复合酶解法提取香菇多糖蛋白的研究

存在于香菇中的多糖物质,具有增强人体非特异性免疫功能的作用。本文报道采用复合酶解和热水浸提法分离纯化香菇中多糖蛋白的综合程序。与单纯热水浸提法等其它方法相比,本法能显著提高香菇有效成分的浸提效果,总氨基酸与必需氨基酸百分比含量均提高２倍以上,香菇多糖含量提高了４倍,一些特殊成分及较高分子量的葡聚糖物质含量也明显提高。     

复合酶解法提取香菇多糖蛋白的研究

存在于香菇中的多糖物质,具有增强人体非特异性免疫功能的作用。本文报道采用复合酶解和热水浸提法分离纯化香菇中多糖蛋白的综合程序。与单纯热水浸提法等其它方法相比,本法能显著提高香菇有效成分的浸提效果,总氨基酸与必需氨基酸百分比含量均提高２倍以上,香菇多糖含量提高了４倍,一些特殊成分及较高分子量的葡聚糖物质含量也明显提高。     

鸭毛水解制备复合氨基酸新工艺的研究

采用正交试验方法,对鸭毛水解制备复合氨基酸工艺条件进行优选,试验结果表明,鸭毛水解的最佳工艺条件为：水解时间10小时,反应温度100℃,盐酸浓度为4摩尔/升。     

玉米秸秆酶水解正交试验的研究

经蒸汽爆破预处理的玉米秸杆用里氏木霉（Ｔｒｉｃｈｏｄｅｒｍａ ｒｅｅｓｅｉ Ｒｕｔ Ｃ３０）制备的纤维素酶进行水解,其影响因素主要为ｐＨ值、温度、微量元素,考虑了上述三因素对酶解的影响,以酶解得率为指标来评价酶水解效果,设计了三因素三水平正交实验。研究表明,酶最佳工艺条件为：ｐＨ＝４．８,温度４５℃,微量元素０．５ｍｌ。     

鲜猪血加压水解制备复合氨基酸新工艺的研究

采用正交试验方法,对鲜猪血加压水解制取复合氨基酸工艺条件进行优选。试验结果表明,采用鲜猪血加压水解制取复合氨基酸与采用猪血粉常压水解相比,简化了生产工序,缩短水解时间８～１２小时,降低能耗２倍多,减少硫酸用量２～３倍,而产品质量稳定可靠。     

香菇柄松加工工艺研究

以香菇柄柄为原料,通过单因素试验及正交试验,探讨香菇柄松加工中主要工艺参数的最佳组合及辅料的最佳用量。结果表明:辅料添加量的最佳配比为:白砂糖5%、酱油6%、食盐1.5%;工艺参数的最佳组合为:预煮温度温度60℃、初烘温度70℃、初烘含水量30%～40%,打松时间3 min,复烘温度80℃。制得的产品含水量在18%以下,产品色泽浅黄褐色,外观呈松散的絮状,具有浓郁的香菇风味。     

正交实验法优选香菇多糖的提取工艺及其硫酸酯化研究

目的:考察香菇多糖的提取工艺,制备香菇多糖硫酸酯。方法:采用正交试验法考察加水量、提取时间、提取温度和粒度4个因素对香菇多糖硫酸酯提取率及其中总糖含量的影响,应用硫酸法制备香菇多糖硫酸酯并对得到的成分进行鉴别。结果:通过对正交实验结果的极差分析。得出提取温度和加水量对多糖提取率影响比较著性,提取温度和提取时间对多糖含量的影响比较著性。确定香菇多糖提取的最佳工艺为:应用40倍量的水,每次提取4 h,提取温度90℃,香菇粒度为80目。制备的多糖硫酸酯中硫酸基含量为22.80%,显示了相对较强的生物活性。结论:本实验成功的确定了提取香菇多糖的最佳工艺,制备了硫酸基含量较高的硫酸酯化香菇多糖。     

鸭毛梗制备复合氨基酸工艺条件的研究

采用正交试验方法 ,研究了鸭毛梗水解制备复合氨基酸的工艺条件 ,结果表明 :温度 /压力是影响氨基酸转化率最主要的因素。鸭毛梗水解制备的复合氨基酸转化率盐酸法最高 (82 .36 % ) ,氢氧化钠法最低 (5 8.4 6 % ) ,硫酸法与盐酸法接近(79.4 4 % )。硫酸法产率较高 ,操作方便 ,环境污染和设备腐蚀均小 ,适合大量生产 ,确定为水解制备复合氨基酸介质 ,其最佳工艺条件为 :水解时间 8.0h ,硫酸浓度 3.0mol·L-1,水解温度 12 5℃。氨基酸分析表明 ,水解液中均含有 18种以上氨基酸。     

木瓜蛋白酶水解壳聚糖的工艺研究

本文通过正交试验对木瓜蛋白酶水解壳聚糖的工艺进行优化,并对降解过程中粘度、还原糖等一些指标的动态变化进行研究。结果显示,木瓜蛋白酶在反应温度45℃下降解壳聚糖的最佳工艺条件为壳聚糖的脱乙酰度70%,pH4.0,底物浓度1%,壳聚糖与酶的比例为25∶1(w/w)。其中底物脱乙酰度对酶解效果影响呈极显著水平,pH值影响呈显著水平。木瓜蛋白酶可较为有效地降解脱乙酰度为70%的壳聚糖,在其最适条件下对壳聚糖水解约60min,可控制产物平均分子量在1万以内。木瓜蛋白酶起始降解速率很快,20min后VDP变化趋于平稳,60min后基本维持在93～94%上下。反应进行60min后产物的平均分子量约为9000。还原糖含量在反应进行150min之后,还原糖的生成速度基本趋于平稳。     

毕赤酵母水解工艺的研究

在发酵过程中产生的总体积为30%～40%的毕赤酵母菌体,大部分在发酵后,会直接把酵母菌体排入环境中,不仅浪费资源,还污染环境,因此,实现资源再利用是文章的研究目的。最终结果表明,对毕赤酵母自溶破壁的最佳自溶水解条件为50℃、pH 6.0,作用时间为30 h、4%Na Cl,酵母悬浮液终体积分数为10%。此外,通过对木瓜蛋白酶、中性蛋白酶、碱性蛋白酶和酸性蛋白酶进行研究发现,添加木瓜蛋白酶效果最佳,添加后的酵母水解物氨基氮得率为4.5%,固形物得率为59%,粗蛋白含量为45.38%。     

香菇品种遗传多样性RAPD分子标记的研究

对32个中国栽培香菇品种和2个野生子实体的遗传多样性进行了RAPD标记研究,9个引物共扩增出113条DNA带,83.19%具有多态性。结果显示,34个香菇菌株间均有遗传上的差异,但遗传相关性极高,表明中国栽培菌株间的遗传背景单一。     

Mitochondrial Effects on the Physiological Characteristics of Lentinula edodes

In the mating of filamentous basidiomycetes, dikaryotic mycelia are generated through the reciprocal movement of nuclei to a monokaryotic cytoplasm where a nucleus of compatible mating type resides, resulting in the establishment of two different dikaryotic strains having the same nuclei but different mitochondria. To better understand the role of mitochondria in mushrooms, we created four sets of dikaryotic strains of Lentinula edodes, including B2 × E13 (B2 side) and B2 × E13 (E13 side), B5 × E13 (B5 side) and B5 × E13 (E13 side), E8 × H3 (E8 side) and E8 × H3 (H3 side), and K3 × H3 (K3 side) and K3 × H3 (H3 side). The karyotypes and mitochondrial types of the dikaryotic strains were successfully identified by the A mating type markers and the mitochondrial variable length tandem repeat markers, respectively. Comparative analyses of the dikaryotic strains on the mycelial growth, substrate browning, fruiting characteristics, and mitochondrial gene expression revealed that certain mitochondria are more effective in the mycelial growth and the production of fruiting body, possibly through the activated energy metabolism. Our findings indicate that mitochondria affect the physiology of dikaryotic strains having the same nuclear information and therefore a selection strategy aimed at mitochondrial function is needed in the development of new mushroom strain.     

香菇对潮霉素的抗性实验

选用4株不同品系的香菇菌种,比较了香菇在固体、液体2种不同培养条件下,对潮霉素抗性的差异;研究了香菇以原生质体、原生质体再生菌丝、冷藏菌种等3种不同生理状态为实验材料,对潮霉素的抗性特点。试验表明,香菇对潮霉素极为敏感,在固定的条件下,抗性稳定;而当条件改变时,抗性有一定变化。     

耐高温香菇新品种的选育

正香菇(Lentinula edodes)是产于北半球温带与亚热带地区的一种腐生真菌,不仅营养丰富,而且具有较高的保健价值,自古以来深受人们的喜爱[1]。但香菇属中低温型变温结实性菇类,在福建、浙江等香菇主产区,因夏季温度较高,能够高温出菇的香菇品种少,导致夏季鲜香菇供应不足。目前可用于夏季香菇栽培的方法主要有两种:一是在海拔500 m以上的高山上栽培;二是利用林下或山沟出菇、覆土栽培出菇等。但这两种栽培方法也有其局限性。因此,要从根本上解决香菇高温栽培的问     

Effect of cereal brans on Lentinula edodes growth and enzyme activities during cultivation on forestry waste

AIMS: To develop strategies for increasing the growth of Lentinula edodes in eucalyptus residues. To this end, we have examined the effects of cereal brans additions on production of mycelial biomass and enzymes. METHODS AND RESULTS: Three isolates of the mushroom shiitake, L. edodes (Berk. Pegler), were evaluated for enzyme and ergosterol production on eucalyptus residue supplemented with 5, 10, 15 and 20% (w/w) of soya, wheat or rice brans. Nitrogen imput on eucalyptus residues accelerated mycelial growth by supplying the L. edodes with this limiting nutrient. High levels of enzymes activities were produced in eucalyptus residues supplemented by soya bran. Comparison of cellulose and xylanase production with manganese peroxidase (MnP) at 20% soya bran indicated that hydrolytic enzymes, but oxidative enzymes were reduced. CONCLUSIONS: Mycelial growth measurements revealed that eucalyptus residues supplemented with cereal brans supported fast growth of L. edodes, indicating that mycelium extension is related to the bioavailability of nitrogen. The type and concentration of nutrient supplement has a considerable effect both on substrate colonization and on the type of hydrolytic and oxidative enzymes produced. These characteristics may be useful for mushroom growing. SIGNIFICANCE AND IMPACT OF THE STUDY: Lentinula edodes is commercially important for edible mushroom production and supplements which enhance growth and enzymes production might also be beneficial for mushroom yields.     

利用原生质体紫外诱变技术选育耐高温香菇菌株

【目的】运用原生质体紫外诱变技术选育香菇耐高温新菌株。【方法】以香菇菌株18为出发菌株,紫外诱变处理其原生质体,通过47°C热激3 h后菌丝恢复生长的情况来筛选获得耐高温诱变株,测定18及其所有诱变株在木屑培养基中的恒温长速、高温长速以及恢复长速,并进行高温出菇试验。【结果】筛选得到57株耐高温诱变株,其中诱变株N6、N44和N24的综合性状较好。恒温长速、高温长速以及恢复长速与出菇性状具有相关性,恢复长速与出菇产量、单菇性状、耐高温能力呈正相关,可初步作为预测耐高温菌株综合性状的指标。【结论】利用原生质体紫外诱变技术,可初步选育出耐高温香菇新菌株。     

Strain typing of Lentinula edodes by random amplified polymorphic DNA assay

Abstract Single 10-base primers were used to generate randomly amplified polymorphic DNA (RAPD) markers in the shiitake mushroom, Lentinula edodes . Seven primers produced polymorphisms in all 15 strains tested, producing 12–19 bands ranging from 0.34 to 2.52 kb. Thirteen of the 15 strains had unique DNA fingerprints, whereas L. edodes ATCC 28759 and ATCC 28760 exhibited identical RAPD profiles for all the primers. Molecular-genetic markers obtained with the RAPD assay can be used to differentiate strains of L. edodes and have potential applications in mushroom breeding and strain improvement programs.     

Extracellular enzyme activities in six Lentinula edodes strains during cultivation in wheat straw

Lentinula edodes (Berk.) Pegler is found in nature on dead broadleaf trees, but it is commercially produced on different substrates. The question of adaptation to different lignocellulosic substrates was addressed by measuring enzyme activities produced by six strains that were cultivated on wheat straw and that were able to produce sporophores. Despite quantitative variations, each strain of L. edodes had similar patterns of enzyme secretion into the wheat straw log matrix. Two peaks of carbohydrase activities were observed, the first relating to the early mycelial growth during the first days after spawning and the second during sporophore extension. Laccase activity in the early stage of colonization was related to the degradation of soluble phenolic compounds present in wheat straw. Manganese peroxidase activity was associated with mycelia th. The strains with the earlier production and higher yield were able to hydrolyse and utilize straw cell wall components soon aft er inoculation, and developed high metabolic activities.     

硝普钠对香菇多糖代谢及关键酶基因表达的影响

香菇多糖是香菇中特有的生物活性成分。硝普钠在调控食用菌生长方面具有重要影响,但其对香菇生长及多糖合成的影响尚不清楚。本文以香菇新808为研究材料,通过添加不同浓度硝普钠作为外源一氧化氮对新808菌丝的生物量、生长速率、香菇多糖含量、香菇多糖代谢关键酶活性及其表达调控基因相对表达量进行综合研究。结果表明：硝普钠浓度为100 μmol/L可显著提高香菇菌丝生物量,与对照组相比增加了1.61倍;生长速率与对照组无显著差异;香菇菌丝的香菇多糖含量显著提高,为对照组的3.71倍;漆酶、锰过氧化物酶和木质素过氧化物酶活性显著提高,分别为对照组的1.73倍、2.23倍和1.55倍;与多糖合成有关的辅助模块酶基因LENED_010207、碳水化合物结合模块基因LENED_012941和多糖裂解酶基因LENED_004566基因相对表达量有所上调,其中LENED_010207基因上调最明显,而多糖合成关键酶基因UDP-葡萄糖焦磷酸化酶基因(UGP)、葡萄糖磷酸变位酶基因(PGM)与葡萄糖磷酸异构酶基因(PGI)相对表达量均显著下调。在100 μmol/L浓度硝普钠处理下,香菇生物量、多糖含量、多糖代谢关键酶活性及部分多糖合成关键酶的基因相对表达量均显著高于对照组,表明添加适宜浓度的硝普纳能有效地促进香菇多糖的合成,提高香菇多糖的含量。本文为进一步探索香菇多糖的代谢通路提供了理论依据,为选育高多糖含量的香菇新品种提供了新思路,对改进香菇栽培技术有一定的参考意义。     

运用萎锈灵抗性基因构建香菇聚乙二醇介导的遗传转化方法

【背景】萎锈灵抗性基因作为筛选标记在植物和真菌中得到广泛应用。【目的】构建可以使用萎锈灵作为筛选标记的香菇遗传转化技术。【方法】利用溶壁酶消化培养4 d的香菇菌株411-4的菌丝体获得原生质体,加入适量pL-cbx质粒和聚乙二醇溶液,混合物涂布于再生筛选培养基上,培养后挑选菌落进行验证试验。【结果】在原生质体数目108个和添加4μg质粒DNA的情况下,得到了40个抗性转化子。利用PCR实验和转代实验对转化子进行验证,结果显示38个转化子的抗性可稳定遗传,表明萎锈灵抗性基因整合进入了供试菌株的基因组中。【结论】利用香菇411-4菌株建立了一套运用萎锈灵抗性基因作为分子标记的遗传转化技术体系。