When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>...When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>3</sub>,-N, 1.56× 10<sup>-4</sup>mol/L, PO<sub>4</sub>-P and supplementsof other elements like Mn, Fe, I, etc.), mate and female gametophytes of U pinnatifida keptgrowing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. Theempirical formula G<sub>m</sub>=G<sub>o</sub>. 3<sup>m</sup> was established to estimate the output of vegeative gametophytes. Vigorousvegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, whenthe tmperature was lower than 25℃ and other environmental factors wrre kept optimal. The sufficientsupply of gametophyte cells provided enough seeds for raising Undaria sporelings on prodiction scale.Controlled cross-breeding experiments using selcted male and female gametophyte clones which increasetheir cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes fromthe展开更多
Unicellular gametophytes of Undaria pinnatifida (Harv.) Sur. were isolated in Qingdao, P. R. China in April 1993 and in Tokushima, southem Japan in March 1995. Diferent intraspecific crossings by using unicellular mal...Unicellular gametophytes of Undaria pinnatifida (Harv.) Sur. were isolated in Qingdao, P. R. China in April 1993 and in Tokushima, southem Japan in March 1995. Diferent intraspecific crossings by using unicellular male and female gametophytes were successfully undertaken in Sept. of 1995 in Qingdao.Sporophytes were transplanted to two different locations for open an cultivation. One was at Zhanqiao (ZQ) Bay where the water current was slower than that of another location - Taipingjiao(TPJ). A total of218 adult sporophytes were harvested on January 12 and 18 from TPJ and ZQ repectively. For eacncombination, 10 sporophytes un cultivated. Analysis of the mprpholgical characteristics of adult spprophytes indicated that the longest length between two bases of the serration of pinnate bldes (W2) is a morphological characteristic that can be transferred from the parent plant to the next generations regardless of environmental variations. There was evidence that W2 was apparently determined by sex-linked factors, i.e, by male parental grametophyte.. Sporophytes from certain crossing combinations showed more vigorous growth than those from other crossing combinations. It is therrfore possible to select grametophyte strains which can be used as parental gametophytes for the seeding production of sporophytes with more vigorous growth within shorter cultivation period. The morphology of hybrids from a Qingdao strain and a Tokushima cultivated strain resembled that of both parental plants in frond feaures (wrinkled or smooth) and W2. Sporophyll formation also varied with strains. The fact that adult sporophytes resulting from the same crossing combinations have identical morphological characteristics under the same environmental conditions indicates the possibility of a new way to select strains which are expected to be ideal for commerical production by purposely selecting, propagating, and seeding unicellular gametophytes for sporeing production through freeliving techniques of gametophytes.展开更多
Fucoxanthin is a xanthophyll-type carotenoid that provides many benefits to human health. However, the mechanism by which fucoxanthin interacts with microbes and inhibits pathogenic bacteria is unknown. In this study,...Fucoxanthin is a xanthophyll-type carotenoid that provides many benefits to human health. However, the mechanism by which fucoxanthin interacts with microbes and inhibits pathogenic bacteria is unknown. In this study, we investigated the effects of fucoxanthin isolated from the edible seaweed Undaria pinnatifida on pathogenic bacteria Escherichia coli and lactobacilli both in vitro and in vivo. Fucoxanthin strongly inhibited the growth of Gram-positive pathogenic bacteria but was less effective against Gram-negative bacteria. Fucoxanthin extracted from the crude mixture had a recovery rate of 93.38% and a purity of 82.70%, which were higher than those of fucoxanthin extracted using a previous method. Fucoxanthin also promoted the growth of intestinal mi- crobes in mice. Fucoxanthinol, a metabolite of fucoxanthin, was generated in the culture media. Fucoxanthin can be deacetylated into fucoxanthinol not only by conventional digestive enzymes in the digestive tract, but also by E. coli and lactobacilli in the intestine. These results indicate that fucoxanthin interacts with and influences E. coli and lactobacilli in the intestine. Therefore, fucoxanthin isolated from Undaria pinnatifida possibly can be applied in human health maintenance.展开更多
Circadian growth rhythm of the juvenile sporophyte of the brown alga Undaria pinnatifida was measured with the computer-aided image analysis system in constant florescent white light under constant temperature （ 10 ...Circadian growth rhythm of the juvenile sporophyte of the brown alga Undaria pinnatifida was measured with the computer-aided image analysis system in constant florescent white light under constant temperature （ 10 ℃ ）. The growth rhythm persisted for 4 d in constant light with a free-running period of 25.6 h. Egg release from filamentous gametophytes pre-cultured in the light - dark regime was evaluated for six consecutive days at fixed time intervals in constant white light and 12 h light per day. Egg release rhythm persisted for 3 d in both regimes, indicating the endogenous nature. Temporal scale of egg release and gametogenesis in 18, 16, 12 and 8 h light per day were evaluated respectively using vegetatively propagated filamentous gametophytes. Egg release occurred 2 h after the onset of dark phase and peaked at midnight. Evaluation of the rates of oogonium formation, egg release or fertilization revealed no significant differences in four light-dark regimes, indicating the great plasticity of sexual reproduction. No photoperiodic effect in gametogenesis in terms of oogonium formation and egg release was found, but fertilization in short days was significantly higher than in long days. Results of this investigation further confirmed the general occurrence of circadian rhythms in intertidal seaweed species.展开更多
A sulfated galactoftucan designated as UpG was obtained from the brown algae Undaria pinnatifida by calcium chloride extraction.Chemical analyses showed that UpG is composed of galactose and fucose at a high sulfation...A sulfated galactoftucan designated as UpG was obtained from the brown algae Undaria pinnatifida by calcium chloride extraction.Chemical analyses showed that UpG is composed of galactose and fucose at a high sulfation level.Low-molecular weight UpGP-0.5 was prepared from UpG through acid hydrolysis for structure characterization.The backbones of UpG are determined to beα-(1,3)-Fuc,α-(1,4)-Gal,α-(1,3)-Gal,andα-(1,6)-Gal by GC-MS,FT-IR,NMR,and LC-MS analyses.Sulfate groups are modified at C2 and/or C4 of fucose and C3 and/or C4 of galactose.UpG could partially lower blood sugar and serum lipid levels in type 2 diabetic mice.Moreover,UpG treatment regulates the abundance of some specific gut microbiota,such as enriching the abundance of Muribaculum and Christensenellaceae,and reducing that of Bilophila,Tannerellaceae,Candidatus Saccharimonas and Anaerotruncus.The findings characterized the detailed structure of a sulfated galactofucan and investigated its potential for the treatment of type 2 diabetes mellitus.展开更多
During the induction of gamete-producing gametangia, induced gametophytes werecollected at 4 days intervals (0,4,8, 12 d) and total RNAs were isolated by CsCl gradient ultracentrifu-gation. Some stage-specific express...During the induction of gamete-producing gametangia, induced gametophytes werecollected at 4 days intervals (0,4,8, 12 d) and total RNAs were isolated by CsCl gradient ultracentrifu-gation. Some stage-specific expressed mRNAs were identified by differential display of mRNAs from dif-ferent developing stages of the gametophytes. The cDNA of one specific mRNA was verified, cloned andsequenced. This gene was specifically expressed during 4 days of induction, and had partial homologoussequence with tobacco IAA-binding protein gene. It suggests that this cDNA may represent a gene whichis related to the LAA regulating function during the development of the gametophytes.展开更多
In order to prevent salt damage because seaweed enzymes can only operate under hypohaline conditions (salinity ≈ 6‰ - 12‰) but also obtain for photosynthesis an in the aquatic environment—due to a 10,000 fold stro...In order to prevent salt damage because seaweed enzymes can only operate under hypohaline conditions (salinity ≈ 6‰ - 12‰) but also obtain for photosynthesis an in the aquatic environment—due to a 10,000 fold strongly limited carbon source—seaweeds developed several mechanisms to meet these vital demands for survival in the harsh euhaline oceanic environment (salinity range: 32‰ - 35‰), we tested this range of adaptation mechanisms in the euhaline oceanic collected water in combination with the seaweed moisture. We obtained under laboratory conditions at 10 bar mechanical pressure for four seaweed species: Ulva lactuca, Caulerpa sertularioides, Caulerpa cf. brachypus (all three green) and Undaria pinnatifidia (brown). Oceanic water and seaweed moisture were measured for salinity, pH and by Inductively Coupled Plasma Spectroscopy (ICP)-techniques concentrations for macro-elements: (Ca, Fe, K, Mg, Mn, Na, P, & S), micro-elements ≈ [HM]: (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) and nutrients (N-total & P-total). The [seawater compound X]/[oceanic compound X] ration is a reflection of an inward (uptake) or excretion mechanism over the seaweed cellular membrane which is operative. Our observations gave a clear dispersion to salinity stress with on one hand the green seaweed U. lactuca and on the other the brown seaweed U. pinnatifidia. Both Caulerpa spp. took in an intermediate position. Observed in compensatory responses to salinity stress was ranging Ulva sp. both Caulerpa spp.-Undaria sp.: 1) amount pressed seaweed moisture: [ml/g Fresh Weight];2) salinity: (in ‰);3) Na+ storage vacuole volume;4) Na+:K+ ratio (reflection of K+ as osmolyticum);5) ∑[HM] (as osmolyticum);6) pH (seaweed moisture);7) Nutrients (N & P);8) availability of essential metal elements for plants (Cu, Fe, Zn, Mn, Mo, Ni);9) transport direction of micro- and macro-elements. Finally, the role of brown vs. green seaweeds in the evolutionary eukaryotic tree of life in relation to the ability of the brown seaweeds to produce the展开更多
Response surface methodology was used to optimize the extraction conditions of polysaccharides from Undaria pinnatifida.The effects of three independent variables,extraction time,extraction temperature and ratio of wa...Response surface methodology was used to optimize the extraction conditions of polysaccharides from Undaria pinnatifida.The effects of three independent variables,extraction time,extraction temperature and ratio of water to raw material were investigated by a central composite design.The experimental data were fitted to a second-order polynomial equation via multiple regression analysis and also examined with the appropriate statistical methods.The adjusted coefficient of determination（R^2Adj） for the model was 0.9171.An optimum extraction yield of 30.78% was obtained when the extraction temperature was 95 °C,extraction time was 4.5 h,and the ratio of water to raw material was 35（mL/g）.Under these conditions,validation experiments were done and the mean extraction yield of polysaccharides was 30.79%,which was in good agreement with the predicted model value.展开更多
In the invading course of Undaria pinnatifida, zoospore attachment in a dynamically changed subtidal water environment is crucial for the establishment of a potential population in alien waters. Among many abiotic fac...In the invading course of Undaria pinnatifida, zoospore attachment in a dynamically changed subtidal water environment is crucial for the establishment of a potential population in alien waters. Among many abiotic factors that may interfere with the attachment process, water velocity is the most important one. In this investigation, the effect of water velocity on zoospore attachment of U. pinnatifida was investigated in an artificially designed system. It was found that freshly released zoospores that were transported by water flowing at 0 -16 cm/s showed no difficulty in attaching the smooth surface. Zoospore attachment decreased at elevated water flowing rates. At 70 cm/s no spore attachment occurred. Spores that have settled on glass slide for up to 1 h could not be stripped away by flowing water at a rate of 129 cm/s, the same was true of the 20 d old filamentous gametophytes. It was found that more than 70% of free-swimming zoospores tended to settle down adjacent to the settled spores and formed conjugated clusters from two up to a few hundred cells in still culture.展开更多
This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) ...This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.展开更多
Gold nanoparticles recently showed great interest for many uses including food, drug and medical applications. The algae </span><i style="font-family:"white-space:normal;">Undaria</i...Gold nanoparticles recently showed great interest for many uses including food, drug and medical applications. The algae </span><i style="font-family:"white-space:normal;">Undaria</i><span style="font-family:"white-space:normal;"> <i>sp.</i></span><span style="font-family:"white-space:normal;"> well known as wakame in South Asia are considered to be large edible brown algae. It provides nutritious source of dietary fiber, vitamin Bs and mineral. The present study aimed to investigate the use of </span><i style="font-family:"white-space:normal;">Undaria</i><span style="font-family:"white-space:normal;"> <i>sp.</i></span><span style="font-family:"white-space:normal;"> for green synthesis of metallic gold nanoparticles. The synthesized nanoparticles were characterized for physicochemical properties including size measurement and tested </span><i style="font-family:"white-space:normal;">in</i><span style="font-family:"white-space:normal;"> <i>vitro</i></span><span style="font-family:"white-space:normal;"> for their effect on viability of human non-small lung cancer H-460 cell line using the MTT assay. From the results, brown algae were able to chemically form nanoparticles with chloroauric acid solution possibly due to the sulphated polysaccharides found in algae. The particle sizes were found to be approximately 10 nm. The gold nanoparticles stabilized by the algae could decrease the cancer cell viability. However, the properties and biological activity of nanoparticles seemed to depend upon reaction time and temperature. Conclusively, gold nanoparticles synthesized and stabilized by the algae could decrease the cancer cell viability, thus indicating the potential of such nanoparticles for further study for anticancer activity.展开更多
Undaria pinnatifida, Wakame is a popular edible seaweed in its native Asia and was first recorded in New Zealand in Wellington Harbor in 1987. It is classified as an unwanted species under the Biosecurity Act 1993, bu...Undaria pinnatifida, Wakame is a popular edible seaweed in its native Asia and was first recorded in New Zealand in Wellington Harbor in 1987. It is classified as an unwanted species under the Biosecurity Act 1993, but there is growing interest in harvesting this seaweed for human consumption. The aim of this study was to evaluate the concentrations of metals in U. pinnatifida from several locations (Marlborough Sounds and Wellington harbor) and across seasons. In brief, the highest monthly mean concentration of metals found in New Zealand wild U. pinnatifida was Ca (16.97g·kg-1), K (48.48 g·kg-1), Mg (9.47 g·kg-1), P (12.05 g·kg-1), Cr (1.04 mg·kg-1), Cu (3.78 mg·kg-1), Mn (14.61 mg·kg-1), Ni (2.78 mg·kg-1), Se (0.83 mg·kg-1), Zn (35.03 mg·kg-1), As (46.71 mg·kg-1), Cd (2.91 mg·kg-1), Hg (0.042 mg·kg-1) and Pb (0.31 mg·kg-1). These results showed that New Zealand U. pinnatifida is a good source of the nutritionally important minerals calcium, magnesium, potassium and phosphorus. They also contained trace amounts of minerals such as chromium, copper, manganese, nickel, selenium and zinc. Contaminants such as arsenic, cadmium, mercury and lead were found at very low, safe, levels.展开更多
The aim of this study is to isolate protoplasts from Undaria pinnatifida. Protoplasts of the alga were isolated enzymatically by using alginate lyase, which was prepared by fermenting culture of a strain Vibrio sp. 51...The aim of this study is to isolate protoplasts from Undaria pinnatifida. Protoplasts of the alga were isolated enzymatically by using alginate lyase, which was prepared by fermenting culture of a strain Vibrio sp. 510. Monofacterial method was applied for optimizing digestion condition. The optimum condition for protoplast preparation is enzymatic digestion at 28 ℃ for 2 h using alginate lyase at the concentration of 213.36 U (8 mL) every 0.5 g fresh thalline with NaCl 50 and at the shaking speed of 150 r min -1 during digestion. The protoplast yield can reach 2.62±0.09 million per 0.5 g fresh leave under the optimum condition. The enzyme activity is inhibited by Ca 2+ and slightly enhanced by Fe 2+ and Mn 2+ at concentrations of 0.05, 0.08 and 0.10 mol L -1.展开更多
基金Supported by National Natural Science Foundation of China.
文摘When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>3</sub>,-N, 1.56× 10<sup>-4</sup>mol/L, PO<sub>4</sub>-P and supplementsof other elements like Mn, Fe, I, etc.), mate and female gametophytes of U pinnatifida keptgrowing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. Theempirical formula G<sub>m</sub>=G<sub>o</sub>. 3<sup>m</sup> was established to estimate the output of vegeative gametophytes. Vigorousvegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, whenthe tmperature was lower than 25℃ and other environmental factors wrre kept optimal. The sufficientsupply of gametophyte cells provided enough seeds for raising Undaria sporelings on prodiction scale.Controlled cross-breeding experiments using selcted male and female gametophyte clones which increasetheir cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes fromthe
文摘Unicellular gametophytes of Undaria pinnatifida (Harv.) Sur. were isolated in Qingdao, P. R. China in April 1993 and in Tokushima, southem Japan in March 1995. Diferent intraspecific crossings by using unicellular male and female gametophytes were successfully undertaken in Sept. of 1995 in Qingdao.Sporophytes were transplanted to two different locations for open an cultivation. One was at Zhanqiao (ZQ) Bay where the water current was slower than that of another location - Taipingjiao(TPJ). A total of218 adult sporophytes were harvested on January 12 and 18 from TPJ and ZQ repectively. For eacncombination, 10 sporophytes un cultivated. Analysis of the mprpholgical characteristics of adult spprophytes indicated that the longest length between two bases of the serration of pinnate bldes (W2) is a morphological characteristic that can be transferred from the parent plant to the next generations regardless of environmental variations. There was evidence that W2 was apparently determined by sex-linked factors, i.e, by male parental grametophyte.. Sporophytes from certain crossing combinations showed more vigorous growth than those from other crossing combinations. It is therrfore possible to select grametophyte strains which can be used as parental gametophytes for the seeding production of sporophytes with more vigorous growth within shorter cultivation period. The morphology of hybrids from a Qingdao strain and a Tokushima cultivated strain resembled that of both parental plants in frond feaures (wrinkled or smooth) and W2. Sporophyll formation also varied with strains. The fact that adult sporophytes resulting from the same crossing combinations have identical morphological characteristics under the same environmental conditions indicates the possibility of a new way to select strains which are expected to be ideal for commerical production by purposely selecting, propagating, and seeding unicellular gametophytes for sporeing production through freeliving techniques of gametophytes.
基金supported by the Independent Innovation Major Project of Huangdao District, Qingdao City (No. 2014-3-11)the National Natural Science Foundation of China (No. 31371731)
文摘Fucoxanthin is a xanthophyll-type carotenoid that provides many benefits to human health. However, the mechanism by which fucoxanthin interacts with microbes and inhibits pathogenic bacteria is unknown. In this study, we investigated the effects of fucoxanthin isolated from the edible seaweed Undaria pinnatifida on pathogenic bacteria Escherichia coli and lactobacilli both in vitro and in vivo. Fucoxanthin strongly inhibited the growth of Gram-positive pathogenic bacteria but was less effective against Gram-negative bacteria. Fucoxanthin extracted from the crude mixture had a recovery rate of 93.38% and a purity of 82.70%, which were higher than those of fucoxanthin extracted using a previous method. Fucoxanthin also promoted the growth of intestinal mi- crobes in mice. Fucoxanthinol, a metabolite of fucoxanthin, was generated in the culture media. Fucoxanthin can be deacetylated into fucoxanthinol not only by conventional digestive enzymes in the digestive tract, but also by E. coli and lactobacilli in the intestine. These results indicate that fucoxanthin interacts with and influences E. coli and lactobacilli in the intestine. Therefore, fucoxanthin isolated from Undaria pinnatifida possibly can be applied in human health maintenance.
文摘Circadian growth rhythm of the juvenile sporophyte of the brown alga Undaria pinnatifida was measured with the computer-aided image analysis system in constant florescent white light under constant temperature （ 10 ℃ ）. The growth rhythm persisted for 4 d in constant light with a free-running period of 25.6 h. Egg release from filamentous gametophytes pre-cultured in the light - dark regime was evaluated for six consecutive days at fixed time intervals in constant white light and 12 h light per day. Egg release rhythm persisted for 3 d in both regimes, indicating the endogenous nature. Temporal scale of egg release and gametogenesis in 18, 16, 12 and 8 h light per day were evaluated respectively using vegetatively propagated filamentous gametophytes. Egg release occurred 2 h after the onset of dark phase and peaked at midnight. Evaluation of the rates of oogonium formation, egg release or fertilization revealed no significant differences in four light-dark regimes, indicating the great plasticity of sexual reproduction. No photoperiodic effect in gametogenesis in terms of oogonium formation and egg release was found, but fertilization in short days was significantly higher than in long days. Results of this investigation further confirmed the general occurrence of circadian rhythms in intertidal seaweed species.
基金Supported by the National Key Research and Development Program(Nos.2018YFC0311003,2017YFE0103100)the National Natural Science Foundation of China(Nos.81903534,81773628,81741165)the HighLevel Talent Special Support Plan of Zhejiang Province(No.2019R52009)。
文摘A sulfated galactoftucan designated as UpG was obtained from the brown algae Undaria pinnatifida by calcium chloride extraction.Chemical analyses showed that UpG is composed of galactose and fucose at a high sulfation level.Low-molecular weight UpGP-0.5 was prepared from UpG through acid hydrolysis for structure characterization.The backbones of UpG are determined to beα-(1,3)-Fuc,α-(1,4)-Gal,α-(1,3)-Gal,andα-(1,6)-Gal by GC-MS,FT-IR,NMR,and LC-MS analyses.Sulfate groups are modified at C2 and/or C4 of fucose and C3 and/or C4 of galactose.UpG could partially lower blood sugar and serum lipid levels in type 2 diabetic mice.Moreover,UpG treatment regulates the abundance of some specific gut microbiota,such as enriching the abundance of Muribaculum and Christensenellaceae,and reducing that of Bilophila,Tannerellaceae,Candidatus Saccharimonas and Anaerotruncus.The findings characterized the detailed structure of a sulfated galactofucan and investigated its potential for the treatment of type 2 diabetes mellitus.
文摘During the induction of gamete-producing gametangia, induced gametophytes werecollected at 4 days intervals (0,4,8, 12 d) and total RNAs were isolated by CsCl gradient ultracentrifu-gation. Some stage-specific expressed mRNAs were identified by differential display of mRNAs from dif-ferent developing stages of the gametophytes. The cDNA of one specific mRNA was verified, cloned andsequenced. This gene was specifically expressed during 4 days of induction, and had partial homologoussequence with tobacco IAA-binding protein gene. It suggests that this cDNA may represent a gene whichis related to the LAA regulating function during the development of the gametophytes.
文摘In order to prevent salt damage because seaweed enzymes can only operate under hypohaline conditions (salinity ≈ 6‰ - 12‰) but also obtain for photosynthesis an in the aquatic environment—due to a 10,000 fold strongly limited carbon source—seaweeds developed several mechanisms to meet these vital demands for survival in the harsh euhaline oceanic environment (salinity range: 32‰ - 35‰), we tested this range of adaptation mechanisms in the euhaline oceanic collected water in combination with the seaweed moisture. We obtained under laboratory conditions at 10 bar mechanical pressure for four seaweed species: Ulva lactuca, Caulerpa sertularioides, Caulerpa cf. brachypus (all three green) and Undaria pinnatifidia (brown). Oceanic water and seaweed moisture were measured for salinity, pH and by Inductively Coupled Plasma Spectroscopy (ICP)-techniques concentrations for macro-elements: (Ca, Fe, K, Mg, Mn, Na, P, & S), micro-elements ≈ [HM]: (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) and nutrients (N-total & P-total). The [seawater compound X]/[oceanic compound X] ration is a reflection of an inward (uptake) or excretion mechanism over the seaweed cellular membrane which is operative. Our observations gave a clear dispersion to salinity stress with on one hand the green seaweed U. lactuca and on the other the brown seaweed U. pinnatifidia. Both Caulerpa spp. took in an intermediate position. Observed in compensatory responses to salinity stress was ranging Ulva sp. both Caulerpa spp.-Undaria sp.: 1) amount pressed seaweed moisture: [ml/g Fresh Weight];2) salinity: (in ‰);3) Na+ storage vacuole volume;4) Na+:K+ ratio (reflection of K+ as osmolyticum);5) ∑[HM] (as osmolyticum);6) pH (seaweed moisture);7) Nutrients (N & P);8) availability of essential metal elements for plants (Cu, Fe, Zn, Mn, Mo, Ni);9) transport direction of micro- and macro-elements. Finally, the role of brown vs. green seaweeds in the evolutionary eukaryotic tree of life in relation to the ability of the brown seaweeds to produce the
基金research was a part of the project titled "Korea Sea Grant Program(Gyeong-gi Sea Grant)" funded by the Ministry of Land,Transport and Maritime Affairs,Korea
文摘Response surface methodology was used to optimize the extraction conditions of polysaccharides from Undaria pinnatifida.The effects of three independent variables,extraction time,extraction temperature and ratio of water to raw material were investigated by a central composite design.The experimental data were fitted to a second-order polynomial equation via multiple regression analysis and also examined with the appropriate statistical methods.The adjusted coefficient of determination（R^2Adj） for the model was 0.9171.An optimum extraction yield of 30.78% was obtained when the extraction temperature was 95 °C,extraction time was 4.5 h,and the ratio of water to raw material was 35（mL/g）.Under these conditions,validation experiments were done and the mean extraction yield of polysaccharides was 30.79%,which was in good agreement with the predicted model value.
基金The"863"Hi-Tech Research and Development Program of China under contract No. 2006AA10A412 a project from the Chinese Academy of Sciences under contract No.KSCX2-YW-N-47-07
文摘In the invading course of Undaria pinnatifida, zoospore attachment in a dynamically changed subtidal water environment is crucial for the establishment of a potential population in alien waters. Among many abiotic factors that may interfere with the attachment process, water velocity is the most important one. In this investigation, the effect of water velocity on zoospore attachment of U. pinnatifida was investigated in an artificially designed system. It was found that freshly released zoospores that were transported by water flowing at 0 -16 cm/s showed no difficulty in attaching the smooth surface. Zoospore attachment decreased at elevated water flowing rates. At 70 cm/s no spore attachment occurred. Spores that have settled on glass slide for up to 1 h could not be stripped away by flowing water at a rate of 129 cm/s, the same was true of the 20 d old filamentous gametophytes. It was found that more than 70% of free-swimming zoospores tended to settle down adjacent to the settled spores and formed conjugated clusters from two up to a few hundred cells in still culture.
文摘This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.
文摘Gold nanoparticles recently showed great interest for many uses including food, drug and medical applications. The algae </span><i style="font-family:"white-space:normal;">Undaria</i><span style="font-family:"white-space:normal;"> <i>sp.</i></span><span style="font-family:"white-space:normal;"> well known as wakame in South Asia are considered to be large edible brown algae. It provides nutritious source of dietary fiber, vitamin Bs and mineral. The present study aimed to investigate the use of </span><i style="font-family:"white-space:normal;">Undaria</i><span style="font-family:"white-space:normal;"> <i>sp.</i></span><span style="font-family:"white-space:normal;"> for green synthesis of metallic gold nanoparticles. The synthesized nanoparticles were characterized for physicochemical properties including size measurement and tested </span><i style="font-family:"white-space:normal;">in</i><span style="font-family:"white-space:normal;"> <i>vitro</i></span><span style="font-family:"white-space:normal;"> for their effect on viability of human non-small lung cancer H-460 cell line using the MTT assay. From the results, brown algae were able to chemically form nanoparticles with chloroauric acid solution possibly due to the sulphated polysaccharides found in algae. The particle sizes were found to be approximately 10 nm. The gold nanoparticles stabilized by the algae could decrease the cancer cell viability. However, the properties and biological activity of nanoparticles seemed to depend upon reaction time and temperature. Conclusively, gold nanoparticles synthesized and stabilized by the algae could decrease the cancer cell viability, thus indicating the potential of such nanoparticles for further study for anticancer activity.
文摘Undaria pinnatifida, Wakame is a popular edible seaweed in its native Asia and was first recorded in New Zealand in Wellington Harbor in 1987. It is classified as an unwanted species under the Biosecurity Act 1993, but there is growing interest in harvesting this seaweed for human consumption. The aim of this study was to evaluate the concentrations of metals in U. pinnatifida from several locations (Marlborough Sounds and Wellington harbor) and across seasons. In brief, the highest monthly mean concentration of metals found in New Zealand wild U. pinnatifida was Ca (16.97g·kg-1), K (48.48 g·kg-1), Mg (9.47 g·kg-1), P (12.05 g·kg-1), Cr (1.04 mg·kg-1), Cu (3.78 mg·kg-1), Mn (14.61 mg·kg-1), Ni (2.78 mg·kg-1), Se (0.83 mg·kg-1), Zn (35.03 mg·kg-1), As (46.71 mg·kg-1), Cd (2.91 mg·kg-1), Hg (0.042 mg·kg-1) and Pb (0.31 mg·kg-1). These results showed that New Zealand U. pinnatifida is a good source of the nutritionally important minerals calcium, magnesium, potassium and phosphorus. They also contained trace amounts of minerals such as chromium, copper, manganese, nickel, selenium and zinc. Contaminants such as arsenic, cadmium, mercury and lead were found at very low, safe, levels.
文摘The aim of this study is to isolate protoplasts from Undaria pinnatifida. Protoplasts of the alga were isolated enzymatically by using alginate lyase, which was prepared by fermenting culture of a strain Vibrio sp. 510. Monofacterial method was applied for optimizing digestion condition. The optimum condition for protoplast preparation is enzymatic digestion at 28 ℃ for 2 h using alginate lyase at the concentration of 213.36 U (8 mL) every 0.5 g fresh thalline with NaCl 50 and at the shaking speed of 150 r min -1 during digestion. The protoplast yield can reach 2.62±0.09 million per 0.5 g fresh leave under the optimum condition. The enzyme activity is inhibited by Ca 2+ and slightly enhanced by Fe 2+ and Mn 2+ at concentrations of 0.05, 0.08 and 0.10 mol L -1.
