硒元素对平菇菌丝体GSH-Px、SOD及MDA的影响

于培养基中加入一定量的亚硒酸钠溶液 ,分别测定了 2个品种平菇菌丝体内GSH Px、SOD活性及MDA含量。结果表明 :3 0、60mg/L组菌丝体内GSH Px、SOD活性极显著升高 (P <0 .0 1 )而MDA含量明显降低 (P <0 .0 5 ) ,随着硒水平的升高 ,GSH Px、SOD活性呈下降趋势而MDA含量则显著升高 (P <0 .0 5 )。因此 ,在培养富硒平菇菌丝体时应适当考虑培养基的硒浓度。     

富硒姬松茸液体培养条件的研究

采用液体摇瓶培养法 ,对姬松茸 (Agaricusblazei)富硒培养条件进行初步研究 ,结果表明 :富硒姬松茸液体培养的最佳培养基配方为玉米粉 30 g/L ,葡萄糖 2 0g/L ,硫酸铵 2 g/L ,酵母膏 3g/L ,KH₂ PO₄ 2 g/L ,MgSO₄ ·7H₂ O 1 g/L ,维生素B11 0 0mg/L ;采用 1mg/L亚硒酸钠驯化菌种 ,2 5 0mL三角瓶装量 80mL ,p     

含硒类球红细菌的研究

为了确定类球红细菌转硒培养的最佳条件 ,研究了无机硒的加入浓度、时间以及分批补料培养对菌体生长和转硒效率的影响。实验表明 ,无机硒的浓度低于 1× 10 -5mol/L时 ,对类球红细菌的生长基本没有影响 ,并能将6 3.9%的无机硒转化为有机硒。转硒的最佳时间是在接种后 12h左右 ,此时转硒效率最高。实验还表明 ,分批补料培养可以提高菌体浓度 ,可使转硒效率和绝对量增加。体内试验表明 ,用 5mL/kgbw和 10mL/kgbw剂量的含硒类球红细菌灌养小鼠 ,可以使其全血GSH Px酶活性提高 2 0 .9%和 2 5 .5 % ,使其血清丙二醛 (MDA)含量降低2 1.0 %和 2 3.2 %。     

施用硒肥对圆叶决明生长、酶活性及其叶肉细胞超显微结构的影响

通过盆栽试验 ,研究在红壤中施用不同浓度的硒肥对豆科牧草圆叶决明植株生长、叶片硝酸还原酶活性、根瘤固氮酶活性及其叶肉细胞超显微结构的影响。试验结果表明 ,施 0 .5～ 2 mg Se/ kg土不同用量的硒肥处理的圆叶决明植株株高、分枝数和植株干重 ,比不施硒肥的对照处理分别提高 11.71%～ 18.97%、0 .5 5 %～ 2 2 .6 1%和 5 2 .9%～ 14 4 .9% ;植株的硒含量随施硒浓度的提高而明显增加 ,不施硒 (CK)处理的植株含硒量仅为 0 .0 2 5 mg/ kg,当施硒肥量为 2 mg Se/ kg土 (S2 )时 ,植株的硒含量达到0 .2 2 2 mg/ kg,比对照增加了 7.88倍 ;施硒量为 1mg Se/ kg土 (S1)处理圆叶决明的叶片硝酸还原酶活性最大 ,比对照提高2 81.5 % ,比施 2 m g Se/ kg土的增加了 2 0 6 .1% ;根瘤固氮酶活性以施用 2 mg Se/ kg土的处理为最大 ,比对照增加了 4 9.4 1%。植株叶肉细胞超显微结构变化的观察结果表明 :施不同用量硒肥处理均能比对照处理增加植株叶绿体的数量 ,其中以1.5 mg Se/ kg土的施用量处理效果最好 ,而 1.5 m g Se/ kg土和 2 mg Se/ kg土处理对提高叶绿体的基粒数量和片层密度效果较佳 ,但对稳定叶绿体的双层膜结构效果则不明显 ;而施用 1.5 m g Se/ kg土和 1mg Se/ kg土处理则显示了减少线粒体的数量 ,降低线     

三个不同省份富硒大蒜硒含量分析

目的：检测山东、黑龙江、江西三个省份富硒大蒜、普通大蒜、土壤及水源的硒含量,为当地富硒大蒜产业发展提供科学依据。方法：采集山东、黑龙江、江西三个省份富硒大蒜、普通大蒜、土壤及水源共120份,采用电感耦合等离子体质谱法测定总硒含量。结果：山东省富硒大蒜硒含量高于普通大蒜中硒的含量;黑龙江省来信子村富硒大蒜硒含量明显高于其他4个基地;江西省5个地区富硒大蒜硒的含量可以分为两个区间：硒含量较低的区间（11.660 0～31.984 0 μg/100 g）、硒含量较高的区间（86.530 0～97.224 0 μg/100 g）。结论：山东省的富硒大蒜富硒效果好,黑龙江省宝清县来信子村富硒大蒜的富硒效果好,江西省宜春县富硒大蒜均为超富硒农产品。     

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 )。     

亚硒酸钠对肝细胞L-02端粒酶活性和端粒长度的作用

通过研究硒对端粒酶活性和端粒长度的作用 ,探讨硒抗衰老的生物学机制。实验以人肝细胞株L 0 2为研究对象 ,分别补充 0 .5和 2 .5 μmol L亚硒酸钠 ,采用端粒重复序列扩增 焦磷酸根酶联发光法、逆转录聚合酶链式反应法及流式荧光原位杂交法 ,分别检测细胞的端粒酶活性、人端粒酶逆转录酶催化亚基基因 (hTERT)的表达及端粒长度的变化。结果表明 :常规培养的肝细胞株L 0 2的端粒酶活性和hTERT基因表达水平均较低。补充 0 .5和2 .5 μmol L亚硒酸钠三周后细胞生长状况良好、端粒酶活性和hTERT基因表达水平显著性增高 ,且呈一定的剂量 效应关系。细胞补充亚硒酸钠四周后端粒长度显著增长。说明营养浓度的亚硒酸钠可通过提高端粒酶活性和增长端粒长度来减缓L 0 2肝细胞衰老、延长细胞寿命。     

文摘

030 0 2 9搅拌式生物反应器悬浮培养水母雪莲细胞的研究〔中〕/黄艳… //生物工程学报 .- 2 0 0 1,17(5 ) .- 5 6 1～ 5 6 5应用 2L通气搅拌式生物反应器一步批式培养水母雪莲细胞。采用倾斜式搅拌桨代替透平桨 ,研究了搅拌转速、通气量和接种量对细胞生长和黄酮合成的影响 ,发现在 75r/min、70 0～ 10 0 0L/min和 4 .0～ 5 .0gDCW /L接种量下细胞生长和黄酮合成比较好。经过 12d培养细胞干重达 13.8gDCW /L ,黄酮产量 4 16mg/L ,黄酮含量占细胞干重的 3.0 %。水母雪莲细胞生长及黄酮合成的进程表明 ,黄酮积累与细胞生长呈正相关。对细…     

高生物量富硒酵母的选育及培养条件初步优化

通过筛选、单倍体分离、诱变和原生质体融合,从融合子中选育了一株高生物量富硒酵母菌株（编号为ZFF-28）,其细胞硒总含量分别是原始亲株ZY-67和ZY-198的2.8倍和2.0倍。通过单因素实验和正交试验设计,确定了优化培养条件：6%糖浓度的蔗糖糖蜜,添加0.5% (NH4)2SO4、0.1% H3PO4、60μg/mL Se,pH60～6.5,装液量50mL/250mL三角瓶,接种量10%,培养时间25h。在优化培养条件下,菌株ZFF_28的生物量可达8.2g/L,细胞中硒的含量达2050μg/g,硒总含量达到了16810μg/L,是培养条件优化前的1.3倍。细胞硒含量的91%为有机硒。     

木立芦荟组织培养pH分化特性及快速繁殖的研究

以木立芦荟的叶片、叶鞘、带腋芽的茎段为外植体进行试管培养 ,结果叶鞘和茎段可诱导形成愈伤组织 ,腋芽直接萌生。经试验筛选出各培养阶段最适宜的培养基为 :( 1 )愈伤组织诱导 ,MS BA 2 .5mg/L NAA0 .1 5mg/L ;( 2 )腋芽萌生 ,MS BA 2 .0mg/L NAA 0 .1 5mg/L ;( 3 )丛生芽分化及继代 ,MS BA 2 .0mg/L NAA0 .1 0mg/L ;( 4)生根 ,MS BA 0 .3～ 0 .5mg/L IBA 0 .2mg/L 活性碳 0 .5%。研究还发现 ,培养基酸碱度对木立芦荟组织培养分化效果的影响非常显著。     

黄粉虫幼虫对硒的生物积累

在饲料中添加含硒化合物喂养黄粉虫Tenebrio molitor L.幼虫,测定幼虫硒含量、粪便硒含量和体重的变化,计算黄粉虫幼虫特定生长率及幼虫对硒生物积累系数,分析黄粉虫有效积累硒的条件。结果表明,饲料硒含量在15~20mg/kg时,幼虫硒含量明显提高,对硒的生物积累系数高于其它试验组水平,饲料硒含量过高,幼虫硒含量降低,正常生长受到抑制。黄粉虫幼虫特定生长率、取食量、排粪量、干物质含量随着饲料硒含量的增加而降低,死亡率、粪便硒含量随着饲料硒含量的增加而增大。饲料硒含量为15～20mg/kg时黄粉虫幼虫对硒的生物积累效果最好。     

Parental origin and genome evolution in the allopolyploid Iris versicolor

BACKGROUND AIMS: One of the classic examples of an allopolyploid is Iris versicolor, 'Blue Flag' (2n = 108), first studied by Edgar Anderson and later popularized by George Ledyard Stebbins in cytogenetics and evolutionary text-books. It is revisited here using modern molecular and cytogenetic tools to investigate its putative allopolyploid origin involving progenitors of I. virginica (2n = 70) and I. setosa (2n = 38). METHODS: Genomic in situ hybridization (GISH), fluorescent in situ hybridization (FISH) and Southern hybridization with 5S and 18-26S ribosomal DNA (rDNA) probes were used to identify the parental origin of chromosomes, and to study the unit structure, relative abundance and chromosomal location of rDNA sequences. KEY RESULTS: GISH shows that I. versicolor has inherited the sum of the chromosome complement from the two progenitor species. In I. versicolor all the 18-26S rDNA units and loci are inherited from the progenitor of I. virginica, those loci from the I. setosa progenitor are absent. In contrast 5S rDNA loci and units from both progenitors are found, although one of the two 5S loci expected from the I. setosa progenitor is absent. CONCLUSIONS: These data confirm Anderson's hypothesis that I. versicolor is an allopolyploid involving progenitors of I. virginica and I. setosa. The number of 18-26S rDNA loci in I. versicolor is similar to that of progenitor I. virginica, suggestive of a first stage in genome diploidization. The locus loss is targeted at the I. setosa-origin subgenome, and this is discussed in relation to other polyploidy systems.     

Reduction of selenium oxyanions by unicellular,polymorphic and filamentous fungi: Cellular location of reduced selenium and implications for tolerance

Summary The ability of several filamentous, polymorphic and unicellular fungi to reduce selenite to elemental selenium on solid medium was examined.Fusarium sp. andTrichoderma reeii were the only filamentous fungi, of those tested, which reduced selenite to elemental selenium on Czapek-Dox agar resulting in a red colouration of colonies. Other organisms (Aspergillus niger, Coriolus versicolor, Mucor SK, andRhizopus arrhizus) were able to reduce selenite only on malt extract agar. Several fungi were able to grow in the presence of sodium selenite but were apparently unable to reduce selenite to elemental selenium, indicating that other mechanisms of selenite tolerance were employed, such as reduced uptake and/or biomethylation to less toxic, volatile derivatives. Sodium selenate was more toxic toFusarium sp. than selenite, and the toxicity of both oxyanions was increased in sulphur-free medium, with this effect being more marked for selenate. Scanning electron microscopy ofAspergillus funiculosus andFusarium sp. incubated with sodium selenite showed the presence of needle-like crystals of elemental selenium on the surfaces of hyphae and conidia, while transmission electron microscopy ofA. funiculosus revealed the deposition of electron-dense granules in vacuoles of selenite-treated fungi. Several yeasts were able to grow on MYGP agar containing sodium selenate or sodium selenite at millimolar concentrations. Sone, notablyRhodotorula rubra andCandida lipolytica, and the polymorphic fungusAureobasidium pullulans were also effective at reducing selenite to elemental selenium, resulting in red-coloured colonies.Schizosaccharomyces pombe was able to grow at selenite concentrations up to 5 mmol L^–1 without any evidence of reduction, again indicating the operation of other tolerance mechanisms.     

彩绒革盖菌漆酶产酶条件研究

本文研究了碳源、氮源、愈创木酚、香兰素及培养条件对漆酶分泌的影响;结果表明,淀粉作碳源、干酷素作氮源有利于漆酶的分泌,适宜浓度的愈创木酚和香兰素等对漆酶的产生有一定的作用;pH在3.0－8.0的范围内对漆酶的分泌影响差别不大,培养温度,接种量、通气量对漆酶的分泌有较大影响。     

彩绒革盖菌漆酶产酶条件研究

本文研究了碳源、氮源、愈创木酚、香兰素及培养条件对漆酶分泌的影响;结果表明,淀粉作碳源、干酪素作氮源有利于漆酶的分泌,适宜浓度的愈创木酚和香兰素等对漆酶的产生有一定的作用;pH在3.0～8.0的范围内对漆酶的分泌影响差别不大,培养温度、接种量、通气量对漆酶的分泌有较大影响。     

Temperature affects the production,activity and stability of ligninolytic enzymes in<Emphasis Type="Italic">Pleurotus ostreatus</Emphasis> and<Emphasis Type="Italic">Trametes versicolor</Emphasis>

Enzyme activity was determined in cultures of Pleurotus ostreatus and Trametes versicolor with cellulose as a sole C source and high C/N ratio. The fungi were able to grow and produce laccase and Mn-peroxidase (MnP) at 5-35 degrees C, the highest production being recorded at 25-30 degrees C in P. ostreatus and at 35 degrees C in T. versicolor. Production of both enzymes at 10 degrees C accounted only for 4-20% of the maximum value. Temperature optima for enzyme activity were 50 and 55 degrees C for P. ostreatus and T. versicolor laccases, respectively, and 60 degrees C for MnP. Temperatures causing 50% loss of activity after 24 h were 32 and 47 degrees C for laccases and 36 and 30 degrees C for MnP from P. ostreatus and T. versicolor, respectively.     

Occurrence of toxigenic Aspergillus versicolor isolates and sterigmatocystin in carpet dust from damp indoor environments

Over the past decade, there has been growing concern regarding the role of toxigenic fungi in damp indoor environments; however, there is still a lack of field investigations on exposure to mycotoxins. The goal of our pilot study was to quantify the proportion of toxigenic Aspergillus versicolor isolates in native carpet dust from damp dwellings with mold problems and to determine whether sterigmatocystin can be detected in this matrix. Carpet dust samples (n = 11) contained from <2.5 x 10(1) to 3.6 x 10(5) (median, 3.1 x 10(4)) A. versicolor CFU/g of dust, and the median proportion of A. versicolor from total culturable fungi was 18%. Based on thin-layer chromatography detection of sterigmatocystin, 49 of 50 A. versicolor isolates (98%) were found to be toxigenic in vitro. By using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry, sterigmatocystin could be detected in low concentrations (2 to 4 ng/g of dust) in 2 of 11 native carpet dust samples. From this preliminary study, we conclude that most strains of A. versicolor isolated from carpet dust are able to produce sterigmatocystin in vitro and that sterigmatocystin may occasionally occur in carpet dust from damp indoor environments. Further research and systematic field investigation are needed to confirm our results and to provide an understanding of the health implications of mycotoxins in indoor environments.     

彩绒革盖菌在猪粪堆肥中应用的初步研究

在以猪粪为原料的静态条垛堆肥的堆体试验中添加了彩绒革盖菌,研究其对堆肥发酵的影响。研究表明彩绒革盖菌在堆肥二次发酵时期有利于堆体温度的提升和保温,说明了在进入堆肥后期彩绒革盖菌对其中剩余的木质素等成分有很好的分解能力,有利于堆肥的腐熟和养分的释放,初步表明彩绒革盖菌是一株理想的堆肥发酵菌株。     

Cloning of novel cellulases from cellulolytic fungi: heterologous expression of a family 5 glycoside hydrolase from Trametes versicolor in Pichia pastoris

Total cDNA isolated from cellulolytic fungi cultured in cellulose was examined for the presence of sequences encoding for endoglucanases. Novel sequences encoding for glycoside hydrolases (GHs) were identified in Fusarium oxysporum, Ganoderma applanatum and Trametes versicolor. The cDNA encoding for partial sequences of GH family 61 cellulases from F. oxysporum and G. applanatum shares 58 and 68% identity with endoglucanases from Glomerella graminicola and Laccaria bicolor, respectively. A new GH family 5 endoglucanase from T. versicolor was also identified. The cDNA encoding for the mature protein was completely sequenced. This enzyme shares 96% identity with Trametes hirsuta endoglucanase and 22% with Trichoderma reesei endoglucanase II (EGII). The enzyme, named TvEG, has N-terminal family 1 carbohydrate binding module (CBM1). The full length cDNA was cloned into the pPICZαB vector and expressed as an active, extracellular enzyme in the methylotrophic yeast Pichia pastoris. Preliminary studies suggest that T. versicolor could be useful for lignocellulose degradation.     

Polysaccharopeptides of Coriolus versicolor: physiological activity, uses, and production

The protein-bound polysaccharides or polysaccharopeptides produced by Coriolus versicolor are effective immunopotentiators, which are used to supplement the chemotherapy and radiotherapy of cancers and various infectious diseases. Antitumor activity of polysaccharopeptides has been documented. Several kinds of protein-bound polysaccharides have been shown to be produced by the white rot fungus, C. versicolor. Although some of these polymers are structurally distinct, they are not distinguishable in terms of their physiological activity. This review focuses on the physiologically active polysaccharopeptides of C. versicolor. In nature, C. versicolor occurs as a mushroom body, but the fungus can be grown as mycelial biomass in submerged culture in bioreactors. Mushrooms gathered in the wild, cultivated mushrooms, and the mycelial biomass of submerged culture are used to produce the polysaccharopeptides. Submerged cultures are typically carried out in batches lasting 5-7 days and at 25-27 degrees C. Hot water extraction of the biomass is used to recover the thermostable polysaccharopeptides that are concentrated, purified, and dried into a powder for medicinal use. In view of the documented physiological benefits of these compounds, extensive research is underway on the structure, composition, production methods, and use of new C. versicolor strains for producing the therapeutic biopolymers. Properties, physiological activity, recovery, and purification of the bioactive polysaccharopeptides are discussed.