赤芝原生质体分离与再生研究

以赤芝(Ganoderma lucidum)为供试菌种,研究了不同酶解温度、酶解时间、渗透压稳定剂浓度及菌龄、再生培养基等对赤芝菌丝的原生质体制备与再生的影响。结果表明:菌龄为4 d的菌丝,以0.4 mol/m L的甘露醇作渗透压稳定剂配制成浓度为0.02 g/m L的溶壁酶,于p H 5.0、25℃条件下酶解2.0 h,其原生质体数最高可达3.87×107/m L,MYG再生培养基上再生率达到0.016%。     

蓝色犁头霉原生质体的制备与再生

研究了氢化可的松生产菌蓝色犁头霉原生质体的形成与再生。通过对溶解酶系统的选择,影响原生质体形成的因素如渗透压稳定剂、酶浓度、菌龄、菌丝培养基和培养方式等因素进行考察,发现以0．4mol/L NH4Cl做为稳定剂、2．5mg/mL溶壁酶和5mg/mL纤维素酶组成的混合酶液溶解菌丝,4h后原生质体量可达10^6cell/mL。通过显微镜观察原生质体的形成过程以及在高渗培养基上的再生情况,再生率为15．6％。     

黄曲霉菌原生质体的制备和再生技术优化

黄曲霉菌的遗传转化是研究黄曲霉菌致病相关功能基因的前提和基础,而原生质体是研究和建立真菌遗传转化系统的重要工具。本文分别以黄曲霉孢子和菌丝为材料,研究不同条件下黄曲霉原生质体的形成和再生,结果表明,黄曲霉孢子在酶液浓度为纤维素酶∶蜗牛酶∶溶壁酶=1.5%∶1.5%∶1.5%,30℃酶解3 h,原生质体制备率高达97.3%,再生率达89.2%;黄曲霉菌丝在菌龄为42 h,酶液浓度为纤维素酶∶蜗牛酶∶溶壁酶=1.5%∶1.5%∶1.5%,30℃酶解1 h,可获得最高原生质体产量为2.0×10^6个/m L,再生培养基中以1 mol/L蔗糖作为渗透压稳定剂时,原生质体再生率达5.5%。故本实验条件下,黄曲霉孢子原生质体的形成和再生优于菌丝。     

松茸菌丝原生质体形成与再生条件的研究

采用多因素实验正交优选法比较不同酶、渗透压稳定剂、菌丝生理状况、菌丝培养基、预处理液和酶解时间等因素对松茸原生质体形成的影响和再生培养基、明胶、酪蛋白对松茸原生质体再生的影响.以0.6MMgSO4作为渗透压稳定剂,2-硫基苏糖醇为预处理液,用2%蜗牛酶在30℃酶解6h,每克菌丝可以得到1×106个原生质体.再生最优条件0.6MMgSO4,PDY再生培养基,2.5%明胶,松茸菌丝再生率最高4.97%.     

平菇原生质体制备与再生条件初探

平菇原生质体制备最佳条件是菌丝培养5 d、酶浓度1.5%、pH 5.5、0.6 mol/L甘露醇渗透压稳定剂、酶解温度30℃、酶解时间2 h、OS培养基。原生质体过滤、纯化、稀释后涂布再生培养基,再生率为2.6%。     

假丝酵母原生质体形成与再生的研究

本文研究了菌龄、酶系统、脱壁促进剂、渗透压稳定剂对假丝酵母Y002 原生质体形成与再生的影响。综合考虑形成率与再生率后,选用对数生长中期的菌体于1%蜗牛酶、 35℃下作用60分钟制备原生质体,并于以17%蔗糖作渗透压稳定剂的再生培养基中再生效果为好。     

木质层孔菌原生质体的制备与再生条件的研究

目的：提高木质层孔菌原生质体的产量和再生率,为进一步诱变育种提高菌株产木质纤维素酶活力打下基础。方法：通过单因素实验分别筛选合适的酶浓度、菌丝的菌龄、酶解温度、酶解时间、渗透压稳定剂与pH值。结果：在酶解液浓度为2.0%纤维素酶＋2.0%蜗牛酶、菌龄60h、酶解温度32℃、酶解时间3h,以0.8mol/L的NaCl溶液为渗透压稳定剂,pH值为5.0时,原生质体形成量达4.13×10^5个/mL,再生率可达6.95%。有效地提高了木质层孔菌原生质体的产量和再生率。     

不同因素对金针菇原生质体制备和再生的影响

比较了不同浓度裂解酶及组合、渗透压稳定剂、酶解时间等因素对金针菇原生质体得率的影响以及不同渗透压稳定剂、培养基、接种方法等因素对金针菇原生质体再生的影响。试验结果表明:固体培养10d的金针菇菌丝,以0.5mol/L KCl作渗透压稳定剂,加入1%纤维素酶和1%溶菌酶在25℃下酶解1.5h,分离原生质体效果最佳,原生质体产量可达27.8×105个/ml以上;以0.5mol/L KCl作渗透压稳定剂,在25℃条件下,金针菇原生质体采用直接涂布法接种在RCM培养基上培养,再生率最高为0.5%。     

斜卧青霉原生质体制备和再生的研究

研究了斜卧青霉原生质体制备和再生的条件,确定了培养方式、菌龄、渗透压稳定剂、酶的配比、酶解时间等因素对原生质体制备和再生的影响。最佳条件：菌丝体培养12h,用1％溶壁酶＋1％纤维素酶＋1％蜗牛酶的混合酶液酶解,将NaCl作为渗透压稳定剂,酶解时间为1．5h。在此条件下原生质体的形成量达到5．3×10^5个／mL,再生率为19．4％。     

γ—亚麻酸生产菌深黄被孢霉原生质体的形成和再生

采用2％的溶壁酶加4％的蜗牛酶,从深黄被孢霉的菌丝中获得了大量的原生质体。同时对菌丝的培养时间、渗透压稳定剂、酶解系统和酶解温度等因素进行了系统的观察,从而获得了制备深黄被孢霉原生质体的最适条件。并对该原生质体在高渗培养基上进行了再生实验,其再生率为32％。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.