蜈蚣衣内生真菌研究

对北京东灵山地衣蜈蚣衣进行内生真菌分离,经过6种不同的方法消毒后,内生真菌的定殖率为55.4%~100%;从316个地衣组织块上共分离到28个真菌分类单元,其中包括1个子囊菌,22个丝孢菌,3个腔孢菌,1个毛霉和1个酵母菌。根据定殖率和分离到的内生真菌的种类两个指标综合考虑,消毒方法IV(75%乙醇1min,2%次氯酸钠3min,75%乙醇30s)为进行地衣内生真菌研究的最佳消毒方法。     

花梨木组织培养外植体消毒方法初步探讨

针对在花梨木(Dalbergia odofifera T. Chen)组织培养过程中外植体的有效消毒方法进行研究。外植体消毒主要以2年生以上实生苗的茎段为材料,开展了茎段外植体次氯酸钠(5%,10%,15%)和升汞(0.05%,0.1%,0.2%)3个浓度水平的消毒试验。在此基础上,开展了外植体消毒的时间试验,次氯酸钠消毒时间为10 min、20 min、30 min,升汞消毒时间为5 min、10 min、15 min。结果表明：茎段外植体采用10%浓度的次氯酸钠消毒效果较好,最佳消毒方式75%的酒精浸泡2 min,10%次氯酸钠消毒20 min,该方法污染率最低、存活力最高。     

无花果的组织培养和快速繁殖

1 植物名称无花果(Ficus carica)品种绿抗一号、绿抗二号、紫果一号、红果一号、日本黄和布兰瑞克。 2 材料类别茎尖、带腋芽的茎段、幼叶。 3 培养条件将外植体用流水冲洗20 min后,投入70％酒精内消毒30 s,再用0.1％升汞溶液浸泡8～10 min,无菌水冲洗4～5次.消毒滤纸吸干表面水     

红豆杉中产紫杉醇内生真菌分离部位的比较研究

目的 探讨红豆杉不同部位在内生真菌分离效率以及产紫杉醇菌株筛选率方面的规律性,为红豆杉产紫杉醇内生菌菌株的分离与筛选提供一定的理论依据.方法 从根、茎、叶3个器官取大小和表面积相同的太行山野生红豆杉(Taxous chinensis)材料,用组织块法分离红豆杉内生真菌,计算各部位内生真菌的分离效率;用高效液相法时分离到的内生真菌发酵液提取物进行紫杉醇含量分析,计算各部位产紫杉醇内生真菌的筛选率.结果 共分离到109株红豆杉内生真菌,根部、茎部和叶部分离效率指数分别为0.90、0.63和0.28;其中有28株产紫杉醇,紫杉醇菌株筛选率分别为31.48%、21.05%和17.65%.结论 在内生真菌的分离效率及其产紫杉醇内生真菌的筛选率上,均为根部>茎部>叶部,即根部在内生真菌分离效率和筛选产紫杉醇内生真菌效率上均具有明显的优势.     

植物内生放线菌的选择性分离

[目的]更好地发掘内生菌资源,建立有效的植物内生放线菌分离方法.[方法]比较不同消毒剂和消毒程序、样品预处理、选择性分离培养基等分离内生放线菌的效果,通过形态及16S rRNA基因序列分析进行菌种鉴定.[结果]用5％的次氯酸钠处理样品4-7 min消毒效果最好;100℃处理样品15 min能较好地减少真菌和细菌的干扰.丙酸钠、琥珀酸钠等培养基分离放线菌出菌率较高且类群多样性丰富.[结论]植物样品表面消毒干燥后,100℃处理15 min,用无菌搅拌杯打碎,直接撒植物于分离培养基中的分离方法效果较好.     

红锥不同外植体消毒技术初探

以红锥种子、茎段为材料,进行外植体消毒试验。结果表明,种子灭菌的条件:75%酒精5~15min+0.1%HgCl230~40min(不剥壳去皮),75%酒精1min+0.1%HgC220min(剥壳去皮),这2种处理污染率均较低,种子发芽率相差不大;茎段用0.1%升汞+20%次氯酸钠组合消毒效果最好,在0.1%升汞+20%次氯酸钠组合消毒时间为8min+5min时污染率最低,平均仅为28.89%。     

红锥不同外植体消毒技术初探

以红锥种子、茎段为材料,进行外植体消毒试验。结果表明,种子灭菌的条件:75%酒精5~15min+0.1%HgCl230~40min(不剥壳去皮),75%酒精1min+0.1%HgC220min(剥壳去皮),这2种处理污染率均较低,种子发芽率相差不大;茎段用0.1%升汞+20%次氯酸钠组合消毒效果最好,在0.1%升汞+20%次氯酸钠组合消毒时间为8min+5min时污染率最低,平均仅为28.89%。     

南方红豆杉内生细菌分离鉴定及系统发育分析

目的:了解南方红豆杉内生细菌类群及其系统发育关系;方法:对分离菌株进行形态学、生理生化和分子鉴定,并做系统发育分析.结果:从南方红豆杉茎、皮和叶中共分离到内生细菌52株.对12株内生细菌16S rDNA进行PCR扩增,扩增产物大小约为1 400bp,对11株内生细菌16S rDNA测序结果,用BLAST软件进行相似性比对,发现TB02株为Enterobacter属,相似性99％;9株为Bacillus属,相似性99％～ 100％:TB13株为Lysinibacillus,相似性97％.通过构建系统发育树发现这11株内生细菌明显聚为两大支.结论:11株内生细菌分别鉴定为肠杆菌、芽孢杆菌和Lysinibacillus,芽孢杆菌为南方红豆杉内生细菌优势菌属.芽孢杆菌和Lysinibacillus亲缘关系较近,二者和肠杆菌之间亲缘关系较远.     

河南太行红豆杉产紫杉醇内生真菌的筛选

目的：筛选出高产紫杉醇的内生菌株,为发酵生产紫杉醇提供菌种。方法：从不同来源的红豆杉根、茎、叶中分别分离内生真菌,并对其进行发酵,用HPLC法对菌丝体和发酵液中的紫杉醇含量进行检测,获得高产菌株。结果：获得54株产紫杉醇的内生真菌,其中根、茎、叶分别为29株、16株、9株。根、茎、叶三部位产紫杉醇菌株的平均产量分别为248.57μg/L、149.09μg/L、104.94μg/L;其中一株产量高达622.75μg/L。结论：从野生红豆杉的根部分离内生真菌效果较好,并获得了一株高产菌株。     

象草腋芽外植体消毒方法的筛选

为了解决象草组织培养中外植体污染问题,提高象草组织培养的成功率。本研究运用正交设计实验设置自来水冲洗、0.1%升汞浸泡和2%次氯酸钠浸泡3因子的不同消毒组合,通过直观分析和方差分析对象草腋芽外植体消毒灭菌结果进行分析。结果表明,象草腋芽外植体消毒的最佳组合为:自来水冲洗60min,0.1%升汞浸泡25min,2%次氯酸钠浸泡20min。该组合不仅能使污染率降低到13.33%,同时又在外植体的承受范围之内,没有对外植体造成伤害,本文结果将为象草的离体再生培养提供技术参考。     

不同消毒和培养基条件对兰花菌根真菌分离的影响

研究了不同的消毒时间和培养基类型对兰花菌根真菌分离效果的影响,以期获得兰花菌根真菌的最佳分离方法.采用了次氯酸钠和酒精作为消毒试剂,发现依次浸没于75 %酒精60 s、2 %次氯酸钠60 和75 %酒精30 s的组合消毒条件下分离效果最佳;选择了3种培养基（PDA、CZA和MEA）,结果表明MEA培养基的分离效果最为稳定.通过组织分离法分离兰花菌根真菌,筛选得到最佳的分离培养条件,旨在为兰花菌根真菌的多样性以及共生效应研究提供研究基础.     

The effect of surface sterilization and the type of sterilizer on the genus composition of lichen-inhabiting fungi with notes on some frequently isolated genera

Surface sterilization is generally used for isolating lichen-inhabiting fungi as well as endophytic fungi, and ethanol and sodium hypochlorite are commonly used as the sterilizer. However, there are few studies on whether the type of chemicals used for surface sterilization affects the isolation results of lichen-inhabiting fungi. In this study, the genus composition of the lichen-inhabiting fungi of two lichen species (Flavoparmelia caperata and Peltigera dilacerata) were investigated 1) to reveal how the isolation result changes before and after surface sterilization and 2) to examine the effect of the sterilizer (ethanol, sodium hypochlorite, or hydrogen peroxide) on the composition of the isolated fungi. We isolated 652 non-lichenized fungal isolates from the two-lichen species and identified 84 genera. It was found that 1) every sterilizer effectively removed the fungi on the lichen surface and that 2) the composition of isolated fungi varied depending on the type of surface sterilizer. It was also shown that, such as the genus Sarea, there were some lichen-inhabiting fungi which could not be isolated at all by surface sterilization with ethanol or sodium hypochlorite, which are commonly used. In addition, the genus Virgaria was detected as lichen-inhabiting fungi for the first time. Our results suggest that single surface sterilization alone may underestimate the genus composition of lichen-inhabiting fungi.     

Surface-sterilization of Glomus mosseae sporocarps for studying endomycorrhization in vitro

 The effects of sterilization time, sterilizing agents (ethanol, Chloramine T, calcium hypochlorite) and antibiotics (streptomycin and gentamycin) on Glomus mosseae (BEG 12) sporocarp germination and contamination were evaluated. Incubation for 10 s in 96 % ethanol, followed by 10 min in a solution of 2% Chloramine T, 0.02% streptomycin, 0.01% gentamycin and Tween 20, and then 6 min in 6% calcium hypochlorite greatly reduced fungal and bacterial contamination from sporocarps and caused little change in germination rate in water agar medium. Accepted: 4 March 1999     

Development of a Simple Culture Method for the Tissues Contaminated with Microorganisms and Application to Establishment of a Fish Cell line

Cell cultures are good in vitro model systems in place of using living animals. In the present study, we developed a simple culture method in which tissues were pretreated with a low concentration of sodium hypochlorite solution (NaClO) to prevent not only bacteria but also fungi. Scales removed from a goldfish (Carassius auratus) body were treated with 70% ethanol and then with 0.3% of sodium hypochlorite solution, and cultured in vitro in an atmosphere containing 0.5% CO2. The doubling time of the established cells (GAKS) was 24 hr. The GAKS cells contained alkaline phosphatase activity (8.3+/-1.1 nmol/min/mg protein) and secreted 0.32+/-0.07 pg/ml endothelin during a 3 day culture of a full monolayer sheet.     

低温条件下常用环境消毒剂对新冠病毒灭活效果的CFD模拟和分析

新冠肺炎疫情以来,冷链食品外包装上的新冠病毒频繁引起局部疫情,对现有的环境消杀体系带来了巨大挑战。为了探究低温环境消毒剂灭活效果下降的内在机制,并为冷链过程中合理选用消毒剂提供依据,对低温条件下消毒剂的灭活过程进行计算流体力学(CFD)建模。以环境消杀常用的75%乙醇溶液和次氯酸钠溶液为工作体系,探讨了不同温度下两种溶液对新冠病毒灭活特性的影响规律。结果表明,75%乙醇溶液的灭活特性在低温环境下受温度的影响较小,而次氯酸钠溶液在环境温度为253.15 K时会发生凝固现象使得其灭活效率显著降低。该模型的模拟结果与实验结果趋势一致,可为冷链运输中疫情防控提供参考。     

Evaluation of chemical seed coat sterilants

Summary Three seed coat sterilants were evaluated for effectiveness as surface sterilants and for effects on seed germination. Several exposure times in sodium hypochlorite, hydrogen peroxide and peracetic acid were evaluated. Seeds of the following crop plants were used: wheat (Triticum aestivum L.); sorghum [Sorghum bicolor (L.) Moench]; soybean [Glycine max (L.) Merrill]. All treatments reduced germination of wheat and soybean seed, but only the most severe peracetic acid treatments substantially reduced germination of sorghum seed. Considering both sterilization effectiveness and seed germination, a treatment with 5% sodium hypochlorite for 45 min appeared to be the most satisfactory of the treatments used.     

Viability of sporulated oocysts of Neospora caninum after exposure to different physical and chemical treatments

The aim of the present study was to evaluate the viability of Neospora caninum sporulated oocysts after various chemical and physical treatments. Bioassays in gerbils and molecular techniques (PCR-RFLP) were used for identification of the oocysts shed by experimentally infected dogs. Sporulated oocysts were purified and divided into 11 treatment groups as follows: absolute ethanol for 1 hr; 20 C for 6 hr; 4 C for 6 hr; 60 C for 1 min; 100 C for 1 min; 10% formaldehyde for 1 hr; 10% ammonia for 1 hr; 2% iodine for 1 hr; 10% sodium hypochlorite for 1 hr; 70% ethanol for 1 hr; and one group was left untreated and kept as a positive control. All chemical treatments were performed at room temperature (37 C). A total of 33 gerbils, or 3 gerbils per treatment, were used for bioassays. After treatment, the oocysts were divided into aliquots of 1,000 oocysts and orally administered to gerbils. After 63 days, the gerbils were anesthetized and killed with 0.2 ml of T61; blood and tissue samples were collected for serological (IFAT and western blotting), molecular (real-time PCR), histopathology, and immunohistochemical tests. Treatments were considered effective only if all 5 detection techniques tested negative. High temperatures at 100 C for 1 min and 10% sodium hypochlorite for 1 hr were the only treatments that met this condition, effectively inactivating all oocysts.     

Evaluation of the efficacy of chemical disinfectants for disinfection of heat‐polymerised acrylic resin

doi: 10.1111/j.1741‐2358.2010.00400.x
Evaluation of the efficacy of chemical disinfectants for disinfection of heat‐polymerised acrylic resin Objective: This study evaluated the efficacy of disinfectants on the internal aspect of heat‐polymerised acrylic resin contaminated with microbial strains. Background: Dentures absorb oral fluids and become contaminated by different microorganisms. Methods: Two hundred and fifty rectangular specimens were made of heat‐polymerised acrylic resin, and then divided into five groups corresponding to the microbial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, S. mutans and Enterococcus faecalis). After contamination, the specimens were immersed in 1 and 2% sodium hypochlorite and 2% glutaraldehyde for periods of 5, 10 and 15 min. The specimens were placed into tubes containing different broths and incubated at 35°C and then visually analysed. Turbidity in the medium indicated microbial growth. The Fisher’s exact test was used in the analysis of the results. Results: The strain E. faecalis was the most resistant to the disinfectant solutions, and among them, glutaraldehyde was more effective than 2 and 1% hypochlorite for disinfection for 5 min; in the 10‐min period there were no differences between the disinfectants. In 15 min of immersion, 1% hypochlorite and glutaraldehyde were more effective than 2% hypochlorite. Conclusions: Disinfection for 10 min with 1% hypochlorite and glutaraldehyde is effective in disinfecting the internal aspect of heat‐polymerised acrylic resin.     

滇黄精组培褐化影响因素研究

以滇黄精Polygonatum kingianum块茎芽为外植体,对组培过程中褐化的影响因素(灭菌方式、基本培养基及培养温度)进行探讨。结果表明,先经过75%乙醇处理30s消毒表面,再用NaClO 12min+HgCl2 8min消毒的抗褐化效果最好;选用1/2MS基本培养基能有效抑制褐化;低温环境(20℃)能进一步降低褐化发生率。