Sort By:
Relevance
Published
Display per page:
10
20
30
50
Morphology, ultrastructure and phylogeny of Cyanothece sp. (Cyanobacteriaceae: Cyanophyceae) isolated from the eastern Indian Ocean
ZHANG Xiaodong, YANG Shuang, SUN Jun, WU Chao, WANG Jing, ZHANG Guicheng, DING Changling
2018, 37(10): 4-10. doi: 10.1007/s13131-018-1297-y
Keywords: Cyanothece, cyanobacteria, morphology, 16S rRNA gene, nifH gene, Indian Ocean
One strain of unicellular greenish algae embedded by mucilage was successfully isolated from equatorial area in the Indian Ocean. Microscopic observation, ultrastructure features and genetic identification confirmed that the strain was closely related to Cyanothece sp., which was a cyanobacteria species with great ecological significance. Cells were solitary with oval or bacilliform shapes. Diameters of this strain were relatively small, ranging from 2.5 to 6.5 μm on average. Ultrastructure of cells was simple. Thylakoids were arranged parietal and keritomized content were observed in the thylakoid region. Various electron-transparent granules with low electron-dense region as well as cyanophycin or glycogen granules-like organelle and carbonxysomes were also observed. For pigment composition, the dominant pigments were chlorophyll a, β-Carotene, Zeaxanthin and an unknown pigment, contributing 23.8%, 26.1%, 14.7% and 15.7% to total pigments respectively. The phylogenetic analysis of 16S rRNA gene and nifH gene confirmed that Strain EIO409 was closely related with Cyanothece sp..
Bacterial and cyanobacterial diversities determined by T-RFLP analyses in the Jiaozhou Bay
REN Jing, DANG Hongyue, SONG Linsheng, SUN Song, AN Liguo
2006(4): 113-123.
Keywords: bacterial diversity, cyanobacteria, 16S rDNA, T-RFLP, Jiaozhou Bay
The methods of DAPI staining epifluorescence microscopy and T-RFLP analysis were used to analyze the microbial abundance and diversity in surface seawater sampled from 12 stations inside and outside of the Jiaozhou Bay during a survey on 12 and 13 September 2004. The abundance of total microbes is in the range of 106~107 cells/cm3, similar to those of most semi-enclosed bays in the temperate areas in the world. The highest microbial densities occur in the northeastern part of the Jiaozhou Bay, around the mouths of Loushan and Licun Rivers and the Hongdao aquacultural farming areas, suggesting that the degree and characteristics of pollutions, along with geographical and hydrological effects, may be important determinants affecting the abundance and distribution of bacteria in the Jiaozhou Bay. Bacterial communities inside and outside of the Jiaozhou Bay can be grouped into three classes based on T-RFLP patterns and cluster analyses. Stations at the water channel of the bay mouth and outside, such as D1, D3, D5, D6 and D7, are grouped together to stand for the outside bacterial community interacting with the environment outside of the Jiaozhou Bay. Stations of the innermost side of the Jiaozhou Bay, such as A3, A5, B2 and Y1, are grouped together to stand for the residential bacteria community. Stations C1, C3 and C4 are grouped together and may stand for the transitional bacterial assemblage between the residential community and the outside community. However, there is no such a defined relationship for the case of cyanobacterial diversity, indicating the fact that cyanobacteria are more flexible and adaptable to all kinds of conditions.
Phylogenetic diversity of bacteria associated with the marine sponge Agelas robusta from South China Sea
SUN Wei, DAI Shikun, WANG Guanghua, XIE Lianwu, JIANG Shumei, LI Xiang
2010, 29(5): 65-73. doi: 10.1007/s13131-010-0064-5
Keywords: South China Sea, Agelas robusta, phylogenetic diversity, sponge-specific bacteria
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.
Phylogenetic diversity of Type I polyketide synthase genes from sediments of Ardley Island in Antarctica
ZHAO Jing, YANG Ning, CHEN Xinglin, JIANG Qingru, ZENG Runying
2011(6): 104-111. doi: 10.1007/s13131-011-0167-7
Keywords: polyketide synthase, diversity, Antarctica
The diversity of modular polyketide synthase (PKS) genes in sediments of Ardley Island in Antarctica, was studied by restriction fragment length polymorphism (RFLP) analysis. Phylogenetic analysis of 14 amino acid (AA) sequences indicates that the identified ketosynthase (KS) domains were clustered with those from diverse bacterial groups, including Cyanobacteria, γ-Proteobacteria, Actinobacteria, Firmicutes, and some unidentified microorganisms from marine sponge, bryozoan and other environmental samples. The obtained KS domains showed 43%-81% similarity at the AA level to reference sequences in GenBank. Six identified KS domains showed diverse sequences of the motif (VQTACSTS) that was used to identify the hybrid PKS/nonribosomal peptide synthetase (NRPS) enzyme complex, and formed a new branch. These results reveal a high diversity and novelty of PKS genes in antarctic sediments.
Grazing impact of microzooplankton on phytoplankton in the Xiamen Bay using pigment-specific dilution technique
HUANG Bangqin, LIU Yuan, XIANG Weiguo, TIAN Haojie, LIU Hongbin, CAO Zhenrui, HONG Huasheng
2008(5): 147-162.
Keywords: microzooplankton, growth rate, grazing mortality, photosynthetic pigments, Xiamen Bay, dilution method
Phytoplankton group-specific growth and microzooplankton grazing were determined seasonally using the dilution technique with high-performance liquid chromatography (HPLC) in the Xiamen Bay, a subtropical bay in southeast China, between May 2003 and February 2004. The results showed that growth rates of phytoplankton ranged from 0.71 to 2.2 d-1 with the highest value occurred in the inner bay in May. Microzooplankton grazing rates ranged from 0.5 to 3.1 d-1 with the highest value occurred in the inner bay in August. Microzooplankton grazing impact ranged from 39% to 95% on total phytoplankton Chl a biomass, and 65% to 181% on primary production. The growth and grazing rates of each phytoplankton group varied, the highest growth rate (up to 3.3 d-1) was recorded for diatoms in August, while the maximum grazing rate (up to 2.1 d-1) was recorded for chlorophytes in February in the inner bay. Among main phytoplankton groups, grazing pressure of microzooplankton ranged from 10% to 83% on Chl a biomass, and from 14% to 151% on primary production. The highest grazing pressure on biomass was observed for cryptophytes (83%) in August, while the maximum grazing pressure on primary production was observed for cyanobacteria (up to 151%) in December in the inner bay. Net growth rates of larger phytoplanktons (diatoms and dinoflagellates) were higher than those of smaller groups (prasinophytes, chlorophytes and cyanobacteria). Relative preference index showed that microzooplankton grazed preferentially on prasinophytes and avoided to harvest diatoms in cold seasons (December and February).
A snapshot on spatial and vertical distribution of bacterial communities in the eastern Indian Ocean
WANG Jing, KAN Jinjun, BORECKI Laura, ZHANG Xiaodong, WANG Dongxiao, SUN Jun
2016, 35(6): 85-93. doi: 10.1007/s13131-016-0871-4
Keywords: eastern Indian Ocean, water column, bacterial community, pyrosequencing
Besides being critical components of marine food web, microorganisms play vital roles in biogeochemical cycling of nutrients and elements in the ocean. Currently little is known about microbial population structure and their distributions in the eastern Indian Ocean. In this study, we applied molecular approaches including polymerase chain reaction-denaturant gradient gel electrophoresis (PCR-DGGE) and High-Throughput next generation sequencing to investigate bacterial 16S rRNA genes from the equatorial regions and the adjacent Bay of Bengal in the eastern Indian Ocean. In general, Bacteroidetes, Proteobacteria (mainly Alpha, and Gamma), Actinobacteria, Cyanobacteria and Planctomycetes dominated the microbial communities. Horizontally distinct spatial distribution of major microbial groups was observed from PCR-DGGE gel image analyses. However, further detailed characterization of community structures by pyrosequencing suggested a more pronounced stratified distribution pattern: Cyanobacteria and Actinobacteria were more predominant at surface water (25 m); Bacteroidetes dominated at 25 m and 150 m while Proteobacteria (mainly Alphaproteobacteria) occurred more frequently at 75 m water depth. With increasing water depth, the bacterial communities from different locations tended to share high similarity, indicating a niche partitioning for minor groups of bacteria recovered with high throughput sequencing approaches. This study provided the first "snapshot" on biodiversity and spatial distribution of Bacteria in water columns in the eastern Indian Ocean, and the findings further emphasized the potential functional roles of these microbes in energy and resource cycling in the eastern Indian Ocean.
Distribution pattern of marine flagellate and its controlling factors in the central and north part of the Huanghai Sea in early summer
Huang Lingfeng, Guo Feng, Huang Bangqin, Xiao Tian
2003(2): 273-280.
Keywords: Marine flagellate, distribution, controlling factors, early summer, the Huanghai Sea
A survey was carried out in the central and north part of the Huanghai Sea (34.5°~37.0°N, 120.5°~124.0°E) during June 12~27, 2000. It was found that the abundance of marine flagellate ranged from 45 to 1 278 cell/ml, 479 cell/ml in average. Flagellate was more abundant in the central part than in the north part of Huanghai Sea, and the abundance decreased with the increasing distance from the coast, showing a similar distribution pattern with isotherm. Vertically, high density of flagellate was always presented in the bottom of thermocline, and formed a dense accumulation in the central area of the Huanghai Sea Cold Water Mass. The effects of physical and biological factors on the distribution of marine flagellate in early summer were discussed. Water temperature (especially the existence of thermocline) rather than salinity showed significant effect on the distribution pattern of marine flagellate in the Huanghai Sea in early summer. When comparing the abundance of marine flagellate with that of other microorganisms, it revealed a comparatively stable relationship among these organhisms, with a ratio of heterotrophic bacteria:cyanobacteria:flagellate:dinoflagellate:ciliate being 105:103:102:101:100.
Co-monitoring bacterial and dinoflagellates communities by denaturing gradient gel electrophoresis(DGGE) and SSU rRNA sequencing during a dinoflagellates bloom
KAN Jinjun, CHEN Feng
2004(3): 483-492.
Keywords: bacteria, dinoflagellates, DGOE, SSU rDNA sequencing
Dinoflagellates are unicellular eukaryotic protists that dominate in all coastal waters,and are also present in oceanic waters.Despite the central importance of dinoflagellates in global primary production,the relationship between dinoflagellates and bacteria are still poorly understood.In order to understand the ecological interaction between bacterial and dinoflagellates communities,denaturing gradient gel electrophoresis(DGGE) and SSU rRNA sequencing were applied to monitoring the population dynamics of bacteria and dinoflagellates from the onset to disappearance of a dinoflagellates bloom occurred in Baltimore Inner Harbor,from April 15 to 24,2002.Although Prorocentrum minimum was the major bloom forming species under the light microscopy,DGGE method with dinoflagellate specific primers demonstrated that Prorocentrum micans,Gymnodinium galatheanum and Gyrodinium uncatenum were also present during the bloom.Population shifts among the minor dinoflagellate groups were observed.DGGE of PCR-amplified 16S rRNA gene fragments indicated that cyanobacteria,α,β,γ proteobacteria,Flavobacterium-Bacteroides-Cytophaga(FBC),and Planctomcetes were the major components of bacterial assemblages during the bloom.DGGE analysis showed that Cytophagales and α-proteobacteria played important roles at different stages of dinoflagellates bloom.DGGE can be used as a rapid tool to simultaneously monitor population dynamics of both bacterial and dinoflagellates communities in aquatic environments,which is demonstrated here.
Diversity and distribution of bacterioplankton in the coastal upwelling waters off Hainan Island, China
Fahui Gong, Qixing Ji, Guihao Li, Kedong Yin, Jun Gong
2022, 41(3): 76-85. doi: 10.1007/s13131-021-1807-1  Published:2022-03-01
Keywords: 16S rRNA, bacterioplankton, coastal upwelling, Hainan Island
The diversity, community composition and 16S rRNA gene abundance of bacterioplankton along a transect across an upwelling area off the eastern coast of Hainan Island (the Qiongdong upwelling) were investigated in August of 2016 using high throughput sequencing and quantitative PCR assay of 16S rRNA genes. Compared with the offshore stations, the inner-shelf stations had higher bacterial gene abundance (up to 3 fold) and operational taxonomic unit richness, a result of the influence of upwelled and fresher waters. Overall, a majority of the reads were affiliated with Gammaproteobacteria (11%74%) and Alphaproteobacteria (14%43%). The structure of the bacterial community was significantly affected by salinity, dissolved oxygen, ${\rm{NO}}_3^-$ and ${\rm{NH}}_4^+ $, which also defined the physicochemical features of the upwelled waters. Horizontally, the relative abundances and gene abundances of Rhodobacteraceae, SAR86, Cyanobacteria and Bacteroidetes in eutrophic zone decreased from the inner to outer shelves and slope, whereas Alteromonas, Vibrio and Oceanospirillaceae exhibited an opposite trend. This study stresses the riverine influence on the oceanographic condition and spatial variability of bacterioplankton diversity and distribution in the Qiongdong upwelling.
Ecological provinces of spring phytoplankton in the Yellow Sea: species composition
ZHANG Shan, LENG Xiaoyun, FENG Yuanyuan, DING Changlin, YANG Yang, WANG Jing, WANG Houjie, SUN Jun
2016, 35(8): 114-125. doi: 10.1007/s13131-016-0872-3
Keywords: phytoplankton, ecological province, Yellow Sea, spring
Phytoplanktonic ecological provinces of the Yellow Sea (31.20°-39.23°N, 121.00°-125.16°E) is derived in terms of species composition and hydrological factors (temperature and salinity). 173 samples were collected from 40 stations from April 28 to May 18, 2014, and a total of 185 phytoplanktonic algal species belonging to 81 genera of 7 phyla were identified by Utermöhl method. Phytoplankton abundance in surface waters is concentrated in the west coast of Korean Peninsula and Korea Bay, and communities in those areas are mainly composed of diatoms and cyanobacteria with dominant species ofCylindrotheca closterium, Synechocystis pevalekii, Chroomonas acuta, Paralia sulcata, Thalassiosira pacifica and Karenia mikimotoi, etc. The first ten dominant species of the investigation area are analyzed by multidimensional scaling (MDS) and cluster analysis, then the Yellow Sea is divided into five provinces from Province I (P-I) to Province V (P-V). P-I includes the coastal areas near southern Liaodong Peninsula, with phytoplankton abundance of 35 420×103-36 163×103 cells/L and an average of 35 791×103 cells/L, and 99.84% of biomass is contributed by cyanobacteria. P-Ⅱ is from Shandong Peninsula to Subei coastal area. Phytoplankton abundance is in a range of 2×103-48×103 cells/L with an average of 24×103 cells/L, and 63.69% of biomass is contributed by diatoms. P-Ⅲ represents the Changjiang (Yangtze River) Diluted Water. Phytoplankton abundance is 10×103-37×103 cells/L with an average of 24×103 cells/L, and 73.14% of biomass is contributed by diatoms. P-IV represents the area affected by the Yellow Sea Warm Current. Phytoplankton abundance ranges from 6×103 to 82×103 cells/L with an average of 28×103 cells/L, and 64.17% of biomass is contributed by diatoms. P-V represents the cold water mass of northern Yellow Sea. Phytoplankton abundance is in a range of 41×103-8 912×103 cells/L with an average of 1 763×103 cells/L, and 89.96% of biomass is contributed by diatoms. Overall, structures of phytoplankton community in spring are quite heterogeneous in different provinces. Canonical correspondence analysis (CCA) result illustrates the relationship between dominant species and environmental factors, and demonstrates that the main environmental factors that affect phytoplankton distribution are nitrate, temperature and salinity.
  • First
  • Prev
  • 1
  • 2
  • Last
  • Total:2
  • To
  • Go