A grid of 22 stations, giving a broad coverage of the spawning ground of anchovy in the southern Huanghai Sea was selected. Undis- turbed sediments were taken from sampling stations during the cruise in June 2003. The...A grid of 22 stations, giving a broad coverage of the spawning ground of anchovy in the southern Huanghai Sea was selected. Undis- turbed sediments were taken from sampling stations during the cruise in June 2003. The average abundance of meiofauna is (1 584± 686) ind./10cm2, with corresponding biomass (dwt) of (1 086±425)!μg/10cm2. The pattern of abundance of meiofauna is similar to the pattern of biomass. There are 65.88% meiofauna in 0￣2 cm sediments, 27.66% in 2￣5 cm sediments and 6.47% in 5￣8 cm sediments. The Spearman correlation analysis between meiofauna and environmental factors shows that abundance of meiofauna, free living ma- rine nematodes, benthic copepods has significant positive correlations with Chl-a. And the abundance of copepods has significant posi- tive correlations with several factors such as Chl-a, Pha-a, Chl-a plus Pha-a and organic matter. A total of 18 meiofauna groups are i- dentified. Nematode is the most dominant group, average abundance (1 404±670) ind/10cm2, accounting for 88.65%, and the follow- ing groups are also important: benthic copepods (5.48%), kinorhyncha (1.26%), polychaeta (1.07%). By biomass, dominant groups are nematodes (51.72%), polychaeta (21.84%), copepods (14.87%), ostracoda (4.92%), kinorhyncha (3.67%). A total of 90 species of ne- matodes are identified. The species composition of nematodes is listed based on selected two stations 7794 (coastal area) and 10694 (cold water mass in deep waters).展开更多
Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. T...Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ± 0.347) x10^6 ind m^(-2) and the corresponding biomass 1.748 ± 0.72 g dwt m^(-2) with the maximum 2.35 g dwtm^(-2) at Station 9594 and the minimum 0.537 g dwt m^(-2) at Station 11794. A total of fourteentaxa were identified. Free living marine nematodes were the most dominant group with an averageabundance of (1.026 ± 0.206) x 10~6 ind m^(-2), accounting for 88.5% of total numbers, and anaverage of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight wascalculated, which ranges from 0.01 μg to 31.32 μg with an average of 0.261 μg. One hundred andforty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4orders were identified. Six of them were new species. The common dominant species were Dorylaimopsisrabalaisi, Sphaerolaimus balticus, Sphaerolaimus mini-tus, Metalinhomoeus longicauda,Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema nor-mandicum,Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, thesix stations were clustered into 2 groups with similar species composition at 40% similarity. Thespecies diversity index (H′), evenness index (J) and species richness index (d) of nematode werecalculated and analyzed. Correlation analysis with respect to environmental factors showed that theabundance of meiofauna had a significant correlation with the median diameter of sediment (Md_φ).The species richness of nematodes had a highly significant correlation with Chl-a and significantcorrelations with Pha-a and Chl-a + Pha-a.展开更多
In view of the fact that siderophores from microorganisms in different environments have received much attention in recent years because of their potential applications and diverse physiological functions, this review...In view of the fact that siderophores from microorganisms in different environments have received much attention in recent years because of their potential applications and diverse physiological functions, this review deals with side rophore producing marine microorganisms and the detection, chemical structure and potential applications of siderophores.展开更多
Dilution experiments were performed to examine the growth rate and grazing mortality rate of size-fractionated phytoplankton at three typical stations, inside and outside the bay, in the spring and summer of 2003 in t...Dilution experiments were performed to examine the growth rate and grazing mortality rate of size-fractionated phytoplankton at three typical stations, inside and outside the bay, in the spring and summer of 2003 in the Jiaozhou Bay, China. In spring, the phytoplankton community structure was similar among the three stations, and was mainly composed of nanophytoplankton, such as, Skeletonema costatum and Cylindrotheca closterium. The structure became significantly different for the three stations in summer, when the dominant species at Stas A, B and C were Chaetoceros curvisetus, Pseudo-nitzschia delicatissima, C. affinis, C. debilis, Coscinodiscus oculus-iridis and Paralia sulcata respectively. Tintinnopsis beroidea and T. tsingtaoensis were the dominant species in spring, whereas the microzooplankton was apparently dominated by Strombidium sp. in summer. Pico- and nanophytoplankton had a relatively greater growth rate than microzooplankton both in spring and summer. The growth rate and grazing mortality rate were 0.18~0.44 and 0.12~1.47 d-1 for the total phytoplankton and 0.20~0.55 and 0.21~0.37 d-1 for nanophytoplankton in spring respectively. In summer, the growth rate and grazing mortality rate were 0.38~0.71 and 0.27~0.60 d-1 for the total phytoplankton and 0.11~1.18 and 0.41~0.72 d-1 for nano- and microphytoplankton respectively. The carbon flux consumed by microzooplankton per day was 7.68~39.81 mg/m3 in spring and 12.03~138.22 mg/m3 in summer respectively. Microzooplankton ingested 17.56%~92.19% of the phytoplankton standing stocks and 31.77%~467.88% of the potential primary productivity in spring; in contrast, they ingested 34.60%~83.04% of the phytoplankton standing stocks and 71.28%~98.80% of the potential primary productivity in summer. Pico- and nanophytoplankton appeared to have relatively greater rates of growth and grazing mortality than microphytoplankton during the experimental period. The grazing rate of microzooplankton in summer was a little bit greater than that in spring because of the relatively higher incubation temperature and different dominant microzooplankton species. Microzooplankton preferred ingesting nanophytoplankton to microphytoplankton in spring, while they preferred ingesting picophytoplankton to nanophytoplankton and microphytoplankton in summer. Compared with the results of dilution experiments performed in various waters worldwide, the results are in the middle range.展开更多
Yeast strain Y68 producing high level of pullulan was isolated from the phyton collected in Toulouse, France. This strain was identified to be Rhodotorula bacarum by BIOLOG analysis. This is the first report that pull...Yeast strain Y68 producing high level of pullulan was isolated from the phyton collected in Toulouse, France. This strain was identified to be Rhodotorula bacarum by BIOLOG analysis. This is the first report that pullulan was produced by Rhodotorula bacarum. The optimal medium (g L -1) for pullulan production by this strain was 80 glucose, 20 soybean cake hydrolysate, 5 K 2HPO 4, 1 NaCl, 0.2 MgSO 4·7H 2O, 0.6 (NH 4) 2SO 4, pH 7.0. Under this condition, 54 g L -1 pullulan was produced within 60 h at 30 ℃. Pullulan is a better starting material for producing marine prodrugs.展开更多
The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure lin...The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences.展开更多
A continuous marine fish cell line RSBF (i.e. Red Sea Bream Fin) was utilized to screen the cytotoxicity and genotoxicity of polyethylenimine (PEI) and nickel chloride (NiCl 2) in this study on the deleterious effects...A continuous marine fish cell line RSBF (i.e. Red Sea Bream Fin) was utilized to screen the cytotoxicity and genotoxicity of polyethylenimine (PEI) and nickel chloride (NiCl 2) in this study on the deleterious effects of aquatic genotoxins on fish. At the 0.01 to 1 μg/ml concentration tested, PEI had acute toxicity to the treated RSBF cells (IC 50 =1.12, 0.92, 0.88 and 0.64 μg/ml PEI for time 0 h, 24 h, 48 h and 72 h after treatment, respectively) and markedly inhibited their proliferation in a dose dependent manner. At the 0.001 to 5 μmol/L concentration tested, NiCl 2 posed no acute toxicity but significantly stimulated their growth (107%-214% of control). Random amplified polymorphic DNA (RAPD) technique was used to detect the genotoxic effects of PEI and NiCl 2 by comparing the RAPD banding patterns of the control and treated cells. RAPD analysis indicated that at the concentrations tested, PEI was more genotoxic than NiCl 2 to RSBF cells; that there was a slight dose dependent response in the genotoxic effect of PEI but not NiCl 2; and that RAPD technique might provide a sensitive, non specific genotoxic endpoint. And the potent cytotoxicity and genotoxicity of PEI on fish cells showed that we should be cautious in utilizing it as gene vector in fish gene transfer and human gene therapy.展开更多
The distribution of sediment chloroplastic pigments (Chl-a, i.e. chlorophylla and Pha-a, i.e. phaeophorbide a) in the Southern Yellow Sea of China was studied. Samples werecollected from four cruises in January and Ju...The distribution of sediment chloroplastic pigments (Chl-a, i.e. chlorophylla and Pha-a, i.e. phaeophorbide a) in the Southern Yellow Sea of China was studied. Samples werecollected from four cruises in January and June 2003, and January and June 2004. The results showthat the vertical distribution of Chl-a and Pha-a in the sediment layers 0-2cm, 2-5cm and 5-8cm,follows a stable ratio, 5:3:2. The average ratio of Pha-a to Chl-a in sediment is 2.83. Spearman2-tailed rank correlation analysis shows that Chl-a and Pha-a contents in each sediment layer have ahighly significant correlation. The average contents of Chl-a and Pha-a in the sediment of the0-8cm layer in the investigated area are 0.31-0.47 μg g^(-1) and 1.28-1.40 μg g^(-1) sediment (dryweight), respectively. The average Chl-a and Pha-a contents in sediment are higher in summer thanin winter. ANOVA analysis shows that there is a highly significant variation among the Chl-acontents (P = 0.002 【 0.01) of the four cruies, but this is not true for the case of Pha-a content(P = 0.766 】0.05). The average Chl-a and Pha-a contents in the 2 sediment layers (0-2cm and 2-5cm)have significant or highly significant correlations with organic matter (OM), median diameter(Md_φ), silt plus clay percentage in the January 2003 cruise. In the June 2003 cruise, the averageChl-a content in the 3 sediment layers (0-2cm, 2-5cm, and 5-8cm) has a significant correlation withmeiofauna biomass, and Pha-a content has highly significant correlations with water depth, bottomwater temperature, OM and Md_φ. The contents of Chl-a and Pha-a are lower than those in estuariesand intertidal areas, but close to those in the same area studied previously.展开更多
An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae sp...An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH + 4 and NO - 3. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH + 4 than using NO - 3. U. pertusa grows best and shows higher capability of removing nitrogen at 200 μmol L -1 , but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 μmol L -1 . The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200 μmol L -1 , but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments.展开更多
Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS- Ce4+ complexes have some enzyme-like activities....Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS- Ce4+ complexes have some enzyme-like activities. Fucoidan and its complex with Ce4+ have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS- Ce4+ complexes show these measurable activities under the comparable condition when APS bind Ce4+ and form homogenous solu-tions. The laminaran- Ce4+ complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropy-rifos under neutral conditions.展开更多
Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40 d was carried out. The pronephric kidney duct appeared early in ha...Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40 d was carried out. The pronephric kidney duct appeared early in hatching although the primordial haemopoietic stem cells were observed within a week after hatching. The spleen was first seen after 8 d of hatching. The thymus appeared after 15 d, situated near the pronephric kidney. Small lymphoid cells appeared during the later phase of the post-larval stage in the sequence of thymus, kidney and spleen. During the 40 d of observations, there were no distinct inner or outer zones in thymus and no red or white pulp in spleen. These results suggest that the nonspecific defense immune system plays a very important role in the early larval stage of Japanese flounder.展开更多
From Oct. 1999 to Oct. 2000, the heterotrophic bacterial floras in the industrial marine environment around the Qingdao Power Plant (QPP) and in the unpolluted marine environments were investigated. The results showed...From Oct. 1999 to Oct. 2000, the heterotrophic bacterial floras in the industrial marine environment around the Qingdao Power Plant (QPP) and in the unpolluted marine environments were investigated. The results showed that the numbers of the heterotrophic bacteria around QPP were much higher than those in unpolluted environments, and the average numbers in QPP Seawater, QPP Sediment, Unpolluted Seawater and Unpolluted Sediment were 5.4×104cfu(mL) -1, 5.0×105cfug -1, 3.0×102cfu(mL) -1 and 1.3×105cfug -1 respectively. Totally, 118 strains were isolated from QPP and 99 of them were Gram-negative. One hundred and twenty one strains were isolated from the unpolluted environments and 104 of them were Gram-negative. All the Gram-negative bacteria belonged to 13 genera. The distribution of the bacteria was varied in different marine environments. The results showed that the unpolluted marine environments contained much more Vibrio than seawater and sediment around QPP.展开更多
From Oct., 1999 to Oct., 2000, the heterotrophic bacterial flora in the aquaculture area around Xuejiadao was investigated. The result shows that the populations of the heterotrophic bacteria are heavier in summer and...From Oct., 1999 to Oct., 2000, the heterotrophic bacterial flora in the aquaculture area around Xuejiadao was investigated. The result shows that the populations of the heterotrophic bacteria are heavier in summer and autumn than those in winter and spring. The average populations in seawater, sediment, the surface of seaweed and the surface of fish are 1.4×10 4 cfu mL -1, 5.4×10 6 cfu g -1, 1.5×10 6 cfu g -1 and 1.8×10 3 cfu cm -2, respectively. A total of 301 strains were isolated, among them 259 were Gram-negative. All the Gram-negative bacteria belong to 13 genera and some genera of Enterobacteriaceae. The communities of bacteria are slightly different among the samples. In the body surface of fish, Genus vibrio is dominant. In the remaining samples, dominant genus is Aeromonas.展开更多
Vibrio pacini synthesizes multiple chitinases, of which three have been purified in this study by ammonium sulphate fractionation, chitin affinity chromatography and gel chromatography. Molecular weights of the three ...Vibrio pacini synthesizes multiple chitinases, of which three have been purified in this study by ammonium sulphate fractionation, chitin affinity chromatography and gel chromatography. Molecular weights of the three chitinases, Chi1, Chi2 and Chi3 are 27×103, 39×103 and 46×103 respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The purified enzymes have optimal activity at pH 7–8, and retain 50% enzymatic activity pH 4–9. The activities of chitinases are inhibited by Pb2+, Fe3+ and Cu2+, and increased by Ca2+, Mg2+ and Mn2+. Chi3 is found to inhibit the growth of six species of fungi. Such characters of chitinase are different from those of any other chitinase that were reported before. Key words chitinase - Vibrio pacini - purification - inhibit CLC number Q 55 Foundation item: Supported by the Key Technologies Research and Development Programme of the Tenth Five-Year Plan of the Nation Scientific and Technological Development (2001 BA708B04-07)Biography: HAN Bao-qin (1963-), female, Professor.展开更多
Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wil...Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wild are higher in the medium supplemented with DCMU than in the control without DCMU. Without DCMU, the growth rates and chlorophyll a contents of the mutants are similar to those of the wild. Significant changes of fatty acid content and composition have occurred in DCMU-resistant mutants growing in the medium supplemented with DCMU. The total lipid, palmitic acid (16∶0), palmitoleic acid (16∶1ω9) and oleic (18∶1ω9) contents decrease significantly, while the vaccenic acid (18∶1ω11) increases significantly and the EPA content of dried powder increases slightly in the mutants. The study may provide a basis to improve EPA content in Nannochloropsis oculata in the future.展开更多
The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer c...The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.展开更多
Abstract: This study investigated whether increased solar UV-B radiation (280–315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platym...Abstract: This study investigated whether increased solar UV-B radiation (280–315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium(Ehrenb.) W. Sm, were exposed to a range of UV-B radiation and both showed reductions in their growth rates, and the chlorophyll a (Chl a) and carotenoid (Car) contents when UV-B radiation dose increased. Superoxide anion radical (O2-.) production and the concentration of hydrogen peroxide (H2O2) and malodiadehyde (MDA) also increased with the increasing of UV-B radiation. Antioxidant systems, non-enzymic components (Car and glutathione content) and enzymic components (superoxide dismutase (SOD) and catalase (CAT) activity), decreased as a result of enhanced UV-B radiation. When the exogenous glutathione (GSH) was added, the effects of UV-B radiation on the growth of the two species were alleviated. These results suggest that enhanced UV-B radiation suppressed the antioxidant systems and caused some active oxygen species to accumulate, which in turns retarded the development of the marine microalgae.展开更多
基金supported by the National Key Basic Research Programs from Ministry of Science and Technology of China under contract Nos G1999043709 and 2002CB412400the National Natural Science Foundation of China under contract No.40176033.
文摘A grid of 22 stations, giving a broad coverage of the spawning ground of anchovy in the southern Huanghai Sea was selected. Undis- turbed sediments were taken from sampling stations during the cruise in June 2003. The average abundance of meiofauna is (1 584± 686) ind./10cm2, with corresponding biomass (dwt) of (1 086±425)!μg/10cm2. The pattern of abundance of meiofauna is similar to the pattern of biomass. There are 65.88% meiofauna in 0￣2 cm sediments, 27.66% in 2￣5 cm sediments and 6.47% in 5￣8 cm sediments. The Spearman correlation analysis between meiofauna and environmental factors shows that abundance of meiofauna, free living ma- rine nematodes, benthic copepods has significant positive correlations with Chl-a. And the abundance of copepods has significant posi- tive correlations with several factors such as Chl-a, Pha-a, Chl-a plus Pha-a and organic matter. A total of 18 meiofauna groups are i- dentified. Nematode is the most dominant group, average abundance (1 404±670) ind/10cm2, accounting for 88.65%, and the follow- ing groups are also important: benthic copepods (5.48%), kinorhyncha (1.26%), polychaeta (1.07%). By biomass, dominant groups are nematodes (51.72%), polychaeta (21.84%), copepods (14.87%), ostracoda (4.92%), kinorhyncha (3.67%). A total of 90 species of ne- matodes are identified. The species composition of nematodes is listed based on selected two stations 7794 (coastal area) and 10694 (cold water mass in deep waters).
基金the National Key Basic Research Program from the Ministry of Science and Technology,P.R.China(Grant No.19990437,2002CB412400)National Science Foundation of China(No.40176033).
文摘Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ± 0.347) x10^6 ind m^(-2) and the corresponding biomass 1.748 ± 0.72 g dwt m^(-2) with the maximum 2.35 g dwtm^(-2) at Station 9594 and the minimum 0.537 g dwt m^(-2) at Station 11794. A total of fourteentaxa were identified. Free living marine nematodes were the most dominant group with an averageabundance of (1.026 ± 0.206) x 10~6 ind m^(-2), accounting for 88.5% of total numbers, and anaverage of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight wascalculated, which ranges from 0.01 μg to 31.32 μg with an average of 0.261 μg. One hundred andforty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4orders were identified. Six of them were new species. The common dominant species were Dorylaimopsisrabalaisi, Sphaerolaimus balticus, Sphaerolaimus mini-tus, Metalinhomoeus longicauda,Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema nor-mandicum,Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, thesix stations were clustered into 2 groups with similar species composition at 40% similarity. Thespecies diversity index (H′), evenness index (J) and species richness index (d) of nematode werecalculated and analyzed. Correlation analysis with respect to environmental factors showed that theabundance of meiofauna had a significant correlation with the median diameter of sediment (Md_φ).The species richness of nematodes had a highly significant correlation with Chl-a and significantcorrelations with Pha-a and Chl-a + Pha-a.
文摘In view of the fact that siderophores from microorganisms in different environments have received much attention in recent years because of their potential applications and diverse physiological functions, this review deals with side rophore producing marine microorganisms and the detection, chemical structure and potential applications of siderophores.
基金supported by the National Natural Science Foundation of China under contract Nos 40206020 and 40306025the National Fundamental Rescarch Program of China under contract No.2001CB409702.
文摘Dilution experiments were performed to examine the growth rate and grazing mortality rate of size-fractionated phytoplankton at three typical stations, inside and outside the bay, in the spring and summer of 2003 in the Jiaozhou Bay, China. In spring, the phytoplankton community structure was similar among the three stations, and was mainly composed of nanophytoplankton, such as, Skeletonema costatum and Cylindrotheca closterium. The structure became significantly different for the three stations in summer, when the dominant species at Stas A, B and C were Chaetoceros curvisetus, Pseudo-nitzschia delicatissima, C. affinis, C. debilis, Coscinodiscus oculus-iridis and Paralia sulcata respectively. Tintinnopsis beroidea and T. tsingtaoensis were the dominant species in spring, whereas the microzooplankton was apparently dominated by Strombidium sp. in summer. Pico- and nanophytoplankton had a relatively greater growth rate than microzooplankton both in spring and summer. The growth rate and grazing mortality rate were 0.18~0.44 and 0.12~1.47 d-1 for the total phytoplankton and 0.20~0.55 and 0.21~0.37 d-1 for nanophytoplankton in spring respectively. In summer, the growth rate and grazing mortality rate were 0.38~0.71 and 0.27~0.60 d-1 for the total phytoplankton and 0.11~1.18 and 0.41~0.72 d-1 for nano- and microphytoplankton respectively. The carbon flux consumed by microzooplankton per day was 7.68~39.81 mg/m3 in spring and 12.03~138.22 mg/m3 in summer respectively. Microzooplankton ingested 17.56%~92.19% of the phytoplankton standing stocks and 31.77%~467.88% of the potential primary productivity in spring; in contrast, they ingested 34.60%~83.04% of the phytoplankton standing stocks and 71.28%~98.80% of the potential primary productivity in summer. Pico- and nanophytoplankton appeared to have relatively greater rates of growth and grazing mortality than microphytoplankton during the experimental period. The grazing rate of microzooplankton in summer was a little bit greater than that in spring because of the relatively higher incubation temperature and different dominant microzooplankton species. Microzooplankton preferred ingesting nanophytoplankton to microphytoplankton in spring, while they preferred ingesting picophytoplankton to nanophytoplankton and microphytoplankton in summer. Compared with the results of dilution experiments performed in various waters worldwide, the results are in the middle range.
基金National Natural Science Foundation of China(Grant No.39970005)for its financial support
文摘Yeast strain Y68 producing high level of pullulan was isolated from the phyton collected in Toulouse, France. This strain was identified to be Rhodotorula bacarum by BIOLOG analysis. This is the first report that pullulan was produced by Rhodotorula bacarum. The optimal medium (g L -1) for pullulan production by this strain was 80 glucose, 20 soybean cake hydrolysate, 5 K 2HPO 4, 1 NaCl, 0.2 MgSO 4·7H 2O, 0.6 (NH 4) 2SO 4, pH 7.0. Under this condition, 54 g L -1 pullulan was produced within 60 h at 30 ℃. Pullulan is a better starting material for producing marine prodrugs.
文摘The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences.
文摘A continuous marine fish cell line RSBF (i.e. Red Sea Bream Fin) was utilized to screen the cytotoxicity and genotoxicity of polyethylenimine (PEI) and nickel chloride (NiCl 2) in this study on the deleterious effects of aquatic genotoxins on fish. At the 0.01 to 1 μg/ml concentration tested, PEI had acute toxicity to the treated RSBF cells (IC 50 =1.12, 0.92, 0.88 and 0.64 μg/ml PEI for time 0 h, 24 h, 48 h and 72 h after treatment, respectively) and markedly inhibited their proliferation in a dose dependent manner. At the 0.001 to 5 μmol/L concentration tested, NiCl 2 posed no acute toxicity but significantly stimulated their growth (107%-214% of control). Random amplified polymorphic DNA (RAPD) technique was used to detect the genotoxic effects of PEI and NiCl 2 by comparing the RAPD banding patterns of the control and treated cells. RAPD analysis indicated that at the concentrations tested, PEI was more genotoxic than NiCl 2 to RSBF cells; that there was a slight dose dependent response in the genotoxic effect of PEI but not NiCl 2; and that RAPD technique might provide a sensitive, non specific genotoxic endpoint. And the potent cytotoxicity and genotoxicity of PEI on fish cells showed that we should be cautious in utilizing it as gene vector in fish gene transfer and human gene therapy.
基金funded by the National Key Basic Research Program from the Ministry of Science and Technology,People’s Republic of China(G1999043709,2002CB412400)supported by the National Natural Science Foundation of China(No.40176033)
文摘The distribution of sediment chloroplastic pigments (Chl-a, i.e. chlorophylla and Pha-a, i.e. phaeophorbide a) in the Southern Yellow Sea of China was studied. Samples werecollected from four cruises in January and June 2003, and January and June 2004. The results showthat the vertical distribution of Chl-a and Pha-a in the sediment layers 0-2cm, 2-5cm and 5-8cm,follows a stable ratio, 5:3:2. The average ratio of Pha-a to Chl-a in sediment is 2.83. Spearman2-tailed rank correlation analysis shows that Chl-a and Pha-a contents in each sediment layer have ahighly significant correlation. The average contents of Chl-a and Pha-a in the sediment of the0-8cm layer in the investigated area are 0.31-0.47 μg g^(-1) and 1.28-1.40 μg g^(-1) sediment (dryweight), respectively. The average Chl-a and Pha-a contents in sediment are higher in summer thanin winter. ANOVA analysis shows that there is a highly significant variation among the Chl-acontents (P = 0.002 【 0.01) of the four cruies, but this is not true for the case of Pha-a content(P = 0.766 】0.05). The average Chl-a and Pha-a contents in the 2 sediment layers (0-2cm and 2-5cm)have significant or highly significant correlations with organic matter (OM), median diameter(Md_φ), silt plus clay percentage in the January 2003 cruise. In the June 2003 cruise, the averageChl-a content in the 3 sediment layers (0-2cm, 2-5cm, and 5-8cm) has a significant correlation withmeiofauna biomass, and Pha-a content has highly significant correlations with water depth, bottomwater temperature, OM and Md_φ. The contents of Chl-a and Pha-a are lower than those in estuariesand intertidal areas, but close to those in the same area studied previously.
基金supported by the Natural Science Foundation of China(Nos. 40206020,40306025)National Fundamental Research Program of China(No.2001CB409702)the US National Science Foundation
文摘An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH + 4 and NO - 3. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH + 4 than using NO - 3. U. pertusa grows best and shows higher capability of removing nitrogen at 200 μmol L -1 , but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 μmol L -1 . The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200 μmol L -1 , but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments.
文摘Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS- Ce4+ complexes have some enzyme-like activities. Fucoidan and its complex with Ce4+ have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS- Ce4+ complexes show these measurable activities under the comparable condition when APS bind Ce4+ and form homogenous solu-tions. The laminaran- Ce4+ complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropy-rifos under neutral conditions.
基金supported by the National Natural Science of China(No.30000129)Ministry of Science and Technology of China(G1999012005).
文摘Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40 d was carried out. The pronephric kidney duct appeared early in hatching although the primordial haemopoietic stem cells were observed within a week after hatching. The spleen was first seen after 8 d of hatching. The thymus appeared after 15 d, situated near the pronephric kidney. Small lymphoid cells appeared during the later phase of the post-larval stage in the sequence of thymus, kidney and spleen. During the 40 d of observations, there were no distinct inner or outer zones in thymus and no red or white pulp in spleen. These results suggest that the nonspecific defense immune system plays a very important role in the early larval stage of Japanese flounder.
文摘From Oct. 1999 to Oct. 2000, the heterotrophic bacterial floras in the industrial marine environment around the Qingdao Power Plant (QPP) and in the unpolluted marine environments were investigated. The results showed that the numbers of the heterotrophic bacteria around QPP were much higher than those in unpolluted environments, and the average numbers in QPP Seawater, QPP Sediment, Unpolluted Seawater and Unpolluted Sediment were 5.4×104cfu(mL) -1, 5.0×105cfug -1, 3.0×102cfu(mL) -1 and 1.3×105cfug -1 respectively. Totally, 118 strains were isolated from QPP and 99 of them were Gram-negative. One hundred and twenty one strains were isolated from the unpolluted environments and 104 of them were Gram-negative. All the Gram-negative bacteria belonged to 13 genera. The distribution of the bacteria was varied in different marine environments. The results showed that the unpolluted marine environments contained much more Vibrio than seawater and sediment around QPP.
文摘From Oct., 1999 to Oct., 2000, the heterotrophic bacterial flora in the aquaculture area around Xuejiadao was investigated. The result shows that the populations of the heterotrophic bacteria are heavier in summer and autumn than those in winter and spring. The average populations in seawater, sediment, the surface of seaweed and the surface of fish are 1.4×10 4 cfu mL -1, 5.4×10 6 cfu g -1, 1.5×10 6 cfu g -1 and 1.8×10 3 cfu cm -2, respectively. A total of 301 strains were isolated, among them 259 were Gram-negative. All the Gram-negative bacteria belong to 13 genera and some genera of Enterobacteriaceae. The communities of bacteria are slightly different among the samples. In the body surface of fish, Genus vibrio is dominant. In the remaining samples, dominant genus is Aeromonas.
文摘Vibrio pacini synthesizes multiple chitinases, of which three have been purified in this study by ammonium sulphate fractionation, chitin affinity chromatography and gel chromatography. Molecular weights of the three chitinases, Chi1, Chi2 and Chi3 are 27×103, 39×103 and 46×103 respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The purified enzymes have optimal activity at pH 7–8, and retain 50% enzymatic activity pH 4–9. The activities of chitinases are inhibited by Pb2+, Fe3+ and Cu2+, and increased by Ca2+, Mg2+ and Mn2+. Chi3 is found to inhibit the growth of six species of fungi. Such characters of chitinase are different from those of any other chitinase that were reported before. Key words chitinase - Vibrio pacini - purification - inhibit CLC number Q 55 Foundation item: Supported by the Key Technologies Research and Development Programme of the Tenth Five-Year Plan of the Nation Scientific and Technological Development (2001 BA708B04-07)Biography: HAN Bao-qin (1963-), female, Professor.
基金support of the National Advanced Technology‘863’Project Foundation(819-02-01).
文摘Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wild are higher in the medium supplemented with DCMU than in the control without DCMU. Without DCMU, the growth rates and chlorophyll a contents of the mutants are similar to those of the wild. Significant changes of fatty acid content and composition have occurred in DCMU-resistant mutants growing in the medium supplemented with DCMU. The total lipid, palmitic acid (16∶0), palmitoleic acid (16∶1ω9) and oleic (18∶1ω9) contents decrease significantly, while the vaccenic acid (18∶1ω11) increases significantly and the EPA content of dried powder increases slightly in the mutants. The study may provide a basis to improve EPA content in Nannochloropsis oculata in the future.
文摘The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.
基金国家自然科学基金，Encouraging Foundation for Outstanding Youth Scientists of Shandong Province
文摘Abstract: This study investigated whether increased solar UV-B radiation (280–315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium(Ehrenb.) W. Sm, were exposed to a range of UV-B radiation and both showed reductions in their growth rates, and the chlorophyll a (Chl a) and carotenoid (Car) contents when UV-B radiation dose increased. Superoxide anion radical (O2-.) production and the concentration of hydrogen peroxide (H2O2) and malodiadehyde (MDA) also increased with the increasing of UV-B radiation. Antioxidant systems, non-enzymic components (Car and glutathione content) and enzymic components (superoxide dismutase (SOD) and catalase (CAT) activity), decreased as a result of enhanced UV-B radiation. When the exogenous glutathione (GSH) was added, the effects of UV-B radiation on the growth of the two species were alleviated. These results suggest that enhanced UV-B radiation suppressed the antioxidant systems and caused some active oxygen species to accumulate, which in turns retarded the development of the marine microalgae.
