蛹虫草菌胞外多糖发酵及其发酵动力学

蛹虫草菌(Cordyceps militaris)胞外多糖(EPS)的发酵过程和发酵动力学进行了研究。基于Logitic方程和Luedeking-Piret方程,得到了描述发酵过程的动力学数学模型和模型参数,同时对实验数据与模型进行了验证比较。模型计算与实验结果拟合良好,模型正确地反应了蛹虫草菌胞外多糖的发酵过程及其动力学机制。     

蛹虫草对腺嘌呤致肾阳虚证小鼠影响的实验研究

目的研究人工栽培的蛹虫草对腺嘌呤致肾阳虚小鼠的防治作用。方法将小鼠随机分为正常对照组,肾阳虚模型组和蛹虫草低、中、高剂量组(1.25 g·kg-1、2.5 g·kg-1、5 g·kg-1),除正常对照组外,各组均用腺嘌呤(25 mg·kg-1)造模,给药组同时灌胃给予3个剂量的蛹虫草子实体细粉悬液,连续处理28 d。实验结束后,测定小鼠体质量、自主活动次数、低温游泳时间、脏器湿重、血清睾酮和皮质醇含量,并同时观察小鼠睾丸组织病理结构变化。结果与正常对照组小鼠比较,肾阳虚模型组小鼠体质量明显下降,自主活动次数减少,低温游泳时间变短,血清睾酮和皮质醇的含量降低,睾丸组织发生了退行性变化。与肾阳虚模型组小鼠相比,给予适当剂量的蛹虫草后,小鼠的体质量增加,自主活动次数增多,低温游泳时间延长,脏器湿重增加,血清睾酮和皮质醇含量显著升高,睾丸组织损伤减轻。结论蛹虫草对腺嘌呤致肾阳虚小鼠有一定的防治作用。     

Exopolysaccharide Produced by Lactobacillus Plantarum Induces Maturation of Dendritic Cells in BALB/c Mice

Lactobacillus plantarum (L. plantarum) exopolysaccharide (EPS) is an important bioactive component in fermented functional foods. However, there is a lack of data concerning the effects of L. plantarum EPS on maturation of mouse dendritic cells (DCs). In this study, we purified L. plantarum EPS and examined its effects on cytokines production by dendritic cells in serum and intestinal fluid of BALB/c mice, then investigated its effects on phenotypic and functional maturation of mouse bone marrow-derived dendritic cells (BMDCs). Cytokines (nitric oxide, IL-12p70, IL-10 and RANTES) in serum and intestinal fluid were analyzed by enzyme linked immunosorbent assay (ELISA) after the mice received EPS for 2, 5 and 7 days, respectively. DCs derived from bone marrow of BALB/c mouse were treated with EPS, then the phenotypic maturation of BMDCs was analyzed using flow cytometer and the functional maturation of BMDCs was analyzed by ELISA, and, lastly, mixed lymphocyte proliferation was performed. We found the molecular weight of purified EPS was approximately 2.4×10⁶ Da and it was composed of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in a molar ratio of 2:1:1:10:4:205:215. We observed that L. plantarum EPS enriched production of nitric oxide, IL-12p70 and RANTES, and decreased the secretion of IL-10 in the serum or intestinal fluid as well as in the supernatant of DCs treated with the EPS. The EPS also up-regulated the expression of MHC II and CD86 on DCs surface and promoted T cells to proliferate in vitro. Our data provide direct evidence to suggest that L. plantarum EPS can effectively induce maturation of DCs in mice.     

冬虫夏草和蛹虫草发酵液抗菌活性研究

研究了冬虫夏草和蛹虫草发酵液的抑菌特性,结果表明:两种虫草的发酵液对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、苏云金芽胞杆菌均有较好的抑制作用,且对前两者的抗菌作用强于后两者;热稳定性试验表明发酵液中的抑菌物质具有较强的热稳定性;虫草发酵液与25%糖液和10%盐液协同作用可以增加对参试细菌的抑菌作用;对比试验得出蛹虫草发酵液的抑菌活性较冬虫夏草发酵液的抑菌活性强.     

Chiral inversion of 2-phenylpropionic acid by Cordyceps militaris

Y.-F. HUNG, M.J. THOMASON, W. RHYS-WILLIAMS, A.W. LLOYD AND G.W. HANLON. 1996. Fifty-nine microbial cultures were screened for their ability to carry out the chiral inversion of (R,S) and (R)-2-phenylpropionic acid under both growing and non-growing conditions. While a number of these micro-organisms metabolized the substrate, only Verticillium lecanii IMI 68689 and Cordyceps militaris CBS 128.25 were able to invert the (R)-enantiomer to its (S)-antipode with no other biotransformation occurring. The rate of inversion was faster for C. militaris but in both cases the reaction was independent of growth and reached an equilibrium after 5 d incubation. Evidence suggests that the (R) to (S) inversion is inhibited in the presence of excess (S)-enantiomer which may account for the equilibrium enantiomeric ratios (S:R) of 90:10 and 70:30 for C. militaris and V. lecanii , respectively. Optimization studies revealed that the fastest rates of reaction for C. militaris were found at lower substrate concentrations (100 μg ml^-1) whilst the greatest yield of (S)-2-PPA was obtained at 250 μg ml^-1. Optimum inversion was found to occur using Sørensen's phosphate buffer at pH 5.5. These results may have implications for the use of micro-organisms in the production of pure enantiomers from racemic mixtures and, in addition, provide an in vitro model system for the study of a unique and interesting biotransformation.     

低聚半乳糖对肠道益生菌产胞外多糖作用的研究

旨在研究低聚半乳糖对肠道益生菌产胞外多糖的作用。以低聚半乳糖、葡萄糖、半乳糖和乳糖4种碳源作比较,分别从碳源的利用、胞外多糖的产量和种类及其对有害菌的黏附作用进行研究。结果显示,低聚半乳糖不仅能促进长双歧杆菌和植物乳杆菌的增殖,而且有利于胞外多糖的产生,其含量分别为208.78μg/m L和192.78μg/m L,产生的胞外多糖种类较其他3种碳源更多,对肠道有害菌大肠杆菌具有明显黏附作用。结果证明,与其他3种碳源相比,低聚半乳糖能促进植物乳杆菌和两歧双歧杆菌生成更多的胞外多糖。     

低能离子束修饰蛹虫草菌株高产虫草素

虫草素具有抗肿瘤、免疫调节、抗炎等多种功效。为了更好地开发蛹虫草资源,选择合适剂量的低能离子束注入蛹虫草,优化虫草素的提取工艺条件,采用紫外分光光度法检测注入前后菌株中虫草素的含量。结果表明:最佳注入剂量为2.60×1015ions/cm2,虫草素最佳的微波-超声波提取工艺为:乙醇浓度70%,提取功率200W,提取时间110s,料液比1:240。选育出虫草素含量较高的15株菌株,最高含量达(11.924±0.063)mg/g,比原始菌株增长了近30%。     

蛹虫草优良菌株的筛选

通过对5株蛹虫草的菌丝形态和生长速率、液体培养生物量和胞外多糖、人工栽培和子实体中活性物质虫草多糖和虫草素的对比研究,筛选出优良的蛹虫草菌株。试验结果表明：蛹虫草6号菌株的菌丝的生长速率比其他菌株快;液体培养生物量和胞外多糖含量明显高于其他菌株;人工栽培的蛹虫草子实体头部大,子囊壳丰富,颜色橘黄,出草整齐均匀,出草率高,子实体中虫草多糖和虫草素的含量均高于其他菌株,表明6号菌株具有较高的经济价值,是值得开发和推广的好品种。     

蛹虫草研究进展

蛹虫草（Cordyceps militaris）作为一种药（食）用菌已经被广泛接受,在药理作用、有效成分、人工栽培等方面得到了广泛而深入的研究,具有重要开发价值。依据近年来的有关研究成果,就以上3个方面的研究进展状况展开论述,为蛹虫草进一步的研究与开发提供参考。     

Improvement of fruiting body production in Cordyceps militaris by molecular assessment

Cordyceps militaris is a heterothallic ascomycetous fungus that has been cultivated as a medicinal mushroom. This study was conducted to improve fruiting body production by PCR assessment. Based on single-ascospore isolates selected from wild and cultivated populations, the conserved sequences of α-BOX in MAT1-1 and HMG-BOX in MAT1-2 were used as markers for the detection of mating types by PCR. PCR results indicated that the ratio of mating types is consistent with a theoretical ratio of 1:1 (MAT1-1:MAT1-2) in wild (66:70) and cultivated (71:60) populations. Cross-mating between the opposite mating types produced over fivefold more well-developed fruiting bodies than self- or cross-mating between strains within the same mating type. This study may serve as a valuable reference for artificial culturing of C. militaris and other edible and medicinal mushrooms and may be useful to develop an efficient process for the selection, domestication, and management of strains for industrial-scale production.     

蛹虫草菌生物合成虫草素的研究进展

蛹虫草Cordyceps militaris是我国传统的药用真菌,虫草素是蛹虫草的主要活性成分,具有抗癌、抗肿瘤、抗病毒等多种生理功能。蛹虫草菌液体发酵是最有希望实现高效生产虫草素的途径,但现阶段生产强度低,亟需应用发酵工程及代谢工程手段提高虫草素产量。文中对液体发酵体系中培养基组分(碳/氮源、前体物质、金属离子等)和培养条件(pH、溶氧量、光照等)对虫草素产量的影响进行了总结,并对虫草素的分离纯化、生物合成基因簇及合成代谢途径进行了阐述,最后探讨了实现虫草素高效生产的关键环节。     

蛹虫草子实体中海藻糖含量的测定

为分析食用菌中海藻糖的含量,以蛹虫草子实体为材料,比较了提取溶剂、提取方式及提取时间等条件对海藻糖提取效果的影响,确定海藻糖分析的前处理方法为：1g子实体粉中加入100mL 90%乙醇热回流提取1h。采用高效液相色谱法测定海藻糖,优化后的色谱条件为：SUGAR SP0810柱（300mm×8mm）,超纯水洗脱,流速0.5mL/min,柱温70℃,示差折光检测器检测,进样量10μL。方法学考察结果表明,该方法准确度高,稳定性、精密度、重现性好,对海藻糖标准品的检测特异性良好,适用于蛹虫草子实体中海藻糖含量的     

Enterobacter cloacae Z0206细菌胞外多糖的体外抗氧化活性研究

本实验旨在对Enterobacter cloacae Z0206菌进行发酵培养,以制备胞外多糖,并对其体外抗氧化活性进行初步研究。通过产多糖菌E.cloacaeZ0206的深层发酵制备细菌胞外多糖,在此基础上对其清除DPPH自由基、超氧阴离子、抑制羟自由基的能力以及还原力等四个方面进行实验,评价其抗氧化活性。结果表明,深层发酵制备的E.cloacaeZ0206胞外多糖产量为6.62g/L,其在5mg/mL时对DPPH自由基和羟自由基的清除率分别达到61.57%和40.08%。提示E.cloacaeZ0206细菌胞外多糖具有显著的抗氧化能力,具有开发为抗氧化类食品或药品的潜力。     

人工栽培蛹虫草的病原真菌

蛹虫草规模化栽培过程中,真菌病害普遍发生且危害严重。本研究对人工栽培蛹虫草中真菌病害进行调研,对病原真菌进行分离、纯化、鉴定及致病性检验,并分析病害发生的特点。结果发现引起蛹虫草病害的病原真菌主要有虫草生齿梗孢、产扁虫菌素单端孢、镰刀菌、裂褶菌、哈茨木霉、淡紫拟青霉、稻绿核菌、粉红枝穗霉、卵孢单端孢、扩展青霉、黄曲霉和黑曲霉。其中虫草生齿梗孢为引起蛹虫草侵染性病害的主要病原真菌。虫草生齿梗孢、产扁虫菌素单端孢、镰刀菌、裂褶菌和哈茨木霉主要为害蛹虫草子实体;淡紫拟青霉、稻绿核菌、粉红枝穗霉、卵孢单端孢、扩展青霉、黄曲霉和黑曲霉主要为害栽培料与蛹虫草菌丝体。镰刀菌、裂褶菌、哈茨木霉、淡紫拟青霉、稻绿核菌和粉红枝穗霉为引起蛹虫草病害的首次报道。本研究为蛹虫草病害防控奠定基础,以促进产业健康发展。     

蛹虫草子实体中甘露醇含量的测定

建立了HPLC法测定蛹虫草子实体中甘露醇含量的方法。通过比较提取溶剂、提取方式及提取时间等条件对甘露醇提取效果的影响,确定甘露醇分析的前处理方法为:1g子实体粉中加入150 mL 90%乙醇热回流提取1h。采用SUGAR SP0810柱(300 mm×8 mm)为分析柱,超纯水为流动相,流速1.0 mL/min,柱温70℃,示差折光检测器检测,进样量10μL。甘露醇在0.04-9.9 mg/mL范围内线性关系良好,回归方程为y=103860x+2183.9(r=0.9999),平均回收率为104.27%,RSD=2.19%(n=9)。本方法准确度高,稳定性、精密度、重现性好,适用于蛹虫草子实体中甘露醇含量的分析。     

蛹虫草光受体研究进展

光调控真菌的生长发育和代谢产物合成,是大多数食用菌子实体分化必不可少的环境因子。蛹虫草是一种具有重要药用价值的食用真菌,光因素对蛹虫草的分生孢子数量、生长速率、子实体发育、昼夜节律以及次级代谢产物虫草素和类胡萝卜素的合成均有较大的影响。目前,基于蛹虫草全基因组的解析和遗传操作系统的建立,已鉴定出7种光受体,white collar-1（WC-1）、WC-2、Drosophila-Arabidopsis- Synechocystis-human type cryptochromes（CRY-DASH）、CRY-2、环丁烷嘧啶二聚体光裂合酶（cyclobutane pyrimidine dimer,CPD）、VIVID（VVD）和光敏色素（phytochrome,PHY）。本文较系统地总结了上述光受体的蛋白结构特征,全面阐述了光受体介导光信号调控蛹虫草菌丝生长、子实体发育及次级代谢产物合成等方面的分子机制,并对后续研究进行了展望,为深入研究蛹虫草光受体的具体功能和相关机制提供参考。     

不同北虫草菌种的收集与分离

北虫草高产菌株的筛选非常重要,优质的北虫草菌株在PDA培养基培养初期菌丝为白色,粗壮浓密,边缘整齐,匍匐状紧贴培养基生长,培养后期或者见光后,分泌黄色色素,菌落呈浅黄色到橘黄色。     

Enhancement of cordycepin production from Cordyceps militaris culture by epigenetic modification

Biotechnology Letters - Cordycepin (3′-deoxyadenosine) is a nucleoside analogue and biosynthesised by Cordyceps militaris, an entomopathogenic fungus. In this study, an epigenetic modifier...     

一种双歧杆菌胞外多糖免疫调节功能研究

根据保健食品功能评价规范?功能学评价程序研究一种双歧杆菌胞外多糖(Bifidobacterium spp. exopolysaccharide, EPS)的免疫调节功能。通过脾淋巴细胞增殖反应、绵羊红细胞诱导小鼠迟发型变态反应(DTH)、血清溶血素测定以及巨噬细胞吞噬实验探讨该EPS的免疫调节活性。EPS分别以高、中、低剂量组连续口服给药10天, 结果发现低剂量的EPS[100 mg/(kg·d)]可以促进脾淋巴细胞增殖; 高、中、低剂量对绵羊红细胞诱导的小鼠迟发型变态反应均无促进作用; 但是, EPS 高、中、低剂量组均能明显提高小鼠血清半数溶血值HC50以及增强小鼠腹腔巨噬细胞吞噬鸡红细胞的吞噬能力。根据规范可知, 该双歧杆菌EPS 具有一定的免疫调节活性。     

蛹虫草TTC-脱氢酶测定方法的优化

TTC-脱氢酶还原法可用于检测和鉴别优良及退化蛹虫草菌株.这一方法的应用依赖测定参数的优化.本文优化了蛹虫草TTC-脱氢酶的测定方法,结果显示:测定蛹虫草TTC-脱氢酶活性时,培养6d的蛹虫草菌液先以生理盐水洗涤4次后配成0.15 g/mL的待用菌液;反应缓冲液为Tris - HCI,最适pH值为8.4;最适反应温度为...