半知菌JYX-201菌株对海洋污染重金属反应的研究

从胶州湾污染区域的沉积物样品中筛选获得1株对重金属元素反应敏感的菌株,经鉴定为灰黄青霉(Penicillium griseofulvum),对该菌株在重金属胁迫下的生物学特征及酶的活性变化进行了研究,结果表明,一定量的重金属铜、锌离子对菌株产生显著的影响,并通过形态与色素变化的方式表现出来。当培养基中 Cu2+浓度为125 mg/dm3,Zn2+浓度为800 mg/dm3时,孢子萌发会完全受到抑制,同时菌丝也发生严重变异。菌株色素随着 Cu2+浓度的增加呈现从灰绿色到浅黄色的颜色变化,随着Zn2+浓度的增加呈现从灰绿色到白色的颜色变化。在菌株生长的离子浓度范围内,一定量的 Cu2+浓度能提高 CAT,GOD 酶的活性作用,在Cu2+浓度为25 mg/dm3时活性作用最强;在25～75 mg/dm3时,随着 Cu2+浓度的增加,活性作用逐渐减弱,浓度增加至100 mg/dm3时菌丝不能生长。Cu2+对菌体金属硫蛋白的影响不规则。在 Zn2+浓度为100～400 mg/dm3的培养基中,CAT,GOD酶和金属硫蛋白的活性作用随着Zn2+浓度的增加逐渐增强,在Zn2+浓度为400 mg/dm3时酶和金属硫蛋白活性达到最强。Zn2+浓度增加至600 mg/dm3 时,菌株不能生长。     

半知菌JYX-201菌株(Penicillium griseofulvum)对海洋污染重金属反应的研究

从胶州湾污染区域的沉积物样品中筛选获得1株对重金属元素反应敏感的菌株,经鉴定为灰黄青霉(Penicillium griseofulvum),对该菌株在重金属胁迫下的生物学特征及酶的活性变化进行了研究,结果表明,一定量的重金属铜、锌离子对菌株产生显著的影响,并通过形态与色素变化的方式表现出来。当培养基中Cu2+浓度为125 mg/dm3,Zn2+浓度为800 mg/dm3时,孢子萌发会完全受到抑制,同时菌丝也发生严重变异。菌株色素随着Cu2+浓度的增加呈现从灰绿色到浅黄色的颜色变化,随着Zn2+浓度的增加呈现从灰绿色到白色的颜色变化。在菌株生长的离子浓度范围内,一定量的Cu2+浓度能提高CAT,GOD酶的活性作用,在Cu2+浓度为25 mg/dm3时活性作用最强;在25～75 mg/dm3时,随着Cu2+浓度的增加,活性作用逐渐减弱,浓度增加至100 mg/dm3时菌丝不能生长。Cu2+对菌体金属硫蛋白的影响不规则。在Zn2+浓度为100～400 mg/dm3的培养基中,CAT,GOD酶和金属硫蛋白的活性作用随着Zn2+浓度的增加逐渐增强,在Zn2+浓度为400 mg/dm3时酶和金属硫蛋白活性达到最强。Zn2+浓度增加至600 mg/dm3时,菌株不能生长。     

单一与混合重金属在泥蚶体内的累积特征

通过室内半静态暴毒实验, 在铜、铅、镉三种重金属的单一胁迫与两两联合胁迫条件下, 研究了繁殖期泥蚶(Tegillarca granosa)对重金属的富集规律。结果表明: 泥蚶对单一Cu²⁺、Pb²⁺、Cd²⁺的生物富集系数(BCF)分别为210.16～1 178.66、128.15～603.84 和198.84～659.37; 联合重金属胁迫条件下, Cd²⁺对Cu²⁺的富集具有一定的拮抗作用; Cd²⁺和Cu²⁺在泥蚶体内以可溶形式存在, 而Pb²⁺以不溶形式存在;Cu²⁺和Cd²⁺对泥蚶富集Pb²⁺有一定的协同效应; 砂滤海水中的暂养的泥蚶, 其体内的重金属含量除Cu²⁺外都较为稳定。     

热稳定κ-卡拉胶酶产生菌Bacillus sp. Car19的发酵条件优化

对一株分泌热稳定κ-卡拉胶酶印尼热泉菌进行了种属鉴定, 并采用响应面法对该菌发酵产酶条件进行了优化。鉴定结果表明, 该菌株属于芽孢杆菌属(Bacillus), 命名为Bacillus sp. Car19(GeneBank: KT865196)。发酵条件优化结果显示, 9个环境因子影响Bacillus sp. Car19产酶量。其中影响Bacillus sp. Car19产酶量的三个主要因素分别为培养温度、培养基中Cu²⁺浓度和培养基中NaCl浓度。综合次要因素对Bacillus sp. Car19产酶影响, Bacillus sp. Car19最佳产酶发酵条件为: 培养温度52.31℃、Cu²⁺浓度6.93 mmol/L、NaCl浓度37.03 g/L, 培养基pH为6, 接种量1%, 培养时间36h, 半乳糖浓度0.3 g/L,硝酸铵浓度7g/L, 卡拉胶浓度0.5g/L。优化后发酵上清液酶活力达到15.21 U/mL, 与优化前相比提高了1.5 倍。     

可口革囊星虫(Phascolosoma esculenta)重组铁蛋白富集Pb2+等重金属特性和功能研究

利用可口革囊星虫重组铁蛋白富集Pb²⁺、Fe³⁺、Cd²⁺、Cr³⁺、Cu²⁺、Mn²⁺、Sn²⁺和Zn²⁺等8 种重金属离子后, 通过透射显微镜和傅里叶红外光谱测定蛋白的超微结构变化和内部基团特性。以 天然的马脾铁蛋白为对照, 观察重组铁蛋白与天然铁蛋白的差别。结果显示, 重组铁蛋白富集Pb²⁺ 和其它7 种重金属离子后蛋白体积大小与重金属离子种类直接相关。重组铁蛋白相对天然铁蛋白来 说在富集不同种类重金属离子后, 除了非特异性酰胺特征峰和蛋白特征峰外, 还出现一些专门富集 某些重金属离子的特异基团, 如:-CH₃、-CH₂-、-CH-、-NH-、-SO₃-、-COOH、-S=S-和-C-S-C 等。 通过细胞实验进一步验证了铁结合蛋白能够通过富集重金属离子Pb²⁺来保护小鼠成骨前体细胞 MRC3T3-E1, 使细胞的死亡率明显降低(P<0.05).     

致病性副溶血弧菌生物膜形成特性研究

采用改良的微孔板法测定了12株弧菌的形成生物膜的效果,选择形成生物膜效果最好的副溶血弧菌ND-02,进一步研究了环境因子对其生物膜形成的影响。实验结果显示副溶血弧菌ND-02菌株在静置培养24~36 h后形成成熟的生物膜,在起始菌浓度为10⁷~10⁸CFU/mL形成生物膜的量最大;在30 ℃,NaCl浓度为3%~ 5%,pH偏弱碱性时的生物膜OD₅₉₀值最大;Ca²⁺ 促进副溶血弧菌生物膜的形成,而Mg²⁺ 抑制生物膜的形成;副溶血弧菌在分别经大黄鱼表皮黏液、肠黏液和肝脏提取液包被的的基质上形成生物膜的作用明显,鳃黏液和脾脏提取液中次之,肌肉提取液包被后生物膜形成量最低。以上结果表明,副溶血弧菌ND-02菌株能形成稳定而明显的生物膜,而且生物膜的形成受温度、NaCl浓度、pH值等环境因子的影响。     

三价钛还原法分析硝酸根氮氧同位素的方法研究

本研究利用三价钛还原法将标准样品、海水、湖水和雨水中硝酸根转化为N₂O测试其氮氧同位素值,并优化实验条件（NO^-₃浓度、试剂量、反应时间和温度等）。结果表明：4 cm³硝酸根水样（浓度约为20 μmol/dm³）,加入100 mm³TiCl₃溶液（浓度为150 g/dm³）,25 ℃反应24 h,NO^-₃还原为N₂O的平均转化率为86.3%（n=5）。5种丰度硝酸根氮氧同位素标样校准曲线斜率分别为0.947和0.617,相关系数R²分别为0.999和0.994;方法检出限的NO^-3浓度为2.5 μmol/dm³,其δ¹⁵N的标准偏差小于0.7‰(n=5),δ¹⁸O_VSMOW值的标准偏差小于2.5‰(n=5);20 μmol/dm³硝酸根样品δ¹⁵N的标准偏差小于0.5‰（n=5),δ¹⁸O_VSMOW值的标准偏差小于1.0‰（n=5）。该方法测定3种不同类型水样δ¹⁵N的标准偏差分别为0.3‰、0.6‰和0.5‰;δ¹⁸O_VSMOW的标准偏差分别为2.1‰、2.0‰和1.6‰。三价钛还原法分析水体中硝酸根氮氧同位素操作步骤简单,测试效率高,但氧同位素结果需要系统校正。     

原油WSF对三种海洋鱼类肝微粒体EROD活性的诱导和恢复的比较

研究了实验室条件下原油水溶性组分(WSF)暴露对黑鲷、黄鳍鲷和褐菖鲉肝微粒体EROD活性的剂量-效应,时间-效应和恢复过程。实验结果表明,在剂量诱导实验中,褐菖鲉肝EROD活性在原油WSF浓度为50 μg/dm³时呈现生物统计学上的显著差异,而黑鲷和黄鳍鲷肝EROD活性在75 μg/dm³时才呈现生物统计学上的显著差异;褐菖鲉肝EROD活性诱导倍数最高,但黑鲷的诱导浓度范围较广。在时间诱导实验中, 在40 μg/dm³原油WSF暴露下黄鳍鲷肝EROD活性在2 d时首先呈现显著差异; 三种鱼肝EROD活性均在第4天达到最高,并呈现显著性变化,此后随着暴露时间的延长而逐渐下降并接近对照组水平。在恢复实验中三种鱼肝EROD活性下降并恢复到对照组水平。研究结果表明:对于石油污染物,黑鲷、黄鳍鲷和褐菖鲉肝EROD活性都可以作为污染生化效应监测指标,然而就三种鱼类比较而言,褐菖鲉最敏感,更适合于作为石油类污染及其生化效应,尤其是低剂量效应的监测生物。     

厦门西港和九龙江口悬浮颗粒中主要元素含量及其控制因素的研究

厦门西港和九龙江口春季（3月）表层海水TSM含量分别为17.80±6.16和60.11±75.25mg/dm³,整个调查海区平均为38.96±56.50mg/dm³。河流输入是河口区悬浮颗粒的主要来源。悬浮颗粒中Si,Al,Fe的含量最大(47.4～190×10^-3,C,Ca,Mg,Ti,Mn的含量次之(平均在1.6～29.5×10^-3),其它元素的含量一般小于1×10^-3。因子分布表明:陆源输入     

1.5 μm波长n-p-n型InGaAsP-InP晶体管激光器材料外延生长

基于器件模拟仿真,设计了一种1.5 μm波长InGaAsP-InP晶体管激光器材料外延结构. 其多量子阱有源区置于基区非对称波导中. 仿真结果显示该外延结构能够获得较好的光场限制和侧向电流限制. 对该材料MOCVD生长研究表明,基极重掺杂接触层中Zn²⁺扩散将导致量子阱严重退化. 通过对其扩散过程的模拟仿真,采用平均掺杂浓度为1×10¹⁸ cm^-3的梯度掺杂,有效地抑制了Zn²⁺向量子阱区的扩散. 所获得的外延材料在     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.