环境条件对水网藻(Hydrodictyon reticulatum)生长的影响

研究了温度、光照强度及Ｎ、Ｐ浓度与水网藻生长的关系．结果表明,水网藻能在较大的温度范围（１０～３１℃）、光照强度（３００～５３００Ｌｘ）和Ｎ浓度（１．０～８４．０ｍｇ·Ｌ－１）和Ｐ浓度（０．０５～３．７２ｍｇ·Ｌ－１）等条件下生长．最适生长温度为２５℃,当光照强度大于１３００Ｌｘ,Ｎ、Ｐ含量分别为１６．８～５０．４和０．７４４～２．２３ｍｇ·Ｌ－１时,水网藻生长良好．低温有利于水网藻忍耐低光照和低Ｎ低Ｐ．     

浒苔Enteromorpha prolifera组织培养初步研究

通过将大型绿藻--浒苔切成一定大小的藻体片段,在实验室条件下用液体和固体平板组织培养的方法,系统地研究了在藻体切段条件下,浒苔组织块中细胞的发育路径和趋势.在培养的过程中发现叶状体中细胞的发育能力和方向都具有明显的极性,且浒苔组织块中细胞的发育速度和规模与组织块大小和其组织块中的位置有关.在切段培养的条件下,浒苔细胞有5种发育途径:1.分化为孢子囊,2.细胞极化下端延伸形成类似于假根的结构,3.分裂成细胞团并在后续的发育过程中成苗,4.细胞进一步极化形成带假根的单细胞苗,5.维持一定状态不再分化.而切段培养条件下,藻段中的不同细胞可能发生不同的发育情况.     

rDNA兰绿藻可能有助于植物遗传工程

康奈尔大学的研究人员已成功地将一个外源基因扦入到一种兰绿藻-Anacystis nidulans,并加以表达,从而可利用该藻作为研究包括光合作用基因表达的模型系统。遗传工程师们试想提高植物光合作用的能效的同时,将高等植物核和叶绿体DNA的功能分开的企图遭到了失败。康奈尔B.Thompson研究所(Ithaca,NY)植物分子遗传实验室主任A.Szalay解释研究关于叶绿体光合作用和膜装配的分子遗传学是极其困难的。     

滑囊腔/关节腔穿刺液直接镜检有助于无绿藻致感染性滑囊炎/关节炎的早期诊断

目的 探讨滑囊腔/关节腔穿刺液直接镜检对于无绿藻致感染性滑囊炎/关节炎的早期诊断价值及临床应用。方法 报道我科2022年3月发现的1例小型无绿藻致感染性指间关节炎病例的检查经过,并回顾1964年1月1日至2022年5月31日之间在PubMed、中国知网及万方数据库上发表的无绿藻致感染性滑囊炎/关节炎病例的主要病原学检查方法。通过比较不同患者主要病原学检查方法的异同点,探讨滑囊腔/关节腔穿刺液直接镜检的早期诊断价值。结果 经删选,最终纳入符合研究目的的文章18篇(21例病例)。病原学检查的主要方法为真菌培养、组织病理,而真菌直接镜检常常被忽略。在22例患者中,只有2例患者同时行真菌直接镜检和真菌培养检查,18例患者行真菌培养检查但未行真菌直接镜检,其余2例患者未行真菌直接镜检及真菌培养检查而依靠病理检查结果进行诊断。结论 滑囊腔/关节腔穿刺液直接镜检有助于无绿藻致感染性滑囊炎/关节炎的早期诊断,但临床缺乏正确应用,值得引起重视并推广。     

下肢小型无绿藻感染1例

患者,男,39岁,8年前体检时发现全血细胞减少,行骨髓、流氏细胞术等检查确诊阵发性夜间血红蛋白尿(paroxysmal nocturnal hemoglobinuria, PNH)后,长期服用“环孢素、泼尼松”治疗,2个月余前左下肢部位皮肤划破后出现破溃伴红肿热痛,取创面组织及分泌物行病理检查与病原学检测,选用哌拉西林/他唑巴坦经验性抗感染治疗。在确诊为小型无绿藻所致左下肢软组织感染,药敏试验提示其对两性霉素B敏感后,更改抗菌药物为两性霉素B静滴：首日1 mg试针,第2～4日10 mg,第5～10日剂量增加至25 mg,每日一次。10天后因肌酐升高,将用量减至15 mg,隔日一次,同时进行创口护理,经对症治疗1个月后复查,患者左下肢皮肤破溃无明显炎性分泌物,创面已基本愈合。     

月绿藻属一新种(团藻目)——饶氏月绿藻

根据饶钦止教授生前手稿记录及图认定饶氏记载的是月绿藻属1新种,命名为饶氏月绿藻(Selenochlorisjaoii):细胞侧扁,正面观卵形,后端裂成两瓣,钝圆,无乳头状突起;侧面观卵形,后端钝圆;2条等长的鞭毛从细胞顶端伸出,长度为细胞长的1.5倍;色素体杯状,无蛋白核,具1个大的细胞核。细胞长10.5~12μm,宽8.75μm,厚6μm。本种与S.reniform is(P layfair)Ettl近似,但后者细胞正面观为肾形,与前者明显不同。     

封面说明

二角盘星藻Pediastrum duplex属于绿藻门、绿藻纲、盘星藻科、盘星藻属。该属大约有30余种。为淡水池塘、湖泊等各种水体中常见的浮游藻类。二角盘星藻是由4、8、16、32、64、128个细胞组成的扁平盘状或星状定形群体,所有的细胞均排列为一层。细胞间有穿孔,群体缘边的细胞具2个突起,群体里面的细胞多少近四方形,细胞壁平滑。     

Characterization of the Main Light-Harvesting Chlorophyll a／b-Protein Complex of Green Alga, Bryopsis corticulans

The main light-harvesting chlorophyll a/b -protein complex (LHC Ⅱ) has been isolated directly from thylakoid membranes of shiphonous 8Teen alga, Bryopsis corticulans Setch. by using two consecutive runs of anion exchange and gel-filtration chromatography. Monomeric and trimeric subcomplexes of LHC Ⅱ were obtained by using sucrose gradient ultracentrifugation. Pigment analysis by reversed-phase high performance liquid chromatography showed that chlorophyll a (Chl a), chlorophyll b (Chl b), neoxanthin, violaxanthin and siphonaxanthin were involved in LHC Ⅱ from B. corticulans. The properties of electronictransition of monomeric LHC Ⅱ showed similarities to those of trimeric LHC Ⅱ. Circular dichroism spectroscopy showed that strong intramolecular interaction of excitonic dipoles between Chl a and between Chl b exist in one LHC Ⅱ apoprotein, while the intermolecular interaction of these dipoles can be intensified in the trimeric structure. The monomer has high efficient energy transfer from Chl b and siphonaxanthin to Chl a similarly to that of the trimer. Our results suggest that in B. corticulans, LHC Ⅱ monomer has high ordered pigment organization that play effective physiological function as the trimer, and thus it might be also a functional organization existing in thylakoid membrane of B.corticulans.     

Dissecting the Heat Stress Response in Chlamydomonas by Pharmaceutical and RNAi Approaches Reveals Conserved and Novel Aspects

To study how conserved fundamental concepts of the heat stress response （HSR） are in photosynthetic eukaryotes, we applied pharmaceutical and antisense/amiRNA approaches to the unicellular green alga Chlamydomonas reinhardtii. The Chlamydomonas HSR appears to be triggered by the accumulation of unfolded proteins, as it was induced at ambient temperatures by feeding cells with the arginine analog canavanine. The protein kinase inhibitor staurosporine strongly retarded the HSR, demonstrating the importance of phosphorylation during activation of the HSR also in Chlamydomonas. While the removal of extracellular calcium by the application of EGTA and BAPTA inhibited the HSR in moss and higher plants, only the addition of BAPTA, but not of EGTA, retarded the HSR and impaired thermotoler- ance in Chlamydomonas. The addition of cycloheximide, an inhibitor of cytosolic protein synthesis, abolished the attenu- ation of the HSR, indicating that protein synthesis is necessary to restore proteostasis. HSP90 inhibitors induced a stress response when added at ambient conditions and retarded attenuation of the HSR at elevated temperatures. In addition, we detected a direct physical interaction between cytosolic HSP90A/HSP70A and heat shock factor 1, but surprisingly this interaction persisted after the onset of stress. Finally, the expression of antisense constructs targeting chloroplast HSP70B resulted in a delay of the cell＇s entire HSR, thus suggesting the existence of a retrograde stress signaling cascade that is desensitized in HSP7OB-antisense strains.     

失水-吸水过程中集球藻的生理生化特性研究

荒漠结皮藻类广泛分布于干旱、半干旱地区,经常面临生存水源的短缺。以一种从荒漠结皮中分离的典型绿藻-集球藻(Palmellococcus sp.)为材料,研究其在失水-吸水过程中的某些生理生化特性。即在温室模拟条件下设置相对湿度分别为0%(极度失水)、43%(适度失水)和98%(水合,对照),测定不同失水处理对集球藻光合活性、膜脂过氧化产物丙二醛含量、细胞内可溶性物质含量和抗氧化酶活性的影响,并测定蒸馏水、BBM培养基、0.2 g/L蔗糖溶液、0.2 g/L蓝藻多糖、0.2 g/L脯氨酸和2.5 mmol/L氯霉素及50μmol/L敌草隆进行吸水处理时对失水藻体光合活性的恢复效果。结果表明,与对照处理相比,集球藻在失水过程中光合活性迅速降低,SOD和CAT活性大量升高,细胞内可溶性糖含量和可溶性蛋白含量明显增加,并且膜脂丙二醛含量出现大量积累。不同的失水-吸水处理发现,外源蔗糖和胞外多糖吸水对集球藻的光合活性有较好的恢复作用,添加脯氨酸和氯霉素吸水时光合活性也获得了一定程度的恢复,采用敌草隆吸水时则出现光合活性的明显抑制。研究结果对于更好地理解荒漠结皮绿藻对干旱的生理适应机制提供了有意义的参考。