担子菌纲8种真菌的营养成分

分析 8种担子菌纲真菌的蛋白质、脂肪、多糖、微量元素、矿物质、维生素质量分数和蛋白质的氨基酸组成 .结果表明 :8种真菌均含有较丰富的蛋白质 ,除金耳、猪苓外 ,其余的蛋白质质量分数均在 2 0 %以上 ,最高的达 3 8.84 % .脂肪的质量分数低 ,且变化不大 ,在 1 .4 4 %～ 3 .82 %之间 .氨基酸质量分数为 7.0 3 %～ 3 5.1 1 % ,均含有 8种人体必需氨基酸 ,且必需氨基酸占总氨基酸含量的 2 9.1 8%～ 50 .0 7% .真菌的多糖质量分数在 0 .4 8%～ 0 .87%之间 .8种真菌含有一定的微量元素和矿物质 ,其中灵芝、金针菇、竹荪、香菇和金耳分别含有较高的锗、锌、铬、钙和铁 .8种真菌含有大量的VB1、VB2 、VB6 、VB12 和VE .     

Biodegradation of cell wall components of maize stover colonized by white-rot fungi and resulting impact on in-vitro digestibility

Treatment of crop residues with some species of white-rot fungi can enhance digestibility. This study was conducted to investigate changes in in-vitro dry matter disappearance (IVDMD) and degradation of cell wall constituents in maize (Zea maize L) stover treated with three white-rot fungi: Cyathus stercoreus, Phlebia brevispora and Phanerochaete chrysosporium. Solid fermentation of maize stover for 28 days at 27°C improved IVDMD from 409 g kg^?1 (control) to 514 g kg^?1 for P brevispora and 523 g kg^?1 for C stercoreus. In contrast, growth of P chrysosporium reduced IVDMD from 409 to 298 g kg^?1. All fungi degraded cell wall p-coumaric acid (PCA) and ferulic acid (FA), but P chrysosporium was the least effective in degrading PCA and FA. Conversely, P chrysosporium degraded lignin 1·6 times more effectively than C stercoreus and 1·4 times more than P brevispora, indicating that lignin degradation alone cannot account for the IVDMD enhancement and that degradation of PCA and FA may be important. Hemicelluloses were preferentially and highly utilized by all the fungi. Cellulose was extensively degraded only by P chrysosporium (69% lost after 28 days of incubation), while substrate colonized by the other two fungi retained more than 84% original cellulose. Incubation of C stercoreus and P brevispora decreased the concentrations of both xylose and arabinose, but increased glucose concentration, whereas P chrysosporium removed less xylose and decreased glucose concentration. Preferential removal of arabinose over xylose by the fungi caused an increase in the xylose to arabinose ratio of the treated residues. Enhanced digestibility may have resulted from cleavage of lignin-carbohydrate bonds. Results of this study suggest that digestibility enhancement of maize stover colonized by white-rot fungi is regulated by a complex combination of various factors, including the degradation of structural carbohydrates, cell wall phenolic acids and lignin.     

Production and analysis of ochratoxin A produced by Aspergillus ochraceus ITEM 5137 in submerged culture

A rapid simple and economical method was described for the determination of ochratoxin A produced by Aspergillusochraceus ITEM 5117 grown in a biofermenter in submerged culture. The ochratoxin A was determinate with RP-HPLC-FLD (reverse phase high performance liquid chromatography) with direct injection in the HPLC apparatus using a C18 column. The mycotoxin was completely resolved by using the mixture acetonitrile, water and acetic acid (49:49:2 v/v) as the mobile phase with a flow rate of 1.0 mL/min. Mean recoveries of ochratoxin A ranged from 95.36% to 103.15%. The limit of detection for ochratoxin A in medium was found to be 1 μg L⁻¹.     

Antifungal activity of films and solutions based on chitosan against typical seed fungi

The use of eco-freindly polymers as antimicrobial materials is in growth due to the need to reduce the negative impact of conventional treatments on the environment and the human health. The purpose of the present study was to assess the antifungal properties of films and solutions based on chitosan with different molecular weight at different concentrations. Surfactants were added to the formulation to assess their impact on treatment efficiency. The antifungal activity was conducted against tree fungi, Aspergillus niger, Alternaria alternata and Rhizopus oryzae. Results indicated important and significant differences of the antifungal activity between chitosan based solutions and chitosan based films. Furthermore, the antifungal activity of the different treatment depended on the type of fungus treated. Thus, chitosan film treatments were significantly more effective on A. niger than solution treatments. On the other hand, solution treatments resulted in higher radial inhibition when applied against A. alternata or R. oryzae. The highest radial inhibition was observed against A. alternata (97%) using a chitosan solution. The influence of the other parameters (concentration, molecular weight and surfactant type) on treatment efficiency was not as important and their significance depended on treatment type and fungus nature.     

食用菌产胞外纤维素半纤维素降解酶类的研究进展

我国是食用菌生产大国。食用菌可以分泌降解纤维素、半纤维素和木质素相关的酶,能够利用秸秆、木屑、棉籽壳等多种农业废弃物,具有广泛的应用前景。本文以食用菌所产的主要胞外水解酶类纤维素酶和木聚糖酶为研究对象,从其种类、发酵条件、理化性质和基因克隆等方面综述了食用菌产胞外水解酶的研究现状。     

Allelopathic effect of phenolic acids from humic solutions on two spruce mycorrhizal fungi:Cenococcum graniforme andLaccaria laccata

The aim of this investigation was to determine the impact ofp-hydroxyacetophenone,p-hydroxybenzoic acid, catechol, and protocatechuic acid on respiration of two spruce mycorrhizal fungi:Laccaria laccata andCenococcum graniforme. These phenols are produced byVaccinium myrtillus,Athyrium filixfemina, andPicea abies, predominant species of spruce forests in the Alps, and they are also present in humic solutions at 10^–10 M or 10^–5 M. Respiration of the two fungi was inhibited by the four phenolic acids, even at concentrations ranging from 10^–5 M to 10^–7 M. These data show phenolic acids from humic solutions have biological activity at extremely low concentrations, suggesting a contribution ofV. myrtillus, A. filixfemina, andP. abies to allelopathic inhibition of mycorrhizal fungi.     

食用菌等生鲜食品液态N2和CO2深冷冻结技术

介绍了食用菌等生鲜食品速冻技术的最新研究进展与应用情况,就速冻食用菌等生鲜食品加工技术的方法、设备、冻结与冻藏工艺进行综述,并对食用菌等生鲜食品的开发利用前景进行了展望。     

中国食用菌产业发展现状, 机遇和挑战——走中国特色菇业发展之路, 实现食用菌产业强国之梦

食用菌营养丰富,是优质蛋白质的潜在来源。本研究以18个常见食用菌品种为研究对象,分析了食用菌中的水分、灰分、蛋白、总糖和L-麦角硫因等营养成分,并采用顶空固相微萃取结合气相色谱-质谱联用法（HS-SPME-GC-MS）分析了其中6种食用菌子实体、菌丝体及发酵液的风味物质。结果表明,18种食用菌水分含量为6.7~13.77 g/100 g、灰分含量为2.24~10.9 g/100 g、脂肪含量为0.3~2.92 g/100 g、总糖含量为2.11~10.5 g/100 g。粗蛋白含量在7.88~35.87 g/100 g之间,其中双孢菇的蛋白质含量高达35.87 g/100 g。氨基酸种类齐全、含量丰富且含有人体必需的8种必需氨基酸。主成分分析表明香菇、黑木耳、灰树花、草菇和金针菇等食用菌的氨基酸组成比例与鸡蛋最相似,但与肉类、大豆和小麦等氨基酸组成相差较大。高效液相色谱结果表明香菇中富含麦角硫因,含量高达336 mg/kg,且灰树花、羊肚菌、双孢菇和鸡腿菇的麦角硫因含量也高于100 mg/kg。HS-SPME-GC-MS在6种食用菌中共鉴定出34种主要挥发性化合物,包括醛类、酮类、酯类、醇类、酚类、醚类、烷烃类和杂环化合物。灵芝菌丝体富含己醛、甲基壬基甲酮、反-2-辛烯醛、2-正戊基呋喃、2,4-壬二烯醛等成分,与其他17种样品有明显差异;6种食用菌发酵液的风味物质相似,均具有庚酸乙酯、18-冠醚-6等特有风味物质;而灵芝、鸡腿菇子实体以及杏鲍菇菌丝具有2,6-二叔丁基对甲酚、苯甲酸甲酯等特有风味。本研究通过分析常见食用菌的营养成分及风味物质,为食用菌的高值化开发提供了数据基础。     

Purification of an Inducible DNase from a Thermophilic Fungus

The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 μm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the presence of DNA and/or deoxyribose. Static growth of the organism resulted in significantly higher DNase production than agitated growth. The DNase was purified 145-fold using a novel affinity membrane purification system with 25% of the initial enzyme activity remaining. Electrophoresis of the purified enzyme resulted in a single protein band, indicating DNase homogeneity.     

几种真菌油脂的分析

在实验室条件下培养提取所得的几种真菌油脂经水解后进行薄层层析 ,结果表明油溶性成分因菌种而异 ;脂肪酸分析表明在不同培养条件下菌种脂结构也不同 ;对土生假丝酵母在优化条件下合成的类可可脂经甘三酯组成测定和差示扫描量热法分析 ,证明了此条件下所产的类可可脂是较理想的类可可脂