雷帕霉素菌株的常压室温等离子体(ARTP)诱变选育

雷帕霉素由放线菌次级代谢产生,具有抗真菌、抗肿瘤以及免疫抑制等生理活性,是临床重要的器官移植、抗肿瘤原料药物。为了获得具有高发酵潜力的工业用菌株,对雷帕霉素菌株的摇瓶发酵工艺进行了优化。采用常压室温等离子体(ARTP)的方法对高产雷帕霉素菌株的单孢子悬液进行诱变处理,通过高压液相的方法对诱变菌株的发酵代谢产物进行检测,成功地从诱变菌株中筛选获得了发酵产量提高30%以上的诱变菌株,建立了ARTP诱变选育高产雷帕霉素菌株的方法,为后期进行该菌株的选育研究工作以及中试发酵工艺优化提供了方法和物质的基础。     

基于核糖体工程理论的常压室温等离子体诱变筛选多杀菌素高产菌

利用核糖体工程理论,采用常压室温等离子体(ARTP)诱变对刺糖多孢菌(Saccharopolyspora spinosa)进行诱变筛选。以刺糖多孢菌QYLZ 88912菌株为出发菌株,对其进行ARTP诱变,选取三个不同致死率的照射时间,将孢子悬液混合,以增加抗性筛选几率。然后基于核糖体工程技术理论对混合孢子悬液进行初筛,最终筛选出了1株多杀菌素高产菌Sg200Rif110St40Er90-028。该菌株同时具有磺胺胍、利福平、链霉素、红霉素的多重抗性,摇瓶发酵试验表明,发酵7d后多杀菌素浓度可达到1 516.93 mg/L,较出发菌株QYLZ 88912的产量610.75 mg/L提高了148.37%,且遗传性稳定。以得到的高产菌Sg200Rif110St40Er90-028作为出发菌株,对发酵培养基进行响应面优化实验,优化后的培养基(g/L):葡萄糖46.97、麦芽糊精35、酵母粉40.36、水浸棉籽粉32.88、碳酸钙3,多杀菌素的产量为2 361.81 mg/L,比出发菌株的产量提高了286.71%。     

阿魏菇多糖高产菌的离子束和激光复合诱变育种

目的:诱变筛选阿魏菇多糖高产菌,探索食用菌的离子束和激光复合诱变育种方法。方法:尝试用阿魏菇菌丝单细胞为靶材,以离子束注入和激光辐照为复合诱变手段,采用营养缺陷型筛选办法定性初筛,摇瓶发酵定量复筛。结果:通过离子束注入诱变,获得了2株菌丝体多糖产量分别达到551.80mg/L和659.46mg/L、较1号出发菌株提高了46.5%和75.2%的多糖高产菌PFPH-1和PFPH-2;在此基础上,以激光辐照为复合诱变手段,获得了1株菌丝体多糖产量达到762.50 mg/L、较出发菌株PFPH-2提高了15.63%的多糖高产菌PFPH-3。结论:离子束和激光复合诱变育种方法在改良阿魏菇多糖高产性状方面诱变功效显著。     

南昌霉素高产菌株的链霉素抗性基因突变诱变筛选研究

通过对链霉素对南昌霉素（Nanchangmycin)产生菌NS－41－80菌株孢子的致死浓度测定基础上,采用诱变剂甲基磺酸乙酯（EMS）的不同诱发剂量对菌株孢子进行诱变处理,诱变处理的孢子涂布在含链霉素（10ug/mL)致死浓度的高氏平板上,获得了大量的链霉素抗性基因（str)突变株。然后从3,000株链霉素抗性基因（str)突变株中通过初筛获得比诱变出发菌株产素能力提高20％以上的菌株202株,再进一步通过摇瓶复筛,获得比出发菌株产素能力分别提高100％,200％,300％高产菌株为48株,7株和1株,分别为复筛菌和初筛菌株的23．76％和1．60％,3．46％和0．23％,0．5％和0．03％,将产素能力提高240％以上5个菌株连同出发菌株连续3批次进行摇瓶发酵结果,5个突变株的产素能力均比出发菌株的产素能力提高57％－96．4％,其中突变株80－5．3－165菌株摇瓶发酵单位达6,000ug/mL以上,3批次摇瓶平均发酵单位达5,855ug/mL,建立了南昌霉素高产菌株的链霉素抗性基因突变诱变快速高效的筛选方法。     

常压室温等离子体-紫外复合诱变选育β-法尼烯高产菌株

【背景】大肠杆菌(Escherichia coli)由于生长性能优良、遗传背景清楚、遗传操作手段成熟,是合成β-法尼烯的合适生产菌,但其合成β-法尼烯的产量目前仍不能满足工业化生产的需求。【目的】通过诱变筛选技术选育β-法尼烯高产突变株。【方法】采用常压室温等离子体(atmosphericand room temperature plasma,ARTP)诱变技术和紫外线照射对出发菌株大肠杆菌EC-16进行复合诱变,并以异戊烯焦磷酸耐受性为选择压力进行平板初筛,之后进行摇瓶复筛,最后进行发酵罐验证。通过连续多代培养筛选到的高产突变菌株,观察其遗传稳定性。【结果】经复合诱变选育筛选出一株β-法尼烯高产突变株E.coliHVK-9,其产量高达22.1g/L,相比出发菌株提高了168.74%。【结论】采用ARTP-紫外复合诱变,再结合异戊烯焦磷酸抗性筛选的集成方法,使得诱变菌株的正突变率大大提高,可以有效地提高诱变菌株的β-法尼烯产量。突变株HVK-9作为工业化发酵生产菌种具有较好的遗传稳定性,为β-法尼烯的工业化生产和应用奠定了良好的基础。     

黑曲霉a-鼠李糖苷酶高产菌株的选育

本文首次报道利用Davis方法制备的透明圈法筛选α-鼠李糖苷酶高产菌株。用甲基磺酸乙酯对出芽8 h的黑曲霉孢子进行诱变处理, 用透明圈法初筛出的菌株中, 产量提高40%以上的突变菌株占11%; 用摇瓶培养对初筛出的菌株进行两轮复筛α-鼠李糖苷酶高产突变株T-226, 摇瓶培养α-鼠李糖苷酶活达373.4 U/mL, 比出发菌株提高了22.7%。对该高产突变株进行5 L罐发酵实验, 发酵84 h测得α-鼠李糖苷酶活为631.9 U/mL。用新建立的方法选育高产α-鼠李糖苷酶的高产菌株, 不仅具有较高的筛选效率, 还具有良好的准确性。     

紫外、离子注入法对白腐真菌诱变效应的初步研究——多酚氧化酶菌株的选育

对白腐真菌F4孢子悬液进行紫外、N+离子注入诱变.诱变后待孢子长出单菌落,滴加茴香胺等多酚氧化酶底物,观察其颜色变化;经发酵筛选,获得一株多酚氧化酶高产菌POP5,漆酶活力是原出发菌株的16倍,并且得到一株多酚氧化酶缺失菌株POL1.紫外诱变,孢子浓度为106～108个/ml,照射时间1～2min;N+离子注入,孢子浓度为105～106个/ml,能量20Kev,剂量为5×1014ons/cm2,每个平板上生长30个左右菌落是最佳诱变选育条件.与其它真菌的孢子相比,N+离子注入法对白腐真菌F4孢子的致死率较大.     

抗性基因报告系统辅助选育厦门霉素A高产菌株

【背景】厦门霉素A是厦门链霉菌(Streptomyces xiamenensis) 318菌株的主要次级代谢产物,具有显著的抗纤维化活性及药用潜力。但野生型菌株中厦门霉素A的产量仅有14 mg/L,其生产水平亟待提升。【目的】通过随机诱变-抗性标记筛选获得高产菌株并进行培养基优化,以提高厦门霉素A的产量。【方法】在厦门霉素A的生物合成基因簇后融合一个抗性基因,用于报告整个基因簇的表达水平。对构建的基因工程菌株进行常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变,从抗性水平高的突变菌株中筛选高产菌株,并通过培养基优化,使厦门霉素A产量显著提升。【结果】构建携带卡那霉素抗性标记的产厦门霉素A的工程菌MT-XN作为出发菌株,对该菌株进行一轮ARTP诱变,使用90 mg/L卡那霉素筛选,得到了厦门霉素A产量为101.7 mg/L的突变菌株MA-8。进一步通过响应面法优化培养基配方,在最佳培养基中MA-8菌株产生的厦门霉素A达到134.2 mg/L,较野生型菌株提高了845.1%。【结论】采用随机诱变-报告基因筛选系统,可快速筛选出厦门霉素A产量大幅提升的高产菌株,为后续的药物开发奠定良好的基础。     

UV与NTG复合诱变选育咪唑立宾高产菌

为选育咪唑立宾的高产菌株,对咪唑立宾产生菌Eupenicillum sp.E-0509-2的孢子分别进行了紫外线照射(UV)、亚硝基胍(NTG)和UV+NTG复合诱变处理筛选突变株。结果表明试验所确定的咪唑立宾产生菌的孢子诱变适宜条件为:将孢子悬液在电磁搅拌下,经紫外线照射处理60s后,以3.0g/L NTG处理20min。经发酵筛选试验,获得了一株遗传性状稳定、高产咪唑立宾的诱变菌株Eupenicillum sp.E-UN41,其咪唑立宾产量较出发菌株提高13倍。     

紫外线诱变原生质体选育核黄素高产菌株

以产核黄素生产用菌——阿舒假囊酵母RS-89为出发菌株,用对致期生长的菌丝体,经0.5%蜗牛酶+0.5%纤维素酶作用2h可获得大量原生质体,其再生率为6.1%。对经UV诱变的原生质体再生株进行初筛、发酵复筛,从中获得了菌落大、色素深、产量高于出发菌株30%的高产稳定株——UP-91。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The mechanism of hatching of eggs of Haemonchus contortus

Fluid collected from hatching eggs of Haemonchus contortus contained a lipase which hydrolysed 2-naphthyl laurate (about 0·7 μmol naphthol freed /h/10⁶ eggs). The fluid also hydrolysed l-leucinamide (about 2·3 μmol leucine freed/h/10⁶ eggs). The fluid when added to normal or heated eggs caused ‘hatching’. ‘Hatching’ also occurred in exsheathing fluid from infective juveniles and in a preparation of pancreatic lipase containing leucine aminopeptidase. A purified mammalian leucine aminopeptidase in combination with several different lipases did not attack egg shells.The ‘spontaneous’ hatching of eggs of H. contortus was strongly inhibited by 1,10-phenanthroline, 10^?3M, and this inhibition was reversed by Zn²⁺. However, the inhibition of ‘hatching’ of eggs in externally applied hatching fluid, or the hydrolysis of leucinamide in hatching fluid was generally less marked.