二氧化氯对球形棕囊藻的抑制和杀灭作用

以海洋赤潮生物-球形棕囊藻汕头株(Phaeocystis globosa,ST strain)为材料,研究了ClO2对不同起始藻密度的棕囊藻的抑制和杀灭作用．结果表明,ClO2对球形棕囊藻有明显的抑制和杀灭作用．藻密度为2．35×10^9cells·L-1时,高于0．74×10-2mmol·L-1的ClO2对棕囊藻生长有一定的抑制作用。高于2．96×10-2mmol·L-1的ClO2对棕囊藻具有显著的杀灭作用．藻密度与ClO2浓度之间存在一定的剂量关系．藻密度为2．35×10^9、1．18×10^9、4．70×10^8、1．18×10^8 cells·L-1时。其96h的有效杀藻浓度分别为2．96×10^-2、2．22×10^-2、1．48×10^-2和0．59×10^-2mmol·L^-1．藻密度越高。杀灭单位藻细胞所需ClO2的浓度越低．ClO2作为杀藻剂在赤潮治理中具有很好的应用前景．     

Characterization of the Hemolytic Properties of an Extract from Phaeocystis globosa Scherffel

Phaeocystis globosa Scherffel, an organism that causes harmful algal blooms, is a genus of the family Prymnesiophyta (or Haptophyta) with eurythermal and euryhaline characteristics. P. globosa has been confirmed to produce hemolytic substances, which are a mixture of liposaccharides. In the present study, the hemolytic properties of extract of P. globosa are analyzed further. The effects of temperature, pH,different divalent cations, and membrane lipids on extract-induced hemolysis are discussed, as is the possible hemolytic mechanism. The results of the present study showed that the hemolytic activity of the extract was approximately 127.1 hemolytic units (HU)/L. The hemolytic reaction became fastest and a 50% decrease in absorbance was induced at 30 min at 37℃, and at pH 7.0; Hg^2 was the strongest inhibitor of the hemolysis compared with the other divalent cations and many membrane lipids, except for phosphatidic acid, inhibited the hemolytic activity to different degrees. These results suggest that the toxin may make pores in the surface of red blood cells and that Hg^2 either combines with the hemolysin or closes the pores,hence inhibiting its further hemolytic reaction. The toxin probably has no specific membrane receptor in the red blood cell membrane.     

二氧化氯对球形棕囊藻叶绿素a、蛋白质、DNA含量的影响

分析了二氧化氯(1.0、1.5、2.0、2.5mgL-1,作用96h;2.5、6.0、8.0、16.0mgL-1,作用60min)对球形棕囊藻叶绿素a、蛋白质含量、氨基酸组成、核酸含量的影响,用透视电镜对二氧化氯(0.5mgL-1,0.8mgL-1)作用24h后藻细胞形态的变化进行了观察,以探讨二氧化氯去除赤潮藻的机理。结果表明,二氧化氯对球形棕囊藻叶绿素a、蛋白质、DNA的含量均有影响。实验各组(1.0-2.5mgL-1,2.5-16.0mgL-1)球形棕囊藻的叶绿素a、蛋白质、DNA的含量均显著低于对照。二氧化氯浓度超过2mgL-1时,球形棕囊藻的叶绿素a、蛋白质、DNA的含量持续降低,氨基酸相对含量发生明显变化;半胱氨酸、酪氨酸和赖氨酸等的相对含量明显降低,而组氨酸、缬氨酸和苯丙氨酸则明显增加。当二氧化氯(2.5-16.0mgL-1)作用3min后,DNA漏出率在13%-18%之间;电镜观察发现,二氧化氯可使细胞膜破损,引起内容物外泄。这些结果显示,二氧化氯能以单分子形式进入细胞,引起叶绿素、蛋白质结构的变化,并破坏藻细胞膜系统,最终导致藻细胞死亡。     

厦门港球型侧腕水母(Pleurobrachia globosa Moser)的生殖

球型侧腕水母是厦门港最常见、数量最大的栉水母。雌雄同体。主要生殖季节在4—7月,是水产养殖业的重要敌害。精、卵多在下半夜排放。精子和卵子分别由位于两栉毛板之间的输精孔和输卵孔排出。卵子呈圆球状,其外为一层透明的胶质卵膜。平均卵径为319.2±57.5μm。胚胎发育在胶质膜内进行。当膜内幼体的雏形平衡囊、栉毛带、口及口道形成之后,幼体便用口及口道顶破胶质膜而孵出。     

中国顶丝藻科新记录

继续报导中国顶丝藻科新记录６种。渐尖旋体藻Ａｕｄｏｕｉｎｅｌａａｔｅｎｕａｔａ,球状旋体藻Ａ．ｇｌｏｂｏｓａ,纤细旋体藻Ａ．ｇｒａｃｉｌｉｓ,无柄旋体藻Ａ．ｈｙｐｎｅａｅ,偏枝旋体藻Ａ．ｓｅｃｕｎｄａｔａ,连续旋体藻Ａ．ｓｅｒｉａｔａ。     

高摄食压力下球形棕囊藻凝聚体的形成

棕囊藻包含囊体和游离单细胞两种生活史阶段。囊体是棕囊藻藻华爆发时的优势形态,藻华衰退时囊体能够形成凝聚体,但是棕囊藻游离单细胞的凝聚体极少被发现。本次研究将球形棕囊藻单细胞和高密度的海洋弯曲甲藻共同培养,使球形棕囊藻的生长承受高摄食压力,通过观察摄食者和棕囊藻的生长、凝聚体的数量和形态,阐明单细胞凝聚体的形成以及与摄食压力的关系。当球形棕囊藻进入衰退期时,高摄食压力引发游离单细胞聚合形成凝聚体,无摄食压力情况下,单细胞不形成凝聚体。凝聚体由无鞭毛细胞组成,细胞排列紧密,近似球体。凝聚体形成伊始,凝聚体内部可见凝胶状物质将细胞互相粘结,并且粘附了纤维等物质。凝聚体的体积和粘附的细胞数量逐渐提高,细胞排列愈加紧密,凝聚体内部形态和结构不易分辨。凝聚体的形成有效保护了部分单细胞免受摄食压力的影响,减少了摄食死亡率。凝聚体的形成是球形棕囊藻面临高摄食压力时采取的主动的防御策略。球形棕囊藻能够频繁引发大规模藻华的原因可能在于其在生长的各个阶段中均具有优越的竞争策略。     

Burrow defense behaviors in a sand-bubbler crab, Scopimera globosa, in relation to body size and prior residence

The burrow defense behaviors in a sand-bubbler crab, Scopimera globosa, living on a tidal flat, were experimentally examined. Body size and prior residence influenced the results of struggles for the burrows, and large individuals or the burrow owners won in most cases when the intruders were not significantly larger than the owners. Most large owners defended their burrows by directly fighting their opponents. On the other hand, small owners defended their burrows in three different ways. (1) Owners fought directly against same-sized or smaller intruders. For larger intruders, (2) most owners returned to their burrows when the owner was nearer to the burrow than the intruder (returning behavior), and (3) owners sat motionless when the intruder was nearer to the burrow than the owner (sitting behavior). Success ratios of the three types of burrow defense were 38.2%, 88.5%, and 100%, respectively. It was considered that sitting behavior of the cryptically colored S. globosa has evolved because intruders cannot see motionless owners and consequently cannot detect the owner's burrow. Received: October 6, 2000 / Accepted: January 22, 2001     

金藻基因组DNA的提取与PCR扩增

以金藻门群体和单细胞藻类的典型代表--球形棕囊藻和绿色巴夫藻为研究对象,对金藻基因组DNA的提取方法进行了深入研究,并以psbA基因的PCR扩增结果对4种DNA提取方法进行了检测.结果显示,PVP法和高盐法安全、快速、经济,获得的基因组DNA产量高,但DNA杂质含量也较高.CTAB法虽然也具有安全、快速等优势,但提取的DNA产量较低.玻璃粉法提取的DNA质量好,产量也较高,但操作略为烦琐,经济费用高.结论:就球形棕囊藻而言,玻璃粉法是4种方法中最好的DNA提取方法.就绿色巴夫藻而言,4种方法都行,但是从经济和方便考虑,以高盐法为最好.     

Isolation and characterization of a major antigenic component of Malassezia globosa to IgE antibodies in sera of patients with atopic dermatitis

Three major components of Malassezia globosa were isolated from 2-ME extracts of this fungus by ion-exchange column chromatography and are referred to as Malg46a, Malg46b and Malg67, respectively. IgE antibodies to these components in the sera of patients with AD were detected by immunoblots. In Western blot, IgE antibodies to Malg46b were most frequently detected in the sera of AD patients. Dot blot with the Malg46b-containing fraction immunologically reacted with 69% of the sera of the patients, and with 83% of the sera of the patients who were positive for IgE antibodies to the 2-ME extract of M. globosa in the Western blot. The intensities generated for each dot correlated well with the total intensities generated for the 2-ME extract of M. globosa in the Western blot (r=0.763). In the lectin blot, Con A reacted with both Malg46a and Malg46b but not with Malg67. The polyclonal antibody to Malg46b reacted strongly only with the 2-ME extract of M. globosa and reacted slightly with M. restricta. In conclusion, a glycoprotein, Malg46b of M. globosa, is dominantly expressed in this fungus and is a possible major antigen for IgE antibodies in patients with AD.