Biosorption of Cd2+, Cu2+, Ni2+ and Zn2+ ions from aqueous solutions by pretreated biomass of brown algae

In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+.

Biosorption of Cd2+, Cu2+, Ni2+ and Zn2+ ions from aqueous solutions by pretreated biomass of brown algae

In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+. The experimental data have been analyzed using Langmuir, Freundlich and Redlich-Peterson isotherms. The results showed that the biosorption equilibrium was well described by both the Langmuir and Redlich-Peterson isotherms.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 May 2009-31 July 2009

This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.

藻体对水环境中N、P及重金属Cu2+、Pb2+、Cd2+、Cr6+的吸附特征研究

随着全球生态环境的恶化，各国日益重视对水体中各种污染物的治理。利用藻类的吸收、富集和降解作用，可以去除污水中的营养物质、重金属离子和有机污染物，与其他物理、化学及工程的方法相比，该技术具有以下优点：成本低、能耗小、治理效果较好，对环境污染小，有利于资源化，有利于整体生态环境的改善，是治理水质污染的新途径。 本文利用几种大型海藻对富营养化海水进行处理，结果发现孔石莼、刚毛藻均有很强的吸收N、P的能力，吸收能力依次为褶曲刚毛藻>束生刚毛藻>孔石莼。水体中褶曲刚毛藻3 g/L含量，在3～5小时之内，可把中等以上富营养化海水中的N、P降低至一类海水水平。利用刚毛藻处理富营养化地下海水和养殖废水，进行海参和大菱鲆养殖试验，探索藻类净化水质和废水循环利用的新模式，使水体保持较低的营养盐状态，减轻养殖废水对环境的影响，实现了海水养殖业与环境的可持续发展。 刚毛藻在我国近海滩涂分布广泛，利用它来处理富营养化水体，并和水产养殖业相结合，既净化水体，使养殖废水能循环利用，满足水产养殖的需求，又改善水产业生态环境。同时，将回收藻体生产优质饲料、食品和药物等，实现藻类资源的高值利用。刚毛藻营养丰富，用其替代鼠尾藻作海参饲料，资源丰富，成本低，效果好，是一种值得加以开发利用的宝贵资源，具有广泛的应用前景。 生物吸附法是一种经济有效的移除废水中有害重金属离子的方法。由于藻类细胞壁中的多聚糖可提供吸附重金属的位点，廉价而蕴藏丰富的海藻对多种重金属表现出很强的吸附能力。所以本文通过分批实验，研究了非活体刚毛藻对水体中重金属Cu2+、Pb2+和Cd2+的吸附影响因子、吸附热力学、吸附动力学及吸附机理，得到了平衡等温线及动力学数据。吸附过程的最佳pH值为5.0，吸附量随温度的升高而增加，水体中常见的Na+、K+、Ca2+、Mg2+阳离子及Cl-、NO3-、SO42-、C2O42-等阴离子的存在对吸附的影响并不显著。EDTA存在时，吸附百分率大大降低。吸附等温线符合Langmuir和Freundlich方程。刚毛藻对重金属Cu2+、Pb2+和Cd2+的吸附容量很高，25℃时，对Cu2+、Pb2+和Cd2+的最大吸附容量分别为1.61 mmol/g、0.96 mmol/g和0.98 mmol/g，且吸附过程为吸热反应。刚毛藻对重金属Cu2+、Pb2+和Cd2+的吸附过程为化学吸附，在吸附过程中藻体表面的官能团可能与金属离子发生了螯合作用。吸附动力学过程符合pseudo-二级动力学模型，在初始的30min内，吸附速率很快，随后速率逐渐降低。解吸试验表明，用EDTA可以对重金属进行回收，刚毛藻可以循环利用。实验结果表明刚毛藻是一种高效、经济实用的生物吸附材料，可用来吸附回收水体中的重金属Cu2+、Pb2+和Cd2+等。 通过非活体刚毛藻对重金属Cr6+的吸附影响因子、吸附动力学、吸附机理的研究发现，刚毛藻对Cr6+具有很强的还原能力，对电镀废水中的Cr6+的还原去除提供了非常好的方法。吸附过程的最佳pH值为2～3，实际电镀废水通常在此pH范围，因此处理实际废水时，首先在原酸性条件下，对Cr6+进行还原去除，然后调废水pH至5.0，继续进行吸附，去除其他二价离子及被还原的三价Cr离子，实现了利用同一材料还原Cr6+为Cr3+，并将Cr3+和其他重金属离子同时去除。通过对机理的讨论，认为刚毛藻对Cr6+的生物吸附过程不是一个简单的“离子交换过程”，而是一个“吸附还原过程”。在海藻量足够的前提下，只要时间足够长，Cr6+可被彻底还原去除。 利用工业废弃物褐藻渣，对水体中重金属离子Cu2+、Pb2+、Cd2+及Cr6+的生物吸附特性分别进行了讨论，结果表明褐藻渣对重金属离子的吸附特性与刚毛藻一致，吸附等温线符合Langmuir和Freundlich方程，在25℃时，pH为5.0时，由Langmuir方程求出褐藻渣对Cu2+、Pb2+和Cd2+的最大吸附容量分别为4.20 mmol/g、3.13 mmol/g和2.97 mmol/g。褐藻渣对低、高浓度的重金属Cr6+都具有很强的吸附能力，且移除效果比较彻底。实际应用结果表明，褐藻渣是一种高效、经济实用的生物吸附材料，可用来吸附回收水体中的重金属离子，具有广泛的应用前景。

Phytoplankton biomass size structure and its regulation in the Southern Yellow Sea (China): Seasonal variability

Phytoplankton size structure plays a significant role in controlling the carbon flux of marine pelagic ecosystems. The mesoscale distribution and seasonal variation of total and size-fractionated phytoplankton biomass in surface waters. as measured by chlorophyll a (Chl a), was studied in the Southern Yellow Sea using data from four cruises during 2006-2007. The distribution of Chl a showed a high degree of spatial and temporal variation in the study area. Chl a concentrations were relatively high in the summer and autumn, with a mean of 142 and 1.27 mg m(-3), respectively. Conversely, in the winter and spring. the average Chl a levels were only 098 and 0.99 mg m(-3) Total Chl a showed a clear decreasing gradient from coastal areas to the open sea in the summer, autumn and winter cruises. Patches of high Chl a were observed in the central part of the Southern Yellow Sea in the spring due to the onset of the phytoplankton bloom. The eutrophic coastal waters contributed at least 68% of the total phytoplankton biomass in the surface layer. Picophytoplankton showed a consistent and absolute dominance in the central region of the Southern Yellow Sea (>40%) in all of the cruises, while the proportion of microphytoplankton was the highest in coastal waters The relative proportions of pico- and nanophytoplankton decreased with total biomass, whereas the proportion of the micro-fraction increased with total biomass. Relationships between phytoplankton biomass and environmental factors were also analysed. The results showed that the onset of the spring bloom was highly dependent on water column stability. Phytoplankton growth was limited by nutrient availability in the summer due to the strong thermocline. The combined effects of P-limitation and vertical mixing in the autumn restrained the further increase of phytoplankton biomass in the Surface layer. The low phytoplankton biomass in winter was caused by vertical dispersion due to intense mixing. Compared with the availability of nutrients. temperature did not seem to cause direct effects on phytoplankton biomass and its size structure. Although interactions of many different environmental factors affected phytoplankton distributions. hydrodynamic conditions seemed to be the dominant factor. Phytoplankton size structure was determined mainly by the size-differential capacity in acquiring resource. Short time scale events, such as the spring bloom and the extension of Yangtze River plume, can have substantial influences, both on the total Chl a concentration and on the size structure of the phytoplankton. (C) 2009 Elsevier Ltd. All rights reserved.

A field study on the conversion ratio of phytoplankton biomass carbon to chlorophyll-a in Jiaozhou Bay, China

A one-year field study was conducted to determine the conversion ratio of phytoplankton biomass carbon (Phyto-C) to chlorophyll-a (Chl-a) in Jiaozhou Bay, China. We measured suspended particulate organic carbon (POC) and phytoplankton Chl-a samples collected in surface water monthly from March 2005 to February 2006. The temporal and spatial variations of Chl-a and POC concentrations were observed in the bay. Based on the field measurements, a linear regression model II was used to generate the conversion ratio of Phyto-C to Chl-a. In most cases, a good linear correlation was found between the observed POC and Chl-a concentrations, and the calculated conversion ratios ranged from 26 to 250 with a mean value of 56 A mu g A mu g(-1). The conversion ratio in the fall was higher than that in the winter and spring months, and had the lowest values in the summer. The ratios also exhibited spatial variations, generally with low values in the near shore regions and relatively high values in offshore waters. Our study suggests that temperature was likely to be the main factor influencing the observed seasonal variations of conversion ratios while nutrient supply and light penetration played important roles in controlling the spatial variations.

Marine bacteria associated with marine macroorganisms: the potential antimicrobial resources

In order to explore marine microorganisms with medical potential, marine bacteria were isolated from seawater, sediment, marine invertebrates and seaweeds collected from different coastal areas of the China Sea. The antimicrobial activities of these bacteria were investigated. Ethyl acetate extracts of marine bacterial fermentation were screened for antimicrobial activities using the method of agar diffusion. The results showed that 42 strains of the isolates have antimicrobial activity. The proportion of active bacteria associated with marine invertebrates (20%) and seaweeds (11%) is higher than that isolated from seawater (7%) and sediment (5%). The active marine bacteria were assigned to the genera Alteromonas, Pseudomonas, Bacillus and Flavobacterium. The TLC autobiographic overlay assay implied that the antimicrobial metabolites produced by four strains with wide antimicrobial spectrum were different. Due to a competitive role for space and nutrient, the marine bacteria associated with marine macroorganisms (invertebrates and seaweeds) could produce more antibiotic substances. These marine bacteria were expected to be potential resources of natural antibiotic products.

Microbial modulation in the biomass and toxin production of a red-tide causing alga

The effect of S-10, a strain of marine bacteria isolated from sediment in the Western Xiamen Sea, on the growth and paralytic shellfish poison (PSP) production in the alga Alexandrium tamarense (A. tamarense) was studied under controlled experimental conditions. The results of these experiments have shown that the growth of A. tamarense is obviously inhibited by S-10 at high concentrations, however no evident effect on its growth was observed at low concentrations. Its PSP production was also inhibited by S 10 at different concentrations, especially at low concentrations. The toxicity of this strain of A. tamarense is about (0.9512.14) x 10(-6) MU/cell, a peak toxicity value of 12.14 x 10(-6) MU/cell appeared on the 14th day, after which levels decreased gradually. The alga grew well in conditions of pH 6-8 and salinities of 20-34 parts per thousand. The toxicity of the alga varied markedly at different pH and salinity levels. Toxicity decreased as pH increased, while it increased with salinity and reached a peak value at a salinity of 30 parts per thousand, after which it declined gradually. S-10 at a concentration of 1.02 x 10(9) cells/ml inhibited growth and the PSP production of A. tamarense at different pH and salinity levels. S-10 had the strongest inhibitory function on the growth of A. tamarense under conditions of pH 7 and a salinity of 34 parts per thousand. The best inhibitory effect on PSP production by A. tamarense was at pH 7, this inhibitory effect on PSP production did not relate to salinity. Interactions between marine bacteria and A. tamarense were also investigated using the flow cytometer technique (FCM) as well as direct microscope counting. S-10 was identitied as being a member of the genus Bacillus, the difference in 16S rDNA between S-10 and Bacillus halmapalus was only 2%. The mechanism involved in the inhibition of growth and PSP production of A. tamarense by this strain of marine bacteria, and the prospect of using it and other marine bacteria in the biocontrol of red-tides was discussed. (c) 2005 Elsevier Ltd. All rights reserved.

Size dependence of biomass spectra and abundance spectra: the optimal distributions

Based on the hypothesis of self-optimization, we derive four models of biomass spectra and abundance spectra in communities with size-dependent metabolic rates. In Models 1 and 2, the maximum diversity of population abundance in different size classes subject to the constraints of constant mean body mass and constant mean respiration rate is assumed to be the strategy for ecosystems to organize their size structure. In Models 3 and 4, the organizing strategy is defined as the maximum diversity of biomass in different size classes without constraints on mean body mass and subject to the constant mean specific respiration rate of all individuals, i.e. the average specific respiration rate over all individuals of a community or group, which characterizes the mean rate of energy consumption in a community. Models 1 and 2 generate peaked distributions of biomass spectral density whereas Model 3 generates a fiat distribution. In Model 4, the distributions of biomass spectral density and of abundance spectral density depend on the Lagrangian multipler (lambda (2)). When lambda (2) tends to zero or equals zero, the distributions of biomass spectral density and of abundance spectral density correspond to those from Model 3. When lambda (2) has a large negative value, the biomass spectrum is similar to the empirical fiat biomass spectrum organized in logarithmic size intervals. When lambda (2) > 0, the biomass spectral density increases with body mass and the distribution of abundance spectral density is an unimodal curve. (C) 2001 Elsevier Science B.V. All rights reserved.

Size-fractionated phytoplankton biomass in autumn of the Changjiang (Yangtze) River Estuary and its adjacent waters after the Three Gorges Dam construction

A cruise was undertaken from 3rd to 8th November 2004 in Changjiang (Yangtze) River Estuary and its adjacent waters to investigate the spatial biomass distribution and size composition of phytoplankton. Chlorophyll-a (Chl-a) concentration ranged 0.42-1.17 mu g L-1 and 0.41-10.43 mu g L-1 inside and outside the river mouth, with the mean value 0.73 mu g L-1 and 1.86 mu g L-1, respectively. Compared with the Chl-a concentration in summer of 2004, the mean value was much lower inside, and a little higher outside the river mouth. The maximal Chl-a was 10.43 mu g L-1 at station 18 (122.67 degrees E, 31.25 degrees N), and the region of high Chl-a concentration was observed in the central survey area between 122.5 degrees E and 123.0 degrees E. In the stations located east of 122.5 degrees E, Chl-a concentration was generally high in the upper layers above 5 m due to water stratification. In the survey area, the average Chl-a in sizes of > 20 mu m and < 20 mu m was 0.28 mu g L-1 and 1.40 mu g L-1, respectively. High Chl-a concentration of < 20 mu m size-fraction indicated that the nanophytoplankton and picophytoplankton contributed the most to the biomass of phytoplankton. Skeletonema costatum, Prorocentrum micans and Scrippsiella trochoidea were the dominant species in surface water. The spatial distribution of cell abundance of phytoplankton was patchy and did not agree well with that of Chl-a, as the cell abundance could not distinguish the differences in shape and size of phytoplankton cells. Nitrate and silicate behaved conservatively, but the former could probably be the limitation factor to algal biomass at offshore stations. The distribution of phosphate scattered considerably, and its relation to the phytoplankton biomass was complicated.

Fast microzooplankton grazing on fast-growing, low-biomass phytoplankton: a case study in spring in Chesapeake Bay, Delaware Inland Bays and Delaware Bay

Dilution experiments were performed to examine the growth and grazing mortality rates of picophytoplankton (< 2 mu m), nanophytoplankton (2-20 mu m), and microphytoplankton (> 20 mu m) at stations in the Chesapeake Bay (CB), the Delaware Inland Bays (DIB) and the Delaware Bay (DB), in early spring 2005. At station CB microphytoplankton, including chain-forming diatoms were dominant, and the microzooplankton assemblage was mainly composed of the tintinnid Tintinnopsis beroidea. At station DIB, the dominant species were microphytoplanktonic dinoflagellates, while the microzooplankton community was mainly composed of copepod nauplii and the oligotrich ciliate Strombidium sp. At station DB, nanophytoplankton were dominant components, and Strombidium and Tintinnopsis beroidea were the co-dominant microzooplankton. The growth rate and grazing mortality rate were 0.13-3.43 and 0.09-1.92 d(-1) for the different size fractionated phytoplankton. The microzooplankton ingested 73, 171, and 49% of standing stocks, and 95, 70, and 48% of potential primary productivity for total phytoplankton at station CB, DIB, and DB respectively. The carbon flux for total phytoplankton consumed by microzooplankton was 1224.11, 100.76, and 85.85 mu g C 1(-1) d(-1) at station CB, DIB, and DB, respectively. According to the grazing mortality rate, carbon consumption rate and carbon flux turn over rates, microzooplankton in study area mostly preferred to graze on picophytoplankton, which was faster growing but was lowest biomass component of the phytoplankton. The faster grazing on Fast-Growing-Low-Biomass (FGLB) phenomenon in coastal regions is explained as a resource partitioning strategy. This quite likely argues that although microzooplankton grazes strongly on phytoplankton in these regions, these microzooplankton grazers are passive.