微生物诱导子对诺卡氏菌属№5205菌株发酵的影响

在培养基中分别添加从深红酵母 (Rhodotorlarubra)、紫红红球菌 (RhodococcusrhodochrousATCC1380 8)、深红诺卡氏菌 (N .rubropertincta)制备的诱导子 ,诺卡氏菌属№ 5 2 0 5菌株的生物量、类胡萝卜素含量均有所提高 ,其中在含深红诺卡氏菌诱导子 (添加量为 12 0 μg/ml)的分批发酵中 ,№ 5 2 0 5菌株的生物量可达 13.7mg/ml;类胡萝卜素含量可达 6 33.5 μg/g干菌体 ,分别比对照提高了39 .8%和 16 .8%。     

陕西三种特种稻米氨基酸及品质分析

以陕西洋县产茉莉香米、红香米和绿香粳米等 3种特种稻米为材料 ,分析了氨基酸及其它品质指标。结果表明 ,茉莉香米、红香米和绿香粳米均含有 1 7种氨基酸 ,氨基酸总含量 (mg/ 1 0 0 g)分别为 730 0、72 70、74 90 ;除Trp外 ,7种必需氨基酸占氨基酸总量分别为 34 .6 %、34 .5 %、34 .8% ;Lys含量 (mg/ 1 0 0g)分别为 5 5 0、5 2 0、5 30 ;粗蛋白质含量分别是 9.94 %、9.2 3%、8.5 2 % ;Cu含量 (mg/ 1 0 0g)分别是 0 .6 2、0 .94、0 .79;Zn含量 (mg/ 1 0 0 g)分别是 1 .99、1 .75、2 .0 2 ;Fe含量 (mg/ 1 0 0 g)分别是 1 .5 5、3.70、4 .5 0 ;直链淀粉含量分别是 1 5 .6 %、3.7%、1 5 .1 % ;胶稠度分别是 33mm、4 0 .6mm、78mm ;糊化温度分别是 6 .1级、6 .8级、7级 ;水分含量分别是 1 1 .2 7%、1 1 .5 5 %、1 2 .5 2 %。这 3种特种稻品质较优 ,具有推广价值     

利用竞争型ELISA法鉴定硒诱导的金属硫蛋白

利用竞争型ELISA法鉴定硒诱导的金属硫蛋白 (MT) ,发现对照组小鼠肝脏MT含量为 (2 .47± 0 .90 )μg/g湿重组织 ,硫酸锌组小鼠肝脏MT含量为 (8.15± 2 .2 0 ) μg/ g湿重组织 ,硒麦芽组小鼠肝脏MT含量为(12 .80± 1.44 ) μg/ g湿重组织。锌组和硒组的MT含量与对照组相比有显著性差异 (P <0 .0 5 ,P <0 .0 5 )。硒组MT含量要显著高于锌组的MT含量 (P <0 .0 5 )。     

矿质营养与其他生长物质对荷叶离褶伞菌丝生长的影响

1mg／mL KCl促进荷叶离褶伞菌丝生长;5或10mg／mL NaCl、5或10mg／mL MgSO4、5或10mg／mLKCl、10mg／mL H2PO4和1mg／mL CaSO4抑制菌丝生长;0．8mg／mL的MnSO4和CuSO4以及0．5mg／mL FeSO4、0．2或0．5mg／mL CoCl2和0．2、0．5或0．8mg／mL ZnSO4促进菌丝生长;0．5或0．2mg／mL CuSO4、0．2或0．5mg／mL MnSO4及0．8或0．2mg／mL FeSO4对菌丝生长的影响不显著;维生素B6、维生素C、维生素PP和维生素B1可促进菌丝生长,在含有10μg/L维生素B6的培养基上菌丝生长速度最快,但维生素C试用浓度较低（50μg／L）时对菌丝生长的影响不显著;吲哚丁酸、吲哚乙酸、奈乙酸对菌丝生长具有促进作用,但0．1、0．5或1．0μg／L赤霉素对菌丝生长的影响不显著。     

特种稻种质创新与营养特性评价

将系谱选择和花药培养相结合,分别选育出具有巨胚、甜味、有色种皮、软米、香味等单一特殊性状和聚合上述2个以上特殊性状的特种稻种质12份,并对这些种质进行了营养特性评价。结果表明,创新的特种稻种质营养成分含量明显高于普通稻,其中甜黑米1569和甜红米1571糙米千粒重很小(8．4g、8．2g),蛋白质(12．4％、11．7％)、赖氨酸(0．75％、0．76％)、脂肪(5．29％、4．86％)、油酸(2．15％、1．93％)和亚油酸(1．93％、1．86％)、维生素B1(8．42mg／kg、1．60mg／kg)年口钙含量(36．8mg／100g、29．5mg／100g)较高;巨胚香糯1574和白巨胚米1575的胚较大,千粒胚重1．4g以上,胚重占糙米重的比率8％以上,蛋白质(9．9％、10．6％)、维生素B1(3．30mg／kg、0．98mg／kg)和钙含量(27．7mg／100g、32．5mg／100g)较高;黑糯米1568的维生素B1(6．57mg／kg)、铁扣锌含量(4．0mg／100g、7．2mg／100g)较高;红米1201的蛋白质(11．1％)、锌(7．0mg／100g)和硒(85．4ug／kg）含量较高,巨胚,甜味,有色种皮,香味等2个以上特殊性状的聚合是增加水稻种质营养保健功能性的有效途径之一。     

黄鳝孵卵泡的生化成分及其生理作用

通过对繁殖季节黄鳝为孵卵所吐的泡沫的特性和生化成分分析 ,孵卵泡的黏度为 2 72mPaS ,证明了该孵卵泡是糖蛋白 ,其中糖类含量为 0 15 6mg/mL ,蛋白质含量为 0 2 5 0mg/mL ,蛋白质 /糖类比值为 1 6 0。分离的泡沫蛋白经SDS PAGE电泳含 4种组分 ,分子量从小到大依次为 4 2 5kDa、5 8 6kDa、6 5 3kDa、98 2kDa。泡沫蛋白含 16种氨基酸 ,氨基酸总含量为 2 0 1 88mg/ 10 0mL。同时对孵卵泡的生理作用进行了分析和讨论     

葡萄色顶枝瑚菌中矿质元素及氨基酸含量的测定

采用原子吸收分光光度法和FDBN柱前衍生高效液相色谱等方法测定了葡萄色顶枝瑚菌中的矿质元素、氨基酸和蛋白质的含量。矿质元素K、Ca、Mg、Cu、Zn、Fe的含量分别是 :4 2 .5 0 0 0mg/g、0 .90 0 0mg/g、0 .4 1 3 0mg/g、0 .0 1 1 2mg/g、0 .0 64 3mg/g、0 .0 3 1 7mg/g、0 .0 73 7mg/g;蛋白质含量为 2 8.1 7% ;氨基酸总量为 2 2 6.91mg/g,其中七种必需氨基酸含量占氨基酸总量的 4 9.2 5 %     

青岛奥运帆船赛区理化、生物要素现状及富营养化诱发赤潮的围隔实验

于 2 0 0 1年 8月和 9月对青岛 2 0 0 8年奥运会帆船比赛海域进行了理化、生物等要素的综合调查 ,并利用围隔生态实验手段 ,在太平湾进行了营养盐与赤潮的关系研究。结果显示 ,本海域水质良好 ,基本符合一类海水水质标准 ,仅有个别站位出现某种污染物超标现象 ,如 8月份麦岛附近海域氨氮和无机磷超标 ,石油烃 8月份在浮山湾东侧北海船厂附近超出一类海水水质标准。该水域的叶绿素 a含量较低 ,平均 0 .4 2 m g· m- 3,总的分布状况是太平湾西侧的海域较高。初级生产力 8月高于 9月 ,分别为 179.0 mg C m- 2· d- 1和 114 .0 mg C m- 2· d- 1。浮游植物以硅藻中的中肋骨条藻、奇异菱形藻、旋链角刺藻和塔形冠盖藻为主 ,其细胞数量 8月明显高于 9月 ,分别为 4 5 7.2 6× 10 4 m- 3和 16 .38× 10 4 m- 3,数量密集中心在调查区西部。浮游动物生物量 8月比 9月高近 10倍 ,分别为 2 39.1m g· m- 3和 2 4 .7mg· m- 3,强壮箭虫在生物量中起主要作用 ,生物量和个体数量的分布与浮游植物基本相反。加营养盐的围隔实验表明 ,加硅会导致海链藻、短弯角藻、丹麦细柱藻和中肋骨条藻中的任何一种赤潮 ,硅成为该海域的主要限制因子。     

微生物诱导子对诺卡氏菌属N(o)5205菌株发酵的影响

在培养基中分别添加从深红酵母(Rhodotorla rubra)、紫红红球菌(Rhodococcusrhodochrous ATCC13808)、深红诺卡氏菌(N.rubropertincta)制备的诱导子,诺卡氏菌属No5205菌株的生物量、类胡萝卜素含量均有所提高,其中在含深红诺卡氏菌诱导子(添加量为120μg／ml)的分批发酵中,No5205菌株的生物量可达13．7mg／ml;类胡萝卜素含量可达633．5μg/g干菌体,分别比对照提高了39．8％和16．8％。     

土壤砷污染对蔬菜砷含量及食用安全性的影响

对湖南郴州砷污染区的土壤和蔬菜砷含量进行了研究 ,结果表明该地区土壤含砷量为 19.5～ 2 37.2 mg/ kg、平均为 6 3.9mg/ kg、中值为 4 7.8mg/ kg,比全国平均土壤含砷量 (9.2 m g/ kg)高 2～ 2 5倍 ;蔬菜可食部分砷含量范围为 0 .0 4～ 2 .6 4 m g/ kg、平均为 0 .74 mg/ kg、中值为 0 .5 4 mg/ kg,5 4 %的蔬菜可食部分含砷量超过了《蔬菜卫生标准》规定的最大允许量 (MPC≥ 0 .5mg/ kg) ;菠菜 ,茼蒿和生菜可食部分超标比较严重 ,最大砷含量超出 MPC 5倍左右。     

海藻多糖的单糖组成对体外抗氧化活性的影响

比较广西北部湾石莼(Ulva lactuca L.)、海带(Laminaria japonica)、裙带菜(Undaria pinnatifida Surin-gar)、紫菜(Porphyra)的单糖组成及抗氧化活性的差异,揭示多糖结构与其体外抗氧化活性的关系。利用PMP柱前衍生化HPLC分析海藻多糖的单糖组成,采用羟自由基清除试验、超氧阴离子自由基清除试验及DPPH自由基清除试验指征其体外抗氧化活性,结果表明,4种海藻多糖的单糖组成在主成分空间分布离散,石莼及紫菜主要由葡萄糖组成,海带主要由甘露糖组成,裙带菜则主要由半乳糖组成;其体外抗氧化活性存在显著差异,裙带菜多糖对DPPH的清除能力(半抑制浓度IC₅₀值为0. 56±0. 02 mg/mL)显著高于其他3种海藻多糖;石莼、裙带菜与海带对羟自由基均有较强的清除活性,而紫菜多糖对羟自由基的清除能力较差(IC₅₀值为26. 59±0. 98mg/mL);石莼与裙带菜对超氧阴离子的清除活性较强,显著高于海带与紫菜,其中石莼显著高于裙带菜,IC₅₀值分别为1. 61±0. 17、2. 73±0. 06 mg/mL。相关性分析及冗余分析结果表明,对抗氧化活性影响较为显著的因子为葡萄糖(Glc)、核糖(Rib)、木糖(Xyl)(P <0. 01)。     

海洋生物质的热解特性与动力学研究

以定生浒苔、漂浮浒苔、石莼、大叶藻、海带、龙须菜和裙带菜7种海洋生物质为研究对象,以1种草类生物质玉米秸秆、1种木质类生物质锯末为对照,用热重分析法对其热解过程及其动力学规律进行了研究。利用TG-DTG-DTA曲线分析了它们的基本热解特性。结果表明,整个热解过程主要为干燥失水、剧烈失重和缓慢失重3个阶段,海洋生物质的Tmax明显低于2类陆生生物质,而且大叶藻的热解稳定性相对较高,而漂浮浒苔的热解稳定性较低,燃烧特性较好。同时,用Coats-Redfern法求得相应的活化能E和频率因子A,发现3类生物质的热解反应机理函数不同。     

褐藻77 K荧光特异性研究

测定了裙带菜、叉开网地藻、海带、囊藻、海蒿子、鼠尾藻、萱藻和水云等8种褐藻的77K荧光光谱并同菠菜和红藻条斑紫菜作了比较。结果表明与红藻和高等植物明显不同,褐藻没有作为PSⅠ特征的730 nm荧光峰。按荧光主峰的波长,可以分为二种类型：裙带菜、叉开网地藻、海带和囊藻的荧光主峰位于690 nm,海蒿子、萱藻、水云和鼠尾藻的荧光主峰在705-720 nm。这种77K荧光特异性预示褐藻同高等植物之间在PSⅠ结构上的差异。     

Dietary protein levels affect growth and protein metabolism in trunk muscle of cod,Gadus morhua

Summary Cod (Gadus morhua) of 50 g body weight were kept at 14°C. The fish were fed ad libitum during 80 days a diet containing protein levels which in terms of total energy corresponded to 25%, 45% or 65%. Growth increased in accordance with protein-energy levels. The protein content per gram of wet weight of white trunk muscle was unchanged, as was the myofibrillar protein myosin heavy chain determined by the antigen-antibody reaction of the enzyme-linked immunosorbent assay. The amount of messenger ribonucleic acid (mRNA) coding for myosin heavy chain was lower at 25% than at 45% or 65% protein-energy intake, the differences being significant per gram of wet weight of muscle. Acid proteinase activity was highest at the lowest protein-energy intake. Glycogen content in muscle increased with the protein-energy levels. It is concluded that the metabolic response of white trunk muscle to graded protein-energy intake included a change in the capacity to synthesize myosin heavy chain as judged by its mRNA content. The protein content per gram of wet weight was unaffected by dietary protein-energy levels of 25%, 45% and 65%, but protein accretion and thus growth of the animals increased with the protein intake. Dietary protein-energy restriction caused a rise in acid proteinase activity and a decrease in content of mRNA for myosin heavy chain, resulting in a diminished growth rate at an unchanged protein content per gram of wet weight of muscle.Abbreviations CTP cytidine triphosphate - DNA desoxyribonucleic acid - EDTA ethylenediaminetetra-acetic acid - mRNA messenger ribonucleic acid - TRIS tris(hydroxymethyl)aminomethane     

A Two-Step Strategy to Enhance Activity of Low Potency Peptides

Novel strategies are needed to expedite the generation and optimization of peptide probes targeting G protein-coupled receptors (GPCRs). We have previously shown that membrane tethered ligands (MTLs), recombinant proteins comprised of a membrane anchor, an extracellular linker, and a peptide ligand can be used to identify targeted receptor modulators. Although MTLs provide a useful tool to identify and/or modify functionally active peptides, a major limitation of this strategy is the reliance on recombinant protein expression. We now report the generation and pharmacological characterization of prototype peptide-linker-lipid conjugates, synthetic membrane anchored ligands (SMALs), which are designed as mimics of corresponding MTLs. In this study, we systematically compare the activity of selected peptides as MTLs versus SMALs. As prototypes, we focused on the precursor proteins of mature Substance P (SubP) and Cholecystokinin 4 (CCK4), specifically non-amidated SubP (SubP-COOH) and glycine extended CCK4 (CCK4-Gly-COOH). As low affinity soluble peptides these ligands each presented a challenging test case for assessment of MTL/SMAL technology. For each ligand, MTLs and corresponding SMALs showed agonist activity and comparable subtype selectivity. In addition, our results illustrate that membrane anchoring increases ligand potency. Furthermore, both MTL and SMAL induced signaling can be blocked by specific non-peptide antagonists suggesting that the anchored constructs may be orthosteric agonists. In conclusion, MTLs offer a streamlined approach for identifying low activity peptides which can be readily converted to higher potency SMALs. The ability to recapitulate MTL activity with SMALs extends the utility of anchored peptides as probes of GPCR function.     

The characteristics of bio-oil produced from the pyrolysis of three marine macroalgae

The pyrolysis of two brown macroalgae (Undaria pinnatifida and Laminaria japonica) and one red macroalgae (Porphyra tenera) was investigated for the production of bio-oil within the temperature range of 300-600°C. Macroalgae differ from lignocellulosic land biomass in their constitutional compounds and high N, S and ash contents. The maximum production of bio-oil was achieved at 500°C, with yields between 37.5 and 47.4 wt.%. The main compounds in bio-oils vary between macroalgae and are greatly different from those of land biomass, especially in the presence of many nitrogen-containing compounds. Of the gaseous products, CO(2) was dominant, while C(1)-C(4) hydrocarbons gradually increasing at 400°C and above. The pretreatment of macroalgae by acid washing effectively reduced the ash content. The pyrolysis of macroalgae offers a new opportunity for feedstock production; however, the utilization of bio-oil as a fuel product needs further assessment.     

除草剂扑草净和阿特拉津对海草与大型藻类的毒性比较

陆地径流等可引起海域中除草剂浓度升高, 从而威胁海洋大型植物——海草和大型藻类的生长。以叶绿素荧光为主要指标测定除草剂阿特拉津和扑草净的低、中、高(1、5和25 μg/L)浓度对4种常见海草:大叶藻(Zostera marina L.)、丛生大叶藻(Z. caespitosa M.)、矮大叶藻(Z. japonica Aschers. & Graebn.)、红须根虾形藻(Phyllospadix iwatensis M.)和2种常见大型藻类:孔石莼Ulva lactuca L.和海索面Nemalion helminthoides的光合抑制。结果显示, 低浓度1 μg/L的扑草净和5 μg/L的阿特拉津即对矮大叶藻、孔石莼和海索面产生了显著的光合抑制, 抑制率约而7.54%—12.97%; 大叶藻、丛生大叶藻和红须根虾形藻的扑草净和阿特拉津的显著作用浓度为5 μg/L, 在相同浓度下, 扑草净的光合抑制较阿特拉津更强, 同时, 矮大叶藻及两种大型藻类较其他3种海草成体对除草剂作用更为敏感。     

Biochemical characterization of algal coated vesicles

Thin sections of tissue preparations from a green alga, Ulva lactuca (Ulvophyceae), and brown alga, Laminaria digitata (Pheophyceae) showed the presence of coated pits and coated vesicles in these 2 species. A discontinuous sucrose gradient after subcellular fractionation of the tissue homogenate resulted in an enriched coated vesicle fraction. Electron microscopy of negatively stained samples revealed the presence of coated vesicles of diameter ranging from 40-125 nm, together with large sheets of polygonal nets of clathrin. Electrophoresis of the CV purified fraction revealed various polypeptide components. Two of them, a 175 kDa and a 70 kDa, exhibited a positive response to bovine brain anticlathrin antibodies raised in goat or in rabbit. A third component of 30-40 kDa also gave a faint positive response. These 3 components corresponded to the clathrin heavy and light chains already described in higher plants. Clathrin was released from the CV algal preparations by treatment with 2M urea in Tris buffer, pH 8.5. Interestingly, in Ulva lactuca, the proportion of clathrin relative to the other proteins from the CV decreased with plant growth. Biochemical analysis of the purified CV revealed the presence of all the major phospholipids characterized in mammalian CV. The ratio of protein over lipid was also in the same range as that calculated for mammalian CV. Carbohydrate analysis demonstrated a high proportion of N-acetylgalactosamine and N-acetylglucosamine in both algal CV whereas these sugars were not detectable in the crude homogenate. These results demonstrate the presence of clathrin and coated vesicles in 2 species of algae.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lack of evidence in vivo for nitrergic inhibition by Escherichia coli (STa) enterotoxin of fluid absorption from rat proximal jejunum

Fluid absorption from the proximal jejunum of the anaesthetised rat was measured in vivo by fluid recovery. As expected, heat stable (STa) enterotoxin from E. coli reduced fluid absorption. Neither intraperitoneal L-NAME, thought to inhibit a putative neurally mediated action of STa, nor similar doses of D-NAME, ameliorated the inhibitory effect on jejunal fluid absorption of STa. Luminally perfused 10 mM sodium nitroprusside (SNP) had no effect on fluid absorption when expressed per gram dry weight per hour but reduced fluid absorption when expressed per cm length per hour. Similarly, 80 but not 40 mg/Kg of L-NAME reduced fluid absorption when expressed per cm length per hour, while the same dose of D-NAME did not. L-NAME and SNP significantly increased the wet weight to dry weight and the length to dry weight ratio of perfused loops. We conjecture that smooth muscle relaxation caused by these compounds increases interstitial fluid volumes that can be misconstrued as changes in absorption when this is expressed per cm length or per tissue wet weight. When fluid absorption is expressed per gram dry weight of tissue, there is no evidence for a role of nitric oxide in normal or STa inhibited fluid absorption.     

Inhibition of complement activation by water-soluble polysaccharides of some far-eastern brown seaweeds

Fucoidans and laminarans from Laminaria cichorioides, Laminaria japonica, Fucus evanescens, laminaran from Laminaria gurjanovae, other beta-D-glucans (translam, pustulan and zymosan) and lambda-carrageenan from Chondrus armatus were used to study the effect of water-soluble polysaccharides from seaweeds on the alternative pathway of complement (APC). beta-D-Glucans and fucoidans under study differed appreciably from each other by structural characteristics, and also by degree of purification. beta-D-glucans, on ability to bind complement, ranked in a line according to a degree of their purification. Highly purified beta-D-glucans under study did not reveal an ability to bind complement. The fucoidans were divided conventionally into three groups according to their action on APC. Highly sulfated alpha-L-fucan from L. cichorioides with the greatest activity toward APC and caused 50% inhibition of reaction of activation (RA) of APC in a concentration of 0.5-0.7 mg/ml. Opposite 50% of inhibition of lysis of erythrocytes by sulfated heterogeneous fucoidan from L. japonica was achieved with 20 mg/ml. All other fucoidans and lambda-carrageenan have activity at 6-10 mg/ml concentration. Decreasing the sulfate content from 36% up to 9% in sample fucoidans under study was not reflected practically in the 50% inhibition concentration. Apparently, the degree of sulfating of fucoidans did not influence their action on APC. But the positive influence of fucose in structure of polysaccharide was obvious.