Adverse Effect of TiO_2 Nanoparticles on Antioxidant System and Antitumor Activities of Macroalgae Gracilaria lemaneiformis

Recently, the widespread use of TiO_2 nanoparticles(nano-TiO_2) has attracted the global concern regarding their adverse effects to aquatic organisms. Nanoparticles may get to the aquatic environments and harm the growth of algae. This paper presents the studies of nano-TiO_2 concentrations influence on the photosynthetic characteristics, antioxidant system and antitumor activity of marine macroalgae Gracilaria lemaneiformis after exposed to 0, 5, 10, 20 or 40 mg L-1 of nano-TiO_2. Results showed that the photosynthetic pigment content of G. lemaneiformis obviously decreased and the antioxidant defense system was significantly disturbed after exposure to nano-TiO_2. Compared with control, the maximum level of malondialdehyde showed 3.3-fold increase for 15 days exposure to nano-TiO_2. The activity of superoxide dismutase and catalase enhanced obviously by 1.10-2.24-fold. The aqueous extract of G. lemaneiformis(AEGL) possesses anticancer activity against HepG2 liver cancer cells proliferation and the 48 h-cell inhibition exceeds 35%. But the toxicity of nano-TiO_2 would inhibit the anticancer activity of AEGL. When G. lemaneiformis was exposed to nano-TiO_2, the effect of the aqueous extract of G. lemaneiformis on the cell inhibition, reactive oxygen species production, apoptosis, cycle arrest of HepG2 cells significantly lessened, and which were linearly associated with nano-TiO_2 exposure concentration. Those results further confirmed that nano-TiO_2 can inhibit the anticancer activity of G. lemaneiformis. The results in this work imply that macroalgae can be an effective biomarker of nano-TiO_2 contaminant, and can be useful indicator to evaluate ecological effects of increasing pollutants in marine ecosystem.     

Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G. lichenoides (Rhodophyceae)

Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper (Cu2+ ) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu2+ , specifically, more Cu2+ on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast, cell nucleus, mitochondria, and ribosome). In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu2+ -binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu 2+ toxin for decreases in growth, pigment (chlorophyll a, chlorophyll b, phycobiliprotein, and β-carotene) content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities. Therefore, G. lichenoides was less susceptible to Cu2+ stress than G. lemaneiformis.     

Expression of the Phycoerythrin Gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and Evaluation of the Bioactivity of Recombinant PE

Phycoerythrin (PE) is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX (pGEX-PE) and BGL (pBGL). PE expressing in BEX (pGEX-PE) was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bod- ies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX (pGEX-PE) cells were col- lected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indi- cated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein con- centration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were significantly higher than the negative control BL21(pGEX-4T) (P<0.02), and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mg mL-1 BGL (pBGL) products, the scavenging effects of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were stronger than that of negative control BL21(pGEX-4T). However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially de- creased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This re- search showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value.     

Effects of temperature on photosynthetic performance and nitrate reductase activity in vivo assay in Gracilariopsis lemaneiformis (Rhodophyta)

Journal of Oceanology and Limnology - Gracilariopsis lemaneiformis is an economically-valued species and widely cultured in China at present. After being acclimated to different growth temperatures...     

A comparison of different Gracilariopsis lemaneiformis (Rhodophyta) parts in biochemical characteristics,protoplast formation and regeneration

Gracilariopsis lemaneiformis is a commercially exploited alga. Its filaceous thallus can be divided into three parts, holdfast, middle segment and tip. The growth and branch forming trend and agar content of these three parts were analyzed, respectively, in this study. The results showed that the tip had the highest growth rate and branched most, although it was the last part with branch forming ability. The holdfast formed branches earliest but slowly. Holdfast had the highest agar content. We also assessed the difference in protoplast formation and regeneration among three parts. The middle segment displayed the shortest enzymolysis time and the highest protoplast yield; whereas the tip had the strongest vitality of protoplasts formation. Juvenile plants were only obtained from the protoplasts generated from the tip. These results suggested that the differentiation and function of G. lemaneiformis was different.     

Optimization of pectin extraction and antioxidant activities from Jerusalem artichoke

Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the eff ects of processing variables(extraction temperature, p H, extraction time, and liquid-tosolid ratio) on the yield of Jerusalem artichoke pectin. Under the optimal extraction conditions: p H 1.52, 63.62 min, 100°C and a liquid-to-solid ratio of 44.4 m L/g, the maximum pectin yield was predicted to be 18.76%. Experiments were conducted under these optimal conditions and a pectin yield of 18.52±0.90% was obtained, which validated the model prediction. The eff ects of diff erent drying methods(freeze drying, spray drying and vacuum drying) on the properties of Jerusalem artichoke pectin were evaluated and they were compared with apple pectin. FTIR spectral analysis showed no major structural diff erences in Jerusalem artichoke pectin samples produced by various drying treatments. The antioxidant activities of pectin dried by diff erent methods were investigated using in vitro hydroxyl and DPPH radical scavenging systems. The results revealed that the activities of spray dried pectin(SDP) and apple pectin(AP) were stronger than those of vacuum oven dried pectin(ODP) and vacuum freeze dried pectin(FDP). Therefore compared with the other two drying methods, the spray drying method was the best.     

Combining geomatics and conventional methods for monitoring forest conditions under different governance arrangements

Introduction Assessment and systematic resource condition monitoring are essential components of long-term planning and management of forest resources. These requirements can be fulfilled using different methods and techniques. Traditionally, when the primary objective of forest management was tim- ber production, sample-based forest inventories were the sole method of determining forest condi- tions. Aerial photographs were frequently used for forest cover mapping during the third quarter of …     

Comparing rockfall hazard and risk assessment procedures along roads for different planning purposes

Hazard and risk assessment procedures of different types of rockfall were analyzed to compare their outcomes when they are applied to the same case study. Although numerous methodologies are available in literature, rockfall hazard and risk analyses are often limited to standard estimations,affected by a margin of uncertainty, especially when relevant engineering projects are about to be realized.Based on the design purpose, different types of approaches can be chosen among the qualitative and quantitative ones available in literature, which allow different levels of analysis. One of the main criticisms related to rockfall events is the risk affecting linear structures, such as road or railways, due both to their strategic relevance for trade and communications and to the great entity of the exposed value(traffic units)traveling along them. In this perspective, a comparison between the qualitative method known as Evolving Rockfall Hazard Assessment(EHRA), the semi-quantitative modified Rockfall Hazard Rating System(RHRS) and the quantitative Rockfall Risk Management(RoMa) approach is herein commented according to a practical application to a case study. It is the case of the rockfall threat along slopes crossed by a strategic road connecting two of the most known spots of eastern Sicily(Italy), at the Taormina tourist complex. Data were retrieved from both recent literature and technical surveys on field. Achieved results highlight how the approaches are affected by a different level of detail and uncertainty, arising also by some necessary assumption that must be taken into account, especially when mitigation measures or territory planning have to be designed. Achieved results can be also taken into account for similar studies worldwide, in order to choose the most suitable procedure based on the design purpose. This is indeed crucial in the perspective of the optimization of time and economic resources in the territorial planning practice.     

SCREENING FOR ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES IN SOME MARINE ALGAE FROM THE FUJIAN COAST OF CHINA WITH THREE DIFFERENT SOLVENTS

Three different solvents viz ethanol, acetone and methanol-toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlomphyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta (Laurenc/a okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae ) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.     

Effects of different phosphorus concentrations and N/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense

The effects of different phosphorus(P) concentrations(0.36, 3.6, and 36 μmol/L corresponding to low-, middle-, and high-P concentration groups, respectively) and nitrogen(N)/P ratios on the growth and photosynthetic characteristics of S keletonema costatum and Prorocentrum donghaiense were studied. For both species, the high-P(HP) concentration group showed the greatest algal density and highest specifi c growth rate. Changes in the maximum effi ciency of photosystem Ⅱ(F _v/F_m) were monitored under the various P and N/P conditions. The largest decrease in F _v/F_m was in the low-P(LP) group in S. costatum and in the HP group in P. donghaiense. There were high rapid light curves and photochemical quantum yields(Φ _(PSⅡ)) for S. costatum in the HP group, while the actual photosynthetic capacity was higher in P. donghaiense than in S. costatum in the MP group. Under eutrophic but relatively P-restricted conditions, P. donghaiense had higher photosynthetic activity and potential, which could cause this dinofl agellate to increasingly dominate the phytoplankton community in these conditions. Under the same P concentration and N/P ratio, P. donghaiense had a larger relative maximum rate of electron transport and higher Φ _(PSⅡ) values than those of S. costatum. These differences between P. donghaiense and S. costatum may explain the interaction and succession patterns of these two species in the Changjiang(Yangtze) River estuary from a photosynthesis perspective.     

Optimization of culture conditions and medium composition for the marine algicidal bacterium Alteromonas sp. DH46 by uniform design

Harmful algal blooms (HABs) have led to extensive ecological and environmental issues and huge economic losses. Various HAB control techniques have been developed, and biological methods have been paid more attention. Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner, and kill or damage the algal cells. A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp. The culture conditions were optimized using a single-factor test method. Factors including carbon source, nitrogen source, temperature, initial pH value, rotational speed and salinity were studied. The results showed that the cultivation of the bacteria at 28°C and 180 r min^?1 with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46. The optimal medium composition for strain DH46 was determined by means of uniform design experimentation, and the most important components influencing the cell density were tryptone, yeast extract, soluble starch, NaNO₃ and MgSO₄. When the following culture medium was used (tryptone 14.0g, yeast extract 1.63g, soluble starch 5.0 g, NaNO₃ 1.6 g, MgSO₄ 2.3 g in 1L), the largest bacterial dry weight (7.36 g L^?1) was obtained, which was an enhancement of 107% compared to the initial medium; and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.     

Simultaneous optical and radar observations of poleward moving auroral forms under different IMF conditions

Using high temporal resolution optical data obtained from three-wavelength all-sky imagers at Chinese Yellow River Station in the Arctic, together with the EISCAT Svalbard radar （ESR） and SuperDARN radars, we investigated the dayside pole- ward moving auroral forms （PMAFs） and the associated plasma features in the polar ionosphere under difibrent interplanetary magnetic field （1MF） conditions, between 0900 and 1010 UT on 22 December 2003. Simultaneous optical and ESR observations revealed that all PMAFs were clearly associated with pulsed particle precipitations. During northward IMF, particles can precipi- tate into lower altitudes and reach the ionospheric E-region, and there is a reverse convection cell associated with these PMAFs. This cell is one of the typical signatures of the dayside high-latitude （lobe） reconnection in the polar ionosphere. These results indicate that the PMAFs were associated with the high-latitude reconnection. During southward IMF, the PMAFs show larger lati- tudinal motion, indicating a longer mean lifetime, and the associated ionospheric features indicate that the PMAFs were generated by the dayside low-latitude reconnection.     

Optimization of fermentation conditions for 1,3-propanediol production by marine Klebsiella pneumonia HSL4 using response surface methodology

The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.     

Production of DMS and DMSP in different physiological stages and salinity conditions in two marine algae

Dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) production by Scrippsiella trochoidea and Prorocentrum minimum was investigated to characterize the effects of physiological stage and salinity on DMS and DMSP pools of these two marine phytoplankton species.Axenic laboratory cultures of the two marine algae were tested for DMSP production and its conversion into DMS.The results demonstrated that both algal species could produce DMS,but the average concentration of DMS per cell in S.trochoidea(12.63 fmol/L) was about six times that in P.minimum(2.01 fmol/L).DMS and DMSP concentrations in algal cultures varied significantly at different growth stages,with high release during the late stationary growth phase and the senescent phase.DMS production induced by three salinities(22,28,34) showed that the DMS concentrations per cell in the two algal cultures increased with increasing salinity,which might result from intra-cellular DMSP up-regulation with the change of osmotic stress.Our study specifies the distinctive contributions of different physiological stages of marine phytoplankton on DMSP and DMS production,and clarifies the influence of salinity conditions on the release of DMS and DMSP.As S.trochoidea and P.minimum are harmful algal bloom species with high DMS production,they might play an additional significant role in the sulfur cycle when a red tide occurs.     

东海盆地西湖凹陷平湖组煤系烃源岩条件及成烃模式

西湖凹陷是中国近海最重要的煤成油气凹陷。近年来，油气勘探证实平湖组煤系烃源岩为西湖凹陷提供了丰富的油气资源。与陆上其他中生代煤成油气盆地不同，近海新生代海陆过渡相平湖组煤系烃源岩在母质来源、生烃条件和演化特征上都有其独特性。研究表明，平湖组煤和炭质泥岩具有富含树脂体、高I_H指数、Ⅱ₁-Ⅱ₂型干酪根、广覆式分布特点；煤系烃源岩富含三环二萜异海松烷、四环二萜β-扁植烷和五环三萜奥利烷，指示了针叶类裸子植物、蕨类植物和被子植物多植被母质来源；有机质组成差异、"内热外冷"地温和差异的沉积沉降速率造成了煤和泥岩在不同构造带成烃演化具有明显不同。这种差异决定了煤成油气资源具有"油气并举、东气西油"的分布格局，烃源岩成烃演化表现为"早期有利生油，晚期持续生气"模式。      

PREDICTION OF SEDIMENT REDUCING BENEFIT UNDER DIFFERENT RAINFALL CONDITIONS AND CONTROL DEGREES ON THE LOESS PLATEAU DEGREES ON THE LOESS PLATEAU

Soilerosionisoneofthemostseriousenvironmentalproblemsinthepresentworld.Itnotonlyrestrictstheproductionofagriculturebadly,butalsothreatensthenaturalenvironmentonwhichhumanbeinglive.Andthismakethemankindconfrontedwithtremendouschallenge.OntheLoessPlateau,soilandwaterlossisterrible,environmentisweak,anditshighsandyieldmakestheriverwayinthelowerreachesoftheHuanghe(Yellow)Riverfilledup,riverbeddrivenup,floodthreatprickedup,andresultsingreathiddentroublestothecontrollingoffloodandtherunningofirrig…     

渤海海域东部不同富油凹陷烃源岩生烃特征差异及意义

渤海海域东部发育多个富油凹陷,具有较大的生烃潜力,由于各凹陷形成和发育过程不同,导致不同凹陷、不同层段烃源岩热演化和生、排烃特征具有明显差异。通过对渤海海域东部3个富油凹陷多套烃源岩进行埋藏史、热史和生、排烃史研究,厘定了渤中凹陷、渤东凹陷和庙西凹陷烃源岩生、排烃时间以及演化特征。结果表明:①渤海海域东部地区不同构造单元烃源岩热演化程度具有"西高东低"的趋势,渤中凹陷最早生烃时间为31.5 Ma,渤东凹陷和庙西凹陷最早生烃时间分别为28.2,11.2 Ma,渤中凹陷最早排烃时间为27.8 Ma,而渤东凹陷和庙西凹陷最早排烃时间分别为20.9,6.7 Ma;②渤中凹陷烃源岩热演化程度较高,现今主要为储层提供天然气,为环渤中凹陷地区形成天然气藏和凝析气藏提供了气源;渤东凹陷、庙西凹陷热演化程度依次降低,为储层提供大量油源,盆地边缘地区主要以油藏为主。      

Effects of different levels of sweet potato in feeds on body composition and digestive enzymes activities of Apostichopus japonicas Selenka

Journal of Oceanology and Limnology - The aim of this study was to test the effects of including sweet potato tuber and stem powder in feed on the body composition and digestive enzyme activities...     

Optimization of causative factors using logistic regression and artificial neural network models for landslide susceptibility assessment in Ujung Loe Watershed,South Sulawesi Indonesia

Landslide susceptibility maps(LSMs) play a vital role in assisting land use planning and risk mitigation. This study aims to optimize causative factors using logistic regression(LR) and an artificial neural network(ANN) to produce a LSM. The LSM is produced with 11 causative factors and then optimized using forward-stepwise LR(FSLR), ANN, and their combination(FSLR-ANN) until eight causative factors were found for each method. The ANN method produced superior validation results compared with LR. The ROC values for the training data set ranges between 0.8 and 0.9. On the other hand, validation with the percentage of landslide fall into LSM class high and very high, ANN method was higher(92.59%) than LR(82.12%). FSLR-ANN with nine causative factors gave the best validation results with respect to area under curve(AUC) values, and validation with the percentage of landslide fall into LSM class high and very high. In conclusion, ANN was found to be better than LR when producing LSMs. The best Optimization was combination of FSLR-ANN with nine causative factors and AUC success rate 0.847, predictive rate 0.844 and validation with landslide fall into high and very high class with 91.30%. It is an encouraging preliminary model towards a systematic introduction of FSLR-ANN model for optimization causative factors in landslide susceptibility assessment in the mountainous area of Ujung Loe Watershed.