附着基粗糙度及表面沉积物对6种海藻孢子附着和幼苗数量的影响

本项研究试验了人工放散的蜈蚣藻(Grateloupia asiatica)与多管藻(Polysi phonia urceolata)孢子及其幼苗在不同粗糙度的附着基上的附着数量、三叉仙菜(Ceramium kondoi)、假根羽藻(Bryopsis corticulans)、酸藻(Desmarestia viridis)和尾孢藻(Urospora penicilli formis)在海水中自然附着幼苗在不同粗糙度的附着基上的附着数量;还试验了不同粗糙度附着基上不同类型的沉积物对自然附着酸藻和尾孢藻的幼苗数量的影响。试验方法是以市售塑料扎带模拟表面粗糙度不同的人工藻礁,使人工刺激后释放的海藻孢子附着在其表面后,吊挂于海中使孢子萌发;空白附着基吊挂于海水中使海藻繁殖体(孢子、合子或受精卵)附着并萌发生长。以普通海泥、高温灭活海泥、底栖硅藻3种不同沉积物覆盖于人工附着基表面,统计各种沉积物在各种粗糙度的附着基上海藻幼苗数量。结果表明,对于无鞭毛的繁殖细胞(蜈蚣藻、多管藻和三叉仙菜的孢子,假根羽藻的合子、酸藻的受精卵)萌发成的幼苗数量受附着基粗糙度影响显著;在一定范围内,两者呈正相关。而萌发自游动孢子的尾孢藻,附着基的粗糙度影响不显著。3种沉积物中,高温灭活的海泥更有利于尾孢藻和酸藻的附着。     

几种化学官能团对舟形藻在玻璃表面附着的影响

利用单分子自组装膜(SAMs)技术制备表面具有甲基、氨基和碳碳双键以及羧基官能团的材料表面,探讨硅藻附着量随时间变化及附着强度的情况。结果表明硅藻附着量是随着时间变化的动态过程。在不同的化学官能团表面的硅藻附着量不同,24小时内每种化学基团表面的附着量会随着时间变化而变化,其中材料表面的亲水性和表面的正电性有利于硅藻的附着。在模拟水环境的脱附实验中,甲基的附着强度最高,羧基最低。舟形藻的附着强度与附着量并没有直接关系。此项研究不仅对探讨硅藻细胞的附着行为具有意义,同时为研究应用海洋生物防污提供有效的途径。     

一种中心硅藻雄配子的超微结构

报道粗刺根管藻精子发生中的精母细胞，双鞭毛体和精子等阶段细胞的超微结构，比较某些细胞器的形态和数量变化，从该藻的双鞭毛和精子的鞭毛中，我们首次在中心硅藻类中发现具有９＋２鞭毛微管构型。     

微生物膜对海洋无脊椎动物幼体附着变态的影响研究

一般来说,一旦把表面洁净的载玻片等附着基浸入海中,在数分钟到数小时内,该附着基的表面将迅速形成微生物膜[1].起初,各种有机物会吸附在附着基的表面,进而引起附着基表面的电荷变化.随后,海洋细菌开始在该基质上附着和繁殖,并分泌胞外多糖类等有机物,在附着基的表面上形成细菌黏膜[1-2].由于细菌分解有机物产生CO2、 NH3,附着硅藻、原生动物以及其他微细藻类开始在基质上附着,最终形成微生物膜[1-3].     

海洋细菌在不同基质表面微生物粘膜中的组成

在青岛近岸海区两个不同地点 ,分别进行浸海挂片实验研究四种不同基质表面 (玻片、钢片以及涂有防污漆、防锈漆的玻片 )微生物粘膜中细菌组成。从不同基质表面微生物粘膜中共分离32 3株附着细菌 ,大多数为杆状或球杆状革兰氏阴性细菌 ,且大部分具有鞭毛。依据形态及生理生化特征将革兰氏阴性细菌鉴定到属 ,分别属于气单胞菌属 ( Aeromonas)、发光杆菌属 ( Photobacteri-um)、莫拉氏菌属 ( Moraxella)、假单胞菌属 ( Pseudomonas)、弧菌属 ( Vibrio)和产碱菌属 ( Alcali-genes)等 12个属 ,其中气单胞菌属是优势菌属。不同基质表面 ,微生物粘膜细菌组成不同     

海洋假交替单胞菌端生和侧生鞭毛对生物膜形成的影响

海洋假交替单胞菌广泛分布于各种海洋环境中,能分泌多种生物活性物质和胞外酶类,多具有较强的生物膜形成能力。这些生物膜具有诱导矿化和吸引腐蚀生物幼体附着的功能,在海洋生态系统的能量和元素循环中扮演特殊角色。细菌的鞭毛系统介导细菌的运动行为,在营养的获取以及生物膜和浮游状态转化过程中发挥作用。有研究表明,鞭毛也是生物膜基质的有机组分,但目前海洋假交替单胞菌鞭毛系统在生物膜形成中的作用尚不清楚。本文以南海表层来源的假交替单胞菌(Pseudoalteromonas sp.SCSIO 11900)和深海沉积物来源的近源假交替单胞菌(Pseudoalteromonas.sp.SM9913)为研究对象,分别选取了编码鞭毛不同组分的基因进行敲除,研究鞭毛缺失对细胞游动性和生物膜形成能力的影响。结果表明,无论来自表层还是深海的假交替单胞菌都使用端生鞭毛维持细胞游动性,而且其缺失促进生物膜的形成。此外,深海来源的SM9913还具有侧生鞭毛。尽管这种鞭毛有助于提高细胞游动性,却不影响细菌的生物膜形成能力。这些端生鞭毛系统在近缘海洋假交替单胞菌中广泛分布,可能为该属菌株在不同海洋环境中获取营养、定殖及适应环境的...     

南极纽卡姆湾藻体附着硅藻的研究

1980年我国初探南极,进行科学考察.采到了几种藻类及腔肠动物类标本,在这些生物体表上,发现着生许多硅藻,这些附着硅藻类的形态结构、个体大小都有差异.尤其卵形藻类、楔形藻类数量最多,种类变化也复杂,我们对样品进行分离、筛选获得了大量珍贵的附着硅藻标本,并对这些标本做细致观察,个别种类还经电子显微镜作超微结构的拍照与分析.     

防污漆表面微型污损性附着生物的研究

防污漆浸入海中以后,早期都有微型污损性附着生物首先附着。主要是细菌和硅藻等微生物。这些微生物和油漆中的成分相互作用,在海水和防污漆之间形成微生物粘膜。这层粘膜构成一种特殊的生态系,对大型生物幼虫的附着和油漆中毒物的渗出都有着密切的关系。     

一些海洋发光细菌超微结构的电镜观察

本文应用电子显微镜技术观察了从东海(北纬26°30'-30°00',东经124°-129°)海水和海底泥中分离到的8株发光细菌和一株衰失发光性能菌株[#7032(-)]的菌体形态、鞭毛和细胞内部超微结构,结果表明#7032、#7032(-)、#1025菌体有一根粗的端生鞭毛、大量的周生鞭毛和微细的丛生鞭毛.#7032和#7032(-)菌外部形态、鞭毛结构相似,在磷钨酸负染色中鞭毛可显示鞘和核心结构,鞘可呈环饼状或成段脱落.     

附着基粗糙度等因素与海藻密度的相关性研究

海藻附着基表面粗糙度与孢子附着密度有密切的相关性;已经由许多研究证实。但是海藻苗的密度是否仍然受到附着基粗糙度的影响;还缺乏明确的结论。本文以尼龙和亚克力两种材料作为海藻附着基;悬挂于自然海区中使海藻孢子附着并萌发生长;用以研究附着基表面粗糙度对4种海藻密度的影响。结果显示;多管藻、尾孢藻、点叶藻、硬毛藻这4种海藻;在不具沟槽的光滑面;密度显著低于任何有沟槽的粗糙面;但粗糙度不同的附着基之间比较;对海藻密度的影响并不显著。室内培育的海带苗;在尼龙上的密度与粗糙度成正相关;但是将海带苗移至海上培育后;不再与粗糙度有相关性;可能与其假根状固着器下海后的发育有关。本文还试验了海泥、灭活海泥和低栖硅藻3种沉积物与附着基粗糙度对海藻密度的影响;结果表明;沉积物和附着基粗糙度;以及它们的交互作用对海藻密度的影响;因附着基的材料和海藻种类而有差别。     

斜带髭鲷内脏白点病病原的分离鉴定及耐药性分析

本研究采用平板分离法对具有典型症状的斜带髭鲷（Hapalogenys nitens）进行病原微生物的分离培养,结合形态学、生理生化特征和分子生物学技术对病原进行种属鉴定,并对分离得到的病原菌进行了药物敏感性试验。病理切片结果显示,病鱼肝脏、脾脏、鳃、头肾、心脏均可观察到明显的白色炎性肉芽肿病灶,从患病鱼脾脏、肝脏和头肾的白色结节处均分离到单一外观的细菌菌落hn-1。通过生理生化特征鉴定、16S rRNA基因测序和回归感染实验证实斜带髭鲷内脏白点病的致病菌为哈维氏弧菌（Vibrio harveyi）。透射电镜观察显示分离菌具有极生鞭毛及侧鞭毛;毒力基因检测显示分离菌携带toxR、luxR、vvh、vhh和trh基因;药敏试验结果显示,分离菌株主要对喹诺酮类、氨基糖苷类、四环素类等药物具有较强的敏感性。研究结果可为斜带髭鲷的内脏白点病的病害防控提供科学依据。     

对虾池悬浮颗粒附着细菌的研究

用5个实验围隔研究了对虾池悬浮颗粒上的附着细菌,结果表明:附着细菌数量波动在0.65×104～23.49×104个/cm3之间,平均为(4.57±3.64)×104个/cm3,占水体细菌总数的1.47%×1.41%(0.28%～8.73%).附着细菌数为1、2、3、4个的附菌颗粒占总附菌颗粒的比数分别为40%、27%、15%及11%,多于4个附着细菌的附菌颗粒数仅占总附菌颗粒数的7%;总悬浮颗粒中的附菌颗粒所占比例为52%;附着细菌数与水体总悬浮颗粒数关系最为密切,与水温及总细菌数也具有显著相关性,但与水层POC及DOC含量却未呈现显著的相关性.     

养殖大菱鲆烂鳍病病原菌的鉴定及系统发育学研究

从山东半岛3个养殖场各分离到一株大菱鲆烂鳍病的病原菌,均为革兰氏阴性,短杆状,极生鞭毛,有运动能力,菌落半透明。经常规生理生化特征测试和16SrRNA基因序列对比,表明它们都是同一种细菌。理化特征的结果显示这3株菌均与V．anguillarum的表性特征非常相似。对其16SrRNA基因序列进行分析,并构建了系统发育树,结果表明这些菌株与V．anguillarum亲缘关系最近。综合上述研究结果,将该菌鉴定为V．anguillarum.     

STUDY OF MARINE MICROFOULING ORGANISMSSOME CHARACTERISTICS OF THE MICROFOULING TO FIVEMATERIAL SURFACES OBSERVED BY THE SCANINGELECTRON MICROSCOPE

In the last few years, scanning electron microscope (SEM) has been widely used to observeand study community structure and succession of the microfouling organisms on various solid surfaces immersed in the sea, polysaccharide components of bacterial slime layer, two-tier microfouling layer structure , metal corrosion products in the attached process and character-istics of attached microorganisms on the coating surfaces. The SEM observations indicated that substrate components exposed to natural seawater are one of the important factors affecting microbial adhesion. The present paper examined the influences of several metal materials, from which ship is usually made on microbial adhesion during the exposure to seawater by the SEM and discussed the material selecting problems from the anti-microfouling point of view.     

北极细菌Pseudoalteromonas sp.A2对H2O2胁迫的转录组分析

海水中的高溶解氧浓度、低温和UV辐射导致了氧胁迫是北极海洋细菌面临的主要胁迫因素之一。本文对北极细菌Pseudoalteromonas sp.A2对H₂O₂导致的氧胁迫的应答特征进行了转录组测序和基因差异表达的比较分析,以期发现与氧胁迫相关的关键功能基因。研究表明,与对照组相比,1 mmol/L的H₂O₂可导致菌株A2转录组的很大变化,包括109个基因的显著上调与174个基因的显著下调。COG分析表明,在功能已知的基因中,与转录后修饰、蛋白质转换和分子伴侣相关的基因大部分显著上调,而与氨基酸运输和代谢等相关基因则大部分显著下调。值得指出的是,有18个与鞭毛相关的基因和4个与热激蛋白相关的基因显著上调;同时,有9个与细胞色素和细胞色素氧化酶相关的基因和5个与TonB依赖受体相关的基因显著下调。在GO分析表明具有抗氧化活性的18个基因中,只有1个基因的表达显著上调,而有2个显著下调。简言之,RNA-Seq表明,除了传统的抗氧化基因和应激蛋白外,鞭毛相关基因和功能未知基因在菌株Pseudoalteromonas sp.A2的氧胁迫适应性中起着重要作用。该转录组分析和氧胁迫相关基因的发现有助于了解北极细菌的氧胁迫适应机制。     

养殖大菱鲆细菌性红体病病原菌的分离与鉴定

从患有红体病的养殖大菱鲆(Scophthalmus maximus)的肌肉中分离得到一株优势菌并记为H1.经人工注射感染证实H1即为引起养殖大菱鲆红体病的病原菌,其半致死量LD50为2.82×105CFU/mL,而低浓度(1.41×103 CFU/mL)没有造成死亡,但注射部位有脓肿现象,注射相同体积1.5%无菌生理盐水的对照组没有明显的症状,注射部位也无异常.革兰氏染色显示该菌为革兰氏阴性,菌体呈杆状,周生鞭毛.综合该菌的形态、常规生理生化特征和API32E鉴定结果,发现H1与迟钝爱德华氏菌的表性特征非常相似,相似率迭到99.9%.在分子水平上对其16SRNA基因序列的测定,同源性分析,结果表明H1与迟钝爱德华氏菌的亲缘关系最近,相似度达到99%.综合上述研究结果,将该菌株初步鉴定为迟钝爱德华氏茵(Edwardsiella tarda).     

The effect of pressure on leucine and thymidine incorporation by free-living bacteria and by bacteria attached to sinking oceanic particles

The effect of pressure on upper ocean free-living bacteria and bacteria attached to rapidly sinking particles was investigated through studying their ability to synthesize DNA and protein by measuring their rate of ³H-thymidine and ³H-leucine incorporation. Studies were carried out on samples from the NE Atlantic under the range of pressures (1–430 atm) encountered by sinking aggregates during their journey to the deep-sea bed. Thymidine and leucine incorporation rates per bacterium attached to sinking particles from 200 m were about six and ten times higher, respectively, than the free-living bacterial assemblage. The ratio of leucine incorporation rate per cell to thymidine incorporation rate per cell was significantly different between the larger attached (18.9:1) and smaller free-living (10.4:1) assemblages. The rates of leucine and thymidine incorporation decreased exponentially with increasing pressure for the free-living and linearly for attached bacteria, while there was no significant influence of pressure on cell numbers. At 100 atm leucine and thymidine incorporation rate per free-living bacterium was reduced to 73 and 20%, respectively, relative to that measured at 1 atm. Pressure of 100 atm reduced leucine and thymidine incorporation per attached bacterium to 94 and 70%, and at 200 atm these rates were reduced to 34 and 51%, respectively, relative to those measured at 1 atm. There was no significant uncoupling of thymidine and leucine incorporation for either the free-living or attached bacterial assemblages with increasing pressure, indicating that the processess of DNA and protein synthesis may be equally affected by increasing pressure. It is therefore unlikely that bacteria, originating from surface waters, attached to rapidly sinking particles play a role in particle remineralization below approximately 1000–2000 m. These results may help to explain the occurrence of relatively fresh aggregates on the deep-sea bed that still contain sufficient organic carbon to fuel the rapid growth of benthic micro-organisms; they also indicate that the effect of pressure on microbial processes may be important in oceanic biogeochemical cycles.     

Dynamics of attached bacteria at the water-sediment interface in a mesotrophic swampy bog of Japan

The population dynamics of attached bacteria at the water-sediment interface were studied in a mesotrophic swampy bog, Matsumi-ike, near Tsukuba, Japan. The density of attached bacteria was higher at the sediment boundary layer than in the water column, and low inside the sediment (deeper, than 10 mm below the sediment surface) throughout the year. The density of bacteria attached on the glass slide was highest during spring when the source of organic matter in the water column was mainly withered cattail, and gradually decreased toward summer, while the phytoplankton became the dominant source of organic matter in the water column. The epibacterial populations in the water column and at the boundary showed almost the same seasonal fluctuation in attachment and detachment rates. However, bacterial growth rates did not show the same seasonal fluctuation, and annual average growth rates on the glass slides were all lower than that of bacterioplankton (free-living bacteria in water) in the water column.     

Soil Strength Improvement by Microbial Cementation

The biologically induced cementation (BioGrout) method has been used in this study to improve engineering properties of soil. Laboratory tests have been carried out to quantify the effect of BioGrout treatment on the strength of two types of sand by using Sporosarcina pasteurii bacteria. Bearing strength and other parameters, such as colony forming units (number of bacteria), pH level, temperature, and amount of CaCO₃, have also been studied. Calcification (cementation) through precipitation of CaCO₃ on the mineral surfaces has been clearly observed from the images of a scanning electron microscope (SEM). Finally, the effect of sand material on the effectiveness of biocementation was investigated via employement of different sand types.