The inventory and chemical characterization of dissolved proteins in oceanic waters     

Namiha Yamada  Eiichiro Tanoue 《Progress in Oceanography》2006,69(1):1-18

One-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and high resolution two-dimensional electrophoresis (2-DE) were applied to separate protein molecules in dissolved organic matter (DOM) from oceanic waters. Results were: (1) The 2-DE distinguished a total of 412 protein spots in 10 samples from five water columns over the Pacific, although fewer than 30 proteins were resolved as bands from the identical samples by SDS-PAGE. (2) Major and ubiquitous protein bands (34 and 39 kDa proteins) on the SDS-PAGE gel were resolved into horizontally spread arrays (trains) of spots on the 2-DE gels, indicating that these bands were a mixture of protein species that have the same molecular weight (MW) but different isoelectric points (pIs). (3) Proteins that exhibited such electrophoretic patterns on the 2-DE gels were glycosylated with variable linkages between the sugar and polypeptide chains. (4) N-terminal amino-acid sequencing demonstrated that individual spots within each train of spots had identical N-terminal amino-acid sequences.The N-terminal amino-acid sequences of the 39 and 34 kDa glycoprotein spots in samples collected at different sites were also identical. Protein isoforms with the same amino-acid sequence but different glycosylation profiles, termed glycoforms, were often observed on the 2-DE gel. Thirty-one and 24 spots on the 2-DE gels were glycoforms of two glycoproteins with MWs of 39 and 34 kDa, respectively; they were one protein species. The glycoforms of the 39 kDa protein were identified as a low molecular weight alkaline phosphatase (L-AP) of Pseudomonas aeruginosa PAO1 by a homology search through five amino-acid sequence databases. The present and earlier work indicates that all identified source organisms of dissolved proteins belong to the Pseudomonas group. We propose the hypothesis that proteins associated with membrane vesicles liberated from a minor member of the bacterioplankton assemblage, the marine Pseudomonas group, are one of the important sources of dissolved proteins in oceanic waters. This hypothesis may apply to the source pathway and survival not only of proteins and also to the universally occurring bacterial peptidoglycan and lipopolysaccharide components in DOM.  相似文献   

坛紫菜藻红蛋白α,β亚基基因的克隆和序列分析   总被引：1，自引：0，他引：1       下载免费PDF全文

闫国良  杨听林  徐双悦  左正宏  陈瑜芳  陈奕欣 《海洋学报》2007,29(2):167-172

藻胆蛋白(Phycobiliprotein,PBP)是原核藻类和真核藻类进行光合作用的捕光色素蛋白,占藻体干重的2%左右,主要分为3类:藻红蛋白(phycoer-ythrin,PE)、藻蓝蛋白(phycocyanin,PC)和别藻蓝蛋白(allophycocyanin,APC)[1].藻胆蛋白一般由α亚基和β亚基组成,部分藻胆蛋白中还存在γ亚基.一般由α和β亚基形成稳定的单体(αβ),再由单体聚合为多聚体(αβ)_n.从蓝藻和红藻中分离的藻胆蛋白为三聚体(αβ)₃或六聚体(αβ)₆[2].  相似文献   

Seismic and sequence stratigraphy of the central western continental margin of India: late-Quaternary evolution     

S.M Karisiddaiah  M VeerayyaK.H Vora 《Marine Geology》2002,192(4):335-353

Seismic and sequence stratigraphic architecture of the central western continental margin of India (between Coondapur and south of Mangalore) has been investigated with shallow seismic data. Seismic stratigraphic analysis defined nine seismic units, that are configured in a major type-1 depositional sequence possibly related to fourth-order eustatic sea-level changes, comprising regressive, lowstand, transgressive and highstand systems tracts. The late-Quaternary evolution of the continental margin took place under the influence of an asymmetric relative fourth-order sea-level cycle punctuated by higher frequency cycles. These cycles of minor order were characterised by rapid sea-level rises and gradual sea-level falls that generated depositional sequences spanning different time scales. During the regressive periods, dipping strata were developed, while erosional surfaces and incised valleys were formed during the lowstands of sea level. Terraces, v-shaped depressions, lagoon-like structures observed on the outer continental shelf are the result of the transgressive period. In the study area we have recognised a complex erosional surface that records a long time span during the relative sea-level fall (regressive period) and the following sea-level lowstand and has been reworked during the last transgression. We also infer that sedimentation processes changed from siliciclastic sedimentation to carbonate sedimentation and again to siliciclastic sedimentation, marking an important phase in the late-Quaternary evolution of the western continental shelf of India. We attribute this to an abrupt climate change at the end of the oxygen isotope stage 2, between the Last Glacial Maximum and the Bølling-Allerod event (14?000 yr BP). This sensitive climate change (warming) favoured the formation of reefs at various depths on the shelf, besides the development of Fifty Fathom Flat, a carbonate platform on the outer shelf off Bombay developed prior to 8300 yr BP. The highstand systems tracts were deposited after the sea level reached its present position.  相似文献   

Tectonic significance of syn-rift sediment packages across the Gabon-Cabinda continental margin   总被引：1，自引：0，他引：1  

Garry D. Karner  Neal W. Driscoll  John P. McGinnis  William D. Brumbaugh  Nick R. Cameron 《Marine and Petroleum Geology》1997,14(7-8)

The tectonic development of a continental margin is recorded in the stratigraphic successions preserved along and across the margin in terms of stratal relationships (e.g., onlap, downlap, truncation), lithofacies, biostratigraphy, and paleo-water depths. By using these observations coupled to a kinematic and flexural model for the deformation of the lithosphere, we have elucidated the tectonic significance of the preserved stratigraphy that comprises the Gabon-Cabinda margin of west Africa. Two hinge zones, an Eastern and Atlantic, formed along the Gabon-Cabinda margin in response to three discrete extensional events occuring from Berriasian to Aptian time. The Eastern hinge zone demarcates the eastern limit of a broadly distributed Berriasian extension that resulted in the formation of deep anoxic, lacustrine systems as evidenced by the silts and shales of the Sialivakou and lower Djeno Formations and the regressive packages of the upper Djeno Formation. Approximately 1.5 to 2 km of asymmetric footwall uplift was induced across the Eastern hinge zone in response to the mechanical unloading of the lithosphere during this first phase of rifting. In contrast, the Atlantic hinge, located approximately 90 km west of the Eastern hinge, marks the eastern limit of a second phase of extension that began in the Hauterivian. Footwall uplift and rotation exposed earlier syn-rift and pre-rift sediments to at least wavebase causing varying amounts of erosional truncation across the Atlantic hinge zone along much of the Gabon-Cabinda margins. We interpret the thickness variations of reworked clastic sediment of this age (e.g. the Melania Formation) between the hinge zones as indicative of variations in the degree of uplift and erosional truncation of the Atlantic hinge. For example, the absence of Melania Formation across the Congo margin implies that uplift of the Atlantic hinge was relatively minor compared to that across the Cabinda and Gabon margins, the latter being characterized by significant thicknesses of Melania Formation (or equivalent). Material eroded from the Cabinda and Gabon Atlantic hinge zone may in part account for the thick wedge of sediment deposited seaward of the Gabon-Cabinda Atlantic hinge (the Erva Formation). Our modelling suggests that this wedge of reworked elastics represents deposition by along-axis gravity flows within a deep water (≈2 km) environment. A third and final phase of extension in the late Barremian-early Aptian was responsible for breaching the continental lithosphere to form the ocean/continent boundary and thus the installation of open marine conditions. Elsewhere, the environments will tend to be marginal marine to brackish, depending on the efficiency of the Atlantic hinge zone to act as a barrier to marine enchroachment. This third rift phase reactivated both the Eastern and Atlantic hinge0zones thereby creating accomodation for the Marnes Noires Formation (and equivalent) source rock deposition between the hinges and the Falcão source rock equivalent seaward of the Atlantic hinge. Two possible scenarios exist for the lateral distribution of the Marnes Noires Formation. If the reactivated rift flank topography across the Atlantic hinge was significant, then sedimentation would be restricted between the hinge zones within discrete lacustrine settings (e.g., Congo margin). Alternatively, if hinge zone uplift was relatively minor, then a coral-rimmed archipelago may have developed parallel to the margin with restricted communication across the Atlantic hinge zone (e.g., Cabinda margin). In this latter scenario, dilution of the Marnes Noires source rocks by terrigenous input from the eroding Atlantic hinge zone should be relatively minor thereby enhancing source rock quality. Furthermore, potential marine upwelling outboard of the Atlantic hinge zone is likely the cause for the production and accumulation of organic-rich material associated with the Falcão source rock of the Kwanza basin. By late Aptian time, the remaining accomodation between the hinge zones was partially filled by across- and along-axis prograding deltaic systems of the Argilles Vertes and Tchibota Formations. The progradation and interaction of the Argilles Vertes depositional lobes resulted in the formation of residual paleo-relief. Subsequent marine incursions and flooding of this paleo-relief led to the development of basal conglomerates (the Chela ‘lag’ unconformity) grading upward into fine-grained sands and evaporites. Consequently, an inverse relationship should exist betweeb evaporite thickness (in particular, the lower members) and the thickness of the underlying Argilles Vertes and Tchibota Formations. Variations in Loeme evaporite thickness is a consequence of stratigraphic and structural control with salt instability influencing local variability.Our modelling suggests the occurrence of two distinct evaporite sequences on the Congo margin, an earlier evaporite deposited seaward (west) of the Atlantic hinge during the second and third rift phases and the late Aptian Loeme Formation deposited between the hinge zones. An evaporite sequence seaward of the Atlantic hinge is inferred on the basis of extensive diapirs and salt tectonic structures observed in seismic data. In order to match the distribution and thickness of the observed post-salt stratigraphy across the basin, however, we require large paleowater depths west of the Atlantic hinge during the later Aptian. The existence of large paleowater depths precludes the formation of thick evaporite sequences within the outer basin. Consequently, we propose that the evaporites seaward of the Atlantic hinge were formed during the syn-rift development of the margin and are not contemporaneous with the post-rift Loeme salts deposited between the hinge zones. This double salt hypothesis is consistent with observations from the conjugate Brazilian margin.  相似文献   

Marine seismics with a pulsed combustion source and Pseudo Noise codes     

Bjørn Askeland  Halvor Hobæk  Rolf Mjelde 《Marine Geophysical Researches》2007,28(2):109-117

There has been a long-standing debate concerning how dangerous seismic surveys are with respect to marine life. Marine seismic work today is dominated by airgun technology, where high energy is generated by a release of compressed air into the water. The objective of the “Time coded impulse seismic technique” project is to examine whether a new low energy acoustic source can be used for seismic purposes. If the method turns out to be successful, the low output energy and continuous operation will make the source suitable in environmental sensitive areas. The Low level Acoustic Combustion Source (LACS) is a petrol driven pulsed underwater acoustic source. It operates at a few meters depth, and each shot can be digitally controlled from the surface by a computer located in the mother vessel. A presentation of the recorded LACS signal characteristics, the modulation, the Pseudo Noise coding/decoding principles and field test results, is given. The importance of using an optimized code with fine resolution and of using the near field recording as a correlator sequence is demonstrated. Clear correlation peaks could then be seen from the bottom and sub bottom reflectors.  相似文献   

Gene cloning and sequence analysis of the cold-adapted chaperones DnaK and DnaJ from deep-sea psychrotrophic bacterium Pseudoalteromonas sp.SM9913     

ZHAO Dianli  CHEN Xiulan  HE Hailun  SHI Mei  ZHANG Yuzhong 《海洋学报(英文版)》2007,26(6):91-100

Pseudoalteromonas sp.SM9913 is a phychrotrophic bacterium isolated from the deep-sea sediment.The genes encoding chaperones DnaJ and DnaK of P.sp.SM9913 were cloned by normal PCR and TAIL-PCR(GenBank accession Nos DQ640312,DQ504163).The chaperones DnaJ and DnaK from the strain SM9913 contain such conserved domains as those of many other bacteria,and show some cold-adapted characteristics in their structures when compared with those from psychro-,meso-and themophilic bacteria.It is indicated that chaperones DnaJ and DnaK of P.sp.SM9913 may be adapted to low temperature in deep-sea and function well in assisting folding,assembling and translocation of proteins at low temperature.This research lays a foundation for the further study on the cold-adapted mechanism of chaperones DnaJ and DnaK of cold-adapted microorganisms.  相似文献   

中国近海早第三纪海侵层序及地层对比   总被引：1，自引：0，他引：1  

彭世福 《海洋地质与第四纪地质》1992,(1)

中国近海各盆地,据古生物群及沉积特征,在早古新世为陆相沉积,至中晚古新世时为第Ⅰ海侵期。早始新世时为海退期,至中晚始新世为第Ⅱ海侵期。早、中渐新世时为海退期,晚渐新世为第Ⅲ海侵期。在论证地层时代时结合海侵的划分,提出新的见解。海相夹层可作为地层对比的重要标志层。  相似文献   

中国和越南青蟹线粒体16S rRNA基因序列分析   总被引：13，自引：0，他引：13  

王玉江  高天翔  韩志强  刘进贤  于常红 《中国海洋大学学报(自然科学版)》2005,35(4):554-558

为确定我国青蟹的分类地位及其资源的合理利用与保护提供理论依据，对中国和越南青蟹的线粒体16S rRNA基因片段序列进行了测定，并同Genbank中其他青蟹的序列进行了比较，分析研究了青蟹种内和种间的遗传差异及其分类地位。结果显示：中、越青蟹个体间序列差异极小，与Genbank中Scylla paramamosain同源片段序列的相似性达到99％以上．而与其他3种青蟹的差异达3．91％～8．41％。所得序列与S．paramamosain，S．serrata，S．olivacea及s．tranquebarica的遗传距离分别为0．002，0．075，0．087，0．042，种间遗传距离远大于种内距离。序列特征、遗传距离和系统进化分析结果都表明本文研究的中国和越南青蟹均为S．paramamosain。  相似文献   

DNA adducts in mussels and fish exposed to bulky genotoxic compounds     

Dolcetti L  Zuanna LD  Venier P 《Marine environmental research》2002,54(3-5):481-486

Biological and procedural factors can influence DNA adduct detection in aquatic organisms. Among them, functional structure and metabolic traits represent major biological determinants for adducts formed by lipophilic pro-mutagenic contaminants. In detecting DNA adducts through the 32P-postlabelling assay, efficiency in DNA purification, digestion, labelling, as well as adduct enrichment and quantification may explain differences between independent studies. Reference DNA adducts have been used to verify some 32P-postlabelling aspects. Data obtained for mussels and fish treated with benzo[a]pyrene (B[a]P) and environmentally exposed to genotoxins confirm the above assertions. Although the 32P-postlabelling assay cannot be proposed for routine biomonitoring it appears a reliable and very sensitive index of exposure to genotoxic pollutants in both fish and mollusks.  相似文献   

Identification of Porphyra lines using computerized DNA fingerprinting   总被引：3，自引：0，他引：3  

Wang Bin  Jia Jianhang  Shi Jinfeng  Chen Yihu  Jin Demin  Xu Pu  Mei Junxue  Weng Manli 《海洋学报(英文版)》2001,20(3):401-407

ImpIONPorghyra is one of the most important rnarine a1gae with glObal distribution and importanterenomic value. AIthOtJgh the yield of POrPhpo is lower than that of kelp, the output valueof Porghpp occupies the first place in rnarine algae in China. The traditional taxonomy ishanly had on the morpbolOgical characteristics, such as the morpbobeical traits size, rnar-gin celIs and the number of repnductive cells. However, most of morPhobeical traits are af:fected by environrnntal factOrs …  相似文献