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排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
Fomes sclerodermeus produces manganese peroxidase (MnP) and laccase as part of its ligninolytic system. A Doehlert experimental design was applied in order to find the optimum conditions for MnP and laccase production. The factors studied were Cu2+, Mn2+ and asparagine. The present model and data analysis allowed us not only to define optimal media for production of both laccase and MnP, but also to show the combined effects between the factors. MnP was strongly influenced by Mn2+, which acts as an inducer. Under these conditions Cu2+ negatively affected MnP activity. At 13 days of growth 0.75 U ml–1 were produced in the optimized culture medium supplemented with 1 mM MnSO4 and 4 g l–1 asparagine. The laccase titer under optimized conditions reached maximum values at 16 days of growth: 13.5 U ml–1 in the presence of 0.2 mM CuSO4, 0.4 mM MnSO4 and 6 g l–1 asparagine. Mn2+ promoted production of both enzymes. There were important interactions among the nutrients evaluated, the most significant being those between Cu2+ and asparagine.  相似文献   
2.
The degraded triterpenoid, 3β,6β-dihydroxy-4,4,14α-trimethyl-Δ8-5α-pregnene-20-one (II) and 3-keto-dehydrosulfurenic acid (III), have been isolated from the extracts of Fomes officinalis and their structures determined.  相似文献   
3.
目的:研究阿里红黄酮对衰老模型小鼠的抗衰老作用。方法:将小鼠随机分为6组(n=12):正常对照组,衰老模型组,阳性对照组,低、中、高剂量阿里红黄酮组。除正常对照组外,其余各组均采用D-半乳糖颈背部皮下注射建立亚急性衰老小鼠模型,用不同剂量的阿里红黄酮(100、200和400 mg/(kg·d))灌服小鼠6周后,计算衰老模型小鼠脑指数及脾脏指数、胸腺指数,测定其脑组织丙二醛(MDA)含量及谷胱甘肽过氧化物酶(GSH-Px)活性、肝组织过氧化氢酶(CAT)及超氧化物歧化酶(SOD)活性。结果:阿里红黄酮3个剂量组可不同程度的升高衰老模型小鼠的脑指数、脾脏指数、胸腺指数、脑组织中的GSH-Px活性及肝组织中的CAT、SOD活性,降低其脑组织中的MDA含量。结论:阿里红黄酮可能通过提高机体的抗氧化能力而达到抗衰老作用。  相似文献   
4.
The studies of woody organs‐affecting diseases of Platanus × acerifolia can be hampered by the finding of fungi whose identification is difficult with mycological techniques. In a previous study on Platanus × acerifolia affected by severe cankers, Fomitiporia mediterranea/punctata‐like fungi, not associated with fruit bodies and Libertella sp. were recovered. Due to the severity of the associated symptoms, a characterization of fungal ribosomal DNA genes was undertaken in the present study, aimed to specific identification of the pathogens. From DNA of Fomitiporia‐vegetative isolates and Fomitiporia‐fruit body isolates, included in the study for comparison (from fruit body on plane trees typical of F. mediterranea/punctata), and Libertella sp., DNA fragments were amplified in polymerase chain reaction (PCR) with the use of ITS5/ITS4 and 5.8S‐R/LR7 primer pairs. Sequence alignments showed that Fomitiporia‐vegetative/fruit body isolates had highly homologous ITS5/ITS4 sequences, with a nucleotide identity of 98–100%. All the Fomitiporia isolates from plane tree showed 97–100% and 91–94% of nucleotide identity respectively with ITS5/ITS4 sequences of known strains of F. mediterranea and F. punctata, extracted from GenBank. The strong similarity of these identity ranges with those obtained within F. mediterranea (98–100%) and between the two Fomitiporia species (90–94%) confirms the identification of the isolates from plane tree as F. mediterranea. Sequence comparison between Libertella sp. from plane tree and known strains of Eutypa lata/L. blepharis showed 94–99% of nucleotide identity. The comparison with eight additional species of Eutypa showed 90–93% of nucleotide identity. As previously reported for the different taxa within Diatrypaceae, also ITS5/ITS4 sequence of Libertella sp. from plane tree exhibited 11‐bp tandem repeats motifs. Results of sequence alignments, of phylogenetic trees, and of the putative restriction map, identify the Fomitiporia isolates of this work as F. mediterranea, and the isolates of Libertella sp. as E. lata/L. blepharis. For comparative purposes, ITS5/ITS4 sequences of Spongipellis pachyodon and Fomes fomentarius from plane tree, were also obtained in this work.  相似文献   
5.
木腐菌氧化酶系检定及漆酶产生的研究   总被引:2,自引:0,他引:2  
采用丁香醛连氮、苯胺蓝平板脱色等4种方法,定性检测了27种真菌的木素氧化酶系组成。结果表明5个菌种同时具有漆酶(Lac)、木素过氧化物酶(Lip)和锰过氧化物酶(Mnp)3种酶的活性,5个菌种同时具有Lac和Lip2种酶的活性,8个菌种具有1种酶的活性;12个菌种具有Lac活性。选择其中生长速度快、Lac活性高的5个菌种进行Lac产生的研究,发现木蹄层孔菌Fomes fomentarius诱导、静止培养条件下产生的Lac酶活峰值高达9496U/mL,远远高于其它已报道过的菌种;静止培养条件下贝形刺革菌Hymenochaete badio-ferruginea和乳白耙菌Irpexlacteus产Lac,其峰值也分别达到了652和292U/mL,均明显高于其它培养方式,说明木蹄层孔菌等3种真菌静止培养可代替振荡培养进行Lac产生、制备等相关的后续研究。木蹄层孔菌等5种真菌对刚果红等染料脱色作用研究表明,各菌种对4类染料均具有高效广谱的脱色作用。  相似文献   
6.
探讨阿里红多糖(Fomes offficinalis Ames polysaccharides,FOPS)抗氧化应激的作用,并从Nrf2/ARE信号通路研究其作用机制.72只健康雄性SD大鼠称体质量并按随机原则分为空白组、模型组、盐酸多奈哌齐组(0.5 mg/kg)、阿里红多糖高、中、低剂量组(100、50、25 mg...  相似文献   
7.
Aim:  To produce high laccase activities from the white-rot fungus Fomes fomentarius .
Methods and Results:  Different culturing methods, viz, cell immobilization on stainless steel sponges and plastic material and solid-state fermentation (SSF) using wheat bran as substrate were used for laccase production by the white-rot fungus F. fomentarius . The SSF study expresses the highest laccase activities, nearly to 6400 U l−1 after 13 days of laboratory flasks cultivation. When the wheat bran medium was supplemented with 2 mmol l−1 copper sulfate, laccase activity increased by threefold in comparison to control cultures, reaching 27 864 U l−1. With the medium thus optimized, further experiments were performed in a 3 l fixed-bed bioreactor (working volume 1·5 l) leading to a laccase activity of about 6230 U l−1 on day 13.
Conclusions:  The results obtained clearly showed the superiority of wheat bran for laccase production over stainless steel sponges and plastic material. Supplementing the wheat bran solid medium with 2 mmol l−1 copper sulfate allowed obtaining high activities at flask scale. The system was scaled to fixed-bed laboratory reactor.
Significance and Impact of the Study:  The high enzyme production along with the low-cost of the substrate, showed the suitability of the system F. fomentarius – SSF for industrial purposes.  相似文献   
8.
9.
运用硅胶、sephadex LH-20等柱色谱,从木蹄层孔菌子实体的乙醇提取物分离得到12个化合物,通过单体的理化性质、NMR和MS技术鉴定单体的结构为3-十六碳酸酯-7,22-二烯麦角甾醇(1),十八烷酸(2),棕榈酸(3),7,22-二烯麦角甾-3-酮(4),麦角甾-7,22-二烯-3-醇(5),5,8-过氧麦角甾-6,22-二烯-3-醇(6),3,3-二甲氧基-7,22-二烯麦角烷(7),28-乙酰白桦脂醇(8),白桦脂醇(9),β-羟基十八烷酸(10),9,10-二羟基十八烷酸(11),瑞香素(12)。采用Alamar Blue法检测单体化合物对人肺癌细胞NCI-H 460和人胃癌细胞SGC-7901的抑制活性。结果表明,化合物4对NCI-H 460细胞株的抑制活性最高,化合物9对SGC-7901的抑制活性最高。  相似文献   
10.
张媛  包海鹰 《菌物学报》2014,33(1):114-120
对粗毛纤孔菌、椭圆嗜蓝孢孔菌、火木层孔菌、木蹄层孔菌4种多孔菌子实体粗多糖成分的含量及其体内抗肿瘤活性进行了比较研究。结果表明粗毛纤孔菌子实体中的粗多糖含量为4.1%,高于其他3种多孔菌;同时,4种多孔菌子实体粗多糖对H22荷瘤小鼠均显示出一定的抗肿瘤活性,除木蹄层孔菌外,其他3种多孔菌给药剂量为500mg/mL和1 000mg/mL时抑瘤率均大于40%,其中粗毛纤孔菌子实体粗多糖抑瘤率最高,低剂量组(500mg/kg)为58.12%,高剂量组(1 000mg/kg)为47.75%。  相似文献   
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