苏云金杆菌在味精废水中的培养与发酵特性

该文讨论了苏云金杆菌HM－1菌株在以味精废水为原料的培养基上的生长,经多次摇瓶培养,确定了最适培养基成份,在此基础上,进行了30L通风搅拌罐的深层培养,研究了苏云金杆菌HM－1菌株在30升通风发酵罐深层培养的发酵特性。     

经高浓度味精废水驯化的B.t菌株伴胞晶体特性及其活性成分研究

对3株能在味精废水中生长的苏云金芽孢杆菌菌株T.4,G.1,S-2.5进行了废水茄子瓶培养基培养,应用液体双相法分离晶体,通过SDS－PAGE电泳确定了它们的分子量为120KD,104KD,67－68KD,43－45KD,选取菌珠G．1经分离后的晶体通过DEAE－纤维素离子交换层析和Sephadex G-100凝胶排阻层析分离到两上峰,分子量分别为120KD,68KD,致死中浓度LC50分别为0．609,＞25。     

生物防治

960285 设计高效抗鳞翅目和鞘翅目昆虫的重组苏云金芽孢杆菌菌株[俄]/Kuzina, L. V.…∥Biotekhnologiya.-1994,7.-15～19[译自DBA,1995,14(8),95-04683] 将苏云金芽孢杆菌subsp.Kurstaki HD1负责晶体蛋白CryIA(b)合成的44MDa质粒分别接合转入不合成晶体蛋白的苏云金芽孢杆菌subsp.thuringiensis98和苏云金芽孢杆菌subsp.tenebrionis1516变种中,构建了重组的苏云金芽孢杆菌     

我国森林土壤中苏云金芽孢杆菌生态分布的研究

从我国8个森林立地带(寒温带、中温带、暖温带、北亚热带、中亚热带、南亚热带、高原亚热带、热带)所属的13个自然保护区,采集了0—5cm土层林下土壤样品384个.测定了土壤pH、水分和养分.从中分离观察芽孢杆菌菌落1873个,分离出苏云金芽孢杆菌79株,并对其所属亚种进行了初步鉴定.其平均出土率和分离率分别为14.32%和4.21%.研究了芽孢杆菌和苏云金芽孢杆菌在森林土壤中生态分布的规律及苏云金芽孢杆菌对6种昆虫的室内毒力测定,从中筛选出不少的高效菌株.为研究苏云金芽孢杆菌在我国森林生态系中资源的保护、开发和利用,具有重要意义.     

利用PCR技术直接鉴定苏云金芽孢杆菌杀虫晶体蛋白基因型的快速方法

根据PCR程序中热变性温度可使菌体裂解,释放出DNA的原理,利用苏云金芽孢杆菌杀虫晶体蛋白不同基因型的特异混合引物,对苏云金芽孢杆菌营养体直接进行PCR分析。根据不同基因型的特异扩增产物片段的分子量大小便可直接确定该苏云金芽孢杆菌杀虫晶体蛋白的基因型。本文对本室筛选天然菌株和苏云金芽孢杆菌克隆菌株分别进行了cryl基因的PCR分析。表明,该法结果可靠快速易行,在方法学上,为苏云金芽孢杆菌菌株鉴定、新菌株的筛选和基因型分析提供了极大的方便。     

紫外线诱变苏云金芽孢杆菌最佳条件探索

为寻找高毒性的苏云金芽孢杆菌(BT菌)菌株,我们用紫外线对苏云金芽孢杆菌的库尔斯塔克亚种进行诱变,再对得到的突变菌株进行筛选,得到高毒性的菌株。本文设计实验,先对苏云金芽孢杆菌进行生长曲线的测定和表征,再通过控制变量法对苏云金芽孢杆菌进行外线诱变,最后总结出最佳的诱变条件。     

苏云金芽孢杆菌蛋白酶发酵动力学模型的构建

对苏云金芽孢杆菌FS140蛋白酶分枇发酵的代谢特性进行了研究.首先描述了FS140分枇发酵过程中细胞生长、产物积累、糖消耗的变化规律.基于Logistic方程和Luedeking-Piret方程,建立了苏云金芽孢杆菌蛋白酶发酵过程细胞生长、产物合成及基质消耗随时间变化的数学模型.动力学模型计算值结果与实验值拟合良好,较好反映了苏云金芽孢杆菌分批发酵过程的动力学特征.     

蜡状芽孢杆菌活菌制剂(促菌生)大罐深层培养的研究

本试验就蜡状芽孢杆菌大罐深层培养法进行了初步研究,基本解决了蜡状芽孢杆菌大罐液体深层培养条件下芽孢生成、适宜培养基的选择、培养方法的建立以及菌体的收集方法等技术问题,大罐深层培养生产工艺的建立较固体培养法产量大为增加,污染耗损降至最低,减少劳动强度和繁琐的操作,而且产品质量得到保证和提高.     

昆虫病原菌苏云金芽孢杆菌群(Bacillus thuringiensis Group)的分类

采用形态、生化、血清学的方法对国外引种的15株巳知菌和本国51株未知菌进行了变种的分型研究。结果表明：苏云金芽孢杆菌(Bacillus thuringiensis)作为有益的细菌资源在藏国分布较广。51株菌中属于血清型H1苏云金芽孢杆菌苏云金变种(Baeillus thuringiensisvar. Thuringiensis)有11株,血清型H50-5b苏云金芽孢杆菌蜡螟变种(B．Thur．Var．Galleriae)31株,血清型H4-4b苏云金芽孢杆菌松蜩变种(B.thur. Var. dengrolimut)3株,血清型H4-4a。苏云金芽孢杆菌肯尼亚变种(B. thur. Var kenyae) 5株,同时发现血清型H．苏云金芽孢杆菌玉米螟变种(B. thur var. ostrinia,)一株。玉米螟变种不同于该菌群的巳知菌株,认为是一个新变种。实践证明,利用血清学抗原抗体具有高度特异{生的凝集反应来鉴别苏云垒芽孢杆菌变种,简便,快速,准确。而该群噬菌体却不能作为区分变种的标准。     

苏云金芽孢杆菌转座因子研究进展

近年来的研究发现苏云金芽孢杆菌转座因子和许多毒力因子可能是紧密联系的。由于转座因子的特殊性质,使它们在现代农业生物技术中有着广泛的应用前景,科学家对苏云金芽孢杆菌转座因子的研究也在不断深入。本文主要针对苏云金芽孢杆菌转座因子的研究进展进行综述,并对发展前景进行展望。     

华根霉固态与液态培养产胞外蛋白的比较蛋白质组学分析

【目的】考察固态和液态两种培养方式对丝状真菌华根霉(Rhizopus chinensis)CCTCC M201021产胞外蛋白的影响,以加深对微生物固、液态培养特异性产酶的认识。【方法】利用成分相同的培养基对华根霉分别进行平板固态培养和液态培养,提取华根霉所产胞外蛋白,采用二维凝胶电泳(2-DE)结合质谱分析,分离鉴定差异蛋白。【结果】固态培养下华根霉所产胞外蛋白的蛋白酶活性是液态培养的9.2倍。胞外蛋白质组数据分析表明,华根霉固态和液态培养所产胞外蛋白存在显著差异,其中约70%是固态和液态培养下各自产生的特有蛋白。质谱鉴定进一步表明,固、液态培养对华根霉产胞外蛋白的种类和表达量都有显著影响,其中水解酶类所占比例较大,主要是与蛋白质降解相关的蛋白。【结论】固态和液态不同培养方式影响了华根霉产胞外蛋白的组成,有些基因只在特定培养方式下表达。固态培养下华根霉产胞外蛋白酶种类相对更多以及大部分蛋白酶的上调表达,可能是固态培养下胞外蛋白酶活性很高的原因。研究结果提示需要注意固液态不同培养方式下丝状真菌胞外酶的筛选和生产可能存在的不一致性。     

Stimulation of potato (Solanum tuberosum L.) tuberization by semicontinuous liquid medium surface level control

A procedure for the mass propagation of potato (Solanum tuberosum L.) tubers using a laboratory scale jar fermentor is described. Tuberization was clearly suppressed when the shoots were completely submerged in the liquid medium. Tubers were mainly formed at the medium surface. When shoots were cultured by the semi-continuous medium surface level control method, in which the medium surface level was raised or lowered throughout the culture period, tubers were induced and developed in every area in the jar fermentor. Tubers propagated by this method contained about 18 % (w/w) dry matter, slightly less than in field grown tubers, but most of the tubers weighing more than 0.2 g(FW) sprouted under room condition, without any acclimatization, during 3 month after the culture.     

Enhanced Production of Ganoderic Acids and Cytotoxicity of Ganoderma lucidum Using Solid-Medium Culture

Submerged cultures of Ganoderma lucidum are used to produce fungal mycelium, which is used as a functional food and in the production of various triterpenoids, including ganoderic acids (GAs). Specific culture approaches that produce fungal mycelium with high levels of GAs and good biological activity are critical in the functional food industry. In this study, a solid-medium culture approach to producing mycelium was compared to the submerged culture system. Production of GAs, biomass, intracellular polysaccharides, and cytotoxicity of the cultured mycelium were compared as between solid and submerged culture. Growing G. lucidum strains on solid potato dextrose agar medium increased biomass, the production of ganoderic acid 24 (lanosta-7,9(11), 24-trien-3α-o1-26-oic acid), GAs, and total intracellular polysaccharides as compared to fungi grown in submerged culture. Triterpenoid-enriched methanol extracts of mycelium from solid-medium culture showed higher cytotoxicity than those from submerged culture. The IC(50) values of methanol extracts from solid-medium culture were 11.5, 8.6, and 9.9 times less than submerged culture on human lung cancer cells CH27, melanoma cells M21, and oral cancer cells HSC-3 respectively. The squalene synthase and lanosterol synthase coding genes had higher expression on the culture of solid potato dextrose medium. This is the first report that solid-medium culture is able to increase GA production significantly as compared to submerged culture and, in the process, produces much higher biological activity. This indicates that it may be possible to enhance the production of GAs by implementing mycelium culture on solid medium.     

Surface hydrophobicity, viability and efficacy in biological control of Penicillium oxalicum spores produced in aerial and submerged culture

The surface hydrophobicity, viability and biocontrol ability of Penicillium oxalicum spores, produced either in aerial or submerged culture, were characterized. A phase distribution test showed that spores produced in both methods of culture were highly hydrophobic, but those produced in aerial culture were more hydrophobic. Spores stored fresh at either 4 or 25 degrees C retained a high viability (80%) after 27 weeks of storage, although aerial spores survived better. Freeze-drying severely affected viability, especially of submerged spores. Biocontrol ability against Fusarium oxysporum f. sp. lycopersici was studied in the growth chamber. Aerially- produced spores were more effective than submerged ones. Aerially-produced P. oxalicum spores appeared to have more advantages than those produced by submerged culture, in relation to both viability and efficacy. These results demonstrate that physiological changes occur depending on production conditions which significantly influences quality of the biocontrol agent.     

食药用菌制作酸乳深层发酵培养基的比较

利用3种深层发酵培养基对灵芝和云芝进行深层发酵培养,所得的发酵滤液可以制成相应的灵芝和云芝酸乳.经测定采用这两种食药用真菌深层发酵滤液制成的酸乳营养丰富,并具有灵芝和云芝的药用价值;但使用不同的深层发酵培养基,酸乳的营养和理化特性有差异,通过比较可以选择出最佳深层发酵培养基.     

Cell Growth and Shikonin Production of Arnebia euchroma in a Periodically Submerged Airlift Bioreactor

Arnebia euchroma was grown in a 2-l periodically submerged, airlift bioreactor (PSAB) in which the non-submerged (immobilization culture) and submerged (suspension culture) operations were controlled automatically. PSAB had advantages in improving cell growth, shikonin content, shikonin production and cell aggregation compared with suspension culture. Under the optimal submerged/non-submerged period of 10 min/15 h, the shikonin content (4.6%, w/w) and, cell dry mass (16.8 g/l) were 229 and 26% higher than those in suspension culture. Revisions requested 31 October 2005 and 6 December 2005; Revisions received 2 December 2005 and 13 January 2006     

Submerged organ culture: An improved method

Summary Explants of whole ovaries and oviducts from postnatal rats were completely submerged during cultivation as organ cultures in chemically defined medium. The oxygen concentration in the culture chamber was raised to over 90%, and the stainless steel platform, used for cultures at the surface of the medium, was abandoned and excluded from further use. Thus, all of the periphery of an explant had equal access to nutrients and oxygen. Throughout the ovarian explants the tissues appeared uniformly viable, and mitotic figures were distributed evenly. These observations are in contrast to those on organs cultivated at the surface of the medium where a lack of structural uniformity had been detected. The method has general application to a variety of organs.     

Submerged organ culture: An improved method

Summary Explants of whole ovaries and oviducts from postnatal rats were completely submerged during cultivation as organ cultures in chemically defined medium. The oxygen concentration in the culture chamber was raised to over 90%, and the stainless steel platform, used for cultures at the surface of the medium, was abandoned and excluded from further use. Thus, all of the periphery of an explant had equal access to nutrients and oxygen. Throughout the ovarian explants the tissues appeared uniformly viable, and mitotic figures were distributed evenly. These observations are in contrast to those on organs cultivated at the surface of the medium where a lack of structural uniformity had been detected. The method has general application to a variety of organs.     

A comparison of the unfolded protein response in solid-state with submerged cultures of Aspergillus oryzae

The unfolded protein response (UPR) is a regulatory system to maintain the homeostasis of ER functions. Here we report a comparison of express levels of UPR relevant genes in Aspergillus oryzae between solid-state and submerged cultivation. The results were that up-regulation of the UPR mechanism in solid-state culture was higher than in submerged culture (heat-shock or non-stress conditions). This might have been a result of changing culture conditions.