褐藻中高相对分子质量褐藻多酚的抗氧化活性研究

目的　评价鼠尾藻和海黍子两种褐藻中高相对分子质量褐藻多酚的抗氧化活性。方法　分别利用 3种体系 ,通过对羟自由基 (· OH)、超氧阴离子 ( O÷2 )和 1,1-二苯基 - 2 -苦味肼基自由基 ( DPPH· )清除效率来评价其抗氧化活性。结果　两种褐藻中高相对分子质量褐藻多酚对· OH、O÷2 和 DPPH·均有很高的清除效率 ,且效果相近。结论　鼠尾藻和海黍子两种褐藻中高相对分子质量褐藻多酚具有较强的抗氧化活性 ,是一类潜在的海洋生物天然抗氧化剂。     

Evidence for multiple xenogenous origins of plastids: comparison of psbA-genes with a xanthophyte sequence

Summary When only plastidic features are considered, it is difficult to distinguish between monophyletic and polyphyletic xenogenous origins of plastids. We suggest that a direct comparison of nuclear and plastidic sequence-similarity pattern will help to solve this problem. The D1 amino acid sequence of six major groups of photosynthetic eukaryotes and of the two groups of photosynthetic prokaryotes are now available, including the psbA-gene product from Bumilleriopsis filiformis, which is the first molecular sequence reported for a xanthophycean alga. Evidence is provided for an independent and polyphyletic origin of plastids from five out of the six major taxa of photosynthetic eukaryotes. This conclusion is reached by comparing a plastid-based pattern of D1 similarity with a nucleus-based similarity pattern published recently. Furthermore, the availability of D1 sequences from five eukaryotic algae led to a re-evaluation of the taxonomic position of Prochlorothrix.     

天然矿泉水淡水藻类污染检验方法研究

采用天然矿泉水淡水藻类的检验方法，在采自福建省各地区的２０２份样品中检出４２份阳性，共１５属藻类。这些藻在自然界淡水中常见。该方法独特之处是将浓缩培养基直接加入水样瓶中。然后，在培养过程中保持散射光照低于５０００Ｌｘ。瓶中样品的静置，有助于藻类从水处理造成的损伤中恢复。５～１０天后，绿色或蓝绿色的藻细胞将形成明显的斑点或沉淀。经镜检分类，检出了绿藻、蓝藻等１５个属。比较了５种培养基，以改良克诺普液使用效果最好。此培养基容易配制和应用，藻类生长快，观察方便。     

The psbA-gene from a red alga resembles those from Cyanobacteria and Cyanelles

Summary Plastid DNA (ptDNA) from the unicellular red alga Cyanidium caldarium was isolated. A 5.8 kb Eco RI, fragment containing the entire psbA-gene was cloned and the nucleotide sequence of the psbA-gene determined. At the carboxyl terminus the encoded protein (D1) contains the seven amino acid-insertion which was found to be typical of the cyanobacteria and the cyanelles of Cyanophora paradoxa. However, the overall sequence homology does not support a direct relationship between the plastids of Cyanidium, cyanelles and the cyanobacteria. As in other photosynthetic organisms the psbA-gene is transcribed as a monocistronic mRNA. The ribosomal RNA operon was located 4 kb upstream of the psbA-gene.     

Viruses Infecting Marine Brown Algae

Viruses infecting algal hosts possess large double-stranded DNA as genomes. We have recently identified a family of viruses specific for filamentous brown algae. In contrast to the better known Chlorella viruses with their lytic infection cycle, marine brown algal viruses latently occur in their host cells and are induced to multiply in response to a variety of external stimuli such as change in light and temperature. Here, I summarize the known properties of this family of viruses and discuss their taxonomic classification.     

Genomic and Pathologic Findings for Prototheca cutis Infection in Cat

Severe nasal Prototheca cutis infection was diagnosed postmortem for an immunocompetent cat with respiratory signs. Pathologic examination and whole-genome sequencing identified this species of algae, and susceptibility testing determined antimicrobial resistance patterns. P. cutis infection should be a differential diagnosis for soft tissue infections of mammals.     

黄河水源水浮游藻类及藻类毒素污染状况动态研究

目的 :探讨黄河水源水浮游藻类和藻毒素污染状况及影响因素。方法 :于 1998年 5～ 12月在河南省S市、Z市、P市水源水设采样点 ,对水源水浮游藻类、藻类毒素污染情况及总氮、总磷、COD等指标进行了连续检测。结果 :河南省黄河水源水总氮检出范围为 2 5 7～ 6 .79mg/L ,总磷的检出范围为 0 0 1～ 0 .32mg/L ,蓝藻和绿藻为浮游藻类的优势种群。MC的阳性率 ( >2 0ng/L)为 82 6 1% ,最高达到 95 7 9ng/L。结论 :按照Carlson提出的富营养化指数TSI(TP)判定标准 ,结合TN、TP、COD及藻类密度等指标 ,认为河南省境内黄河水源水已呈现富营养化特征。磷是黄河水源水浮游藻类生长的主要限制因子 ,控制黄河水源水富营养化应以控制磷为主。     

Evaluating the hazard of dodecyl alkyl sulphate to natural ecosystems using indigenous protistan communities

The effect of the surfactant dodecyl alkyl sulphate (C12AS) on the structure and function of lotic protistan assemblages was examined using the Experimental Stream Facility (ESF) operated by the Procter and Gamble Company. Population- and community-level responses to C12AS were monitored on introduced substrates placed in the channels 28 days prior to dosing (mature communities) as well as those placed in the channels on day 0 of dosing (immature communities), to allow for a broad assessment of the effect of the chemical on processes contributing both to community development and maintenance. C12AS appeared to elicit a subsidy response from the native protistan assemblage which may have resulted from both positive and negative responses at trophic levels above and below the assemblage. Protistan responses to the surfactant tended to occur more rapidly and be more sensitive than those documented for invertebrates and fish. C12AS elicited a modest response (i.e. a 20% change) from several reliable parameters including community respiration (reduced dissolved oxygen at 289 g per L), protozoan species richness (increased at 63 g per L) and protozoan community composition (increased dissimilarity at 1254 g per L). Responses to C12AS exceeded expected exposures in the real world by a factor of six or greater thereby indicating that the hazard of exposure to C12AS to stream communities is low. The results of this study support the use of mesocosms as decisive tools for evaluating the hazard posed by consumer product chemicals to natural communities and ecosystems     

泰兴地区肝癌高发因素研究

探讨了泰兴地区人群肝癌的高发因素。采用ELISA法分别检测人群体内HBV感染水平和AFT—SHA含量及生活饮用水水体内MC含量。结果发现该地区人群HBsAg携带率为29．5％,HBV感染阳性率68.1％,肝癌高发乡镇人群HBsAg携带率和HBV感染阳性率分别高达45．8％和94．7％;人群体内AFT—HSA检出率达100％,平均含量为16．39pg／ng;高发乡镇人群体内AFT—HSA平均含量31．99pgM;生活饮用水水体内MC阳性检出率13．2％,河水、沟塘水和浅井水内MC的平均含量分别为36ng／L,29ng／L和25ng／L．结论：人群中的HBV高感染;黄曲霉素强暴露;生活饮用水水体内MC的普遍污染是泰兴地区肝癌高发的三个重要因素．     

褐藻铁钉菜化学成分的研究(Ⅱ)

采用稻瘟霉模型生物活性追踪方法，应用多种层析手段，从采自浙江南麂岛的褐藻铁钉菜(Ishigeokamurai)中分离得到6个化合物，应用多种波谱技术，分别确定为：3β，28ξ-二羟基-24-乙基-5，23Z-胆甾二烯(J)，13^2S-羟基脱铁叶绿素a(Ⅱ)。脱镁叶绿素a(Ⅲ)，1-O-二十六烷酰基甘油酯(Ⅳ)，1-O-十六烷酰基甘油酯(V)和l-O-(8Z-十四碳烯酰基)甘油酯(Ⅵ)。6个化合物均为首次从该种海藻中得到，Ⅰ和Ⅵ分别为新化舍物和新天然产物，Ⅰ～Ⅲ具有诱导稻瘟霉菌丝变形活性和肿瘤细胞毒性。