A new nine-membered lactone,cladospolide E（1）,was isolated from a culture broth of a marine fungus Cladosporium sp.F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis,inc...A new nine-membered lactone,cladospolide E（1）,was isolated from a culture broth of a marine fungus Cladosporium sp.F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis,including 1D and 2D NMR data.展开更多
It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has...It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has been previously studied but that of bacteria in sponges inhabiting the open sea has been rarely investigated.In this report,the diversity of bacteria associated with the marine sponge Agelas robusta from a remote coral reef in the South China Sea was documented employing 16S rDNA library construction,amplified ribosomal DNA restriction analysis（ARDRA） and phylogenetic analysis.A total of 32 phylotypes were finally categorized in nine phyla including Cyanobacteria,Proteobacteria,Chloroflexi,Firmicutes,Actinobacteria,Acidobacteria,Planctomycetes,Bacteroidetes and Gemmatimonadetes.The dominant phylum was Proteobacteria whereas the dominant genus was Synechococcus in Cyanobacteria.Some spongespecific bacteria were also found in the bacteria population,but the proportion（5 OTUs/32 OTUs） was much lower than other sponges.This study reveals the phylogenetic diversity of bacteria in A.robusta and confirms the presence of some sponge-specific bacteria in the South China Sea.Understanding the diversity of sponge-associated bacteria in China assists to exploit the bacteria resources for biotechnology.展开更多
Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH, a process known as "ocean acidification". The pearl oyster Pinctada fucata, the noble scallop Chlamys nobilis, and the gre...Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH, a process known as "ocean acidification". The pearl oyster Pinctada fucata, the noble scallop Chlamys nobilis, and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China. We evaluated the effects of seawater acidification on clearance, respiration, and excretion rates in these three species. The animals were reared in seawater at pH 8.1 (control), 7.7, or 7.4. The clearance rate was highest at pH 7.7 for P. fucata and at pH 8.1 for C. nobilis and P. viridis. The pH had little effecton the respiration rate of P. fucata and P. viridis. In contrast, the respiration rate was significantly lower atpH 7.4 in C. nobilis. The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species. Theresults indicate that the reduction in seawater pH likely affected the metabolic process (food intake, oxygenconsumption, and ammonia excretion) of these bivalves. Different species respond differently to seawateracidification. Further studies are needed to demonstrate the exact mechanisms for this effect and evaluateadaptability of these bivalves to future acidified oceans.展开更多
Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is...Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is still unknown. Based on large-scale biological and environmental in situ observations and synchro nous remote sensing data, the distribution patterns of phytoplankton biomass and the primary production, and the role of mesoscale eddies in regulating primary production in different eddy-controlled waters were investigated. The results suggested that the surface chlorophyll a concentrations and water column inte grated primary production （IPP） are significantly higher in cyclonic eddies and lower in the anticyclonic eddies as compared to that in non-eddy waters. Although eddies could affect various environmental factors, such as nutrients, temperature and light availability, nutrient supply is suggested to be the most important one through which mesoscale eddies regulated the distribution patterns of phytoplankton biomass and pri mary production. The estimated IPP in cyclonic and anticyclonic eddies are about 29.5% higher and 16.6% lower than the total average in the whole study area, respectively, indicating that the promotion effect of mesoscale cold eddies on the primary production was much stronger than the inhibition effect of the warm eddies per unit area. Overall, mesoscale eddies are crucial physical processes that affect the biological car bon fixation and the distribution pattern of primary production in the SCS open sea, especially during the spring inter-monsoon period.展开更多
This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artific...This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities(low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities(P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity(P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15(P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70(P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities(15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis.展开更多
Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent...Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent waters（ZREAW） in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated.展开更多
Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea...Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea （6~S to 20~N）, the authors investigated the ciliate abundance and species composition in sur- face waters during May 18 to 27 of 2010. The ciliate abundance decreased latitudinally from 3 080 ind./L （~6~S） to 40 ind./L （-~3~N）, and then increased to 1 180 ind./L （-~ 16~N） at the end of the survey. A total of 22 ciliates belonging to 15 genera were identified with the tintinnids accounted for 50% （11 species）; and the species number showed a same spatial change as the ciliate abundance. Moreover, the Strombidium oc- cupied over 50% of total ciliate abundance in most stations and Mesodiniurn and Tintinnopsis contributed to about 18.7% and 11.4%, respectively. In particular, our results indicate that the geographical changes in ciliate abundance were positively regulated by larger nano- and micro-phytoplankton biomass, rather than smaller pico-phytoplankton in the investigated waters.展开更多
Oyster peptides were produced from Crassostrea hongkongensis and used as a new protein source for the preparation of an oyster peptide-based enteral nutrition formula (OPENF). Reserpine-induced malabsorption mice and ...Oyster peptides were produced from Crassostrea hongkongensis and used as a new protein source for the preparation of an oyster peptide-based enteral nutrition formula (OPENF). Reserpine-induced malabsorption mice and cyclophosphamide-induced immunosuppression mice were used in this study. OPENF powder is light yellow green and has a protein-fat-carbohydrate ratio of 16:9:75 with good solubility in water. A pilot study investigating immune functional impacts of the OPENF on mice show that the OPENF enhanced spleen lymphocyte proliferation and the activity of natural killer (NK) cells in BALB/c mice. Furthermore, OPENF can improve intestinal absorption, increase food utilization ratio, and maintain the normal physiological function of mice. These results suggest that oyster peptides could serve as a new protein source for use in enteral nutrition formula, but more importantly, also indicate that OPENF has an immunostimulating effect in mice.展开更多
16S rDNA sequencing results from this study and literatures demonstrate that sediment bacteria in the South China Sea （SCS） were very diverse,which contained 22 of the 24 phyla of bacteria investigated from marine s...16S rDNA sequencing results from this study and literatures demonstrate that sediment bacteria in the South China Sea （SCS） were very diverse,which contained 22 of the 24 phyla of bacteria investigated from marine sediment,however,it was very imbalance among stations.So bacterial diversity from 15 samples which covered a wide range of sediment types from 20 to 3 888 m in depth was studied in DGGE （denature gradient gel electrophoresis） in this paper.The DGGE results indicate that both sediment bacterial diversity and diversity difference among stations were significant.Thirty representative and differential fingerprints among samples were recovered and sequenced,phylogenetic analysis indicates that they may belong to Proteobacteria （α-,β-,γ-,δ-,ε-）,Planctomycetes,Firmicutes,Chloroflexi,Acidobacteria,Actinobacteria,Nitrospirae,Gemmatimonadetes,candidate division WS3 and so on,of which,Gemmatimonadetes and candidate division WS3 bacteria were first detected in SCS sediment.This study also shows that bacterial diversity analysis based on DGGE was more potential than traditional 16S rDNA clone library in multiple sample analysis.展开更多
Ubiquitin, a highly conserved stress-related protein, is assigned multiple functions, such as DNA processing, protein degradation, and ribosome synthesis. The Crassostrea hongkongensis ubiquitin gene (designated ChUbL...Ubiquitin, a highly conserved stress-related protein, is assigned multiple functions, such as DNA processing, protein degradation, and ribosome synthesis. The Crassostrea hongkongensis ubiquitin gene (designated ChUbL40) was cloned by a combination of suppressive subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE). The full-length cDNA of ChUbL40 is 496 bp in length, consisting of a 5' untranslated region (UTR) of 34 bp, a 3'-UTR of 75 bp and an open reading frame of 387 bp encoding a ubiquitin fusion protein of 128 amino acids. Analysis of the amino acid sequence of ChUbL40 reveals that UbL40 is highly conservative during evolution. The expression patterns of ChUbL40 gene in various tissues were examined by real-time PCR. The expression level of ChUbL40 in haemocytes is down-regulated at 4 h and gradually returned to its original level from 6 h to 24 h after Vibrio alginolyticus challenge. Our results suggest that ChUbL40 is ubiquitously expressed and plays an important role in immune defense against bacterial challenge.展开更多
From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica(Reeve) were studied on the eastern coast of China in relation to the reproductive c...From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica(Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions(e.g.,temperature and food availability).Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad.Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn,whereas spawning occurred in summer(20.4-24.6℃).The seasonal variation in lipid content was similar to that of the mean oocyte diameter.In both neutral and polar lipids,the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids,and polyunsaturated fatty acids were abundant,with series n-3 as the predominant component.Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle.The ∑(n-3) and ∑(n-6) values were relatively high during January-May,and the associated unsaturation index was significantly higher than that in other months.The results suggest that fatty acids play an important role in the gametogenesis of F.mutica.展开更多
Mesozooplankton are key components of coastal ecosystems,linking the microbial food web to the classic food chain.In this study,species composition and abundance of mesozooplankton is studied for the Daya Bay in April...Mesozooplankton are key components of coastal ecosystems,linking the microbial food web to the classic food chain.In this study,species composition and abundance of mesozooplankton is studied for the Daya Bay in April(spring) and October(fall),2006.A total of 27 species of mesozooplankton were identified in spring and 58 species in fall.Dominant species were Oithona tenuis,Flaccisagitta enflata,Penilia avirostris and Centropages tenuiremis in spring,shifting to Microsetella norvegica,Oithona tenuis and Parvocalanus crassirostris in fall.Higher mesozooplankton abundance was found at Aotou Cove and Dapeng'ao Cove compared to other stations,indicating the influence of eutrophication on mesozooplankton community in the Daya Bay.The outbreak of Noctiluca scintillans bloom in spring reduced the species diversity and abundance of mesozooplankton.展开更多
The response of chlorophyll a （Chl a） concentration to wind stress is analyzed in the South China Sea （SCS）, using in-situ data of Chl a and remote sensing data （QuikScat-sea surface wind （SSW）, AVHRR-sea surfa...The response of chlorophyll a （Chl a） concentration to wind stress is analyzed in the South China Sea （SCS）, using in-situ data of Chl a and remote sensing data （QuikScat-sea surface wind （SSW）, AVHRR-sea surface temperature （SST）, AVISO merged-sea level anomalies （SLA）, SeaWiFS- derived Chl a and MODIS Terra-derived Chl a） in August/September/October 2004, 2006 and 2009. The variability of SSW, SST and SLA 7 d before in-situ Chl a sampling （including the work day of in^situ Chl a sampling） with the same latitude and longitude of the study area are investigated, and the correlation coefficients are calculated between these hydrographic factors and in-situ Chl a concentration. The results show that the Chl a-SSW correlation coefficients at upper layers （such as 0 m and 25 m） are more significant than those at deeper layers （such as 50, 75 and 100 m） 1 3 d before, which indicates that there is a time lag of strong surface winds stimulating phytoplankton bloom. By analyzing the relationship among the daily remote sensing derived （RS- derived） SSW, SST, SLA and 3 d averaged SeaWiFS/MODIS-derived Chl a concentration in the northern SCS in September 2004 and 2009 respectively, it shows that the intensity and speed of surface winds could have great influence on extend of Chl a increase. If surface winds reach 4-5 m/s over, Chl a concentration would increase 1-3 d after the process of strong surface winds in open sea area of the northern SCS mainly during September.展开更多
Nutrient limitation is known to inhibit growth and metabolism and to alter elemental stoichiometric ratios in phytoplankton. In this study, physiological changes in Thalassirosira weissflogii were measured under diffe...Nutrient limitation is known to inhibit growth and metabolism and to alter elemental stoichiometric ratios in phytoplankton. In this study, physiological changes in Thalassirosira weissflogii were measured under different dissolved inorganic phosphate (DIP) regimes in semi-continuous cultures to revisit the utility of the Redfield ratio for assessing nutrient limitation. The results showed that cell size increased with decreasing DIP availability. In the P-depleted treatment (f/2-P) the cell size was 1.48 times larger than that in the P-limited (f/100) treatment and 2.67 times larger than that in the P-saturated treatment (f/2 and f/10). The fucoxanthin to chlorophyll a ratio (Fuco/chl a) was relatively stable (about 0.3) in P-saturated cultures and was 10 times higher than that in P-limited and P-depleted cultures. During the experimental period, the photosynthetic efficiency index, ?F/Fm′, was relatively stable at ~0.50 in the P-saturated cultures, but quickly declined with decreasing DIP availability. Although cellular P content showed a significant difference between the P-saturated culture (1.6 pg/cell) and the P-limited culture (0.7 pg/cell), the N/P ratio in T. weissflogii did not show a trend with DIP availability and fluctuated slightly around 25. Our results suggest that cell division in T. weissflogii is not strictly size-gated but is probably regulated by a biochemical, and hence, an elemental stoichiometric ratio threshold, and that deviation of the cellular N/P ratio from the Redfield ratio is not a reliable indicator of algal nutrient stress.展开更多
The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen f...The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COl. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and CO1 so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.展开更多
Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of ...Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16∶1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam; while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis (CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature; while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS.展开更多
The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- ...The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- toplankton biomass, size-structure and carbon fixation were investigated across the SoM during the spring period （May 4 to 9, 2011）. Chlorophyll a concentration increased from 0.12 ptg/L at the northwest entrance of the SoM to a maximal 0.63 #g/L at narrowest section, and decreased to 0.10/.tg/L at the southeast entrance. Photosynthetic carbon fixation by phytoplankton coincided well with Chl a biomass, and increased from 10.8 to 22.3 pg C/（L.d）, then decreased to 9.21/zg C/（L.d）; while the carbon fixation rate showed an inverse pattern to the changes of Chl a, and decreased from 87.1 to 35.5 #g C/（#g Chl a.d） and increased thereafter to 95.3 btg C/（/2g Chl a.d）. Picophytoplankton cells （〈3/2m） contributed to more than 60% and 50% of the total Chl a and carbon fixation at both the entry waters; while the contributions of pico-cells decreased sharply to the minimum of 18.3% and 27.5% at the narrowest part of the SoM. In particular, our results showed that the silicate concentration positively regulated Chl a biomass and carbon fixation, reflecting that the higher silicate favoured the growth of phytoplankton and thus led to higher primary production in this strait.展开更多
We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles w...We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.展开更多
To understand how hydrological and biological factors affect near-to off-shore variations in the siphonophore community,we sampled zooplankton at 82 stations in the northern South China Sea during summer,winter,and sp...To understand how hydrological and biological factors affect near-to off-shore variations in the siphonophore community,we sampled zooplankton at 82 stations in the northern South China Sea during summer,winter,and spring.Forty-one species of siphonophore were collected by vertical trawling.The species richness of siphonophores increased from the nearshore to offshore regions in all three seasons of investigation,with maximum richness in summer and minimum richness in winter.The abundance of siphonophores was also higher in summer than in spring and winter,concentrated in the nearshore region in the warm season and scattered in the offshore region in the cold season.Four siphonophore groups were classified according to the frequency of occurrence:nearshore,near-offshore,offshore,and tropical pelagic.Among them,the nearshore group had higher abundance nearshore compared with the offshore.The tropical pelagic group had higher species number offshore than nearshore.Spatial and temporal fluctuations in taxonomic composition and abundance of siphonophores were due to the influence of the coastal upwelling and surface ocean currents of the South China Sea,driven by the East Asia monsoonal system.展开更多
Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats w...Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.展开更多
基金The authors are grateful to the Knowledge Innovation Program of Chinese Academy of Science(Nos.KZCX2-YW-216-1 and KSCX2-YW-G-073)the National Basic Research Program of China(No.2010CB833800-G)+1 种基金the National Natural Science Foundation of China and Research Grants Council of Hong Kong(NSFC/RGC) Program(No. 40910093)Knowledge Innovation Program of South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LYQY200703) for financial support
文摘A new nine-membered lactone,cladospolide E（1）,was isolated from a culture broth of a marine fungus Cladosporium sp.F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis,including 1D and 2D NMR data.
基金This research was partially funded by the State Principal and Basic Research and Development Program of the Ministry of Sciences and Technology of China under contract No. 2010CB833801the Provincial Collaborative Foundation Project of Guangdong under contract Nos 9351007002000001 and 2008A030203004
文摘It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has been previously studied but that of bacteria in sponges inhabiting the open sea has been rarely investigated.In this report,the diversity of bacteria associated with the marine sponge Agelas robusta from a remote coral reef in the South China Sea was documented employing 16S rDNA library construction,amplified ribosomal DNA restriction analysis（ARDRA） and phylogenetic analysis.A total of 32 phylotypes were finally categorized in nine phyla including Cyanobacteria,Proteobacteria,Chloroflexi,Firmicutes,Actinobacteria,Acidobacteria,Planctomycetes,Bacteroidetes and Gemmatimonadetes.The dominant phylum was Proteobacteria whereas the dominant genus was Synechococcus in Cyanobacteria.Some spongespecific bacteria were also found in the bacteria population,but the proportion（5 OTUs/32 OTUs） was much lower than other sponges.This study reveals the phylogenetic diversity of bacteria in A.robusta and confirms the presence of some sponge-specific bacteria in the South China Sea.Understanding the diversity of sponge-associated bacteria in China assists to exploit the bacteria resources for biotechnology.
基金Supported by National Natural Science Foundation of China (No.41006090)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-03)the National High Technology Research and Development Program of China (863 Program) (No.2006AA10A409)
文摘Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH, a process known as "ocean acidification". The pearl oyster Pinctada fucata, the noble scallop Chlamys nobilis, and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China. We evaluated the effects of seawater acidification on clearance, respiration, and excretion rates in these three species. The animals were reared in seawater at pH 8.1 (control), 7.7, or 7.4. The clearance rate was highest at pH 7.7 for P. fucata and at pH 8.1 for C. nobilis and P. viridis. The pH had little effecton the respiration rate of P. fucata and P. viridis. In contrast, the respiration rate was significantly lower atpH 7.4 in C. nobilis. The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species. Theresults indicate that the reduction in seawater pH likely affected the metabolic process (food intake, oxygenconsumption, and ammonia excretion) of these bivalves. Different species respond differently to seawateracidification. Further studies are needed to demonstrate the exact mechanisms for this effect and evaluateadaptability of these bivalves to future acidified oceans.
基金The CAS Strategic Pilot Science and Technology of China under contract Nos XDA11020205 and XDA05030403the National Project of Basic Sciences and Technology of China under contract Nos 2012FY112400 and 2013FY111200+1 种基金the National Natural Science Foundation of China under contract Nos 41276162,41130855,41276161 and 40906057the Natural Science Foundation of Guangdong Province of China under contract No.S2011040000151
文摘Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is still unknown. Based on large-scale biological and environmental in situ observations and synchro nous remote sensing data, the distribution patterns of phytoplankton biomass and the primary production, and the role of mesoscale eddies in regulating primary production in different eddy-controlled waters were investigated. The results suggested that the surface chlorophyll a concentrations and water column inte grated primary production （IPP） are significantly higher in cyclonic eddies and lower in the anticyclonic eddies as compared to that in non-eddy waters. Although eddies could affect various environmental factors, such as nutrients, temperature and light availability, nutrient supply is suggested to be the most important one through which mesoscale eddies regulated the distribution patterns of phytoplankton biomass and pri mary production. The estimated IPP in cyclonic and anticyclonic eddies are about 29.5% higher and 16.6% lower than the total average in the whole study area, respectively, indicating that the promotion effect of mesoscale cold eddies on the primary production was much stronger than the inhibition effect of the warm eddies per unit area. Overall, mesoscale eddies are crucial physical processes that affect the biological car bon fixation and the distribution pattern of primary production in the SCS open sea, especially during the spring inter-monsoon period.
基金supported by grants from the National Natural Science Foundation of China (31172403)the National Basic Research Program of China (2010CB126406)
文摘This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities(low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities(P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity(P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15(P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70(P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities(15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis.
基金The Knowledge Innovation Project of Chinese Academy of Sciences under contract Nos KZCX2-YW-Q07, KZCX2-YW-T001, KZCX2-YW-213 and SQ200805the National Natural Science Foundation of China under contract Nos U0633007, 40906057 and 40531006
文摘Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent waters（ZREAW） in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated.
基金The National Natural Science Foundation of China under contract No.41130855Key Laboratory for Exploitation&Utilization ofMarine Fisheries Reource in South China Sea,Ministry of Agriculture under contract No.LSF2011-05Financial Fund of the Ministry of Agricultureunder contract No.NFZX2013
文摘Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea （6~S to 20~N）, the authors investigated the ciliate abundance and species composition in sur- face waters during May 18 to 27 of 2010. The ciliate abundance decreased latitudinally from 3 080 ind./L （~6~S） to 40 ind./L （-~3~N）, and then increased to 1 180 ind./L （-~ 16~N） at the end of the survey. A total of 22 ciliates belonging to 15 genera were identified with the tintinnids accounted for 50% （11 species）; and the species number showed a same spatial change as the ciliate abundance. Moreover, the Strombidium oc- cupied over 50% of total ciliate abundance in most stations and Mesodiniurn and Tintinnopsis contributed to about 18.7% and 11.4%, respectively. In particular, our results indicate that the geographical changes in ciliate abundance were positively regulated by larger nano- and micro-phytoplankton biomass, rather than smaller pico-phytoplankton in the investigated waters.
基金Supported by the Knowledge Innovation Program of Chinese Academyof Sciences (No.KZCX2-EW-Q214)the Comprehensive Strategic Cooperation Programs between Guangdong Province and Chinese Academy of Sciences (Nos.2011A090100008,2009B091300018,2010B090300027)the Marine Fisheries Technology Promotion Special Program of Guangdong Province (No.A2009009-035(a))
文摘Oyster peptides were produced from Crassostrea hongkongensis and used as a new protein source for the preparation of an oyster peptide-based enteral nutrition formula (OPENF). Reserpine-induced malabsorption mice and cyclophosphamide-induced immunosuppression mice were used in this study. OPENF powder is light yellow green and has a protein-fat-carbohydrate ratio of 16:9:75 with good solubility in water. A pilot study investigating immune functional impacts of the OPENF on mice show that the OPENF enhanced spleen lymphocyte proliferation and the activity of natural killer (NK) cells in BALB/c mice. Furthermore, OPENF can improve intestinal absorption, increase food utilization ratio, and maintain the normal physiological function of mice. These results suggest that oyster peptides could serve as a new protein source for use in enteral nutrition formula, but more importantly, also indicate that OPENF has an immunostimulating effect in mice.
基金The State Principal and Basic Research and Development Program of the Ministry of Sciences and Technology of China under contract No.2010CB833801the National Supportive Project under contract No.2006BAB19B02Hundred Talents Program of Chinese Academy of Science
文摘16S rDNA sequencing results from this study and literatures demonstrate that sediment bacteria in the South China Sea （SCS） were very diverse,which contained 22 of the 24 phyla of bacteria investigated from marine sediment,however,it was very imbalance among stations.So bacterial diversity from 15 samples which covered a wide range of sediment types from 20 to 3 888 m in depth was studied in DGGE （denature gradient gel electrophoresis） in this paper.The DGGE results indicate that both sediment bacterial diversity and diversity difference among stations were significant.Thirty representative and differential fingerprints among samples were recovered and sequenced,phylogenetic analysis indicates that they may belong to Proteobacteria （α-,β-,γ-,δ-,ε-）,Planctomycetes,Firmicutes,Chloroflexi,Acidobacteria,Actinobacteria,Nitrospirae,Gemmatimonadetes,candidate division WS3 and so on,of which,Gemmatimonadetes and candidate division WS3 bacteria were first detected in SCS sediment.This study also shows that bacterial diversity analysis based on DGGE was more potential than traditional 16S rDNA clone library in multiple sample analysis.
基金Supported by the National Basic Research Program of China (973 Program) (No.2010CB126404)the CAS/SAFEA International Partnership Program for Creative Research Teams (No.KZCX2-YW-T001)the Research Program for Young Scientists at SCSIO
文摘Ubiquitin, a highly conserved stress-related protein, is assigned multiple functions, such as DNA processing, protein degradation, and ribosome synthesis. The Crassostrea hongkongensis ubiquitin gene (designated ChUbL40) was cloned by a combination of suppressive subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE). The full-length cDNA of ChUbL40 is 496 bp in length, consisting of a 5' untranslated region (UTR) of 34 bp, a 3'-UTR of 75 bp and an open reading frame of 387 bp encoding a ubiquitin fusion protein of 128 amino acids. Analysis of the amino acid sequence of ChUbL40 reveals that UbL40 is highly conservative during evolution. The expression patterns of ChUbL40 gene in various tissues were examined by real-time PCR. The expression level of ChUbL40 in haemocytes is down-regulated at 4 h and gradually returned to its original level from 6 h to 24 h after Vibrio alginolyticus challenge. Our results suggest that ChUbL40 is ubiquitously expressed and plays an important role in immune defense against bacterial challenge.
基金the National Marine Public Welfare Research Program(201205023)the Scientific and Technical Supporting Program(2011BAD13B03)
文摘From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica(Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions(e.g.,temperature and food availability).Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad.Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn,whereas spawning occurred in summer(20.4-24.6℃).The seasonal variation in lipid content was similar to that of the mean oocyte diameter.In both neutral and polar lipids,the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids,and polyunsaturated fatty acids were abundant,with series n-3 as the predominant component.Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle.The ∑(n-3) and ∑(n-6) values were relatively high during January-May,and the associated unsaturation index was significantly higher than that in other months.The results suggest that fatty acids play an important role in the gametogenesis of F.mutica.
基金supported by the National Nature Science Foundation of China(Nos.41276159,41130855)the Special Fund of Basic Research for Centre Commonweal Scientific Research Institute(Nos.2007ZD07,2011TS06,2013TS07)
文摘Mesozooplankton are key components of coastal ecosystems,linking the microbial food web to the classic food chain.In this study,species composition and abundance of mesozooplankton is studied for the Daya Bay in April(spring) and October(fall),2006.A total of 27 species of mesozooplankton were identified in spring and 58 species in fall.Dominant species were Oithona tenuis,Flaccisagitta enflata,Penilia avirostris and Centropages tenuiremis in spring,shifting to Microsetella norvegica,Oithona tenuis and Parvocalanus crassirostris in fall.Higher mesozooplankton abundance was found at Aotou Cove and Dapeng'ao Cove compared to other stations,indicating the influence of eutrophication on mesozooplankton community in the Daya Bay.The outbreak of Noctiluca scintillans bloom in spring reduced the species diversity and abundance of mesozooplankton.
基金The National Natural Science Foundation of China under contract Nos 41076011, 40531006, 41130855 and 40906057the Knowledge Innovation Project of Chinese Academy of Sciences under contract No. KZCX2-YW-Q07
文摘The response of chlorophyll a （Chl a） concentration to wind stress is analyzed in the South China Sea （SCS）, using in-situ data of Chl a and remote sensing data （QuikScat-sea surface wind （SSW）, AVHRR-sea surface temperature （SST）, AVISO merged-sea level anomalies （SLA）, SeaWiFS- derived Chl a and MODIS Terra-derived Chl a） in August/September/October 2004, 2006 and 2009. The variability of SSW, SST and SLA 7 d before in-situ Chl a sampling （including the work day of in^situ Chl a sampling） with the same latitude and longitude of the study area are investigated, and the correlation coefficients are calculated between these hydrographic factors and in-situ Chl a concentration. The results show that the Chl a-SSW correlation coefficients at upper layers （such as 0 m and 25 m） are more significant than those at deeper layers （such as 50, 75 and 100 m） 1 3 d before, which indicates that there is a time lag of strong surface winds stimulating phytoplankton bloom. By analyzing the relationship among the daily remote sensing derived （RS- derived） SSW, SST, SLA and 3 d averaged SeaWiFS/MODIS-derived Chl a concentration in the northern SCS in September 2004 and 2009 respectively, it shows that the intensity and speed of surface winds could have great influence on extend of Chl a increase. If surface winds reach 4-5 m/s over, Chl a concentration would increase 1-3 d after the process of strong surface winds in open sea area of the northern SCS mainly during September.
基金Supported by CAS for Key Topics in Innovation Engineering (No. KZCX2-YW-JS206)the CAS/SAFEA International Partnership Program for Creative Research Teams (No. KZCX2-YW-T001)+1 种基金the National Natural Science Foundation of China (Nos. 41076096, 40828006, U1033003)Guangdong Natural Science Fund (No. 2010B031900039)
文摘Nutrient limitation is known to inhibit growth and metabolism and to alter elemental stoichiometric ratios in phytoplankton. In this study, physiological changes in Thalassirosira weissflogii were measured under different dissolved inorganic phosphate (DIP) regimes in semi-continuous cultures to revisit the utility of the Redfield ratio for assessing nutrient limitation. The results showed that cell size increased with decreasing DIP availability. In the P-depleted treatment (f/2-P) the cell size was 1.48 times larger than that in the P-limited (f/100) treatment and 2.67 times larger than that in the P-saturated treatment (f/2 and f/10). The fucoxanthin to chlorophyll a ratio (Fuco/chl a) was relatively stable (about 0.3) in P-saturated cultures and was 10 times higher than that in P-limited and P-depleted cultures. During the experimental period, the photosynthetic efficiency index, ?F/Fm′, was relatively stable at ~0.50 in the P-saturated cultures, but quickly declined with decreasing DIP availability. Although cellular P content showed a significant difference between the P-saturated culture (1.6 pg/cell) and the P-limited culture (0.7 pg/cell), the N/P ratio in T. weissflogii did not show a trend with DIP availability and fluctuated slightly around 25. Our results suggest that cell division in T. weissflogii is not strictly size-gated but is probably regulated by a biochemical, and hence, an elemental stoichiometric ratio threshold, and that deviation of the cellular N/P ratio from the Redfield ratio is not a reliable indicator of algal nutrient stress.
基金Supported by National High Technology Research and Development Program of China (863 Program) (No. 2006AA10A409)the Knowledge Innovation Program of the South China Sea Institute of Oceanology, Chinese Academy of Sciences (No. SQ200906)+2 种基金the Science and Technology Program of Guangdong Province (No. 2008A020100004)the National Key Technology Research and Development Program (No. 2007BAD29B01-8)the Key Plan for Marine Development of Guangdong Province (No. A200708C01)
文摘The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COl. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and CO1 so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.
基金The National Project of Basic Science and Technology under contract No. 2008FY110100the Key Innovation Group Project of Chinese Academy of Sciences under contract No. KZCX2-YW-Q07+1 种基金the National Natural Science Foundation of China under contract Nos 41006066 and 41130855the Knowledge Innovation Program of Chinese Academy of Sciences under contract No. SQ200907
文摘Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16∶1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam; while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis (CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature; while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS.
基金The National Natural Science Foundation of China under contract Nos 41130855,41206132 and 41276162the Natural Science Foundation of Guangdong under contract No.S2011040000151+2 种基金CAS Knowledge Innovation Program under contract No.SQ201115National Project of Sciences and Technology under contract No.2008FY110100CAS Strategic Pilot Science and Technology under contract No.XDA05030403
文摘The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- toplankton biomass, size-structure and carbon fixation were investigated across the SoM during the spring period （May 4 to 9, 2011）. Chlorophyll a concentration increased from 0.12 ptg/L at the northwest entrance of the SoM to a maximal 0.63 #g/L at narrowest section, and decreased to 0.10/.tg/L at the southeast entrance. Photosynthetic carbon fixation by phytoplankton coincided well with Chl a biomass, and increased from 10.8 to 22.3 pg C/（L.d）, then decreased to 9.21/zg C/（L.d）; while the carbon fixation rate showed an inverse pattern to the changes of Chl a, and decreased from 87.1 to 35.5 #g C/（#g Chl a.d） and increased thereafter to 95.3 btg C/（/2g Chl a.d）. Picophytoplankton cells （〈3/2m） contributed to more than 60% and 50% of the total Chl a and carbon fixation at both the entry waters; while the contributions of pico-cells decreased sharply to the minimum of 18.3% and 27.5% at the narrowest part of the SoM. In particular, our results showed that the silicate concentration positively regulated Chl a biomass and carbon fixation, reflecting that the higher silicate favoured the growth of phytoplankton and thus led to higher primary production in this strait.
基金Supported by the Special Promotion Program for Guangdong Provincial Ocean and Fishery Technology(No.A201101F03)the National Natural Science Foundation of China(Nos.41176102,31100260)
文摘We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.
基金Supported by the Key Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-Q07)the National Natural Science Foundation of China(Nos.31101619,41130855)the Chinese Offshore Investigation and Assessment(No.908-01-ST08)
文摘To understand how hydrological and biological factors affect near-to off-shore variations in the siphonophore community,we sampled zooplankton at 82 stations in the northern South China Sea during summer,winter,and spring.Forty-one species of siphonophore were collected by vertical trawling.The species richness of siphonophores increased from the nearshore to offshore regions in all three seasons of investigation,with maximum richness in summer and minimum richness in winter.The abundance of siphonophores was also higher in summer than in spring and winter,concentrated in the nearshore region in the warm season and scattered in the offshore region in the cold season.Four siphonophore groups were classified according to the frequency of occurrence:nearshore,near-offshore,offshore,and tropical pelagic.Among them,the nearshore group had higher abundance nearshore compared with the offshore.The tropical pelagic group had higher species number offshore than nearshore.Spatial and temporal fluctuations in taxonomic composition and abundance of siphonophores were due to the influence of the coastal upwelling and surface ocean currents of the South China Sea,driven by the East Asia monsoonal system.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q214)the Comprehensive Strategic Cooperation Programs between Guangdong Province and Chinese Academy of Sciences(Nos.2011A090100008,2009B091300018,2010B090300027)the Marine Fisheries Technology Promotion Special Program of Guangdong Province,China(No.A2009009-035(a))
文摘Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.
