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选取3株不同种属白腐菌（K1：灵芝属Ganoderma lueidum，B2：侧耳属Pleurots sp.，A3：香菇属Lentinula edodes），2种不同木质纤维素基质（玉米秸粉、稻草秸粉），对白腐菌在木质纤维素基质上固、液培养过程中产生的胞外羟自由基（·OH）清除能力进行了研究，并初步探析了可能的主效物质。结果表明：（1）白腐菌在木质纤维索基质上不同时期的培养物均具有胞外·OH清除能力，显示了该能力在白腐菌中的普遍性；且试验中香菇A3培养物的胞外·OH清除能力最高，玉米秸粉比稻草秸粉更利于白腐菌培养物产生胞外·OH清除效应。（2）对香菇A3进行玉米秸粉液体培养，第8d时胞外·OH清除率达峰值42．53％，清除·OH的主效物质为胞外粗多糖，其作用占胞外液·0H总清除率效果的75．4％。 相似文献
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以产漆酶的红芝LYL263菌株为试材,采用不同微生物混合培养的方法,研究了红芝LYL263与苏平平菇、白金金针菇、凤尾菇混合培养的产酶效果和产酶条件,以期能筛选出提高红芝LYL263产漆酶的相容菌株以及与之相适应的产酶条件。结果表明：红芝LYL263与其相容菌株-苏平平菇混合培养后漆酶活性达到1 346.4 U·mL-1,比红芝LYL263单独培养产酶提高35.7%;红芝LYL263与苏平平菇的接种比例为4:2时,其产酶量最高,最优接种时间是同时接入红芝LYL263和苏平平菇。 相似文献
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以香菇菌株808为试材,研究了赤霉素对培养第9天～第17天香菇发酵液中的淀粉酶、羧甲基纤维素酶和漆酶3种胞外酶、胞外蛋白质活性的变化的影响,同时测定了第15天和第17天多糖以及生物量的变化.结果表明:淀粉酶在不添加赤霉素时酶活性达最高,最高达29.26 U；羧甲基纤维素酶在0.2 mg/L赤霉素浓度下酶活性最高,最高达31.50 U;漆酶在3.0 mg/L赤霉素浓度下酶活性最高,最高达30 U；3种胞外酶的最高值均出现在第15天左右.蛋白质浓度在2.0 mg/L赤霉素浓度下最高,第11天达高峰0.048 mg/mL; 2.0 mg/L赤霉素浓度下胞外多糖含量最高达23.64 g/L,1.0、2.0 mg/L赤霉素浓度下菌丝干重相对较高. 相似文献
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香菇漆酶的纯化及部分性质研究 总被引：2，自引：1，他引：1
对香菇漆酶进行了丙酮分级沉降、半透膜透析、DEAE一纤维素及Sephadex G100柱层析纯化,并研究了漆酶的产酶曲线及酶作用最适条件.,结果表明:在该培养条件下,香菇第10天达产酶高峰,峰值酶活为216 U/mL,酶作用的最适pH值为3.6,在pH值3.6～4.6有较强的稳定性.最适酶解温度为30℃,Ba2 、Cu2 对香菇漆酶有激活作用,而Ag 、Fe3 则能明显抑制漆酶活性,其它离子影响相对较小.以邻联甲苯胺为底物的表观Km值为1.68 mmol/L. 相似文献
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通过比较香菇(Lentinula edodes)野生菌株L3,NCBI已公布的菌株135A、135B、B17、NBRC 111202、W1-26,木腐菌金针菇(Flammulina velutipes)、糙皮侧耳(Pleurotus ostreatus),以及草腐菌双孢蘑菇(Agaricus bisporus)、灰盖鬼伞(Coprinopsis cinerea)、草菇(Volvariella volvacea)的基因组。结果表明:香菇不同菌株间基因组存在较大差异,大小为36.69~46.11 Mb,基因数量为11192~14889;香菇菌株135A、135B、B17、L3、NBRC 111202和W1-26基因组注释的碳水化合物活性酶(carbohydrate-active enzymes,CAZymes)基因数量分别为520、520、483、475、524和537,其中L3最少,为475;纤维素酶在香菇不同菌株中基因数量为19~22,低于灰盖鬼伞和草菇,高于双孢蘑菇;不同香菇菌株的氧化还原酶基因数量为41~55,L3最少,为41,NBRC111202最多,为55,135A和135B最为接近。在基因水平上,木腐菌与草腐菌的木质纤维素降解酶体系没有完全的界限,它们之间存在一定的共性,因此木腐菌草腐化栽培存在可能性。 相似文献
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通过固体培养初选和摇瓶发酵复选,从腐烂的秸秆、腐草、腐树干中筛选获得酶活较高的真菌、放线茵和细菌各2株,将6个菌株分别接种到不同的碳源的牛羊粪中,经过2d培养后测定其CMC酶活.结果表明:不同菌种对同一粪便的酶活力不一样;同一菌株在不同粪便中表现的酶活力也不一样.其中,P2-6和P2-7在牛粪上酶活力最强,P2-6和B2-6及P2-7在羊粪上酶活力较强.最终确定以上3株菌株为牛羊粪堆肥发酵的首选菌株. 相似文献
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木耳漆酶高产菌株筛选及其发酵条件的研究 总被引：4，自引：0，他引：4
通过运用不同检测方法对木耳属中的三个种的 2 7个菌株的产过氧化物酶、漆酶能力的检测 ,筛选得到一漆酶高产菌株毛木耳 (Auriculariapolytricha)AP4。并且对AP4的产漆酶的发酵条件进行了初步研究。摇瓶实验产漆酶的最佳培养基的成分为 :碳源羧甲基纤维素(CMC) 5g/L ,氮源NH4NO3 L -天冬酰胺 (L -As paragine) 2 4mmol/L ,培养基的初始pH4 0 ,培养温度2 5℃。 相似文献
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漆酶制剂及其在食用菌生产中的应用 总被引：2，自引：0，他引：2
漆酶是最先在漆树体内发现的一种含铜多酚氧化酶,后经研究发现许多植物和微生物体内也富含漆酶,属胞外酶类,并对这些生物体的生育起促进作用。关于漆酶在食、药用菌生产中的作用,本文作者已在《食用菌》92年增刊上作过讨论。那么如何生产漆酶制剂并应用于食用菌生产,将是一个十分诱人的课题。所谓酶制剂,按生物化学的观点,即从含某种酶的生产体中分离、提纯、精制并添加活性保护剂后而得到的粗品或结晶。生产酶制剂的品种多、用途广,有的品种生产规模很大。例如用于纤维脱浆的细菌α-淀粉酶制剂,1972年日本年消耗量就达千吨,价值600万日元。随科学技术的进步,生物酶制剂的商品生产已跨入高新技术产业之列。 (一)漆酶来源 据许多研究资料介绍,漆树、野漆树、芒果等漆树科植物和桃树、苹果、银杏、牛蒡、毒长春藤、马铃薯等植物体中富含漆酶,象香菇、平菇、蘑菇、灵芝、漆柄云芝等含漆酶或分泌漆酶的菌类就更 相似文献
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AIM: To examine the autoantibody against α1-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α1-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α1-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α1-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension. 相似文献
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AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation. 相似文献
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《International Journal of Fruit Science》2013,13(1):139-156
Abstract This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality. 相似文献
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AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration. 相似文献
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Fulé Peter Z. Crouse Joseph E. Heinlein Thomas A. Moore Margaret M. Covington W. Wallace Verkamp Greg 《Landscape Ecology》2003,18(5):465-486
Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
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《International Journal of Fruit Science》2013,13(3):101-120
Abstract Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared. 相似文献
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The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species. 相似文献
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以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。 相似文献
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AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G1/S cell cycle transition. METHODS:The DNA synthesis was determined by [3H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [3H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G0/G1 phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G0/G1 phase by increasing PTEN expression through inhibiting synthesis of mevalonate. 相似文献
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多效唑对猕猴桃离体试管苗生长及内源激素的影响 总被引：18，自引：0，他引：18
多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。 相似文献