing vanillin production from ferulic acid by increased acetyl-CoA consumption in recombinant Escherichia coli

The amplification of gltA gene encoding citrate synthase of TCA cycle was required for the efficient conversion of acetyl-CoA, generated during vanillin production from ferulic acid, to CoA, which is essential for vanillin production. Vanillin of 1.98 g/L was produced from the E. coli DH5alpha (pTAHEF-gltA) with gltA amplification in 48 h of culture at 3.0 g/L of ferulic acid, which was about twofold higher than the vanillin production of 0.91 g/L obtained by the E. coli DH5alpha (pTAHEF) without gltA amplification. The icdA gene encoding isocitrate dehydrogenase of TCA cycle was deleted to make the vanillin producing E. coli utilize glyoxylate bypass which enables more efficient conversion of acetyl-CoA to CoA in comparison with TCA cycle. The production of vanillin by the icdA null mutant of E. coli BW25113 harboring pTAHEF was enhanced by 2.6 times. The gltA amplification of the glyoxylate bypass in the icdA null mutant remarkably increased the production rate of vanillin with a little increase in the amount of vanillin production. The real synergistic effect of gltA amplification and icdA deletion was observed with use of XAD-2 resin reducing the toxicity of vanillin produced during culture. Vanillin of 5.14 g/L was produced in 24 h of the culture with molar conversion yield of 86.6%, which is the highest so far in vanillin production from ferulic acid using recombinant E. coli.     

Effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal

The objective of this study was to investigate the effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal. Results show that the specific surface area and iodine number of bamboo charcoal activated at 900 degrees C were larger than those of bamboo charcoal activated at 800 degrees C. The specific surface area of bamboo charcoal activated at 800 degrees C by carbon dioxide was larger than that of charcoal activated by steam. However, a contrary result was observed when the activation temperature was 900 degrees C. The total volume and proportion of micropores in bamboo charcoal activated by carbon dioxide were greater than those in the other sample groups. However, the total volume and bulk volume of meso- and macropores, and average pore diameter for bamboo charcoal activated by steam were greater than those in the other sample groups. Using 5g bamboo charcoal (10-30 mesh) with a soaking time of 24h, a better adsorption effect on Pb2+ (100%), Cu2+ (100%), and Cr3+ (88-98%) was found. However, medium frequencies were observed for the adsorption of Cd2+ (40-80%) and Ni2+ (20-60%). Very limited adsorption of As5+ was detected in this study. For the same charcoal grain sizes, the adsorption capacity of 0.5g of charcoal was better than that of 0.1g. The improved adsorption effect of the sample group activated by steam was compared with the sample group activated by carbon dioxide.