食用菌多糖的研究

食用菌多糖具有独特的生理特性和极高的药用价值,已成为当前药物研发的热点。从食用菌多糖的化学结构、提取分离、药用价值和应用等几个方面对其进行了全面的总结和展望。     

凤尾菇与平菇的鉴别及其分类地位

凤尾菇韧伞（Ｌｅｎｔｉｎｕｓ ｓａｊｏｒ－ｃａｊｕ）和糙皮侧耳（Ｐｌｅｕｒｏｔｕｓ ｏｓｔｒｅａｔｕｓ）为两种广泛栽培的食用菌,在中文文献中经常与侧耳属（Ｐｌｅｕｒｏｔｕｓ）的其它几种食用菌统称为平菇。为了种类鉴别和澄清分类上的关系,本文对两种真菌进行了详细的形态描述和特征比较,确认凤尾菇是韧伞属（Ｌｅｎｔｉｎｕｓ）的成员,不应归放在侧耳属内。凤尾菇韧伞与糙皮侧耳,或韧伞属与侧耳属的最显蓍的差异在     

食用菌多糖的提取纯化及生物活性研究进展

食用菌多糖因具有抗氧化、免疫调节、抗肿瘤、降血糖、降血脂等生物活性而备受关注。食用菌多糖的结构影响其生物活性,具有(1→3)、(1→4)、(1→6)及混合糖苷键的β-D-葡聚糖是高活性食用菌多糖的结构特征之一,展现出提高抗氧化酶活性、促进分泌抗癌因子、刺激脾脏和胸腺细胞增殖等不同功能。酸碱、超声波及微波、Sevag法、树脂法、亲和层析等不同提取纯化方法会影响食用菌多糖得率,同时会改变食用菌多糖结构,影响其生物活性。详述食用菌多糖的提取纯化方法及其对结构与活性的影响,食用菌多糖的组成结构和构效关系,以及食用菌多糖在抗氧化、抗肿瘤、免疫调节、降血糖和降血脂等方面的功能、结构特征及生物活性,并提出了食用菌多糖形成的分子机制、多糖活性位点修饰、多糖代谢动力学等未来研究方向。     

侧耳属真菌经济利用的研究进展

侧耳属真菌分布广泛、是大型真菌中生物多样性最为丰富的类群之一。其含有丰富的多糖、蛋白质、氨基酸、脂肪酸等生物活性物质,在食品、保健和医药等方面具有广泛用途。侧耳属真菌通过产生木质素氧化酶、锰过氧化物酶和漆酶等酶类降解多环芳烃、染料、工农业废弃物等有害物,并广泛应用于纺织厂、造纸厂、橄榄油厂废水及城市废水的处理。同时,侧耳属是食用菌家族中利用基质最为广泛的真菌,可以多种农业、林业、轻工业等废弃物为基质进行栽培生产,且生物学效率较高,具重要农业生产应用价值。     

冷杉侧耳多糖提取工艺优化及体外抗氧化活性

【背景】冷杉侧耳（Pleurotus abieticola）是一种新型食药用真菌,具有潜在的经济价值。【目的】更好地开发利用冷杉侧耳中的多糖成分,挖掘潜在的功能性食品。【方法】采用响应面分析法对冷杉侧耳多糖的提取工艺进行优化,并通过设置不同浓度梯度的多糖和Vc （阳性对照）考察该多糖的1,1-二苯基-2-苦基肼自由基（1,1-diphenyl-2-picrylhydrazyl free radical,DPPH）、2,2''-联氮-双-3-乙基苯并噻唑林-6-磺硫（2,2''-azinobis-3-ethylbenzthiazoline-6-sulphonate,ABTS）和羟基自由基（hydroxyl radical,·OH）的清除能力及铁离子还原能力来评价冷杉侧耳多糖的体外抗氧化活性。【结果】最佳提取工艺：提取时间122.62 min,提取温度60.27℃,液料比28.87：1（体积质量比）,在该条件下,冷杉侧耳纯多糖提取率达到极大值2.39%。该多糖在浓度为1 mg/mL时,DPPH自由基清除率为49.42%,ABTS自由基清除率为88.37%,羟基自由基清除率为19.87%,铁离子还原力为0.273。【结论】本研究为更高效地开发与利用冷杉侧耳多糖提供了理论依据,为进一步挖掘其生物活性及多糖产品打下了基础。     

金顶侧耳胞内多糖生物活性研究

对金顶侧耳Pleurotus citrinopileatus胞内多糖的热水浸提工艺进行研究,并研究了该多糖的抑菌活性以及对超氧阴离子自由基和亚硝基的清除作用。结果表明,金顶侧耳胞内多糖的最佳提取工艺为:提取温度60℃,液料比100:1,时间4h,此条件下多糖提取率可达17.65%。该多糖对埃希氏大肠杆菌和金黄色葡萄球菌均有抑制作用且对超氧阴离子自由基和亚硝基有较强的清除作用,说明该多糖具有明显的生物活性。     

富硒食用菌多糖的体外抗氧化研究

分别采用还原力、羟自由基、超氧阴离子自由基、[DPPH.]体系和卵磷脂脂质过氧化体系等几种不同的体外抗氧化模型,对超声波法提取得到的富硒食用菌多糖的抗氧化能力进行了研究。结果表明,在各种体系中,富硒食用菌多糖均表现出较高的抗氧化性,且其浓度与抗氧化活性呈一定的量效关系,在相同的多糖浓度下,体系的抗氧化活性与硒含量有关。     

食用菌的药用价值

食用菌除含有丰富的蛋白质和碳水化合物外,还含有人体所必需的多种氨基酸、维生素、矿质元素和多糖。对平衡人体代谢十分有益。其中多糖已被证明为功能物质,且具有多种医疗作用。据报道,已经提纯并用于药理研究的多糖有:银耳多糖、银耳孢子多糖、香菇多糖、黑木耳多糖、猴头多糖、侧耳多糖、密环菌多糖、云芝多糖、茯苓多糖、竹荪多糖、猪苓多糖、灵芝多糖、亮菌多糖及苦孢牛肝菌多糖等。其中多数已制成片剂、冲剂、糖浆或针剂应用于临床,收到较好疗效。调节免疫功能的作用食用菌的多糖成分对免疫功能的调节主要体现在以下几方面。 1.对补体的影响据报道,在研究从香菇中提取的β(1→3)主链的葡聚糖和α-甘露聚糖的抗肿瘤作用过程     

热胁迫对糙皮侧耳抗霉菌侵染能力的影响

糙皮侧耳Pleurotus ostreatus具有较高的食用与药用价值,是世界上广泛栽培的食用菌之一,也是中国栽培范围最广的食用菌。糙皮侧耳生产中会受到多种环境因素的影响,其中温度是最重要的环境因子。为了探究高温对糙皮侧耳生理及抗霉菌侵染能力的影响,以生产菌袋为材料,分离并获得3种霉菌,经鉴定为卷枝毛霉Mucor circinelloides、四孢脉孢菌Neurospora tetraspora和长柄木霉Trichoderma longibrachiatum;进一步研究发现,高温显著抑制糙皮侧耳菌丝生长,高温胁迫后,糙皮侧耳抗霉菌侵染的能力降低、微观结构遭到破坏、糙皮侧耳菌丝胞外多糖含量显著增加并且吸附霉菌孢子的能力增强。本研究为阐明高温降低糙皮侧耳霉菌感染抗性的作用机制提供科学依据。     

食用菌多糖研究开发现状与展望

食用菌多糖具有多方面的活性功能,已成为当今研究的热点.对食用菌多糖的研究开发现状及存在问题进行了综述,期望能对今后食用菌多糖的研究和应用有所帮助.     

Changes in lignocellulolytic enzyme activites in six <Emphasis Type="Italic">Pleurotus</Emphasis> spp. strains cultivated on coffee pulp in confrontation with <Emphasis Type="Italic">Trichoderma</Emphasis> spp.

Summary The antagonistic effect of six Pleurotus spp. strains was studied in confrontation with three strains of Trichoderma spp. Pleurotus strains were cultivated on sterile coffee pulp, with and without a Trichoderma inoculant. Laccase, Mn peroxidase and endoglucanase activities were determined during incubation. Laccase production was also studied by PAGE analysis to detect enzymatic isoforms. Results show that the presence of Trichoderma induced a significant increase in oxidase production by the Pleurotus strains. Nevertheless, Trichoderma was not observed to induce laccase isoforms.     

灵芝液态发酵胞内外多糖结构特征及其活性研究进展

灵芝是一味传统的中药材,具有很高的药用价值,多糖是其主要的活性成分之一,可从其子实体、孢子粉、发酵菌丝体和胞外液中获得。近年来,从灵芝菌丝体和胞外液中发现的多糖越来越得到研究者们的关注。本文从发酵培养基成分及发酵条件对灵芝胞内外多糖的影响、灵芝胞内外多糖的结构、灵芝胞内外多糖生物活性3个方面进行综述,为发酵来源灵芝多糖的开发利用提供科学理论依据。     

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.     

Enzyme activities and substrate degradation during white rot fungi growth on sugar-cane straw in a solid state fermentation

Two strains of Pleurotus spp., grown in solid state fermentation on sugar-cane straw, degraded the dry matter by 50% after 60 days. The rate of substrate consumption and the dry weight of fruiting bodies decreased in consecutive flushings. Both strains vigorously attacked hemicellulose (80% of total degradation) and lignin (70%). Fruiting bodies were rich in protein and lipids, and had a low content of carbohydrates and ash.     

Bioconversion of agricultural lignocellulosic wastes through the cultivation of the edible mushrooms Agrocybe aegerita,Volvariella volvacea and Pleurotus spp.

Ten selected wild and commercial strains of Pleurotus ostreatus,Pleurotus eryngii,Pleurotus pulmonarius, Agrocybe aegerita andVolvariella volvacea were cultivated on three agricultural wastes, i.e. wheat straw (WS), cotton waste (CW) and peanut shells (PS). All species demonstrated significantly higher colonization rates on WS and CW than on PS. WS supported faster growth of A. aegerita and Pleurotus spp., whereas V. volvacea performed better on CW. Comparison of growth rates on composted and non-composted WS and CW substrates revealed that in the latter case faster colonization was achieved, particularly for Pleurotus spp. However, one commercial strain of V. volvacea presented higher growth rates when the composted CW medium was used. Furthermore, earliness in the fructification of P. ostreatus, P. pulmonarius and V. volvacea strains was promoted in CW substrates, while WS favoured earliness of P. eryngii and A. aegerita. Similarly, high sporophore yields were obtained by P. ostreatus and P. pulmonarius on both wastes, whereas WS enhanced yield and basidioma size of P. eryngii and A. aegerita strains and CW production of V. volvacea. The substrates cellulose:lignin ratios were found to be positively correlated to mycelial growth rates and to mushroom yield of P. ostreatus and P. pulmonarius; in addition, positive correlation was also detected for carbon:nitrogen ratio and mushroom yield in P. eryngii and A. aegerita and between cellulose content and mushroom yield for V. volvacea strains.     

Differential Patterns of Constitutive Intracellular Laccases of the Vegetative Phase of Pleurotus Species

The constitutive intracellular laccase activity of ten strains of Pleurotus spp. was determined in vitro and by zymograms, using different substrates. Differences in the in vitro activities were observed between all the strains; however, zymogram patterns were only similar for strains within same species, independently of any of the three substrate (2,6-dimethoxyphenol, p-anisidine or o-tolidine) used. The differences observed in the number and positions of the isoforms in the gel suggest that laccase zymograms can be used to differentiate species of this organism.     

Utilization of lignocellulosic waste by the edible mushroom,Pleurotus

Lignocellulosic waste represents huge amounts of unutilized renewable resource. The use of the polysaccharides in the lignocellulosic complex is limited due to their high lignin content. White rot fungi are capable of selectively degrading lignin, thereby upgrading it. The focus of this article is on the potential utilization of edible mushrooms of the genus Pleurotus, via solid state fermentation, using cotton plant stalks as a substrate. This material poses agrotechnical problems since the stalks have a fibrous structure similar to that of hardwood. Potential uses for this material are as a fuel in rural areas, a substrate for mushrooms, an animal feed and substrate for paper making. In this study, degradation of cotton stalks by Pleurotus is described using chemical analyses and scanning electron microscopy. During four weeks of solid state fermentation, lignin content significantly decreased and in vitro digestibility was increased. The fermentation product was consumed by ruminants at a level of up to 40% of their diet.     

Phenotypic diversity amongst strains of Pleurotus sajor-caju: implications for cultivation in arid environments

In arid regions, biodiversity and biomass are limited by water availability, and this problem has been compounded by desertification associated with global climate change. The saprotrophic macrofungi that are indigenous to hot subtropical and tropical regions, such as Pleurotus spp., can play key roles in water sequestration, nutrient cycling, human nutrition, and bioremediation of waste materials. We studied 15 strains of Pleurotus sajor-caju, a widespread and phenotypically-diverse species, to establish variability in growth response and primordium development over a range of stress parameters: osmotic potential (−0.5 to −5 MPa), temperature (5–40 °C) and pH (2–12). The initiation of primordia precedes basidiome production and therefore represents a key stage in bioremediation strategies and fungi-driven nutrient cycles. Primordia were produced at low pH (4–6), at suboptimal growth temperatures (≤25 °C), and under moderate water stress (−0.5 to −3.5 MPa). Although the growth windows for different strains were similar, their maximum growth rates and the optimum conditions for growth varied. We discuss the phenotypic diversity of Pleurotus strains and discuss their potential for cultivation, bioremediation and ecological regeneration.     

Production of xylooligosaccharides from enzymatic hydrolysis of xylan by the white-rot fungi Pleurotus

The white-rot fungi basidiomycetes Pleurotus sp. BCCB068 and Pleurotus tailandia were used to degrade oat-spelt xylan under submerged fermentation over a period of 40 days. Activities of endo-1,4-β-xylanase and β-xylosidase and xylan degradation products were determined. Xylan degradation by Pleurotus sp. BCCB068 and P. tailandia reached 75.1% and 73.4%, respectively. The formation of xylooligosaccharides and the simple sugars xylose, arabinose, cellobiose, mannose, and maltose were observed for both strains. The xylan degradation exhibited by these Pleurotus strains indicates they have potential for use in biotechnological processes related to degradation of hemicellulose sources.     

Effect of antimicrobial activity of Melaleuca alternifolia essential oil on antagonistic potential of Pleurotus species against Trichoderma harzianum in dual culture

Melaleuca alternifolia (tea tree) essential oil was investigated for its “in vitro” ability to control Trichoderma harzianum, a fungal contaminant that causes extensive losses in the cultivation of Pleurotus species. The antifungal activity of M. alternifolia essential oil and antagonist activities between Pleurotus species against three T. harzianum strains were studied in dual-culture experiments on an agar-based medium in which different concentrations of essential oil were incorporated. M. alternifolia essential oil at a concentration of 0.625 μL/mL, inhibited T. harzianum mycelial growth by 5.9–9.0%, depending on the strain. At the same concentrations P. ferulae and P. nebrodensis stimulated mycelial growth by 5.2–8.1%. All strains of T. harzianum were antagonistic to the Pleurotus species in the control. When essential oil was added to the substrate cultural, the antagonistic activity of T. harzianum against the Pleurotus species was weak (0.0625 μL of essential oil) or non-existent (0.125 μL of essential oil). M. alternifolia essential oil could be an alternative to the synthetic chemicals that are currently used to prevent and control T. harzianum in mushroom cultivation.