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Response of bacteria in the deep-sea sediments and the Antarctic soils to carbohydrates: Effects on ectoenzyme activity and bacterial community

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Journal of Environmental Sciences 2010年第11期22卷 1779-1785页

作者： Xiang Zeng School of Life Sciences Xiamen University Xiamen 361005 China. Key Laboratory of Marine Biogenetic Resources Third Institute of Oceanography State Oceanic Administration Xiamen 361005 China School of Life Sciences and Biotechnology Shanghai Jiaotong University Shanghai 200240 China

The response of bacteria to various carbohydrates in the deep-sea sediments and the Antarctic soils was investigated using cellulose, chitin, and olive oil. It was found that the carbohydrates significantly increased the corresponding specific ectoenzyme activity （β- glucosidase, β-N-acetylglucosaminidase, lipase） in the samples from deep-sea sediments. In the case of Antarctic soil samples, the cellulose or olive oil amendments had minor or no effect on β-glucosidase or lipase activity, except the chitin which stimulated β- N-acetylglucosaminidase production. The responses of the bacteria in the deep-sea sediment sample WP02-3 and the Antarctic soil sample CC-TY2 towards the chitin amendment were further analyzed. Chitin amendments were shown to stimulate the ectoenzyme activity in all the tested sediments and the soils. The bacterial response before and after the carbohydrates amendments were compared by denaturing gradient gel electrophoresis and quantitative competitive polymerase chain reaction. Significant changes were found in the structure and density of the bacterial community in the deep sea sediments as compared to the Antarctic soil sample, where the effects were relatively lower. There was no change in the bacterial population in both studied samples in response to carbohydrates amendments. These data indicate that the bacterial communities in the oligotrophic deep-sea sediments are more dynamic than that in the Antarctic soils as they respond to the nutrient sources efficiently by regulation of ectoenzyme activity and/or changing community structure.

关键词： deep-sea sediments Antarctic soils amending cellulose chitin olive oil ectoenzyme activity

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Extreme Enrichment of Tellurium in deep-sea sediments

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Acta Geologica Sinica(English Edition) 2005年第4期79卷 547-551页

作者： LI Yanhe WANG Yimin SONG Hebin YUE Guoliang Laboratory of Isotope Geology Ministry of Land and Resources Beijing 100037 Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 National Geoanalysis Center Beijing 100037

Tellurium is a sort of scattered rare element on the earth. Its concentration is very low in earth＇s crust, only 1.0 ng/g. However, it has extremely high abundance in Co-rich crusts, marine polymetallic nodules, deep-sea sediments and aerolites. To find out the origin of tellurium enrichment in deep-sea sediments, we analyzed and compared tellurium concentrations and helium isotope compositions in the magnetic parts and those in the bulk parts of deep-sea sediments. The result indicates that the helium content, 3He/4He ratio and tellurium concentration are obviously higher in the magnetic parts than those in the bulk parts. The 3He abundance varies synchronously with the tellurium concentration. 3He and Te have a distinct positive correlation with each other. It is the first time that the paper brings forward that the extreme enrichment of tellurium in deep-sea sediments, like helium isotope anomalies, probably results from the input of interplanetary dust particles （IDPs）. Similarly, the extreme enrichment of tellurium in marine polymetallic nodules and Co-rich crusts is possibly related to IDPs.

关键词： deep-sea sediments extreme enrichment of tellurium helium isotope interplanetary dust particles

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Implications of REE incorporation and host sediment influence on the origin and growth processes of ferromanganese nodules from Central Indian Ocean Basin

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Geoscience Frontiers 2021年第3期12卷 609-623页

作者： Simontini Sensarma Abhishek Saha Arghya Hazra CSIR-National Institute of Oceanography Dona PaulaGoa 403004India Indian Institute of Science BangaloreKarnataka 560012India School of Earth Ocean and Atmospheric SciencesGoa UniversityGoa 403206India

This study presents new major,trace and REE data for thirty-five ferromanganese nodules recovered from areas representing three different sediment types(siliceous,red clay and their transition zone)in the Central Indian Ocean Basin(CIOB)to address their genetic aspects,classification,growth rate,nature of host sediments and influence of REE in the processes of nodule *** nodules from CIOB are mostly either hydrogenetic(metals coming from oxygenated bottom water)and diagenetic(metals coming from suboxic sediment pore water)or a combination of both,depending on the source of supply of ***,a number of biogeochemical processes mediate this supply of metals which again changes from time to time,making the nodule growth process highly *** study suggests that at the initial stage of nodule growth,host sediments do not play much role in controlling the growth processes for which REEs can enter both Mn and Fe oxyhydroxide phases ***,the bottom water signature is imprinted in these early formed nodules irrespective of their host sediment substrate but with gradual growth and burial in the sediment,the main mode of metal enrichment becomes diagenetic through sediment pore *** tends to increase the concentration of Mn,Ni and Cu over other elements which are retained in the sediment *** the REEs,Ce concentration of the nodules shows significant positive anomaly due to variation in redox potential and hence its magnitude can be used to get an idea about the metal enrichment procedure and the genetic type of the ***,based on host sediment only,not much difference is found in the magnitude of Ce anomaly in these *** the other hand,discrimination diagram,based on HFSE and REY chemistry,indicates that most of these nodules are of diagenetic origin under oxic condition with a trend towards hydrogenetic ***,the genetic type of the ferromanganese nodules from the CIOB are more effectively differentiated

关键词： Central Indian Ocean Basin Ferromanganese nodules deep-sea sediments Rare earth elements Geochemical discrimination

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Fluid-driven Hydrovolcanic Activity along Fracture Zones and near seamounts:Evidence from deep-sea Fe-rich Spherules,Central Indian Ocean Basin

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Acta Geologica Sinica(English Edition) 2021年第5期95卷 1591-1603页

作者： Ankeeta AMONKAR Sridhar D.IYER Elapavalooru V.S.S.K.BABU Natarajan SHAILAJHA Areef SARDAR S.MANJU CSIR-National Institute of Oceanography Dona PaulaGoa 403004India Marine Science School of EarthOcean and Atmospheric SciencesGoa UniversityGoa 403206India Formerly with CSIR-National Institute of Oceanography Dona PaulaGoa 403004India CSIR-National Geophysical Research Institute HyderabadTelangana 500007India Department of Earth Science Pondicherry UniversityPondicherry 605014India

An insight on occurrence of Fe-rich spherules from the Central Indian Ocean Basin(CIOB)provides an understanding of their distribution at a water depth of>5,000 *** the present study,Fe-rich spherules are identified to occur in two different sediment types(i.e.,siliceous and pelagic)and tectonic settings(*** seamounts and fracture zones).These are single spheres or aggregates,of different sizes(63 to 390μm)and show textural variability(smooth/quenched,brickwork,corkscrew,interlocking and dendritic).A comparative study based on physical morphology and chemical composition suggests a common mechanism of *** association of spherules with fracture zones(FZ)and seamounts signifies that morpho-tectonic features play an important role in fluid-driven *** on the evidence and geologic conditions existing in the basin,we conclude that molten fuel-coolant interaction(MFCI)coupled with submarine hydrothermal exhalations could be an ideal mechanism for the formation of spherules and *** accretion of the spherules on the surface sediments could be a result of recent volcanic phenomena,while those occurring at different depths(280-355,and 460-475 cm-bsf)within the sediment core indicate two different *** study provides a global implication in understanding fluid-driven magmatism in a deep-sea intraplate environment.

关键词： Fe-rich spherules deep-sea sediments hydrovolcanic activity CIOB

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Microbial diversity of sediments from an inactive hydrothermal vent field,Southwest Indian Ridge

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Marine Life Science & Technology 2020年第1期2卷 73-86页

作者： Zhifeng Yang Xiang Xiao Yu Zhang School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Microbial Metabolism and School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China

The Southwest Indian Ridge,which is the slowest-spreading of the main ridges,separates the African and Antarctic *** slow expanding rate is associated with less density of hydrothermal vent fields,shorter longevity of hydrothermal activity,cold mantle temperatures and thick ***,the microbial communities adapting to such specific characteristics of this area have remained largely *** study the microbial diversity at the Southwest Indian Ridge,we sampled three sediment cores in a newly found inactive vent field,the Tianzuo field,and used high-throughput sequencing of 16S rRNA genes to reveal the microbial *** communities of three sampling sites were very similar at the surface,and underwent a gradient change along ***,namely Alteromonadaceae,Nitrosococcus and the JTB255 marine benthic group,were the most dominant bacterial *** Group I was the dominant archaeal taxon in our *** addition,microbial populations capable of ammonia oxidation,nitrite oxidation,sulfur oxidation and manganese oxidation were detected to be the main *** enrichment of sulfur-oxidizing and manganese-oxidizing bacteria was observed in deep *** compared with other vent fields along different ocean ridges,the Tianzuo field showed distinct composition in both archaeal and bacterial *** results provide the first view of microbial communities of the Tianzuo field at the Southwest Indian Ridge,and give a better understanding of metabolic potential possessed by the microbial populations.

关键词： Hydrothermal Microbial diversity High-throughput sequencing deep-sea sediments Ultraslow-spreading ridge

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