Anti-Adhesive Properties of Calcium Alginate from Sargassum fusiforme against Particulate Matter-Induced Inflammation

Fine dust generated by particulate matter (PM) pollution is a serious ecological issue in industrialized countries and causes disorders of the respiratory system and skin in humans. In the previous study, Sargassum fusiforme was treated with citric acid to remove heavy metals. In this study, the transfer of PM-mediated inflammatory responses through the skin to macrophages was evaluated. Moreover, the anti-adhesive effects of calcium alginate isolated from S. fusiforme (SFCA) against PM-induced inflammation were investigated. The structures of processing and unprocessing SFCA were then analyzed by Fourier-transform infrared spectroscopy (FT-IR), revealing minimal change after acid-processing. SFCA had protective effects both in PM-stimulated HaCaT keratinocytes and RAW 264.7 macrophages. In cellular environments, it was found that SFCA attenuated signal protein expressions such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E₂ (PGE₂), and pro-inflammatory cytokines. Furthermore, macrophages were added to the culture medium of PM-stimulated keratinocytes to induce inflammation. SFCA was observed to significantly inhibit inflammatory responses; additionally, SFCA showed an in vivo anti-adhesive effect in zebrafish embryos.     

THE USE OF NEAR INFRARED REFLECTANCE SPECTROMETRY FOR CHARACTERIZATION OF BROWN ALGAL TISSUE1

Measuring qualitative traits of plant tissue is important to understand how plants respond to environmental change and biotic interactions. Near infrared reflectance spectrometry (NIRS) is a cost‐, time‐, and sample‐effective method of measuring chemical components in organic samples commonly used in the agricultural and pharmaceutical industries. To assess the applicability of NIRS to measure the ecologically important tissue traits of carbon, nitrogen, and phlorotannins (secondary metabolites) in brown algae, we developed NIRS calibration models for these constituents in dried Sargassum flavicans (F. K. Mertens) C. Agardh tissue. We then tested if the developed NIRS models could detect changes in the tissue composition of S. flavicans induced by experimental manipulation of temperature and nutrient availability. To develop the NIRS models, we used partial least squares regression to determine the statistical relationship between trait values determined in laboratory assays and the NIRS spectral data of S. flavicans calibration samples. Models with high predictive power were developed for all three constituents that successfully detected changes in carbon, nitrogen, and phlorotannin content in the experimentally manipulated S. flavicans tissue. Phlorotannin content in S. flavicans was inversely related to nitrogen availability, and nitrogen, temperature, and tissue age interacted to significantly affect phlorotannin content, demonstrating the importance of studies that investigate these three variables simultaneously. Given the speed of analysis, accuracy, small tissue requirements, and ability to measure multiple traits simultaneously without consuming the sample tissue, NIRS is a valuable alternative to traditional methods for determining algal tissue traits, especially in studies where tissue is limited.     

黄海太平角鼠尾藻有性繁殖分配

以位于黄海的青岛太平角自然生长的鼠尾藻为对象,研究其有性繁殖分配动态及相关环境因子.结果表明:鼠尾藻于6月初开始进入有性繁殖期,于7月中旬海水温度22℃左右达到繁殖高峰,7月19日平均繁殖分配(RA)达76.7%,8月末有性繁殖结束.鼠尾藻繁殖分配与平均分枝长度呈显著线性相关(r=0.855,P<0.01).长度在10cm以下的藻体在整个繁殖期内的RA较低,而长度在10cm以上的藻体在成熟高峰期的RA在70.0%以上.析因方差分析表明,潮位和浪冲击度均对鼠尾藻有性繁殖分配有显著影响(潮位:F=175.62,P<0.001,浪冲击度:F=95.35,P<0.01),且二者之间存在交互作用(F=9.14,P<0.05).其对RA的影响大小依次为潮位>浪冲击度>潮位×浪冲击度.     

HABITAT DIFFERENCES IN THE TIMING OF REPRODUCTION OF THE INVASIVE ALGA SARGASSUM MUTICUM (PHAEOPHYTA,SARGASSACEAE) OVER TIDAL AND LUNAR CYCLES1

Sargassum muticum (Yendo) Fensholt is an invasive species that is firmly established on intertidal and subtidal rocky shores of Europe and the Pacific coast of North America. Local success and spread of S. muticum is thought to rely on its reproductive potential that seems dependent on exogenous factors like tidal and lunar cycles. This study is the first to compare the reproductive patterns (periodicity of egg expulsion and embryo settlement) of this invader in two different habitats: the middle and low intertidal. The combination of monthly, daily, and tidal samples at triplicate sites within each habitat showed a semilunar periodicity of egg expulsion and embryo settlement coincident with increasing tidal amplitude just before full and new moons. In both habitats, duration of each egg expulsion event was ～1 week, and embryo settlement occurred during the first daily low tide and with the incoming high tide during spring tides. However, both expulsion and settlement started 1–2 d earlier, expulsion saturation was faster, and settlement was higher in the mid‐ compared to the low intertidal. Our results suggest that the exact timing of gamete expulsion and embryo release of S. muticum responds to local factors, including tidal cues, which result in differences between mid‐ and low‐intertidal habitats.     

响应曲面法优化鼠尾藻中脂质的提取工艺

根据中心复合旋转设计原理,在单因素试验的基础上,采用三因素五水平的响应曲面分析法,建立了鼠尾藻中脂质提取的二次多项式数学模型,并以脂质的提取率为响应值作响应面和等高线,考察了提取时间、溶剂的量和石油醚乙醚溶剂配比对脂质提取的影响。结果表明：脂质提取的优化工艺条件为：提取时间19．39h,溶剂的量18．90mL,石油醚百分含量46．26％。在此工艺条件下,脂质的提取率为0．924％。     

An effective DNA extraction protocol for brown algae

Successful extraction of total DNA from brown algae, which are generally polysaccharide and polyphenol rich, is often problematic using current methods. Persistent polysaccharide and polyphenolic compounds can hinder further application of modern molecular techniques requisite to molecular‐based evolutionary studies. Our broad and long‐term research goals with fucalean taxa, especially Sargassum, and problems with existing DNA extraction methods were an impetus to develop a reliable DNA extraction method. Initial research established hexadecyltrimethylammonium bromide (CTAB) based total‐DNA methods as the most viable for further empirical development. Several constituents effective at either complexing secondary compounds or creating a reductive extraction environment were increased in concentration or added to the extraction buffer. These seemingly minor changes resulted in the creation of a highly reductive extraction buffer and effective total‐ DNA harvesting technique. We detail these modifications and demonstrate the reliability of the modified protocol with a variety of brown algae and tissue preservation methods. Such DNA is shown to be suitable for a variety of molecular techniques.     

Measurement of the adhesion of a desmid to a substrate

The paper describes a hydrodynamic method by which the adhesive strength of the mucilage produced from the apical proes of Closterium acerosum has been measured. An equation used to determine the drag force on the cells is presented, as are some measured adhesive strengths of the Closterium mucus to glass slides.     

海蒿子多糖DEⅠ、DEⅡ组分分离纯化、结构及抗癌活性研究

海蒿子干粉经热水抽提、乙醇沉淀、DEAE-Sephadex A-25柱层析分离,得到多糖DEⅠ、DEⅡ,总糖含量分别为52.40%、38.8%.经酸降解、薄层层析、气相色谱-质谱分析,证明其单糖组成均为木糖、岩藻糖、半乳糖、果糖、甘露糖、葡萄糖.其中岩藻糖含量最高.多糖DEⅠ、DEⅡ对P388肿瘤具有抑制活性.     

Biocatalytic efficacy of immobilized cells of Chryseobacterium sp. Alg-SU10 for simultaneous hydrolysis of urethane and urea

Urethane, a carcinogenic and teratogenic compound, in fermented foods and alcoholic beverages can be eliminated either by direct hydrolysis with urethanase, or by hydrolysis of its precursor molecule urea with acid urease. In the present study, a potent bacterium, which concomitantly produced urethanase and acid urease, was isolated from the decomposed Sargassum species. This bacterial isolate was identified as Chryseobacterium sp. Alg-SU10 by the 16S rRNA gene sequencing approach. The biocatalytic efficacy of the calcium alginate immobilized cells of this bacterium for the hydrolysis of urethane and urea was evaluated by characterizing urethanase and acid urease. The immobilized biocatalyst displayed maximal urethanase and urease activities at pH 5, and retained more than 96% of enzymatic activity at 15% (v/v) ethanol. The values of activation energy, enthalpy and entropy of catalysis were calculated as 43.3?kJ/mol, 40.8?kJ/mol and –116?J/mol/K, respectively, for urethanase and 38.1?kJ/mol, 35.6?kJ/mol and –77.8?J/mol/K, respectively, for acid urease. The overall results indicate the biocatalytic potential of immobilized cells of Chryseobacterium sp. Alg-SU10 for efficient abatement of urethane. This is the first report describing the thermodynamic characteristics of urethanase and acid urease co-produced by Chryseobacterium sp.     

GENOMIC DNA ISOLATION FROM GREEN AND BROWN ALGAE (CAULERPALES AND FUCALES) FOR MICROSATELLITE LIBRARY CONSTRUCTION1

A method for isolating high‐quality DNA is presented for the green algae Caulerpa sp. (C. racemosa, C. prolifera, and C. taxifolia) and the brown alga Sargassum muticum. These are introduced, and invasive species in Europe, except for the native C. prolifera. Previous methods of extraction, using cetyl trimethyl ammonium bromide or various commercial kits, were used to isolate genomic DNA but either no DNA or DNA of very low quality was obtained. Genomic libraries were attempted with Caulerpa sp. on three occasions and either the restriction enzyme, the Taq polymerase, or the T4 ligase was inhibited, probably by the large amount of polysaccharides in these algae. The method presented here consists of the rapid isolation of stable nuclei, followed by DNA extraction. Yields of 6–10 μ g genomic DNA from 1 g fresh blades were obtained. After genomic DNA was isolated from fresh material, the quality was checked by agarose gel. Quantification of DNA concentration was performed using UV spectrophotometric measurement of the A ₂₆₀/ A ₂₈₀ ratio. The DNA was suitable for PCR, cloning, and hybridization. The DNA isolated using this method allowed successful construction of microsatellite libraries for Caulerpa species and S. muticum . The technique is inexpensive and appropriate for the isolation of multiple samples of DNA from a small amount of fresh material.