【作者】 吴红艳；

【导师】 赵以军； 郭厚良；

【作者基本信息】 华中师范大学 ， 微生物， 2001， 硕士

【摘要】 蓝藻细胞是否具液泡或能否形成液泡一直是一个悬而未决的问题。曾有报道说，衰老的蓝藻细胞形成液泡，并认为，形成液泡是一个标志，表明细胞濒临死亡。还有人提出，蓝藻正常细胞内就有液泡状结构。但由于未能从蓝藻细胞内分离液泡以进行深入研究，因此蓝藻液泡的存在得不到普遍承认。近年来，郭厚良等人在蓝藻原生质球的研究中发现了液泡，包括无机盐诱导液泡和细胞液泡，并成功地实现了液泡的分离。为了深入开展这方面工作，我们选用了六种蓝藻，对其进行不同的胁迫环境条件处理，结果如下： 一．鱼腥藻595（Anabaena sp.595）在0.05mol/L钾、钠、铵的盐酸盐、硝酸盐、硫酸盐和磷酸盐的诱导下，2天时即出现显著的细胞学效应：细胞体积增大，明显液泡化；少数细胞发生横向和不均等分裂；藻丝片段化，异形胞分化率相对提高。其中，铵盐培养的藻丝细胞内出现特异的浓缩颗粒状区域。钙盐、镁盐也诱导类似细胞学变化，但作用较弱。在含0.1mol/LNaCl的培养基中长期培养，细胞出现周期性分化行为：开始细胞膨大并液泡化，以后色素质重新充满细胞，液泡化消失，然后细胞分裂至正常细胞大小，成为接近正常的藻丝，但接着又膨大液泡化，如此进入新的周期过程。 二．选用0.05mol/L的NaCl、KNO₃、（NH₄）₂SO₄、MgSO₄、CaCl₂五种常用无机盐对分属三科的六种蓝藻进行液泡化诱导，不同蓝藻其盐敏感性不同。鱼腥藻sp.595最为敏感，五种盐均诱导其液泡化；颤藻284（Oscillatoria animlis. 284）和极大螺旋藻438（Spirulina maxima. 438）最不敏感，所试验盐类均不能诱导其液泡化；念珠藻sp.96（Nostoc sp.96）、织线藻246（Plectonema boryanum.246）和伪枝藻248（Scyntonema hofmann.248）液泡化程度居中，少数盐类如NaCl、KNO₃、（NH₄）₂SO₄对其有诱导作用。k奎卖／硕士晕上论大 ＼x ．，、。／Vu二ER＞厂。三三厂＞ 采用压片法观察到诱导形成的液泡，液泡在相差显微镜下显示为圆球形， 基本透明。 三．选用两种重金属汞、锅和两种微量元素铜、锌对鱼腥藻Sp．595、 织线藻246和伪枝藻248进行液泡分化的诱导。0刁urn汞能诱导三种蓝藻 分化液泡，而锅的诱导作用明显弱于汞。当锅浓度达到5刀urn时才能诱导 鱼腥藻Sp．595液泡分化，对织线藻246和伪枝藻248产生诱导作用也需要 0．sn的浓度。而两种微量元素铜和锌之间的诱导作用差异较小。铜和锌 浓度为1刀urn时均能诱导鱼腥藻Sp．595液泡分化，0．sum时均能诱导伪枝 藻248液泡分化，而对织线藻246进行诱导时，铜浓度需为1．oum，锌浓 度则需0．suxn。采用压片法均观察到诱导形成的液泡，液泡在相差显微镜 下显示为圆球形，基本透明。 四．对鱼腥藻Sp．595、织线藻246、伪枝藻248、念珠藻Sp．96、颤藻 284 和极大螺旋藻438等六种蓝藻进行异常PH条件下的液泡化诱导．在 PHS几6．5，7刀条件下，鱼腥藻Sp．595和织线藻246藻细胞均出现液泡化． 其中，鱼腥藻Sp．595变化明显，其藻细胞膨大，两端变圆甚至球形化，液 泡化程度高，且细胞不均等分裂现象普遍，织线藻246藻细胞稍有膨大， 液泡化程度较轻．伪枝藻248表现较弱的敏感性，藻细胞仅在pH6．5时诱导 ＊ 液泡化．念珠藻Sp．96、颤藻284 和极大螺旋藻438在各种pH条件下均不 甲 能发生液泡化，对诱导不敏感．采用压片法检查到鱼腥藻Sp．595和织线藻 246诱导形成的液泡，在相差显微镜下液泡显示为圆球形，基本透明。 五．鱼腥藻sp．595用0刀smoW(NHhSO。诱导液泡化后，用0．l％（w／） 溶菌酶处理，转入蒸馏水分离得到液泡。几乎所有原生质球都放出液泡， 液泡为完全透明状，标准圆球形。泡内无可辨物质，泡外有少数色素物质 粘附，有的几乎无粘附，完全裸露。更多还原

【Abstract】 ~#) S THESIS Abstract The question as to whether the cyanobacteria have vacuoles or can form vacuoles is still controversial. It was reported that vacuoles were formed only in the aged cells and were the sign of being death. Some others even pointed out that vacuoles were presented in the normally growing cells of cyanobacteria. However, it was not generally accepted that vacuole existed in cell of cyanobacteria since the isolation of the vacuole has never been achieved for extensive study. In recent years, in research of cyanobacterial protoplasts, Guo et al. have discovered both the salt-induced vacuoles and the non-induced vacuoles in the cells and achieved success in the isolation.For further study, we have selected six species of cyanobacteria and treated them with different environmental stress conditions. The results are reported as follow: Cultured in the presence of 0.O5molIL chlorinate, nitrate, sulphate and phosphate of K, Na and ammonium for 2 days, the cells of Anabaena sp. 595 inflated, vacuolized and performed longitudinal or unequational division; the trichomes fragmented and the number of heterocysts increased. And what抯 more, special contracted gramulum appeared in the cells when they were induced by animoniuin. In comparison, the cells were less affected by Ca2~ and Mg2~.While cultured in the medium containing 0.0 lmol/L NaC1 for long-term effect, the cell exhibited cyclic differentiation. It inflated and vacuolized firstly, then the pigment expanded and vacuolization disappeared, finally, the cell divided to normal size. In fact, the inflation and vacuolization appeared again in the following days, so the cycle continued. liZ. Six cyanobaceria were cultured in the presence of O.O5mollL NaCl~ KNO3~ (NH4)2SO4~ MgSO4 and CaC12 for vacuole induction, and produced different effects. Anabaena sp.595 was the most sensitive , vacuole could be induced by all salts we tested. In contrast, no salts could induce cell vacuolization in Oscillatoria animlis 284 and Spirulina maxima 438. While Nostoc sp.9 6.. Plectonema boryanum246 and Scytonema hofmanni248 were the relatively sensitive strains, only NaC 1.. KNO3.. or (NI{4)2S04 had the inducing effect on them. The induced vacuole was examed by pressing the sample, it was spherical and transparent in the scope of phase microscope. Two heavy metals, including mercury and cadmium, and two trace iii elements ,such as copper and zinc were used for vacuole induction in the cells of A.sp 595, Pboryanum 246 and S.hofmanni 248. 0.lum mercury induced vacuoles in all the three tested cyanobacteria, while 5.Oum cadmium in A.sp 595, O.Sum cadmium in P.boryanum 246 and S.hofinanni 248. The inducing effect of mercury was more obvious than that of cadmium. In comparision, no severe difference existed in inducing function of the two trace elements copper and zinc. For vacuole induction, A.sp 595 needed l.Oum copper and zinc, which S. hofinanni 248 needed 0.Sum, and Pboiyanum 246 needed 1 .Oum copper and 0.Sum zinc. The induced vacuole was examed by pressing the sample, it was spherical and transparent in the scope of the phase microscope. l~. Six species or strains of cyanobacteria, A.sp. 595, P boryanum 246, S. hofinanni 248, N. sp.96, 0. animlis284 and S.更多还原