Explant exenisation for tissue culture in marine macroalgae

Unialgal explants fromLaminaria digitata, and from a variety of red algae, were obtained by hand removing the visible epiphytes, and stirring the tissue in the presence of glass beads. Two antibiotic mixtures were found to be efficient in removing the contaminating fungi and bacteria from the algae. The procedure proved suitable as a primary step in the tissue culture of the investigated species.     

EFFECTS OF CO-CULTURE AND SALINITY ON THE GROWTH AND AGAR YIELD OF GRACILARIA TENUISTIPITATA VAR LIUI ZHANG ET XIA

ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ｃｏ ｃｕｌｔｕｒｅ (ｉｎｔｅｇｒａｔｅｄｃｕｌｔｕｒｅ )ｏｆｍａｒｉｎｅｓｐｅｃｉｅｓ (ａｌｇａｅａｎｄａｎｉｍａｌｓ)ｈａｓｒｅｃｅｉｖｅｄｇｒｅａｔａｔｔｅｎｔｉｏｎ .Ｉｎｃｏ ｃｕｌｔｕｒｅｓｙｓｔｅｍｔｈｅａｌｇａｅａｃｔｉｖｅｌｙｕｐｔａｋｅＣＯ2 ａｎｄｔｈｅｍｅｔａｂｏｌｉｃｗａｓｔｅｓ(ｓｕｃｈａｓＮＨ4 +,ＮＯ2 - ,ＮＯ3- ｅｔｃ)ａｓｎｕｔｒｉｅｎｔｓｏｕｒｃｅｓ,ａｎｄｒｅｌｅａｓｅＯ2 ｔｏｔｈｅｓｕｒｒｏｕｎｄｉｎｇｅｎｖｉｒｏｎ …     

EFFECTS OF CO—CULTURE AND SALINITY ON THE GROWTH AND AGAR YIELD OF GRACILARIA TENUISTIPITATA VAR LIUI ZHANG ET XIA

Gracilaria tenuistipitata var Liui were mono-cultivated and co-cultivated with Pinctada martensii under high(33) and low(21) salinity conditions in laboratory.The daily growth rate of the alga was determined.Tissue carbon and nitrogen contents,the yield and fractional composition of agar were analyzed.Results showed that:1.Gracilaria grew better under low salinity conditions,the daily growth rate was twice that under high salinity conditions.Co-cultivated algae grew faster than mono-culti-vated algae under low salinity conditions,the daily growth rate was about 37.6?higher.2.Compared with mono-cultivated algae,tissue nitrogen contents of co-cultivated algae were higher,while the C:N ratios were much lower.3.The agar yields of co-cultivated algae were much lower than those of mono-culti-vated algae.Agar yield was found to be negatively correlated to the tissue nitrogen contents,and positively correlated to the C:N ratios.4.The highest fractional yields obtained from co-cultivated algae were extracted with 40?ethanol,while from mono-cultivated algae,the highest fractional yields obtained were extracted with distilled water at room temperature.     

STUDY ON THE PHYTOPLANKTON.IN A LARGE RESERVOIR

A comprehensive study on the community structure and function of the phytoplankton in Taipinghu Reservoir, the largest reservoir (9400 ha) in Anhui Province, China, was carried out dur ing 1985- 1986. A total of 175 species of algae belonging to 8 phyla and 87 genera was noted. The composition of phytoplankton was dominated by species of Chlorophyta, Cyanophyta and Bacillariophyta. The species number, cell density and biomass of the three groups were respectively 88%, 86.5% and 78.9% of the total phytopiankton. The weighted annual average biomass was 1.52 mg/L and cell density was 1.43 x 106 ind/L. The growth maximum was observed in summer. Diatoms were abundant in the region adjoining a river. A large number of flagellated algae such as Euglena and Chromulina occurred in the artificial fish culture bay.It can be inferred from the algal composition and total nitrogen concentration (1.48mg/L) that this reservoir is a mesotrophic water body that had undergone slight natural eutrophication.Presented are an     

Lytic Characteristics and Identification of Two Alga-lysing Bacterial Strains

Lytic Characteristics and Identification of Two Alga-lysing Bacterial StrainsBeaulieu, S. E., M. R. Sengco, and D. M. Anderson, 2005. Using clay to control harmful algal blooms: deposition and resuspension of clay/algal flocs. Harmful Algae . (4): 123-138…     

IDENTIFICATION OF CYTOKININ IN A GREEN ALGAE EXTRACT

Isopentnyladenosine(i~6Ado) was identified, and trans-zeatin (trans-Z) and trans-zeatin riboside(trans-ZR) were detected by high pressure liquld chrmoatoguphy (HPLC) but not verified withchromatography - mass spectrometry (GC - M S ) analysis of cytokinin from the extracts of green algae (Ulvapertusa (Kjellm), Enteromopha compressa and Monostma sp). This indicated that the green algae mixturecontained cytokinin -like substances.     

Abundance, biomass and composition of spring ice algal and phytoplankton communities of the Laptev Sea （Arctic）

Abundance,biomass and composition of the ice algal and phytoplank-ton communities were investigated in the southeastern Laptev Sea in spring 1999.Diatoms dominated the algal communities and pennate diatoms dominated the dia-tom population.12 dominant algal species occurred within sea ice and underlyingwater column,including Fragilariopsis oceanica,F.cylindrus,Nitzschiafrigida,N.promare,Achnanthes taeniata,Nitzschia neofrigida,Naviculapelagica,N.vanhoef fenii,N.septentrionalis,Melosira arctica,Clindrothecaclosterium and Pyrarnimonas sp.The algal abundance of bottom 10 cm sea icevaried between 14.6 and 1562.2×10~4 ceils l~(-1)with an average of 639.0×10~4cells l~(-1),and the algal biomass ranged from 7.89 to 2093.5μg C l~(-1)with an av-erage of 886.9μg C l~(-1),which were generally one order of magnitude higherthan those of sub-bottom ice and two orders of magnitude higher than those ofunderlying surface water.The integrated algal abundance and biomass of lower-most 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 mwater column,respectively,suggesting that the ice algae might play an importantrole in maintaining the coastal marine ecosystem before the thawing of sea ice.Icealgae influenced the phytoplankton community of the underlying water column.However,the“seeding”of ice algae for phytoplankton bloom was negligible be-cause of the iow phytoplankton biomass within the underlying water column.     

Changes of Cellular Superficial Configuration of Symbiotic Algae During Cultivation from Two Anemones Found in the South China Sea

Symbiotic algae from two anemones, Radianthus macrodactylus and Stichodactyla mertensii, found in the South China Sea, were cultivated in ASP-8A medium in this study. Changes of superficial configuration of symbiotic algae during the cultivation were studied by means of a microscope and a scanning electron microscope （SEM）. A number of small cavities appeared on the surfaces of symbiotic algae after they were cultivated for 10 h. The cavities enlarged and the cell contents were lost with extended cultivation. Our data suggested that the presence of cavities on symbiotic algae surfaces may be one of the main reasons for failure to culture symbiotic algae in an artificial medium.     

Involvement of cyclic electron flow in irradiance stress responding and its potential regulation of the mechanisms in Pyropia yezoensis

Pyropia yezoensis, belongs to the genus of P orphyra before 2011, inhabit on intertidal zone rocks where irradiation changes dramatically, implying that the seaweed has gained certain mechanisms to survive a harsh environment. Based on the photosynthetic parameters with or without the inhibitors determined by a Dual-PAM-100 apparatus, we investigated the photosynthetic performance and the changes in electron fl ow that occurred during the algae were stressed with dif ferent light intensities previously. When the irradiation saturation was approaching, the CEF around PS I became crucial since the addition of inhibitors usually led to an increase in non-photochemical quenching. The inhibitor experiments showed that there were at least three dif ferent CEF pathways in Py. yezoensis and these pathways compensated each other. In addition to maintaining a proper ratio of ATP/NAD(P)H to support effi cient photosynthesis, the potential roles of CEF might also include the regulation of dif ferent photoprotective mechanisms in Py. yezoensis. Under the regulation of CEF, chlororespiration is thought to transport electrons from the reduced plastoquinone(PQ) pool to oxygen in order to mitigate the reduction in the electron transfer chain. When irradiation was up to the high-grade stress conditions, the relative value of CEF began to decrease, which implied that the NADP+ pool or PQ + pool was very small and that the electrons were transferred from reduced PS I to oxygen. The scavenging enzymes might be activated and the water-water cycle probably became an ef fective means of removing the active oxygen produced by the irradiation stressed Py. yezoensis. We believe that the dif ferent mechanisms could make up the photoprotective network to allow Py. yezoensis for survival in a highly variable light stress habitat, which may enlighten scientists in future studies on irradiance stress in other algae species.     

Study on Algae Removal by Immobilized Biosystem on Sponge

In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake＇s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time （HRT） was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preyingby microcreatures were the two main modes of algal removal, which occurred in two steps： first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.     

Removal of eutrophication factors and heavy metal from a closed cultivation system using the macroalgae, Gracilaria sp. (Rhodophyta)

In this study, the ability of macroalgae Gracilaria sp. of removing eutrophication factors and toxic heavy metals Al, Cr, and Zn in a closed cultivation system is reported. The results show that the concentration of the three heavy metals decreased significantly during the experimental period in an algal biomass dependent manner. The biofiltration capacity of the alga for Al, Cr, and Zn is 10.1%–72.6%, 52.5%–83.4% and 36.5%–91.7%, respectively. Using more materials resulted in stronger heavy metal removal. Additionally, the concentration of chl-a, TN, TP and DIN of water samples from aquariums involving large, medium, and small algal biomass cultivation increased first and then decreased during the experiment. COD value of all three groups decreased with time and displayed algal biomass dependency: more algae resulting in a greater COD value than those of less biomass. Furthermore, changes in COD reflect an obvious organic particles deprivation process of algae. This is the first report on heavy metal removal effect by Gracilaria species. The results suggest that macroalgae can be used as a biofilter for the treatment of nutrient-enriched or heavy-metal polluted water, to which an appropriate time range should be carefully determined.     

Insertal Orientation Has No Influence on the Expression of gfp Gene and the Growth of the Host Synechococcus sp. PCC7942

In transgenic process, a foreign gene can be integrated in the host genome in two directions, which may influence its expression. In order to study the effects of insertal orientation, the gfp reporter gene was inserted in the isiAB locus of Synechococcus sp.PCC7942 in different directions, and the GFP expression levels and the growth of the transgenic algae were compared. It was showed that the gfp gene could express in each direction, and no significant difference was detected on algal growth and GFP expression levels between the two recombinant algae.     

ASPECTS OF IRON NUTRITION IN MACROALGAE ULVA PERTUSA (CHLOROPHYTA) UNDER IRON STRESS

ＩＮＴＲＯＤＵＣＴＩＯＮＩｒｏｎｉｓａｎｉｍｐｏｒｔａｎｔｎｕｔｒｉｔｉｏｎａｌｅｌｅｍｅｎｔｉｎａｌｇａｅｊｕｓｔａｓｉｔｉｓｉｎｈｉｇｈｐｌａｎｔｍｅｔａｂｏｌｉｃｐａｔｈｗａｙｓ.Ｐｈｏｔｏｓｙｎｔｈｅｓｉｓｉｓｄｅｐｅｎｄｅｎｔｏｎｔｈｉｓｅｌｅｍｅｎｔｂｅｃａｕｓｅｃｈｌｏｒｏｐｈｙｌｌｓｙｎｔｈｅｓｉｓｒｅｑｕｉｒｅｓｉｒｏｎｎｕｔｒｉｔｉｏｎ .Ｉｒｏｎｉｓａｌｓｏｅｓｓｅｎｔｉａｌｆｏｒｃｙｔｏｃｈｒｏｍｅｓ,ｆｅｒｒｅｄｏｘｉｎ ,ａｎｄＦｅ ｓｐｒｏｔｅｉｎ .Ｉｔｓｂｉｏｃｈｅｍｉ…     

CHANGE IN THE ACTIVITY OF THE RESPIRATORY ELECTRON TRANSPORT SYSTEM IN NATURAL PHYTOPLANKTON ASSEMBLAGES AND CULTURED ALGAE

Activities of the respiratory electron transport system (ETS), C uptake, chlorophyll and temperature were determined at a station in the center of Donghu Lake. Seasonal, fluctuations in ETS-activities ranged from 100 to 460μg O2 h-1.L-1. Production: respiration ratio (P/R) calculated from C uptake and ETS-activity, ranged from 0.2 to 6.8. The test on cultured algae ETS-activity revealed marked differences in different growth phases. ETS activity is suggested as an indicator of lake nutrient status.     

海南省三亚海藻资源调查

通过对海南島三亚海藻的分布和种类进行深入调查,采集和整理了标本123号,计35属53种,并分析了三亚的气候和环境条件对海藻的生长与分布的关系,为三亚海藻的开发与利用提供了第一手资料。     

Dynamic Diurnal Changes in Green Algae Biomass in the Southern Yellow Sea Based on GOCI Images

Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007, inducing severe ecological problems and huge economic losses. Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods. In this study, green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI), and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes. The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG), which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method. For the first time, dynamic changes in green algae biomass were studied over an hourly scale. Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR) and tidal phases, but less by sea surface temperature variations on a daily timescale. A new parameter of biomass changes(PBC), calculated by the ratio of the biomass growth rate to movement velocity, could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.     

Involvement of cyclic electron flow in irradiance stress responding and its potential regulation of the mechanisms in <Emphasis Type="Italic">Pyropia yezoensis</Emphasis>

Pyropia yezoensis, belongs to the genus of Porphyra before 2011, inhabit on intertidal zone rocks where irradiation changes dramatically, implying that the seaweed has gained certain mechanisms to survive a harsh environment. Based on the photosynthetic parameters with or without the inhibitors determined by a Dual-PAM-100 apparatus, we investigated the photosynthetic performance and the changes in electron flow that occurred during the algae were stressed with different light intensities previously. When the irradiation saturation was approaching, the CEF around PS I became crucial since the addition of inhibitors usually led to an increase in non-photochemical quenching. The inhibitor experiments showed that there were at least three different CEF pathways in Py. yezoensis and these pathways compensated each other. In addition to maintaining a proper ratio of ATP/NAD(P)H to support efficient photosynthesis, the potential roles of CEF might also include the regulation of different photoprotective mechanisms in Py. yezoensis. Under the regulation of CEF, chlororespiration is thought to transport electrons from the reduced plastoquinone (PQ) pool to oxygen in order to mitigate the reduction in the electron transfer chain. When irradiation was up to the high-grade stress conditions, the relative value of CEF began to decrease, which implied that the NADP⁺ pool or PQ⁺ pool was very small and that the electrons were transferred from reduced PS I to oxygen. The scavenging enzymes might be activated and the water-water cycle probably became an effective means of removing the active oxygen produced by the irradiation stressed Py. yezoensis. We believe that the different mechanisms could make up the photoprotective network to allow Py. yezoensis for survival in a highly variable light stress habitat, which may enlighten scientists in future studies on irradiance stress in other algae species.     

Morphology and molecular identification of Ulva forming green tides in Qingdao, China

Green tides are caused by the proliferation of chlorophytes under suitable hydrographic conditions.These blooms lead to environmental degradation and negatively impact the waters and seagrass beds,as well as fishing and other recreational activities in the bay.A comprehensive ecological understanding of the bloom dynamics,including the origin and persistence,is needed to foster management decisions.The algae in the great majority of green tide blooms usually belong to two genera of Ulvophyceae,Ulva and Enteromorpha.Ulva has been observed more often in recent years.In China,green tides occurred for the first time in the middle area of the Yellow Sea in 2007,and a large-scale algae blooming broke out in the middle and southern areas of the Yellow Sea in late May 2008.We identified them as Ulva prolifera by comparative analysis of the rDNA internal transcribed spacer 1 (ITS1),5.8S and ITS2 sequences in combination with microscopic observation.Morphological differences were found between the free-floating algae and the attached thalli.Various reproduction patterns of the free-floating algae include sexual,asexual and vegetative propagations,which played important roles in the long-term green tide persistence in China.The ITS sequences of the blooming algae were identical to those of the samples from the Lianyungang sea area but were different from the attached samples from the Qingdao sea area.The results infer that the blooms are originated from other sea areas rather than from the local attached populations.     

Bromophenols from marine algae with potential anti-diabetic activities

Marine algae contain various bromophenols with a variety of biological activities,including antimicrobial,anticancer,and anti-diabetic effects.Here,we briefly review the recent progress in researches on the biomaterials from marine algae,emphasizing the relationship between the structure and the potential anti-diabetic applications.Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B,α-glucosidase,as well as other mechanisms.     

Effects of Organic Enrichment on Sandy Beach Meiofauna:A Laboratory Microcosm Experiment

Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three different treatments including non-organic addition as the control, low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL). After 21 d, the meiofauna richness decreased in both organic enrichment treatments. Among the three treatments, t...