In situ Bicarbonate Uptake by Bacteria-Alvinella Associations

Abstract. Three species of Alvinellidae are found on walls of some hydrothermal chimneys at 13^o N on the East Pacific Rise (EPR); numerous epibiotic bacteria were associated with two of these polychaetes, Alvinella pompejana and Alvinella caudata , but not with the third, Paralvinella grasslei. Many studies suggest that chemoautotrophic bacteria play a prominent role in deep-sea hydrothermal vent ecosystems. Particularly important are the intracellular bacteria present in the giant pogonophores and bivalve molluscs.
The abundant epibioses observed on these Alvinella species are unusual and the relationships between these bacteria and the worms are unknown. Previous results, including ¹³C values, morphological insertion of the bacteria on the epidermis, presence of ribulose biphosphate carboxylase, and fixation of ¹⁴C bicarbonate in some bacteria and in the dorsal epidermis, suggest that a trophic relationship could exist between Alvinella and its epibiotic bacteria. The present study compared the incorporation area of ¹⁴C bicarbonate in the 3 species. Paralvinella , which is devoid of epibiotic bacteria, served as a control.     

Community diversity of bacteria in digestive tract of mud snail (Bullacta exarata Philippi) and its rearing shoal

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牡蛎体内及其养殖水体中细菌耐药性研究

为进一步了解牡蛎体内外细菌的耐药性，对分离自阳江的香港牡蛎（Crassostrea hongkongensis）养殖水体及其内脏团的637个异养细菌进行了10种抗生素的药敏试验。采用纸片扩散法（Kirby-Bauer，简称K-B），参照NCCLS抗生素敏感试验操作标准，研究细菌的耐药概况。结果显示：健康牡蛎体内细菌对恩诺沙星和庆大霉素耐药率较低，发病牡蛎体内细菌对庆大霉素耐药率最低，次之为复合磺胺和恩诺沙星；水体细菌对氯霉素、恩诺沙星、环丙沙星耐药率较低，水体及体内细菌对呋喃唑酮耐药率最高，而对卡那霉素及青霉素耐药率则波动较大。结果还显示，不同来源的受试菌株多重耐药状况严重，来源于健康和病牡蛎的菌株在7月份的多重耐药率达到峰值，分别为66.7%和64.3%，养殖水体细菌多重耐药率峰值出现在4月份，最高达76.7%。总体来看，源于牡蛎养殖环境水体及其牡蛎体内的异养菌多重耐药比例较高，值得引起注意。而受试菌株对不同药物的抗性存在较大差异，且异养细菌对呋喃唑酮的耐药率明显高于对其它受测抗生素的耐药率。从时间动态上看，水体菌耐药率峰值出现于4月份，而牡蛎体内菌群耐药率峰值出现于7月份。     

锯缘青蟹细菌性传染病的病原菌研究

从宁波市青蟹主要养殖海区5－9月间不同症状的病蟹体分离到6株细菌，S9901，S9902，S9903，S9904，S9905和S9906，经感染试验确定S9902、S9903、S9905和S9906均为病原菌；此4株菌革兰氏染色呈阴性，具1根极生鞭毛，氧化酶反应阳性，发酵葡萄糖，不产气，不发酵肌醇，对0／129试剂敏感，为弧菌属种类；经赖氨酸、精氨酸、乌氨酸脱羧酶、蔗糖、甘露醇发酵、6％氯化钠胨水生长、水杨素、枸橼酸盐利用等试验，根据第二代GYZ－9V系统，分别将其归为辛辛那提弧菌、溶藻弧菌和副溶血弧菌。4株菌对氯霉素、环丙沙星和硫酸庆大霉素等抗菌素表现出强敏感性，对诺氟沙星、磺胺甲异恶唑等中度敏感，而对头咆唑啉钠、呋喃唑酮不敏感；中草药五倍子和五味子煎出液对4株菌均 表现出较强的抑菌性能。     

弧菌拮抗菌的筛选

用平板划线或点种法对 6 0 2株海洋细菌进行筛选 ,得到 4株对海水养殖动物 (鱼、虾、贝 )的病原菌有拮抗作用的细菌。并对拮抗菌 QJ2的拮抗作用进行了研究 ,结果为 :QJ2有广泛的弧菌抗菌谱 ,对 37株弧菌的抗菌阳性率达到 89.2 % (33/ 37) ;用活菌平板计数法和 O.D.60 0 nm研究了QJ2培养物的去细胞上清液 (CFS)与病原菌 W- 1的作用动力学 ,15min时 W- 1的细菌数便开始减少 ,4 h时细菌数最少 ,6 h后开始增加 ,而对照组的细菌数呈逐渐上升趋势 ;QJ2对自身的拮抗物质不敏感 ;QJ2抗性物质的分子量不大于 80 0 0 Da;经常规生理生化方法和 API- 2 0细菌快速鉴定系统鉴定 ,QJ2为气味黄杆菌 (Flavobacterium odoratum)。     

海洋光合细菌的分离鉴定及其生长条件的研究

用红色硫细菌培养基从青岛沿海潮间带海泥中分离出8株光合细菌,经鉴定菌株HD_1属最小着色菌(Chromatium minutissimum),HD_2、HD_4为细着色菌(Chromatium gracile);菌株SL_1、SL_1x、PL_1和PL_2为嗜酸红假单胞菌(Rhodopseudomonas acidophila),菌株HCx为沼泽红假单胞菌(Rhodopseudomonaspalustris)。分离菌株均具运动性,不需生长因子。菌株HD_1、HD_2和HD_4在厌氧光照条件下利用硫化物,且在细胞内贮存硫粒。菌株HD_1、HD_2的最适盐度为4.0％,最适pH为7.0,8.0。当培养基中硫化物含量为0.01—0.04％时,菌株HD_1、HD_4生长良好。菌株PL_2在初始pH为6时生长最好。酵母膏对菌株HCx具有明显的促生长作用。     

海洋光合细菌对五种活性染料的脱色研究

实验研究了不同条件下海洋光合细菌的混合菌种对五种活性染料的脱色效果。结果表明,海洋光合细菌耐盐性较好,对五种染料都有很好的脱色效果。温度对各类染料影响不同,但五种染料都在30~35℃时达到最佳脱色效果。菌种适应的PH值范围广,驯化后活性增强。在100mg/L的浓度下,染料X-3B对细菌生长没有明显的抑制作用。     

Ecotoxicological evaluation of sewage sludge using bioluminescent marine bacteria and rotifer

Bioassay using the marine bacteria,Vibrio fischeri and rotifer,Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox® bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox® results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.     

海水观赏水族缸中不同挂膜法对氮转化的影响

为了构建生态平衡的海水水族缸闭合循环系统，笔者设置了4种海水水族缸挂膜实验缸，缸内分别加入虾肉（腐尸法）、虾肉和硝化细菌（综合法）、硝化细菌（生物制剂法）、自然海水（对照空白缸），定期测定缸内三态氮的含量，通过三态氮含量的变化来判断缸内生物膜的成熟程度．腐尸法和综合法在15d后就能达到氨氮含量稳定，但硝酸盐含量较高；硝化细菌法氨氮含量达到稳定需要28d，而空白对照缸氨氮达到稳定需要35d．在生物膜挂膜后，加入观赏鱼进行实验，发现硝化细菌法和自然海水法所构建的水族缸氨氮含量变化较小，而腐尸法处理的水族缸易引起藻类大量出现．     

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