光质对紫背天葵生长、次生代谢和抗氧化胁迫的影响

以紫背天葵为供试材料,采用LED灯精量调控光质和光强,研究相同光照强度(350±5 μmol·m^-2·s^-1)下,白光(W)、红光(R)、蓝光(B)、黄光(Y)、红蓝混合光(RB)、红蓝黄混合光(RBY)对紫背天葵生长、次生代谢和氧化胁迫抗性的影响.结果表明:与白光(W)相比,红光(R)能够显著促进紫背天葵植株的生长以及干物质和可溶性糖含量的积累;而蓝光(B)则抑制紫背天葵的生长;叶绿素含量在有色光处理下均显著降低;虽然红蓝黄混合光(RBY)未能显著提升紫背天葵的干物质含量,但总酚、类黄酮和花青素含量显著提升,这些还原态物质的积累有利于提高紫背天葵的抗氧化能力,在增强自身抗逆性的同时提升营养价值.本研究为光质调控紫背天葵的多样化生产提供了理论依据.     

Metabolic response to dietary fibre composition in horses

The hypothesis for this study was that a higher dietary proportion of soluble fibre would result in stable and constant plasma metabolite and regulatory hormone concentrations. The study was a 4×4 Latin Square design with a sequence of 17 days adaptation to the ration followed by 8 sampling days. The feed rations consisted of only timothy hay (H), hay plus molassed sugar beet pulp combined with either whole oats (OB) or barley (BB) and hay plus a loose chaff-based concentrate (M). Four horses were fitted with permanent caecal cannulas and liquid caecal content was withdrawn manually and blood was drawn from the jugular vein at 0, 3 and 9 h postprandial. The horses were exercised daily at medium level for about 1 h. Samples were analysed for short-chain fatty acids (SCFA) and metabolic traits. Caecal SCFA and propionic acid concentrations increased with increased dietary starch and soluble fibre. The diet highest in soluble fibre (M) resulted in the highest plasma glucose and insulin concentrations in the morning, which then remained stable and constant throughout the day. A strong interaction (P<0.01) between time and diet was measured for plasma urea, glucose, insulin and leptin. The greatest variations in plasma glycaemic and insulinaemic responses were associated with the cereal grain diets (OB and BB). There were indications of a negative energy balance, which was reflected in a significantly higher plasma β-hydroxybutyrate concentration and a numerically higher non-esterified fatty acid concentration. In conclusion, this study found that inclusion of soluble fibre resulted in increased total caecal SCFA and propionic acid concentrations. This consequently resulted in stable and constant plasma glycaemic and insulinaemic responses. Diets with a high content of soluble fibre provided enough energy for horses at medium work level.     

红树林内生真菌研究进展

红树林作为一种特殊的植物群落具有丰富的内生真菌资源,目前已分离鉴定的红树林真菌超过200种,成为海洋真菌的第二大类群,已报道的红树林内生真菌主要类群是链格孢霉(Alternaria)、曲霉(Aspergillus)、芽枝霉(Cladosporium)、炭疽菌(Colletotrichum)、镰孢霉(Fusarium)、拟青霉(Paecilomyces)、拟盘多毛孢(Pestalotiopsis)、青霉(Penicillium)、茎点霉(Phoma)、拟茎点霉(Phomopsis)、叶点霉(Phyllosticta)和木霉(Trichoderma)等.大部分红树林内生真菌具有较宽的宿主范围,极少数只有单一的宿主,不同红树林植物的内生真菌区系及优势种群有很大差异.红树林内生真菌的定殖因宿主植物不同部位、植株的年龄及季节和环境的变化明显不同.红树林内生真菌能产生多种代谢产物,具有抗菌、抗肿瘤等药用价值.红树林植物内生真菌的研究和开发具有重要意义.本文综述了红树林内生真菌的生物多样性及其分布、生物学功能和次生代谢产物等方面的研究进展.     

Regulation of the synthesis of aryl metabolites by phospholipid sources in the white-rot fungus Bjerkandera adusta

The white-rot basidiomycete Bjerkandera adusta was cultivated in a liquid medium enriched with l-phenylalanine and various phospholipid sources (lecithin, egg yolk and asolectin). Three aromatic metabolites (benzaldehyde, benzyl alcohol and benzoic acid) were produced under these culture conditions. High concentrations of benzaldehyde (404 mg l^–1) were obtained when the cultures were supplemented with 10 g lecithin l^–1. Benzyl alcohol production was promoted when the strain was grown with 5 or 10 g lecithin l^–1. In the absence of or with a low concentration of lecithin (2.5 g l^–1), benzoic acid was the major aryl metabolite synthesized. The results presented here indicate that aryl alcohol oxidase, an extracellular enzyme catalyzing the oxidation of benzyl alcohol into benzaldehyde, was maximally detected when significant amounts of benzaldehyde were produced. Aryl alcohol oxidase activity was significantly enhanced in the presence of elevated concentrations of phospholipid sources. Together with lignin peroxidase, methoxylated and hydroxylated aryl metabolites were also synthesized under these culture conditions. The possible involvement of phospholipids in the synthesis of aryl metabolites is discussed. Received: 7 August 1998 / Accepted: 30 November 1998     

五种提取马尾松基因组DNA方法的比较

对于含有大量多糖如酚、酯、萜等其它二次代谢产物的松科和杉科等针叶植物,要从其组织中提取高质量的基因组ＤＮＡ一般都比较困难。本文以马尾松（ｐｉｎｕｓ ｍａｓｓｏｎｉａｎａ）针叶为材料,分别采取了简易提取法、高盐沉淀法、ＣＴＡＢ沉淀法、Ｚｉｅｇｅｎｈａｇｅｎ法和ＱＬＡＧＥＮ公司ＤＮｅａｓｙ Ｐｌａｎｔ Ｍｉｎｉ Ｋｉｔｓ５种方法提取基因组ＤＮＡ;并通过琼脂糖凝胶电泳、限制性内切酶自理和ＲＡＰＤ３种方法对     

Partitioning of Photosynthetically Fixed 14CO2 Into Oil and Curcumin Accumulation in Curcuma Longa Grown Under Iron Deficiency

Changes in leaf growth, photosynthetic efficiency, and incorporation pattern of photosynthetically fixed ¹⁴CO₂ in leaves 1 and 2 from plant apex, in roots, and rhizome induced in Curcuma by growing in a solution culture at Fe concentration of 0 and 5.6 g m^–3 were studied. ¹⁴C was incorporated into primary metabolites (sugars, amino acids, and organic acids) and secondary metabolites (essential oil and curcumin). Fe deficiency resulted in a decrease in leaf area, its fresh and dry mass, chlorophyll (Chl) content, and CO₂ exchange rate at all leaf positions. The rate of ¹⁴CO₂ fixation declined with leaf position, maximum being in the youngest leaf. Fe deficiency resulted in higher accumulation of sugars, amino acids, and organic acids in leaves at both positions. This is due to poor translocation of metabolites. Roots and rhizomes of Fe-deficient plants had lower concentrations of total photosynthate, sugars, and amino acids whereas organic acid concentration was higher in rhizomes. ¹⁴CO₂ incorporation in essential oil was lower in the youngest leaf, as well as incorporation in curcumin content in rhizome. Fe deficiency influenced leaf area, its fresh and dry masses, CO₂ exchange rate, and oil and curcumin accumulation by affecting translocation of assimilated photosynthates.     

Microalgae as a source of bioactive molecules – experience from cyanophyte research

Detrimental and beneficial properties of prokaryoticand eukaryotic microalgae may be qualifications givingthem posibillities for their biotechnologicalutilization. Phycotoxins and related products mayserve as material for useful drugs. Cyanotoxins arean example. Bioassay screening methods are used todetect specific biological activity (e.g. antibioticeffects). A study demonstrating antibacterialproperties among cyanophytes showed that these effectswere caused by substances produced by both toxigenicand non-toxigenic strains. Differences inbiosynthetic activity are influenced by the type ofclones and by the culture conditions (genetic andbiochemical variation). Experience of recentscreening (1997–1998) of compounds from cyanophytes –including 25 species from 14 genera – display thediscovery of more than 30 different antibioticsubstances. The further isolation of newpharmaceuticals from natural resources is becomingdifficult, if not uncommon species of producerorganisms are taken into consideration.     

不同年龄大鼠尿液代谢组学研究

旨在探究健康大鼠的尿液代谢物在生长、发育和衰老过程中的年龄相关性变化.采集大鼠出生后3周、5周、7周、9周、12周、56周和111周共7个年龄点的尿液样本,利用GC/TOF-MS平台进行代谢组学检测.结果显示,所有尿液样本在主成分分析与偏最小二乘法判别分析中出现组内聚类和组间分离.氨基酸类、有机酸类和碳水化合物类代谢物...     

一株产低温蛋白酶地衣芽胞杆菌NWMCC0046全基因组测序及分析

地衣芽胞杆菌(Bacillus licheniformis)NWMCC0046是从西藏日喀则地区屠宰场废弃血污放置土壤中分离得到的一株益生菌,产生的碱性蛋白酶在低温下有作为洗涤剂添加酶的潜力。深入分析菌株NWMCC0046的基因组序列信息,并挖掘该菌株功能特性基因及潜在应用价值。使用PacBio RS II平台和Illumina HiSeq 4000平台对菌株NWMCC0046的基因组进行测序,并对测序数据进行基因组组装、基因预测与功能注释、共线性分析、进化分析及次级代谢产物合成基因簇预测。菌株NWMCC0046全基因组大小为4 321 565 bp,平均GC含量为46.78%,共编码4 504个基因。基因注释揭示了其益生菌特性,如胃肠道内独特的适应性、抗氧化活性和抗菌活性。此外,菌株NWMCC0046还编码工业上许多重要的酶。进化树及共线性结果表明,菌株NWMCC0046属地衣芽胞杆菌且与地衣芽胞杆菌ATCC 14580具有较好的共线性。同时,预测到菌株NWMCC0046中有11个次级代谢产物合成基因簇,编码地衣素、丰原素、杆菌肽和丁酰苷菌素等生物活性物质。基因组信息存储于GenBa...     

Stereoselective urinary excretion of bupivacaine and its metabolites during epidural infusion

A sensitive and efficient chiral assay for bupivacaine and its three principal metabolites desbutylbupivacaine, 4′‐hydroxybupivacaine, and 3′‐hydroxybupivacaine has been applied to urine from five male patients receiving postoperative epidural infusions of rac‐bupivacaine fentanyl over 60–120 hr. The fraction of the dose of bupivacaine (total dose 840–2093 mg) accounted for in urine was 75 ± 6%. The rate of excretion of bupivacaine enantiomers approximated a steady state after ∼30 hr with values of 1.27 ± 0.26 and 0.76 ± 0.13 mg hr⁻¹ for (R)‐ and (S)‐enantiomers, respectively. The fraction of the dose of bupivacaine enantiomer excreted unchanged in the urine (fe) varied from 14.3% to 39.1% for (+)‐(R)‐bupivacaine and 9.2% to 14.0% for (−)‐(S)‐bupivacaine in the five patients. The rate of excretion of all metabolites also reached a steady state after ∼30 hr and the relative amounts of metabolites excreted into urine (fm) suggest bupivacaine is subject to regioselective and stereoselective clearance, which may vary from patient to patient. Chirality 11:50–55, 1999. © 1999 Wiley‐Liss, Inc.