三种鲀的毒性及其与种的相关性研究

用小鼠生物检测法及薄层等电聚焦电泳法测定3种河鲀的毒性及其蛋白质组分的种属差异性．结果表明，河鲀的毒性强弱与其种属有密切关系，不同种河鲀的毒性差异很大；同种河鲀的不同个体以及同一个体的不同器官组织也有较大差异．这些结果可为河鲀资源的开发利用提供实验依据。     

副溶血性弧菌产耐热直接溶血毒素对黑色素瘤的抑制作用研究

为探讨耐热直接溶血毒素(Thermostabile direct hemolysin,TDH)在体内和体外对小鼠黑色素瘤细胞B16的抑制作用,本研究通过MTT法、克隆形成试验、凋亡试验、Caspase-8和Caspase-3的活性试验、线粒体膜电位的检测以及体内C57BL/6小鼠(Mus musculus)荷瘤实验,比较TDH作用于不同细胞的半抑制浓度(IC₅₀),评价TDH对小鼠黑色素瘤细胞B16的体内外抑制作用。结果发现:人结肠上皮细胞NCM460、人正常肝细胞LO2、人肝癌细胞SMMC-7721和小鼠黑色素瘤细胞B16在TDH处理24 h之后,细胞的半抑制质量浓度IC₅₀分别为151、118、54和48 μg/mL,正常细胞的IC₅₀高出癌细胞近2~3倍。当质量浓度低于20 μg/mL时,TDH以剂量依赖性的方式抑制B16细胞的克隆形成,6 mg/kg TDH在移植瘤模型中显著抑制体内肿瘤的生长(P<0.001)。流式细胞术和荧光试剂盒检测表明:20 μg/mL的TDH能诱导19.4%的B16细胞发生早期凋亡,并激活Caspase-8和Caspase-3,但不影响线粒体膜电位。TDH具有体内外的抗肿瘤活性,可能通过细胞表面的死亡受体介导的凋亡信号通路引起凋亡,从而发挥抗肿瘤作用。     

钦州湾海水和香港牡蛎体内脂溶性贝类毒素污染特征

近年中国沿海普遍受到脂溶性贝类毒素(lipophilic shellfish toxins,LSTs)的污染。钦州湾是国内外闻名的牡蛎养殖基地,目前仍不了解该海域海水和主要养殖品种香港牡蛎(Crassostrea hongkongensis)沾染LSTs毒素情况与食用安全性。本文于2015年10月至2016年9月,在钦州湾香港牡蛎养殖区海水交换口处,通过固相吸附毒素跟踪技术(solid phase adsorption toxin tracking,SPATT)吸附收集海水中的脂溶性贝类毒素,同时每月采集香港牡蛎样品,应用液相色谱串联质谱法分析海水和香港牡蛎体内的LSTs毒素含量与组成,并对香港牡蛎食用安全性进行评估。结果表明:(1)海水共检出GYM、OA和PTX2三种组分,平均浓度分别为0.44、14.20和1.67μg/(kg resin·30d)。香港牡蛎共检出DTX2、GYM、SPX1、Homo-YTX四种组分,其中Homo-YTX为定性结果, DTX2、GYM、SPX1三者平均浓度分别为0.95、18.86和0.95μg/kg。(2) GYM毒素均值在海水中和香港牡蛎体内含量变化趋势呈正相关,Pearson相关系数为0.70;OAs毒素在海水中和香港牡蛎体内变化趋势类似, Pearson相关系数为0.35。(3)毒素存在一定季节变化。海水OA和PTX2夏季高,其他季节低,均值最高值分别发生在7月和6月;香港牡蛎体内GYM冬季和夏季较高,DTX2春季和夏季较高;但海水中的GYM和香港牡蛎体内的SPX1全年变化均不明显。总体而言,钦州湾海水和香港牡蛎已受到多个LSTs毒素组分污染,海水LSTs毒素含量较国内其他海域低,参考欧盟LSTs毒素标准,本海域的香港牡蛎脂溶性贝类毒素仍未超标,可放心食用。     

Intraspecific diversity of Aureobasidium pullulans strains from different marine environments

Totally more than 500 yeast strains were isolated from seawater, sea sediments, mud of sea salterns, marine fish guts and marine algae. The results of routine and molecular biology identification methods show that nine strains among these marine yeasts belong to Aureobasidium pullulans, although the morphologies of their colonies are very different. The marine yeasts isolated from different marine environments indicate that A. pullulans is widely distributed in different environmental conditions. These Aureobasidium pullulans strains include A. pullulans 4#2, A. pullulans N13d, A. pullulans HN3-11, A. pullulans HN2-3, A. pullulans JHSc, A. pullulans HN4.7, A. pullulans HN5.3, A. pullulans HN6.2 and A. pullulans W13a. A. pullulans 4#2 could produce cellulase and single cell protein. A. pullulans N13d could produce protease, lipase, amylase and cellulase. Both A. pullulans HN3-11 and A. pullulans HN2-3 were able to produce protease, lipase and cellulase. A. pullulans JHSc could secrete cellulase and killer toxin. Both A. pullulans HN4.7 and A. pullulans HN5.3 could yield lipase and cellulase. A. pullulans W13a was able to secrete extracellular amylase and cellulase while A. pullulans HN4.7 and A. pullulans N13d could produce siderophores. This means that different A. pullulans strains from different marine environments have different physiological characteristics, which may be applied in many different biotechnological industries.     

Occurrence and diversity of <Emphasis Type="Italic">Pichia</Emphasis> spp. in marine environments

A total of 328 yeast strains from seawater, sediments, mud of salterns, the guts of marine fish and marine algae were obtained. The results of routine identification and molecular methods show that five yeast strains obtained in this study belonged to Pichia spp., including Pichia guilliermondii 1uv-small, Pichia ohmeri YF04d, Pichia fermentans YF12b, Pichia burtonii YF11A and Pichia anomala YF07b. Further studies revealed that Pichia anomala YF07b could produce killer toxin against pathogenic yeasts in crabs while Pichia guilliermondii 1uv-small could produce high activity of extracellular inulinase. It is advisable to test if Pichia ohmeri YF04d obtained in this study is related to central-venous-catheter-associated infection.     

自然环境下虾夷扇贝(Patinopecten yessoensis)体内麻痹性贝毒的净化研究

为探究在自然环境中虾夷扇贝Patinopecten yessoensis体内麻痹性贝毒(PSTs)的净化过程,从黄海北部大窑湾海域采集了受PSTs污染的虾夷扇贝,将其转移至黄海的棋盘磨水域,该水域未曾有PSTs污染的报道。本研究采用高效液相色谱-荧光检测法(HPLC-FLD)检测30天净化过程中虾夷扇贝体内PSTs的组分和水平。研究结果发现,在第9天,虾夷扇贝软体中的PSTs的含量下降到一个相对较低的水平。而且,初期扇贝体内PSTs的净化率高于后期。扇贝各组织器官中PSTs含量分析发现,消化腺中的PSTs含量最高,这对于人类健康和扇贝养殖具有重要的意义。在本研究中还发现,虾夷扇贝的死亡率与PSTs的水平有一定的关系。     

粘土矿物对尖刺拟菱形藻多列型生长和藻毒素产生的影响

于１９９４年１－７月在加拿大贝德福（Ｂｅｄｆｏｒｄ）海洋研究所进行粘土矿物（ｈａｌｌｏｙｓｉｔｅ）对尖刺拟菱形藻（Ｐｓｕｅｄｏｎｉｔｚｓｃｈｉａｐｕｎｇｅｎｓｆ．ｍｕｌｔｉｓｅｒｉｅｓ）生长和藻毒素软骨藻酸（ＤｏｍｏｉｃＡｃｉｄ,下简称ＤＡ）生成的影响研究,在Ｇｏｍｐｅｒｔｚ菌类生长方程的基础上,建立了尖刺拟菱形藻生长速率模型,得到各实验条件下的藻细胞最大生长速率,结果表明,粘土矿物对藻细胞的“遮     

紫外/氯工艺对水中微囊藻毒素的去除

水体富营养化导致藻类的爆发进而引起藻毒素的释放。微囊藻毒素(MCLR)是最为常见的藻毒素,具有很强的毒性,对人类健康具有潜在危害。本文采用紫外/氯组合工艺,研究其对水中微囊藻毒素的控制效果。结果表明：紫外/氯共同作用下能够产生·Cl、·OH等活性自由基,具有协同降解MCLR的作用,30 min即可实现MCLR的完全去除,其降解效率随着氯投加质量浓度的增加而升高。在酸性及中性条件下,pH的变化对紫外/氯降解MCLR没有影响;在碱性条件下,MCLR的降解效率随pH的升高显著降低,pH升高至9时,30 min MCLR的降解效率仅为41.3%。此外,不同的水样来源和水质特点对紫外/氯联合降解MCLR的效率具有显著影响,纯水、西湖水及水厂滤后水的30 min去除率分别为99.5%,40.2%及63.3%。MCLR 的降解效率随腐殖酸质量浓度增大而降低,在60 min作用时间内,不含腐殖酸水样的MCLR去除率高达99.5%,当腐殖酸质量浓度增加到10 mg/L时,MCLR去除率仅为45.3%。     

Occurrence and diversity of marine yeasts in Antarctica environments

A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,Debaryomyces hansenii,Rhodotorula slooffiae,Rhodotorula mucilaginosa,Sporidiobolus salmonicolor,Aureobasidium pullulans,Mrakia frigida and Guehomyces pullu-lans,respectively.The Antarctica yeasts have wide potential applications in biotechnology,for some of them can produce b-galactosidase and killer toxins.