Study on patterns and chemical features of NO effect on marine phytoplankton growth

With supernatural bioactivation, nitric oxide (NO), which was first regarded as an endothelium- derived relaxing factor, was recognized by Science as the “Molecule of the Year” in 1992. The Nobel Prize of Physiology & Medicine in 1998 was awarded jointly to Furchgatt, Ignarro, and Murad for their discoveries concerning the NO effects in the cardiovascular sys- tem. From then on, researchers have paid more and more attention to the special and diverse functions of NO in organism[1―18].…     

Discovery of nitric oxide in marine ecological system and the chemical characteristics of nitric oxide

Nitric oxide was discovered in both the lab and the alga culture pond of Daya Bay (1―300 m3) before the growth of alga reached the maximum. The results included: (1) NO was detected before the growth of alga reached the maximum in the case of red tide alga and food alga, and the concentration of NO decreased rapidly after the growth maximum; (2) the curve between NO con-centration and time indicated that the concentration of NO in the daytime was more than that at night, and the maximal concentration of NO appeared in the midday (1―3 pm); (3) the growth of alga reached the maximum in the alga culture pond of Daya Bay in about 8―10 d, and NO was discovered in 5―7 d; (4) the measured NO concentration was 10-9 mol/L, 10-9―10-8 mol/L, and 10-8 mol/L for Haeterosigma akashiwo, mixed alga in Daya Bay and Chaetoceros Curvisetus individually; (5) the relation of illumination with NO production was discussed.     

Marine natural products

This review covers the literature published in 2003 for marine natural products, with 619 citations (413 for the period January to December 2003) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (656 for 2003), together with their relevant biological activities, source organisms and country or origin. Biosynthetic studies or syntheses that lead to the revision of structures or stereochemistries have been included (78), including any first total syntheses of a marine natural product.     

Marine natural products

This review covers the literature published in 2002 for marine natural products, with 579 citations (413 for the period January to December 2002) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (677 for 2002), together with their relevant biological activities, source organisms and country of origin. Syntheses that lead to the revision of structures or stereochemistries have been included (114), including any first total syntheses of a marine natural product.     

Marine natural products

This review covers the literature published in 2001 for marine natural products, with 497 citations (373 for the period January to December 2001) and includes 793 compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds and new stereochemical assignments (683 for 2001), together with relevant biological activities, source organisms and country of origin. Syntheses that confirm or revise structures or stereochemistries have been included (95), including any first total synthesis of a marine natural product.     

Marine natural products

This review covers the literature published in 2005 for marine natural products, with 704 citations (493 for the period January to December 2005) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (812 for 2005), together with their relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.     

Marine natural products

This review covers the literature published in 2004 for marine natural products, with 693 citations (491 for the period January to December 2004) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (716 for 2004), together with their relevant biological activities, source organisms and country of origin. Biosynthetic studies (8), and syntheses (80), including those that lead to the revision of structures or stereochemistries, have been included.     

Marine natural products

This review covers the literature published in 2006 for marine natural products, with 758 citations (534 for the period January to December 2006) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, cnidaria, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (779 for 2006), together with their relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.     

平行因子分析在赤潮藻滤液三维荧光光谱特征提取中的应用

在实验室条件下培养我国沿海常见的10种赤潮藻,测定了赤潮藻生长过程中藻滤液的三维荧光光谱.用平行因子分析对光谱进行分解,获得每种赤潮藻滤液荧光峰的个数及类型,即每种赤潮藻的特征光谱.在此基础上比较每种藻特征光谱的相似性和差异性,并分析了赤潮藻生长过程中滤液的荧光峰强度和生长阶段的关系,为基于赤潮藻滤液三维荧光光谱的赤潮藻种类识别测定技术提供依据.结果表明:不同赤潮藻的特征光谱之间存在差异.在指数生长期,类蛋白和类腐殖质荧光峰强度与藻密度呈正相关,说明两类有机物在水体中不断积累;在稳定期和衰亡期,两类有机物的荧光强度迅速增大,这可能是衰老和死亡细胞的破碎释放,以及细菌降解作用所致.平行因子分析可以有效提取赤潮藻的荧光特征,考察了赤潮藻荧光峰强度和生长阶段的关系.     

Winter evolution of DMS and DMSP in Venice lagoon water and sediment

The evolution of dimethylsulphide (DMS) and dimethylsulphoniopropionate (DMSP) concentrations in the water and sediment of the Venice lagoon were studied together with the concentration of chlorophyll a, temperature and the composition and density of phytoplankton to understand the role of the sediment as a source of DMS during the winter period. The temporal trend of water DMS concentration in this period showed a maximum concentration in February (75.7 nmol S l-1) related to low DMSP and chlorophyll a concentrations but to high phytoplanktonic abundance. The DMS and DMSP concentrations were greater in the sediment than in the water. The temporal trend of DMS concentration in sediment showed a maximum in February (1155 nmol S l-1) related to the maximum of DMS concentration in surface water. These observations suggested that in the winter period DMS could be produced by the conversion of the DMSP present in the bulk water but principally by that present in the sediment (microbiological degradation of DMSP or other sulphur-containing compounds) that subsequently diffuse in water.     

Determination of 11 low-molecular-weight carbonyl compounds in marine algae by high-performance liquid chromatography

A new analytical method is reported for the determination of 11 volatile carbonyl compounds isolated at room temperature from the headspace of marine algae. This method is based on the conversion of the carbonyl compounds to their 2,4-dinitrophenylhydrazone derivatives followed by high-performance liquid chromatography analysis. Using this method, 11 carbonyl compounds are detected and identified from the dynamic headspace sampling of 10 species of marine algae. Eight compounds are quantitated and the three remaining are only identified. Under optimized conditions, all carbonyl compounds are separated in 32 min. The detection and quantitation limits of the high-performance liquid chromatography method are, respectively, in the range of 0.26-0.85 ng/g of algae (formaldehyde) to 13.77-45.90 ng/g of algae (E)-2-hexenal. The calibration curves are linear in the concentration range of 2.0-1000 microg/L of solution, corresponding to 0.34-170.00 ng/g of algae. Acetaldehyde and propanal are the most abundant carbonyl compounds identified, with concentrations as high as 980 and 790 ng/g, respectively. The present work, as far as we know, is the first analytical methodology that has been developed to determine low-molecular-weight carbonyl compounds in marine algae. Because many species of marine algae are used as human food, the reported method should be useful to investigators studying the nutritional value as well as oxidative spoilage of fresh and preserved marine algae that is destined for human consumption.     

Study of organic sulphur compounds (DMS,DMSP and CS2) in lagoon ecosystems: the case of the Venice lagoon

This study of the origin and fate of dimethyl sulphide (DMS) in a particular and complex lagoon ecosystem such as that of the Venice lagoon focuses on the temporal evolutions of DMS concentrations in surface water together with those of dimethylsulphoniopropionate (DMSP), carbon disulphide (CS2), nutrients (nitrate, nitrite, ammonium, phosphate, silicate), sulphate, chlorophyll a, chlorinity, water temperature and phytoplankton (composition and density). Measurements were made from 3 March 1997 to 23 July 1998 at three stations in the central part of the Venice lagoon. The temporal trends of DMS concentration showed an absolute maximum concentration in winter (65 nmol S/l, 19/2/1998, Stn. 1; 119 nmol S/l, 19/2/1998, Stn. 2; 29 nmol S/l, 17/2/1998, Stn. 3) and two relative maxima in the spring-summer period. The spring-summer secondary maxima of DMS concentration were related to the maxima of DMSP and chlorophyll a concentrations and consequently to phytoplanktonic abundance while the winter DMS maximum showed no relation to DMSP or to chlorophyll a suggesting that the production and the fate of DMS could be different for the two periods. According to previous studies the CS2 concentration increased in the spring, achieved its maximum in summer, decreased in autumn and fell to its minimum in winter.     

Marine natural products

This review covers the marine natural products literature for the year 2000 and is organized phylogenetically, with sections on marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates. echinoderms and miscellaneous marine organisms. There is an emphasis on new structures, stressing their biological activities, source organisms and countries of origin, and also syntheses that confirm the structures of known compounds. The review contains 869 structures and 592 references, of which 434 appeared between January and December 2000.     

低温等离子体转化NO/O2/N2气氛中NO的实验研究

通过建立低温等离子体实验系统, 研究了介质阻挡放电型低温等离子体反应器作用于NO/O2/N2混合气体系时, NO, O2初始浓度对NO的转化效率的影响以及NOx, O3浓度随能量密度的变化关系. 低温等离子体作用于NO/O2/N2混合气体系时, NO同时发生氧化还原反应, 氧化反应占主导地位, 大部分NO转化为NO2; NO转化率随O2, NO初始浓度增大而降低, 能量密度在450～600 J/L时转化率较高; 产生的O3浓度随能量密度的增大呈先增后减的趋势.     

Marine natural products

Covering: 2010. Previous review: Nat. Prod. Rep., 2011, 28, 196. This review covers the literature published in 2010 for marine natural products, with 895 citations (590 for the period January to December 2010) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1003 for 2010), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.     

Enhancement of rhamnoplipid production in residual soybean oil by an isolated strain of Pseudomonas aeruginosa

In the present work, the production of rhamnolipid from residual soybean oil (RSO) from food frying facilities was studied using a strain of Pseudomonas aeruginosa of contaminated lagoon, isolated from a hydrocarbon contaminated soil. The optimization of RSO, ammonium nitrate, and brewery residual yeast concentrations was accomplished by a central composite experimental design and surface response analysis. The experiments were performed in 500-mL Erlenmeyer flasks containing 50 mL of mineral medium, at 170 rpm and 30 +/- 1 degrees C, for a 48-h fermentation period. Rhamnolipid production has been monitored by measurements of surface tension, rhamnose concentration, and emulsifying activity. The best-planned results, located on the central point, have corresponded to 22 g/L of RSO, 5.625 g/L of NH(4)NO(3), and 11.5 g/L of brewery yeast. At the maximum point the values for rhamnose and emulsifying index were 2.2 g/L and 100%, respectively.     

Effects of Arsenic Compounds on Proliferation and Nitric Oxide Synthesis in C3H 10T 1/2 Murine Fibroblasts

Exposure to arsenic, either through chronic consumption of contaminated water or inhalation, is associated with increased risk of cancer, yet the mechanism by which arsenicals promote neoplastic change remains undefined. The carcinogenic process involves the formation of heritable genetic changes in the DNA of normal cells and this process may be enhanced by environmental agents that increase cellular proliferation, increase DNA damage and decrease the ability to repair damage or cause immunosuppression. We describe the inhibition of cellular proliferation of C3H 10T1/2 murine fibroblasts in the presence of 1.0 μM arsenate or arsenite; yet cacodylic acid had no significant effect on cell growth in culture at this concentration. Both arsenate and cacodylate, at micromolar concentrations, slightly stimulated cell growth and cell density when cells were treated with interferon-γ/lipopolysaccharide (IFN-γ/LPS). At 1 μM , arsenate and cacodylate also slightly increased IFN-γ/LPS-induced nitric oxide (NO) synthesis in this cell line, consistent with the increase in cell number observed, whereas 1 μM arsenite significantly increased NO production on a per-cell basis. In contrast, arsenite significantly inhibited NO synthesis at concentrations above 10 μM arsenite as, to a lesser extent, did arsenate and cacodylate. These results suggest that ingestion of arsenicals could alter cellular generation of NO and interfere with its associated physiological functions. © 1997 by John Wiley & Sons, Ltd.     

Responses of a marine red tide alga Skeletonema costatum (Bacillariophyceae) to long-term UV radiation exposures

UV radiation (280–400 nm) is known to affect phytoplankton in negative, neutral and positive ways depending on the species or levels of irradiation energy. However, little has been documented on how photosynthetic physiology and growth of red tide alga respond to UVR in a long-term period. We exposed the cells of the marine red tide diatom Skeletonema costatum for 6 days to simulated solar radiations with UV-A (320–400 nm) or UV-A + UV-B (295–400 nm) and examined their changes in photosynthesis and growth. Presence of UV-B continuously reduced the effective photosynthetic quantum yield of PSII, and resulted in complete growth inhibition and death of cells. When UV-B or UV-B + UV-A was screened off, the growth rate decreased initially but regained thereafter. UV-absorbing compounds and carotenoids increased in response to the exposures with UVR. However, mechanisms for photoprotection associated with the increased carotenoids or UV-absorbing compounds were not adequate under the continuous exposure to a constant level of UV-B (0.09 W m^?2, DNA-weighted). In contrast, under solar radiation screened off UV-B, the photoprotection was first accomplished by an initial increase of carotenoids and a later increase in UV-absorbing compounds. The overall response of this red tide alga to prolonged UV exposures indicates that S. costatum is a UV-B-sensitive species and increased UV-B irradiance would influence the formation of its blooms.     

Improved DNA probe detection of Listeria monocytogenes in enrichment culture after physical-chemical fractionation

Bacterial detection in foods by nucleic acid probes is limited by microflora competition during selective enrichment. Probe target concentration by extraction and fractionation of enrichments may diminish this limitation. The 1-h AccuProbe chemiluminescent culture identification test for Listeria monocytogenes was used as a model. Its high detection threshold provides a stringent challenge for evaluating enrichment work-up protocols. Detection of L. monocytogenes, at 1-4 colony-forming units/g food, was not consistently possible in 48 h enrichment cultures using AccuProbe. Concentration by cell sedimentation was occasionally helpful but the volume of co-sedimented food limited concentration to about 10-fold. To improve concentration, enrichment sediments were sonicated or enzymatically lysed to release the probe's target, r-RNA. The RNA was separated from non-RNA material by extraction with phenol and precipitation with ethanol. Enrichments (250 mL) were concentrated 2500-fold, and the limitation was food RNA volume. A strongly competitive Enterococcus faecium food isolate was used to demonstrate the effect of artificial competition on the kit's ability to detect L. monocytogenes in enrichments. High competitor concentrations repressed the level of the target below the detection threshold, but concentration of r-RNA enabled detection of L. monocytogenes. The effectiveness of this enrichment sample work-up was demonstrated with naturally contaminated hummus.     

Ecological leads for natural product discovery: novel sesquiterpene hydroquinones from the red macroalga Peyssonnelia sp.

Pharmacologically-motivated marine natural product investigations have yielded a large variety of structurally unique compounds with interesting biomedical properties, but the natural roles of these molecules often remain unknown. While secondary metabolites may function as antimicrobial chemical defenses, few studies have examined this hypothesis. In the present investigation, chromatographic fractions from 69 collections of Fijian red macroalgae representing at least 43 species were evaluated for growth inhibition of three microbial pathogens and saprophytes of marine macrophytes. At least one microbe was suppressed by fraction(s) of all evaluated algae, suggesting that antimicrobial defenses are common among tropical seaweeds. From these leads, peyssonoic acids A-B (1-2), novel sesquiterpene hydroquinones, were isolated from the crustose red alga Peyssonnelia sp. At ecologically realistic concentrations, both compounds inhibited growth of Pseudoalteromonas bacteriolytica, a bacterial pathogen of marine algae, and Lindra thalassiae, a fungal pathogen of marine algae, and exhibited modest antineoplastic activity against ovarian cancer cells. The peyssonoic acids included one novel carbon skeleton and illustrated the utility of ecological studies in natural product discovery.