超声波对蔷薇藻生长及生理特性的影响

目的:用超声波处理蔷薇藻(Rhodella reticulata),研究超声波电流、处理时间和脉冲时间对蔷薇藻生长代谢的影响.方法:通过均匀设计实验结合DPS软件对均匀设计实验结果进行二次多项式模型分析和拟合,以生物量、胞外多糖和藻蓝蛋白为目标建立回归模型,优化超声波处理条件.结果:以生物量为目标:电流39%,超声时间123.27s,脉冲时间0.55s,干重的预测值为2.42g/L;以胞外多糖为目标:电流21%,超声时间245s,脉冲时间9.5s,胞外多糖的预测值为656.22mg/L;以藻蓝蛋白为目标:电流21%,超声时间5.0s,脉冲时间0.5s,藻蓝蛋白的预测值为63.53mg/L;优化后生物量、胞外多糖和藻蓝蛋白的产量比未经优化的分别提高了13.3%、11.4%和31.1%.结论:一定强度的超声波促进了蔷薇藻的生长和胞外多糖及藻蓝蛋白的积累.     

蔷薇藻藻蓝蛋白的稳定性研究

蔷薇藻Rhodella reticulata是属于红藻门的一种海洋单细胞微藻,其生长过程中产生藻胆蛋白、胞外多糖等生物活性物质。蔷薇藻经过破碎,通过硫酸铵沉淀和DEAE Sepharose FF柱层析后,可以分离出较纯的藻蓝蛋白。本文从pH、温度、光照、食品添加剂、金属离子等方面对蔷薇藻藻蓝蛋白稳定性作了较全面的研究：藻蓝蛋白在pH为7时最稳定;低温有利于保持藻蓝蛋白的活性;相对于光照,在避光条件下,藻蓝蛋白有较高的稳定性;适当浓度的蔗糖和葡萄糖都有利于藻蓝蛋白的保存;金属离子影响藻蓝蛋白的稳定性。     

通入CO2和补加氮源对紫球藻生长和代谢物质积累的影响

论文研究了柱状光生物反应器中CO2浓度和氮源添加模式等培养条件对紫球藻(Porphyridium sp.UTEX 637)生长和主要代谢产物积累的影响。结果表明,通入CO2能显著促进紫球藻的生长及胞外多糖、水溶性蛋白和总脂等生物活性物质的积累,其中1%的CO2浓度对紫球藻的生长及活性物质积累最有利,该条件下紫球藻的最高干重可达到8.14 g/L,是对照组的4.93倍;胞外多糖产量明显高于对照组,最高可达到238.8 mg/L;补加氮源KNO3对紫球藻生长及胞外多糖、水溶性蛋白含量均有明显的促进作用,最高干重、胞外多糖含量可分别达到对照组的1.5倍和1.25倍,但不利于总脂的积累。     

营养盐浓度对航天搭载盐藻生长及胞外多糖含量的影响

比较了培养液中不同营养盐浓度对“神舟5号”搭载盐藻(Dunaliella salina)和非搭载盐藻的生长及胞外多糖积累的影响,发现经“神舟5号”搭载后盐藻最适营养盐浓度发生了变化。非搭载盐藻培养液中最佳单因子组合为:CaC l2200 mg/L、MgC l2500 mg/L、KNO31 000 mg/L、KH2PO455 mg/L。搭载盐藻培养液中最佳单因子组合为:CaC l2250 mg/L、MgC l2500 mg/L、KNO31 000 mg/L、KH2PO415 mg/L。搭载和非搭载盐藻胞外多糖累积的最佳单因子组合相同:CaC l2、MgC l2、KNO3、KH2PO4分别为250、2 000、500、15 mg/L,但搭载盐藻胞外多糖的分泌明显高于非搭载盐藻。     

氮、磷营养盐对底栖硅藻的生长及生化组成影响

目的:研究了从福建连江海域分离得到的一株野生底栖硅藻(Nitzschia.constricta)的生长和生理特性.方法:测定了在不同氮磷浓度条件下比增长速率、色素,以及不同时期底栖硅藻蛋白和胞外多糖的积累情况.结果:当硝酸氮浓度为900mg/l时,获得最大比增长速率0.21和叶绿素a含量4.31mg/l、类胡萝卜素含量3.44mg/l、胞外多糖产率90.57μg/ml.当氮浓度为75mg/l时,在第10d得到最大蛋白产率28.90μg/ml.当磷浓度为4.4mg/l时,可得到最大比增长速率0.13、叶绿素a含量3.42mg/l、类胡萝卜素2.82mg/l、蛋白含量23.16μg/ml,无磷培养基中第5d的胞外多糖产率最高13.51μg/ml.结论:氮磷营养盐浓度的增加促进了此种底栖硅藻的生长,但不一定会促进蛋白及胞外多糖的产生.     

培养条件对螺旋藻生长和藻胆蛋白含量的影响

研究了不同质量浓度尿素代替硝酸钠作氮源和不同氯化钠质量浓度改变渗透压对螺旋藻的生长和藻胆蛋白含量的影响。结果发现适宜质量浓度尿素 ( 0 .1g·L-1)培养可加快螺旋藻生长 ,增加藻胆蛋白含量 ;质量浓度高于 0 .2g·L-1其生长受到抑制 ;而质量浓度过高 (≥ 0 .4g/L)时培养几天螺旋藻即断裂并逐渐死亡。培养基中不加氯化钠或质量浓度为 2 0g·L-1时培养 ,生长速度均与对照相当 ,但藻胆蛋白含量比对照要高 ;质量浓度为 40g·L-1～ 6 0g·L-1时培养 ,其生长明显变慢 ,且氯化钠浓度越高生长越慢 ;当质量浓度过高 (≥ 6 0g·L-1)时培养 3d ,螺旋藻细胞即破裂死亡。     

三种微藻细胞破碎方法的比较

目的:获得最佳的微藻藻胆蛋白提取方法.方法:采用溶胀法、反复冻融法、低浓度氯化钙溶液提取法和玻璃珠处理法等四种方法分别对紫球藻、蔷薇藻和念珠藻三种藻细胞进行破碎,通过测定藻红蛋白的纯度和浓度对四种细胞破碎方法效果进行比较.结果:当细胞密度为1.00g/L时,采用反复冻融法处理紫球藻和蔷薇藻时能够获得最高的藻红蛋白纯度(OD545/OD280),分别为1.250和1.669,藻红蛋白的浓度分别为29.788,mg/L和36.026mg/L,细胞密度对藻红蛋白纯度影响较小;低浓度氯化钙溶液提取法能使念珠藻藻红蛋白的纯度(OD545/OD280)达到0.477.结论:紫球藻和蔷薇藻经反复冻融法破碎细胞,藻红蛋白纯度高,提取效果好;而对念珠藻藻红蛋白提纯采用低浓度氯化钙溶液提取法效果好.     

灵芝菌丝体富硒条件优化及其硒多糖抗氧化活性研究

利用正交试验对灵芝菌丝体液体发酵富硒条件进行优化,研究培养基中不同碳源、氮源和亚硒酸钠浓度对菌丝体生物量、硒含量、富硒率以及胞外酶活性的影响,此外还对硒多糖的抗氧化活性进行了初步研究。结果表明:当培养基中碳源为20%马铃薯、氮源为2%麸皮、Na_2SeO_3浓度为5 mg/L时,培养基中菌丝生物量最高达到3.86 g/L,硒含量最高为0.576 mg/g,富硒率也达到最高为44.47%。Na_2SeO_3对菌丝生长的影响大于碳源和氮源;同样的Na_2SeO_3对胞外酶活性的影响最大,最优组的POD和PPO酶活性都较其他组高,且随着Na_2SeO_3浓度的升高,其酶活性逐渐降低。富硒灵芝菌丝体粗多糖都具有较强的体外抗氧化活性,通过相关性分析发现,其粗多糖的抗氧化活性与硒含量、富硒率具有显著的正相关。显示硒多糖在食品和药品等领域具有良好的开发利用前景。     

温度对谷皮菱形藻生长及其理化成分的影响

考察了不同温度对谷皮菱形藻生长及其理化成分的影响。结果表明:温度在10℃或30℃条件下不利于细胞生长,同时也不利于胞内理化成分的积累。在20℃条件下细胞密度、叶绿素含量、胞内蛋白、胞外多糖及胞内多糖达到最大值。谷皮菱形藻的最适生长温度为20℃,10℃可以作为种质保存的温度。     

氮磷对青岛大扁藻和牟氏角毛藻单养和共培养生长的影响

通过实验生态学的方法,分别以KNO3和KH2PO4为氮源和磷源,研究青岛大扁藻(Platymonas helgolandicavar.tsingtaoensis)和牟氏角毛藻(Chaetoceros muelleri Lemmerman)单培养和共培养时的生长状况。结果显示,不同氮磷处理对两种藻的单培养和共培养都有显著影响(P<0.05)。共培养时,青岛大扁藻的最大藻密度与氮磷浓度呈正相关。氮处理时,当培养液中KNO3为110 mg/L时,取得最大值;磷处理时,青岛大扁藻的最大藻密度在KH2PO4为9 mg/L时取得最大值;而牟氏角毛藻分别在KNO3为70 mg/L和KH2PO4为5 mg/L时取得最大值。共培养时两种藻的藻密度都低于单培养。另外,无论低氮高磷还是高氮低磷都不利于两种藻获得较大的终细胞密度。     

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.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

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.     

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.     

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.