食药用菌多糖抑菌作用研究进展

为提高灵芝多糖的提取得率,获得抗氧化活性更高的多糖组分,利用响应面试验优化反复冻融提取灵芝多糖的工艺条件,采用乙醇分级法对冻融多糖进行分离得到3种多糖（GLPf30、GLPf60、GLPf80）,评价热水浸提（G. lucidum polysaccharide water,GLPw）、反复冻融多糖（GLPf）及乙醇分级的多糖GLPf30、GLPf60、GLPf80的抗氧化活性,以高效阴离子交换色谱（HPAEC）和红外光谱（FT-IR）进行结构表征。结果显示,最佳冻融条件为：溶胀比14:1（mL/g）,冻融时间140 min,冻融次数3次。在此条件下,灵芝多糖提取得率为2.71%,明显高于传统水提（2.36%）。HPAEC和FT-IR结果表明,5种多糖均是由六种单糖（岩藻糖、葡糖胺、半乳糖、葡萄糖、木糖和甘露糖）组成的以吡喃糖为骨架的酸性多糖,但它们的单糖组成和理化性质有较大差异,尤其是GLPf30的氨基葡萄糖（GlcN）占比最高（达到37.66%）。GLPf30的抗氧化能力明显高于其他两种多糖（GLPf60和GLPf80）及其前体物GLPf。研究结果为灵芝多糖的合理开发和高值化利用提供科学依据。

     

Qualitative analysis of ganoderic acids in Ganoderma lucidum from Iran and China by RP-HPLC and electrospray ionisation-mass spectrometry (ESI-MS)

Ganoderma lucidum is used as a health food and medicine in Far East and produces different ganoderic acids which are well known for their valuable bioactivities. In this study, two different strains of G. lucidum from Iran and China were investigated for ganoderic acids, using reversed phase HPLC (RP-HPLC) in combination with UV and electrospray ionisation-mass spectrometry (ESI-MS). The results showed a relatively low intensity ganoderic acid C2 peak in the chromatogram of the Iranian sample. However, three high intensity peaks attributed to the well known ganoderic acids including ganoderic acids T, Me and H from the Chinese strain. These findings clearly indicated that different strains of G. lucidum could posses a range of active compounds and hence, bioactivities. Moreover, the variation in the triterpenoid components encourages more studies on the rest of bioactive molecules, and also different strains grown in a variety of climatic and geographical conditions.     

Evaluation of in vivo antioxidant activities of Ganoderma lucidum polysaccharides in STZ-diabetic rats

Effect of Ganoderma lucidum polysaccharides treatment on blood glucose, serum insulin level, lipid peroxidation, nonenzymic and enzymic antioxidants in the plasma and liver of streptozotocin (STZ)-induced diabetic rats was studied. Adult male rats of Wistar strain, weighing 195 to 250 g, were randomized into control and experimental groups. Experiment group rats were induced diabetes by administration of STZ (45 mg/kg b.wt.) intraperitoneally. The diabetic rats were treated with G. lucidum polysaccharides (60, 120, 180 mg/kg b.wt.) dissolved in 15% dimethyl sulphoxide (DMSO) for 30 days. The normal control rats were treated with 15% DMSO for 30 days. Streptozotocin treatment elevated the levels of lipid peroxidation markers (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes), and reduced nonenzymic antioxidants (vitamin C and reduced glutathione, vitamin E) levels, and enzymic antioxidants (superoxide dismutase, catalase and glutathione peroxidase) activities in the plasma and liver of untreated diabetic control rats. Decreased level of serum insulin and increased level of blood glucose (BG) were observed in the plasma of untreated diabetic control rats. G. lucidum polysaccharides treatment significantly and dose-dependently increased nonenzymic and enzymic antioxidants, serum insulin level and reduced lipid peroxidation, blood glucose levels in STZ-diabetic rats. From the present study, it can be concluded that G. lucidum polysaccharides can be considered as a potent antioxidant.     

黑芝胞外多糖提取工艺条件优化及体外抗氧化活性研究

本研究采用改进的苯酚-硫酸法测定黑芝多糖含量,以多糖提取率为评价指标,在单因素试验的基础上,进行正交试验,考察乙醇浓度、提取时间、发酵液pH值三个因素对多糖得率的影响。结果表明,最佳提取工艺条件为乙醇浓度80%、提取时间19h、发酵液pH5.5。在此条件下黑芝胞外多糖得率为5.2343g/L。黑芝多糖浓度为40mg/ml时,对·OH与DPPH自由基的清除率分别达到39.85%和23.4%,表明黑芝多糖具有明显的抗氧化活性。     

灵芝米糠发酵液制作保健饮料的工艺研究

本实验以米糠液为天然培养基的原料,接种灵芝菌发酵培养,得到灵芝米糠发酵液。以此发酵液为主要配料进行保健饮料研制。优化得到灵芝米糠饮料配方为：米糠发酵液20%、枣汁16%、脱脂乳粉2%、安赛蜜0.005%;在饮料中添加0.25% 海藻酸钠、0.06% CMC、0.15% 卡拉胶和0.06% 品质改良剂后,产品体态均一稳定。模糊综合评价表明,灵芝米糠饮料符合消费要求。     

灵芝液体培养菌株的选择及其发酵条件优化

在适于液体培养的灵芝菌株中,经选择试验确定赤芝G22为液体发酵生产多糖的高产菌株,并对赤芝G22菌株的液体发酵条件进行了选择优化.结果表明,实现多糖高产的发酵工艺条件为:发酵温度28 ℃、摇床转速180 r/min、培养基初始pH值6.0、发酵时间144 h.采用此优化的工艺条件进行液体发酵,使灵芝多糖产量由1.823 g/L提高到2.315 g/L,提高了26.98 %.     

灵芝深层发酵中麦角甾醇含量的测定

利用HPLC法研究了灵芝真菌发酵过程中胞内外麦角固醇的含量,经紫外全波长扫描,确定测定波长为282mm,研究表明：此方法测定麦角固醇含量最大标准偏差为O．92％,得到线性回归方程为y=28685x-382．61（R=0．9998）,该回归方程在20～500嵋的范围内。精密度试验,灵芝真菌发酵胞内外麦角固醇含量RsD分别为O．40％和1．96％,说明此试验设计条件精密度良好,经加标后,麦角固醇的回收率在96．82～102．50％之间,表明此方法用于测定灵芝真菌发酵过程中麦角固醇含量准确、可行,经测定灵芝真菌发酵至120h,麦角固醇含量增至最高,胞内含量达到O．64mg／g,胞外含量达到0．07mg／mL。     

灵芝醋酸饮料的研制

为开发以灵芝发酵菌丝体和苹果汁为主要原料的高品质健康饮品——灵芝果醋,对灵芝果醋的发酵工艺参数和口味调配等进行了系统的研究。研究结果表明:酒精发酵的最适发酵条件为温度30℃,活化酵母接种量0.02%,发酵时间为5d;醋酸发酵的最适条件为温度35℃,接种量10%,起始pH值5.5;成品果醋的最佳配比为原醋∶蜂蜜∶苹果汁=5.5%∶3%∶60%。     

灵芝水溶性蛋白提取工艺优化

目的优化破壁灵芝孢子粉及灵芝子实体中水溶性蛋白的提取工艺。方法采用中心组合设计方法,以提取温度、提取时间、固液比为考察因素,研究各因素及其交互作用对水溶性蛋白提取率的影响。应用SAS软件和响应面分析相结合的方法,模拟得到回归方程的预测模型和可信度,并通过岭脊分析得到最佳提取条件。结果破壁灵芝孢子粉中水溶性蛋白最佳的提取条件为:提取温度92℃、提取时间196 min、固液比1:173。而灵芝子实体的最佳提取工艺为:提取温度94℃、提取时间157 min、固液比1:166。结论最佳条件下孢子粉中水溶性蛋白的提取率为1.57%,而子实体中水溶性蛋白的提取率为0.96%。     

基于油酸诱导的高产三萜灵芝菌丝体发酵条件优化

本文对油酸促进灵芝菌丝体高产灵芝三萜发酵条件进行了优化,旨在提高灵芝三萜的产量。实验进行了碳源、氮源等单因素的筛选,利用CCD实验设计对培养基进行优化,以及对发酵条件单因素进行了优化。实验结果表明,促进灵芝菌丝体高产灵芝三萜的最优条件为:培养基成分为可溶性淀粉3.4%、鱼蛋白胨0.72%、KH2PO40.3%、Mg SO40.15%、VB10.005%(m/v),p H5.5,在发酵培养第0 d加油酸4.38%(v/v);装液量为100 m L,接种量为10%(v/v),发酵天数为9 d,胞内三萜产量达到(282.67±3.77)mg/100 m L。该方法不仅大幅度提高了三萜产量,对于灵芝的工业化生产也有重要意义。