北桑寄生产黄酮内生菌的分离鉴定及其抗氧化和抑菌活性评价

【背景】北桑寄生(Loranthus tanakae)植物中黄酮类化合物成分含量较高,生物活性较好。由于植物资源短缺,导致其生物活性成分的研究受限。【目的】从北桑寄生中分离、筛选和鉴定产黄酮类化合物的内生菌,并评估其体外抗氧化和抑菌活性。【方法】以北桑寄生枝条为研究对象分离内生菌,通过显色反应和薄层色谱法(thin-layer chromatography,TLC)筛选产黄酮类化合物的内生菌,并采用NaNO₂-Al (NO₃)₃比色法测定其总黄酮含量。利用清除自由基和抑菌的体外实验来初步评估产黄酮内生菌的生物活性。【结果】共筛选出4株产黄酮内生菌,其中3株为内生真菌,1株为内生细菌,通过形态学和分子生物学方法将其分别鉴定为Botryosphaeria sp.(ZC020)、Phoma sp.(ZZ105)、Nemania sp.(ZS042)和Pseudomonas sp.(ZC026)。4株菌中ZC020和ZS042的总黄酮含量较高,分别为(44.58±0.72) mg/L和(31.98±0.18) mg/L (P<0.05,n=3),并且ZS042可产生与北桑寄生植物相同类型的黄酮类化合物。ZC026和ZS042表现出优异的抗氧化活性,其1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和2,2''-联氮-二(3-乙基苯并噻唑啉-6-磺酸)二铵盐[2,2''-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt,ABTS]自由基清除率分别为72.85%±0.66%(ZC026)、57.01%±0.89%(ZS042)和85.36%±0.75%(ZC026)、88.17%±0.15%(ZS042)(P<0.05,n=3)。ZZ105对革兰氏阳性菌和革兰氏阴性菌均有抑制作用。【结论】从北桑寄生枝条中分离出4株产黄酮类化合物的内生菌,其中有一株为内生细菌。这项工作为北桑寄生黄酮类化合物的生产提供了新的资源,也为其他珍稀药用植物和材料的开发和保护提供了参考。     

药用真菌灵芝液体培养过程中的抗氧化活性研究

灵芝Ganoderma lingzhi是一种重要的药用真菌,已被《中国药典》正式收录。本研究主要以菌丝体干重、多糖含量、多酚含量、黄酮含量、抗坏血酸（ascorbic acid,AA）含量、总抗氧化能力（total antioxidant capacity,T-AOC）、超氧化物歧化酶（superoxide dismutase,SOD）活性、羟自由基清除能力、超氧阴离子清除能力、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、2,2′-连氮-双(3-乙基苯并噻唑-6-磺酸)[2,2′-azino-bis(3- ethylbenzthiazoline-6-sulphonic acid),ABTS]自由基清除能力、铁离子还原能力（ferric reducing antioxidant power,FRAP）和亚铁离子螯合能力为测定指标,对灵芝液体培养过程中的抗氧化活性进行了评价。结果显示,该菌具有较高的抗氧化活性,体现在液体培养过程中生长代谢旺盛,可分泌大量多糖、多酚、黄酮、AA等物质和SOD等酶类,对羟自由基、超氧阴离子、DPPH自由基及ABTS自由基等的清除效果显著,且具有较强的铁离子还原能力和亚铁离子螯合作用,这也说明该菌的抗氧化活性与其自身的生长状况、次级代谢产物分泌及还原能力等密切相关。此外,一定的环境胁迫压力也可以激发该菌启动自身的抗氧化系统以保护机体免受氧化损伤。     

紫色红曲霉对沙棘青稞复合酵素性能的影响研究

【目的】为了对比分析紫色红曲霉是否对沙棘青稞酵素具有促进作用。【方法】以对照组、沙棘组、沙青组、沙青红曲组4种发酵液为研究对象,对其pH、总糖、总酸、可溶性固形物、总酚、总黄酮、抗坏血酸和洛伐他汀、超氧化物歧化酶、脂肪酶和蛋白酶含量、1,1-二苯基-2-苦苯肼自由基清除能力、2,2ʹ-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力、酵母菌活菌数和乳酸菌活菌数进行比较分析。【结果】沙青红曲组的总酚、总黄酮、抗坏血酸和洛伐他汀、超氧化物歧化酶、脂肪酶和蛋白酶含量、1,1-二苯基-2-苦苯肼自由基清除率、2,2ʹ-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率、酵母菌活菌数和乳酸菌活菌数均显著高于沙棘组和沙青组(P<0.05)。【结论】该研究证明了紫色红曲霉的添加可提高酵素的性能,对酵素行业的多元化发展有潜在的促进作用。     

大革耳子实体多糖抗氧化活性

作者对大革耳子实体多糖的抗氧化能力及单糖组分进行了分析,并探究了大革耳子实体多糖体外对羟自由基、超氧阴离子自由基、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、2'-联氨-双-3-乙基苯并噻唑啉-6-磺酸[2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid),ABTS]自由基的清除能力和铁离子还原能力;以人正常肝细胞系LO2为材料建立了过氧化氢细胞氧化损伤模型,并探讨大革耳子实体多糖在细胞水平的抗氧化能力;通过苯酚硫酸法及HPLC检测了子实体多糖的单糖含量及组分。体外化学抗氧化实验结果显示,大革耳子实体多糖对羟自由基、超氧阴离子、DPPH自由基和ABTS自由基的清除能力较强,且具有较高的铁离子还原能力;细胞水平抗氧化实验表明,大革耳子实体多糖对人正常肝细胞系LO2的H₂O₂氧化损伤具有显著的保护作用,并能极显著提高受损细胞内过氧化氢酶（catalase,CAT）（P<0.01）及超氧化物歧化酶（superoxide dismutase,SOD）（P<0.01）的活力。大革耳子实体活性多糖主要单糖含量及组分依次为：葡萄糖（2 985.50mg/kg）、甘露糖（1 867.23mg/kg）、木糖（814.98mg/kg）、半乳糖（724.24mg/kg）、岩藻糖（443.72mg/kg）、葡萄糖醛酸（419.41mg/kg）、鼠李糖（81.18mg/kg）、阿拉伯糖（64.40mg/kg）、核糖（39.95mg/kg）、半乳糖醛酸（24.40mg/kg）。本研究结果为更好的推广应用和科学开发大革耳提供了基础资料。     

仿刺参(Apostichopus japonicus)肠道源植物乳杆菌(Lactobacillus plantarum) HY21的生长及益生特性分析

【目的】在仿刺参(Apostichopus japonicus)健康养殖中为了寻找具有良好耐受性、益生性、安全性的益生菌,本研究从仿刺参肠道内容物中分离获得一株植物乳杆菌(Lactobacillus plantarum) HY21,对其益生潜能进行评价。【方法】利用摇瓶发酵培养、应用环境因子模拟试验、抗生素药敏测试等方法,分析L. plantarum HY21的生长特性、产酸性能、发酵液的抗氧化性质和对水产致病菌的抑制作用;检测菌体的疏水性、自聚性和共聚性、黏附力和药物敏感性,以及对应用环境因子的耐受性。【结果】L. plantarum HY21摇瓶发酵培养温度30℃、初始pH 8.0,于2-10 h为对数生长期,发酵18 h后pH达到最低3.6;发酵液对溶藻弧菌的抑菌直径达到(13.96±0.30) mm,对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-trinitrophenylhydrazine, DPPH)自由基清除率达到95.45%±1.56%;L. plantarum HY21的疏水率为60.42%±2.78%、自聚率为22.69%±1.36%,与溶藻弧菌共聚率为27.98%±1.45%;对体表和肠道黏液蛋白的黏附量分别达到(1.66±0.01)×10⁶ CFU/mL和(1.23±0.15)×10⁶ CFU/mL;对13种常见的抗菌药物均表现敏感;菌体在模拟胃肠液(pH 3.0, pH 6.8)中孵育3 h存活率均可达99%以上,在10%鱼胆汁溶液中孵育3 h存活率达到68.11%±7.98%,在3%海盐溶液中孵育16 h存活率达到97.58%±7.14%。【结论】L. plantarum HY21具有良好的定殖作用、抑菌作用、抗氧化作用等益生特性,而且在应用环境中具有高存活率和高安全性,可以作为一株新的水产益生菌,为开发水产益生菌制剂提供科学理论依据。     

毛尖茶叶多糖的提取分离及其活性测定

本研究对毛尖茶叶多糖结构分析与活性开展了研究。采用水提醇沉法提取毛尖茶叶粗多糖,经除蛋白后得到精制多糖(MP),以柱层析方法对MP进行多次分离纯化,得到一个均一组分毛尖茶叶多糖(Maojian Tea Polysaccharides,MTP)。采用1,1-二苯基–2–三硝基苯肼[1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl,DPPH]自由基清除、小鼠免疫细胞RAW264.7增殖、吞噬能力和产生NO等试验方法对MTP的活性进行研究。结果显示MTP对浓度0.1 mmol/L DPPH自由基清除率为38.26%,对小鼠巨噬细胞RAW264.7的增殖、吞噬能力和产生NO的能力均具有促进作用,与空白对照组有显著性差异(P0.01),且质量浓度为500 mg/L时,活性最大。     

草菇子实体多肽的分离纯化及其结构分析

采用碱性蛋白酶酶解提取草菇子实体多肽,透析法对其进行分离纯化得到3-10、1–3及1 kDa以下3种多肽组分,比较3种组分的体外抗氧化活性。用液相色谱-质谱联用(LC-MS/MS)、紫外吸收光谱、傅里叶红外光谱和氨基酸的测定方法表征纯化后多肽结构。结果表明,1–3kDa组分的抗氧化活性最强,其1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率达到99.81%,铁离子自由基还原能力为1.47, 2,2′-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)[2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS+]自由基和羟自由基的清除能力分别达到99.15%、99.34%。此分子量的草菇抗氧化肽的总蛋白含量为71.12%,灰分含量为12.75%,水分含量为8.44%,其他为7.69%。经鉴定表明草菇子实体多肽是一种优质蛋白质。     

一株耐辐射新菌种的分离鉴定及其多糖的抗氧化研究

【目的】确定新疆辐射污染土样中分离筛选获得的一株产多糖的耐辐射菌株W36-1的分类学地位和抗氧化特性。【方法】对该菌株进行的60Co辐照,结合菌落形态和菌丝特征显微观察、Biolog鉴定以及16S rRNA基因序列分析。采用苯酚硫酸法测定其多糖含量,采用Fenton法测定多糖的粗提物对超氧阴离子清除率;用DPPH法测定抗氧化性;采用邻苯三酚自氧化法测定对超氧阴离子的清除率。【结果】W36-1可耐5 kGy辐照,为一株欧文氏菌属(Erwinia)新种;其粗多糖含量为53.17%,该多糖对超氧阴离子清除率为75.63%,对DPPH清除率为62.43%,羟基自由基去除率为54.89%。【结论】菌株W36-1产的多糖具有抗氧化性。     

川黄连黄酮类成分抗氧化活性研究

文章探究川黄连中黄酮类成分的抗氧化性能，采用正交实验设计法优化川黄连中黄酮类成分的提取工艺，并考查总黄酮提取物对1,1-二苯基-2-三硝基苯肼自由基（DPPH·）、2,2-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐阳离子自由基（ABTS+·）的清除率；提取川黄连中总黄酮的最佳工艺条件为：75%乙醇、料液比1∶15(g/mL)、回流提取时间1.5 h。在该工艺下，川黄连中黄酮的总含量为0.676 8%。质量浓度分别为0.003 6～0.028 75 mg/m L、0.028 75～0.230 0 mg/mL，川黄连总黄酮对DPPH自由基和ABTS自由基的清除能力明显强于VC。川黄连总黄酮对两者均有较好的清除能力，且在一定浓度内体外抗氧化活性明显强于VC。从而得出川黄连黄酮类成分具有一定抗氧化能力的结论，说明生物碱之外的其他化学成分有较好的开发价值，本文为川黄连抗氧化活性的深入研究及开发利用提供了一定的参考。     

桔梗多糖提取、分离纯化以及生物活性研究

本研究以桔梗为原料,研究了桔梗多糖的分离、纯化和体内抗氧化性,采用水提醇沉、脱蛋白脱色、Sephadex G-25和Sephadex G-100分离纯化桔梗多糖,以抗坏血酸作为阳性对照,采用邻二氮菲法、ABTS+自由基清除、铁还原性、·OH自由基清除法和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)研究粗多糖和纯化后的多糖的体外抗氧化性。结果表明:纯多糖和粗多糖都具有较好的抗氧化效果,纯多糖在ABTS+、·OH和DPPH自由基清除性能上要优于粗多糖,还原性和铁离子螯合活性略低于粗多糖,样品的抗氧化能力与样品的浓度呈正相关。本研究表明桔梗纯多糖是天然的抗氧化剂的潜在资源,为桔梗多糖功能性食品的开发提供了理论依据。     

Effects of MULTIFOLIATE-PINNA, AFILA, TENDRIL-LESS and UNIFOLIATA genes on leafblade architecture in Pisum sativum

In order to dissect the genetic regulation of leafblade morphogenesis, 16 genotypes of pea, constructed by combining the wild-type and mutant alleles of MFP, AF, TL and UNI genes, were quantitatively phenotyped. The morphological features of the three domains of leafblades of four genotypes, unknown earlier, were described. All the genotypes were found to differ in leafblade morphology. It was evident that MFP and TL functions acted as repressor of pinna ramification, in the distal domain. These functions, with and without interaction with UNI, also repressed the ramification of proximal pinnae in the absence of AF function. The expression of MFP and TL required UNI function. AF function was found to control leafblade architecture multifariously. The earlier identified role of AF as a repressor of UNI in the proximal domain was confirmed. Negative control of AF on the UNI-dependent pinna ramification in the distal domain was revealed. It was found that AF establishes a boundary between proximal and distal domains and activates formation of leaflet pinnae in the proximal domain.     

Presence of Rhizobium Etli bv . Phaseoli and Rhizobium Gallicum bv . Gallicum in Egyptian Soils

Seven bean rhizobial strains EBRI 2, 3, 21, 24, 26, 27 and 29 identified as Rhizobium etli, and EBRI 32 identified as Rhizobium gallicum, isolated from Egyptian soils and which nodulated Phaseolus vulgaris efficiently, were subjected to hybridization with a nifH probe in order to estimate the copy number of this gene. Seven strains (EBRI 2, 3, 21, 24, 26, 27 and 29) which were only able to nodulate Phaseolus vulgaris, contained three copies of the nifH gene, consistent with their identification as Rhizobium etli bv. phaseoli. Only one strain (EBRI 32) which nodulated both Phaseolus vulgaris and Leucaena leucocephala, had one copy of nifH gene. This confirmed the classification of this strain as Rhizobium gallicum bv. gallicum.     

Characterisation of cell wall polysaccharides, arabinogalactans-proteins (AGPs) and phenolics of Cola nitida, Cola acuminata and Garcinia kola seeds

Many Cola plant species are endemic to West and Central Africa. Cola acuminata and Cola nitida are used as masticatory when fresh, while the dried nuts are used for beverages and pharmaceutical purposes in Europe and North America. Garcinia kola seeds, that serve as a substitute for the true kola nuts, are used in African traditional medicine for the treatment of various diseases, including colic, headache and liver cirrhosis. Seeds extracts of G. kola are also known for their anti-inflammatory, antimicrobial and antiviral properties. To gain information on the chemical properties of the kolas, we have isolated and analyzed cell wall polysaccharides, arabinogalactan-proteins and phenolic substances from the seeds of the three kola species. The sugar composition of cell wall material of C. acuminata, C. nitida and G. kola revealed that Gal (up to 30%), Ara, GalA and Glc as the predominant monosaccharides, representing approximately 90% by mol of the total hydrolysable sugar present in this material. In Ammonium oxalate cell wall fraction, GalA was found to be the major sugar present in all kola species. In the alkali-soluble fraction, there were significant differences in the level of Glc and Gal. The level of Glc was high in C. acuminata and C. nitida while the level of Gal and Xyl were high in C. nitida and G. cola. Isolation and quantification of arabinogalactan-proteins demonstrate that G. kola seeds contained four to eight times more of these proteoglycans than the seeds of the other two species. Finally, analysis of soluble phenolic substances shows that caffeine and catechin were largely represented in C. acumina and C. nitida seeds, with caffeine accounting for 50% of all soluble phenolics. These findings indicate that the three Kola seeds are highly enriched in pectins and proteoglycans and that C. acuminata and C. nitida can be used as a possible source of caffeine and catechin.     

Prosthecium species with Stegonsporium anamorphs on Acer

Data from microscopic morphology, single-spore cultures, and DNA analyses of teleomorphs and anamorphs support the recognition of five species of Prosthecium with Stegonsporium anamorphs on Acer: P. acerinum sp. nov., the teleomorph of S. acerinum; P. acerophilum comb. nov., formerly known as Dictyoporthe acerophila; P. galeatum comb. nov., originally described as Massaria galeata; P. opalus sp. nov.; and P. pyriforme sp. nov., the teleomorph of S. pyriforme s. str. The morphology of both type specimens and freshly collected material was investigated. The teleomorphs have brown ellipsoidal ascospores with five distosepta and often a longitudinal distoseptum. The anamorphs of all species described here belong to Stegonsporium; their connection to the Prosthecium teleomorphs was demonstrated by morphology and DNA sequences of single spore cultures derived from both ascospores and conidia. The anamorphs and teleomorphs of all five Prosthecium species are described and illustrated by LM images, and a key to these species is provided. As perceived from this work, S. pyriforme is restricted to Europe and does not occur in North America, whereas S. acerinum is restricted to North America, not found in Europe. The host associations given in the literature are revised and evidence is provided that only A. opalus, A. pseudoplatanus, and A. saccharum are confirmed hosts of Prosthecium with Stegonsporium anamorphs. Molecular phylogenetic analyses of tef1, ITS rDNA, and partial nuLSU rDNA sequences confirm that the species with Stegonsporium anamorphs are closely related to P. ellipsosporum, the generic type species. Stilbospora macrosperma is confirmed as the anamorph of P. ellipsosporum by DNA data of single spore isolates obtained from both ascospores and conidia.     

Comparative study of Bifidobacteriumanimalis, Escherichiacoli, Lactobacilluscasei and Saccharomycesboulardii probiotic properties

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.     

铜绿假单胞菌对青霉素类抗生素异质性耐药研究

【背景】铜绿假单胞菌是临床上常见的条件致病菌,其异质性耐药的发生常导致临床治疗失败。【目的】研究铜绿假单胞菌对青霉素类抗生素的异质性耐药情况,为相关临床感染治疗提供一定的依据。【方法】收集临床分离的50株铜绿假单胞菌,采用纸片扩散法(diskdiffusion method)即Kirby-Bauer (K-B)法、菌落谱型分析(population analysis profile,PAP)法、生长实验以及传代稳定性实验探究铜绿假单胞菌的异质性耐药特征。【结果】K-B法初筛得到铜绿假单胞菌对哌拉西林(piperacillin,PIP)、哌拉西林/他唑巴坦(piperacillin/tazobactam,TZP)和替卡西林/克拉维酸(ticarcillin/clavulanic acid,TIM)的异质性耐药率分别为52%、52%和54%。PAP实验确认后有13株异质性耐药菌,其检出率占总实验菌株的26%。随机选取8株异质性耐药菌株,其耐药亚群的发生频率为7.3×10-7-1.2×10-5。通过无抗生素压力的生长实验发现,异质性耐药菌株PAS92、PAS57与其各自的3株最高PIP浓度平...     

Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless

The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy.     

转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育及其捕食功能的影响

【目的】为探究转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育及其捕食功能的影响。【方法】以转Cry1Ac/1Ab基因棉与其亲本常规棉为实验材料,利用取食不同棉花品种叶片的棉铃虫饲喂异色瓢虫幼虫。【结果】与常规亲本棉相比,取食饲喂转基因棉花叶片的初孵棉铃虫幼虫的异色瓢虫幼虫从1龄发育至化蛹期时间延长0.77 d,但差异不显著;除1龄幼虫体重增加(0.0773 mg)外,其余各龄期幼虫体重均有所下降,但差异均不显著;异色瓢虫1、2、3、4龄幼虫对初孵棉铃虫捕食量均随棉铃虫密度的增加而增加,捕食功能反应均符合HollingⅡ圆盘方程。【结论】转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育无显著影响,饲喂取食转Cry1Ac/1Ab基因棉花的棉铃虫对异色瓢虫捕食功能无显著差异。