蛹虫草SN3菌株生物学特性及栽培学特性研究

对采自沈阳棋盘山的蛹虫草SN3菌株的生物学特性及栽培学特性进行了研究。结果表明：在生物学特性上蛹虫草SN3菌株与人工栽培常用的SN1和E3菌株基本一致,其在培养皿生长过程中菌丝的变化及在不同光照、温度、碳源、氮源、pH值时其生长状况与SN1和E3菌株差别不显著;而瓶栽时,其子实体产量及经济性状都优于SN1和E3菌株,其产量分别比SN1和E3菌株高4．9％和17．4％;其草的平均长度大于SN1和E3菌株,而且其子实体头部大,子囊壳丰富,颜色橘黄,出草整齐均匀,这是该菌株的最大特点和优点,具有较高的经济价值,是值得开发和推广的好品种。     

磁处理冬虫夏草精粉药液对消化功能影响的药效研究

目的：研究磁处理冬虫夏草精粉药液对消化功能影响的药效作用。方法：用对比法,比较磁处理冬虫夏草精粉药液与正常台氏液对离体兔小肠平滑肌收缩运动的影响;用碳末法比较生理盐水与磁处理冬虫夏草精粉药液对小鼠肠推进运动的影响。结果：离体兔小肠平滑肌收缩运动：与正常台氏液相比,磁处理冬虫夏草精粉药液（20％、60％）有促进作用（p〈0．01、p〈0．05）;小鼠肠碳末推进率：与生理盐水组比较,磁处理冬虫夏草精粉药液未见明显的作用（p〉0．05）。结论：磁处理冬虫夏草精粉药液对离体免小肠平滑肌收缩运动有明显作用,对小鼠肠推进运动功能未见明显的作用。     

Molecular cloning and sequence analysis of the β-1,3-glucan synthase catalytic subunit gene from a medicinal fungus, Cordyceps militaris

The entomopathogenic fungus Cordyceps militaris belongs to vegetable wasps and plant worms and is used as herbal medicine, but β-1,3-glucan biosynthesis has been poorly studied in C. militaris. The fungal FKS1 gene encodes an integral membrane protein that is the catalytic subunit of β-1,3-glucan synthase. Here, we isolated cDNA clones encoding a full-length open reading frame of C. militaris FKS1. Cordyceps militaris Fks1 protein is a 1981 amino acid protein that shows significant similarity with other fungal Fks proteins. This study is the first report of molecular cloning of the β-1,3-glucan synthase catalytic subunit gene from vegetable wasps and plant worms.     

Development of a PCR-based mating-type assay for Clavicipitaceae

A new controlled production system to target heterologous proteins to cytoplasm or extracellular medium is described for Lactococcus lactis NCDO2118. It is based on the use of a xylose-inducible lactococcal promoter, P(xylT). The capacities of this system to produce cytoplasmic and secreted proteins were tested using the Staphylococcus aureus nuclease gene (nuc) fused or not to the lactococcal Usp45 signal peptide. Xylose-inducible nuc expression is tightly controlled and resulted in high-level and long-term protein production, and correct targeting either to the cytoplasm or to the extracellular medium. Furthermore, this expression system is versatile and can be switched on or off easily by adding either xylose or glucose, respectively. These results confirm the potential of this expression system as an alternative and useful tool for the production of proteins of interest in L. lactis.     

Population history of Manihot esculenta (Euphorbiaceae) inferred from nuclear DNA sequences

The nature of gene flow in plants -- including the propensity for interspecific introgression -- makes them interesting candidates for phylogeographical analysis. Plant phylogeography studies have been limited, however, by the availability of suitable intraspecific variation. In this study, DNA sequence variation from a nuclear gene [Glyceraldehyde 3-phosphate dehydrogenase; (G3pdh)] was used to examine the population history of Manihot esculenta ssp. flabellifolia and a potentially hybridizing species, M. pruinosa. These species occur in the rainforest-savanna ecotone adjoining the Amazon basin, a region believed to have undergone major habitat shifts since the Pleistocene. Geographical distributions of the G3pdh haplotypes indicate genetic isolation-by-distance across the range of M. esculenta ssp. flabellifolia. However, there is greater genetic similarity between northeastern and western populations than would be expected given the present species distribution. A nested clade analysis suggests that northeastern and western populations were connected by gene flow until relatively recently, when they became fragmented. This inferred fragmentation event is consistent with post-Pleistocene habitat shifts proposed for the Amazon basin. At the interspecific level, haplotype sharing with M. pruinosa may reflect either recent interspecific introgression or incomplete lineage sorting between these closely related species.     

中国弯颈霉的培养性状和药理作用研究

中国弯颈霉ZN923菌株分离自蔗褐蠹蛾PhragmatoeciacastaneaeHubner虫尸。其生长最适温度为25～28℃,最适pH6～7,在富氮培养基上菌丝生长茂盛、洁白,有香气。药理试验表明,该菌株培养物具有镇静、抗炎、增强耐缺氧能力、扩张气管和雄性激素样作用,急性毒性试验以80g／kg（最大允许容积）剂量对小鼠一次灌胃,未见不良作用。中国弯颈霉是与冬虫夏草Cordycepssinensis（Berk．）Sacc．无性型密切相关的真菌。具有潜在的药用价值。     

互补交配型配对诱导蛹虫草有性子实体形成

前期我们获得了优良性状蛹虫草Cordyceps militaris野生菌株W141436,其子实体虫草素含量高达3.72 mg/kg干重,子实体多糖高达6.7 g/100 g干重,但在大规模应用中发现它发生退化。针对蛹虫草人工栽培退化问题,我们提出蛹虫草子实体形成是有性生殖过程,其两种交配型发生交配是蛹虫草子实体形成的必要条件。本文基于交配型基因分子标记研究了优良性状蛹虫草野生菌株W141436的退化机制。具体地,采用单孢子分离的方法对蛹虫草野生分离株W141436的子囊孢子进行分离,得到了72个单孢菌株。进一步采用PCR方法对单孢菌株及亲本菌株进行了交配型基因类型鉴定。在72个单孢菌株中,28株为Mat1-1类型交配基因型,31株为Mat1-2类型交配基因型,13株含有与亲本相同的交配型基因。根据鉴定结果,对2株Mat1-1型(SP28、SP33)和2株Mat1-2型(SP15、SP32)菌株进行了栽培实验。结果表明,形成子实体的栽培用亲本菌株同时含有Mat1-1和Mat1-2两种交配类型基因,即只有含不同交配型基因的菌株具有发育为子实体的能力,而含同种交配型基因的菌株则不能发育为子实体。本研究为防止蛹虫草在大规模种植中退化提供了理论依据。     

拟青霉属的一个新种

从湖南省桃江县采集的亚香棒虫草(Cordyceps hawkesii Gray)的新鲜子座、单子囊孢子及其寄主,一种蝙蝠蛾(Hepialus sp.)的僵死幼虫,培养获得拟青霉属的一个新种,命名为霍克斯拟青霉(Paecilomyces hawkesii Xiao,T.B.Li et Q.T.Chen,sp.nov.)。本文报道该菌的形态学特征及其与近缘种肉色拟青霉(P.carneus)的关系,并认为它可能是亚香棒虫草的无性阶段。     

蛹虫草缓解新型冠状病毒感染研究进展

严重急性呼吸综合征冠状病毒2(SARS-CoV-2)引起的COVID-19在全球范围内大流行,危害了人类健康和公共安全,随着对SARS-CoV-2的结构、功能和致病过程的了解,越来越多的潜在药物被开发。蛹虫草(Cordyceps militaris)是我国传统的药用真菌,具有显著的抗病毒作用,虫草素作为蛹虫草的主要活性成分能够与SARS-CoV-2刺突蛋白、主蛋白酶(Mpro)相结合,抑制病毒RNA依赖的RNA聚合酶(RDRP)活性,阻断SARS-CoV-2在机体内复制。蛹虫草还具有提升机体免疫力、修复受损组织的作用。本文概述虫草素抗SARS-CoV-2的机制和蛹虫草其他相关药理作用,以期为蛹虫草用于新型冠状病毒感染的辅助治疗提供参考。     

蛹虫草菌胞外多糖发酵及其发酵动力学

蛹虫草菌(Cordyceps militaris)胞外多糖(EPS)的发酵过程和发酵动力学进行了研究。基于Logitic方程和Luedeking-Piret方程,得到了描述发酵过程的动力学数学模型和模型参数,同时对实验数据与模型进行了验证比较。模型计算与实验结果拟合良好,模型正确地反应了蛹虫草菌胞外多糖的发酵过程及其动力学机制。