pH对灵芝液态发酵代谢物及抗氧化活性的影响

已有研究报道灵芝栽培生长的最适pH在中性偏酸环境,在碱性范围的生长及代谢情况鲜见报道。本研究主要探究广泛pH对灵芝液态发酵代谢物及其抗氧化活性的影响。采用摇瓶液态培养后分析代谢物中灵芝三萜、胞内外多糖、菌丝体蛋白及抗氧化活性等指标,系统比较灵芝菌丝体在pH值2-11的生长和代谢情况。研究结果表明,灵芝菌丝体生长、合成灵芝三萜、胞内多糖、30E胞外多糖、菌丝体蛋白和菌丝体水解氨基酸的最适pH值分别为10、3、2、7、2和2。对应结果分别为17.13 g/L、33.86 mg/g、72.73 mg/g、7.86 g/L、71.42 mg/g和107.10 mg/g。比对照分别提高28.5%、77.3%、22.4%、96.5%、97.1%和70.8%。胞内多糖组分1和组分2最高分子量均在初始pH 4,分别为1.016×10⁸ g/mol和9.280×10⁴ g/mol,胞外多糖组分1最高分子量在初始pH 10,为4.946×10⁶ g/mol;对菌丝体的总抗氧化能力、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2- picrylhydrazyl,DPPH)自由基清除能力、羟自由基清除能力分析结果表明最佳的初始pH分别为3、7、9。本研究为液态发酵方式下灵芝生长及其代谢物定向调控发酵的工艺优化提供参考依据,同时发现灵芝菌丝体中优质蛋白及抗氧化活性可在功能性食品和化妆品领域推广应用。     

灵芝液态发酵高产胞外多糖菌株筛选及多糖特性分析

对10株灵芝菌株发酵菌丝体生物量、胞内多糖含量、胞外粗多糖得率及其多糖含量和单糖组成特征进行了系统分析。结果表明,随着培养时间的延长,10株菌株的生物量均有不同程度增加,但不同菌株胞内多糖含量和胞外粗多糖得率变化趋势有所不同。在培养至7d时,G0023和G0160菌株胞外粗多糖得率均较高,分别为3.02g/L和3.14g/L,其多糖含量分别达到了84.11%和91.03%,可作为发酵高产胞外多糖的优良菌株。分级醇沉胞外多糖分析结果表明,各菌株胞外液20%乙醇沉淀所得20E组分的得率和多糖含量均高于50%乙醇沉淀所得的50E组分,说明胞外液中主要以大分子量多糖为主。20E主要由葡萄糖组成,含有少量木糖和甘露糖;50E主要由葡萄糖和甘露糖组成,含有少量木糖和半乳糖。胞外液表观粘度随剪切速率变化曲线分析结果显示,各菌株胞外液均呈现剪切变稀非牛顿流体特性,其表观粘度大小与菌株对应20E组分的得率及多糖含量呈正相关。     

灵芝液态发酵胞内外多糖的研究进展

灵芝具有悠久的药用历史,其活性物质灵芝多糖具有广泛的药理活性,利用液态发酵技术获取灵芝多糖展现出独特优势。近年来,关于灵芝多糖液态发酵的研究报道越来越多,引起了研究者的广泛关注。本文从灵芝多糖的生物合成代谢及调控、液态发酵的培养基及工艺优化等方面对近期的研究结果进行总结,以期为灵芝液态发酵制备胞内外多糖及其产业化应用提供参考和依据。     

产灵芝胞外多糖培养基的优化及发酵指标变化

经单因素和正交试验优化,灵芝胞外多糖最佳发酵培养基各成分质量分数为:麦芽糖2%,黄豆粉1%,FeSO4·7H2O0.02%,KH2PO40.1%,土豆汁体积分数30%,pH自然,产量可达到86.36g·L-1(湿重)。灵芝胞外多糖产量受发酵过程各因素的影响,发酵过程中pH、总糖、还原糖和氨基氮有一定的相关性。灵芝多糖整个发酵过程需要144h左右,第6d达到发酵终点。     

灵芝胞外多糖的分离纯化及生物活性

目前,灵芝多糖的抗肿瘤及免疫活性已得到人们的广泛关注[1]。灵芝子实体多糖和发酵过程中产生的胞内和胞外多糖已被国内外的研究者证实都是有效多糖[2]。因此利用深层发酵来大规模地生产生物活性多糖是目前灵芝开发利用技术的热点。国内对灵芝培养基的组成、培养方法等已?..     

用灵芝发酵人参水煎液的工艺优化及其产物的抗疲劳活性研究

以灵芝为发酵菌株,对其发酵所采用的基础培养基和人参水煎液培养基分别进行筛选,并对人参水煎液的灵芝升罐发酵工艺及其发酵产物的抗疲劳活性进行了研究,结果表明灵芝最适基础培养基为葡萄糖5%,玉米浆0.3%,豆饼粉1%,糖蜜0.6%,MgSO4 0.075%,KH2PO4 0.15%;最适人参水煎液培养基为红参水煎液,浓度为40g/L;灵芝在红参水煎液中升罐发酵的最佳条件为：发酵周期58–62h。在此优化条件下,菌丝体干重达到7.0233g/L,胞外粗多糖含量达到0.3167g/L。人参的灵芝发酵产物的高、低剂量能明显延长小鼠游泳耗竭时间,并且降低游泳休息后小鼠的血乳酸含量,其中低剂量与空白组有显著性差异（P<0.05）,高剂量与空白组有极显著性差异（P<0.01）。说明红参水煎液的灵芝发酵产物具有显著的抗疲劳作用。     

13种野生灵芝菌丝体中胞内三萜与多糖含量的比较

为探究不同野生灵芝的主要活性成分以及对野生灵芝的开发利用价值,对13种野生灵芝菌株在同一条件下进行液体发酵,采用化学分析的方法,比较菌丝体胞内三萜和多糖的含量差异。结果显示,13种灵芝菌株的三萜和多糖含量有很大差异,其中无柄紫灵芝Ganoderma mastoporum、亮盖灵芝G. lucidum和树舌灵芝G. applanatum的三萜含量较高;树舌灵芝G. applanatum、紫芝G. sinense和褐灵芝G. brownii的多糖含量较高。目前国内广泛栽培灵芝G. lingzhi的野生菌株发酵产物中的三萜和多糖含量并不是最高的,研究结果表明不同种类的野生灵芝还有进一步挖掘的潜在价值。     

药用昆虫蜣螂对灵芝多糖生物合成的影响

采用液体深层发酵方式,研究了几种药用昆虫对灵芝多糖生物合成的影响。结果表明,药用昆虫蜣螂在添加量为5g/L时能显著促进灵芝胞内多糖(IPS)和胞外多糖(EPS)的形成(P<0.05)。胞内多糖和胞外多糖的产量分别由对照的(1.93±0.09)g/L和(520.3±20.2)mg/L提高到(2.41±0.12)g/L和(608.9±20.2)mg/L。灵芝胞内多糖和胞外多糖在DEAE纤维素柱上都可分离得到5种主要组分,其中IPS-1和EPS-1分别为2类多糖的主要组分。进一步用凝胶柱分离显示,IPS-1由3个单个的组分组成,EPS-1由2个单个的组分组成。添加蜣螂发酵后,灵芝胞内多糖和胞外多糖中没有出现新的组分,且各组分的相对含量也没有显著变化(P>0.05),提示添加蜣螂发酵后,灵芝胞内多糖和胞外多糖主要组分的合成途径并未改变。     

灵芝多糖液体发酵条件的研究

液体发酵灵芝是目前灵芝多糖开发的有效途径。以灵芝的生物量和胞外多糖为指标,对影响灵芝发酵的条件进行了研究。单因素实验表明灵芝发酵的最佳碳源、(?)源和生长因子分别是葡萄糖、酵母膏和维生素B1,最适温度、起始pH值和摇床转速分别是28℃、5．5和160 rpm。最佳培养方式是接种后静置4 h再振荡培养,其生物量和胞外多糖的产量最高,分别为7．743g/L和0．907g/L。     

酿酒酵母发酵降解灵芝胞外多糖组分分析及活性研究

本研究采用酿酒酵母发酵的方法对灵芝胞外多糖进行了降解,并对其产物在表观粘度、分子量、多糖得率和含量及单糖组成和生物活性等方面进行了系统比较和分析。结果表明,灵芝发酵胞外液经酿酒酵母培养后,所得胞外液的表观粘度明显降低,其中多糖的分子量也随酵母培养时间的延长出现下降趋势,大分子多糖的分子量从3.55×10 ⁶g/mol下降到1.93×10 ⁶g/mol,低分子多糖的分子量从6.18×10 ⁴g/mol下降到3.11×10 ⁴g/mol。多糖得率和含量测定结果显示,经酵母培养后,灵芝胞外液中20%乙醇沉淀所得20E组分得率明显降低,从2.43g/L下降到0.98g/L,但该组分多糖含量均较高,达到70%以上;而70%乙醇沉淀所得70E组分得率明显增加,达到1.87g/L。单糖组成分析表明,20E组分主要由葡萄糖组成,70E组分主要由甘露糖组成。各组分均表现出较好的与Dectin-1受体结合激活NF-κB增强免疫的活性,且经酿酒酵母发酵24h所得70E组分的活性最好。     

灵芝真菌液体发酵及其产物应用的研究进展

灵芝作为一种白腐真菌,同时也是珍稀的食药用真菌,富含多种生物活性成分。液体发酵技术生产周期短、效率高、产量大、品质稳定,是开发利用灵芝资源的重要途径。近年来,灵芝属真菌菌丝体液体发酵技术的开发与应用取得了较大进展。本文对灵芝属真菌液体发酵产物的主要活性成分及其药用效果、液体发酵工艺优化和发酵产物的应用进行综述,并对本领域的未来进行展望。     

侧耳属食用菌多糖的研究进展

侧耳多糖是从侧耳属食用菌子实体、菌丝体、发酵液或菌糠中提取的一种活性代谢产物。从侧耳多糖的提取方法、结构以及生理作用等方面进行了综述,并对其应用前景进行了展望,旨在进一步发掘和利用侧耳属食用菌的食用价值和药用价值,扩大其在食品和医药领域的应用范围。     

Formation of antigenic extracellular polysaccharides by selected strains ofMucor spp.,Rhizopus spp.,Rhizomucor spp.,Absidia corymbifera andSyncephalastrum racemosum

In this study, polyclonal IgG antibodies raised against extracellular polysaccharides (EPS) ofMucor racemosus were characterised as almost specific for moulds belonging to the order of Mucorales. Cross-reactivity in the ELISA could be observed only towards the yeastPichia membranaefaciens. EPS were isolated from various cultures ofM. hiemalis growing on six different carbon sources and two nitrogen sources, with ratios varying from 0.13 to 0.44 relative to the amount of biomass. Other strains includingMucor spp.,Rhizopus spp.,Rhizomucor spp.,Absidia corymbifera andSyncephalastrum racemosum also excreted EPS, with ratios varying from 0.05 to 0.23. In all cases, the excreted EPS had similar antigenic properties as determined by ELISA. No enzymatic degradation of the antigenic parts of the polysaccharides could be observed upon prolonged incubation. Considering that all tested strains formed similar amounts of antigenic EPS there might be scope for the specific detection of biomass of Mucoralean moulds using ELISA techniques for example in food.     

From nutraceutical to clinical trial: frontiers in Ganoderma development

Ganoderma spp. are medical mushrooms with various pharmacological compounds which are regarded as a nutraceutical for improving health and treating diseases. This review summarizes current progress in the studies of Gamoderma ranging from bioactive metabolites, bioactivities, production techniques to clinical trials. Traditionally, polysaccharides and ganoderic acids have been reported as the major bioactive metabolites of Ganoderma possessing anti-tumor and immunomodulation functions. Moreover, recent studies indicate that Gandoerma also exerts other bioactivities such as skin lighting, gut microbiota regulation, and anti-virus effects. However, since these medical fungi are rare in natural environment, and that the cost of cultivation of fruiting bodies is high, industrial submerged fermentation of Ganoderma mycelia promotes the development of Ganoderma by dint of an increase of biomass and bioactive metabolites used for further application. In addition, various strategies for production of different metabolites are well developed, such as gene regulation, bi-stage pH, and oxygen control. To date, Ganoderma not only has become one of the most popular nutraceuticals worldwide but also has been applied to clinical trials for advanced diseases such as breast and non-small-cell lung cancer.

     

香菇液体发酵高产多糖菌株筛选

通过评价香菇野生菌株发酵产多糖性能,筛选高产香菇多糖菌株.以采自长白山野生香菇通过组织分离获得的6株菌株和2株人工栽培菌株为出发菌株,对不同发酵培养时间菌丝体生物量、胞内多糖含量、胞外多糖含量等进行测试分析,结果表明,8株菌株随着培养时间的延长,菌丝体生物量均有不同程度的增加,但胞内多糖含量和胞外多糖得率变化趋势不同,...     

Airborne Ganoderma basidiospores in a country with desert environment

Aerobiological studies to identify Ganoderma basidiospores were conducted using Burkard Volumetric 7-Day Recording Sampler (Burkard Manufacturing Co. Ltd., England) at three separate cities in Saudi Arabia. At one site, Jizan, close to the coast of Red Sea, up to 17% of all basidiospores counted were identified as Ganoderma spp. while less than 1% Ganoderma spp. were identified at the two non-coastal sites. A clear seasonal pattern from late autumn to early summer (October-March) with a peak in December was recorded at Jizan and the maximum concentration of Ganoderma basidiospores reached 1.9×10³?m^?3 in December followed by 1.2×10³?m^?3 in January. The diurnal pattern of Ganoderma spore concentrations, when averaged over the year had late-evening maxima (a nocturnal pattern). However, other sites that showed low concentrations of Ganoderma basidiospores did not exhibit any peak or a high maximal level. The study demonstrates that even in a desert environment, airborne activities of Ganoderma basidiospores can be recorded. The impact of Ganoderma on asthmatic patients, particularly in such environments, needs to be investigated.     

出芽短梗霉Aureobasidium sp. SRF的菌株特性分析及胞外多糖结构鉴定

菌株SRF是1株从意大利树莓(Rubus corchorifolius)果实表面分离、可产胞外多糖的新菌株。在鉴定其分类归属的基础上,对其产生的胞外多糖进行了结构分析和发酵条件优化,为寻找微生物多糖提供新的菌株,为开发利用资源微生物提供借鉴。通过形态学和ITS序列对比分析进行菌株鉴定;通过薄层层析和红外光谱分析,确定胞外多糖结构;通过单因素检测试验,确定影响产糖量的主要因素;响应面Plackett-Burman和Box-Behnken设计筛选发酵产胞外多糖的最优条件。结果表明,出发菌株SRF隶属于出芽短梗霉属,命名为Aureobasidium sp. SRF;SRF所产胞外多糖为普鲁兰多糖;单因素检测表明,对多糖产量影响最大的因素为碳源浓度、氮源浓度、无机离子浓度,其次是碳源、氮源、无机离子、pH值;根据响应面结果确定最优发酵条件为麦芽糖8%(质量分数)、酵母提取物3%(质量分数)、钙离子0.3 g/L、pH 6,产糖量达5.93 g/L。SRF是1株来源于树莓浆果表面,可产胞外普鲁兰多糖的出芽短梗霉新菌株,是1株产微生物多糖的候选菌株。     

Applied modern biotechnology for cultivation of <Emphasis Type="Italic">Ganoderma</Emphasis> and development of their products

A white-rot basidiomycete Ganoderma spp. has long been used as a medicinal mushroom in Asia, and it has an array of pharmacological properties for immunomodulatory activity. There have been many reports about the bioactive components and their pharmacological properties. In order to analyze the current status of Ganoderma products, the detailed process of cultivation of Ganoderma spp. and development of their products are restated in this review article. These include the breeding, cultivating, extracting bioactive component, and processing Ganoderma products, etc. This article will expand people’s common knowledge on Ganoderma, and provide a beneficial reference for research and industrial production.     

Regulation of expression of group IA capsular polysaccharides inEscherichia coli and related extracellular polysaccharides in other bacteria

Bacterial surface polysaccharides fulfill a number of important roles in cell-cell interactions, survival in natural environments, and formation of biofilms. Consequently, the mechanisms involved in regulation of extracellular polysaccharides are predicted to have a significant impact on microbial adaptation. Strains ofEscherichia coli, Klebsiella spp, andErwinia spp produce extracellular polysaccharides which share structural features. There are also similarities in the organization of genes required for synthesis of these cell surface polymers and, in some cases, the mechanism of synthesis may be related. Despite the diverse habitats of these bacteria, the systems which regulate expression of their extracellular polysaccharides appear to share components and mechanisms. Understanding these regulatory processes may lead to novel therapeutic approaches for pathogens, or for control of unwanted biofilm formation in industrial settings.