Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed s...Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.展开更多
基金Supported by the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金Supported by the National Key Research and Development Program of China(Nos.2018YFD0900901,2018YFD0900905)the Long Term Observation and Research Plan in the Changjiang River estuary and the Adjacent East China Sea Project(LORCE)(No.14282)+1 种基金the National Natural Science Foundation of China(Nos.41806149,41806181,41706125)the NSFC-Zhejiang Joint Fund,China(No.U1709202)。
文摘Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.