Effects of cable bacteria on vertical redox profile formation and phenanthrene biodegradation in intertidal sediment responded to tide.

Periodic oxygen permeation is critical for pollutant removal within intertidal sediments. However, tidal effects on the vertical redox profile associated with cable bacterial activity is not well understood. In this study, we simulated and quantified the effects of tidal flooding, exposing, and their periodic alternation on vertical redox reactions and phenanthrene removal driven by cable bacteria in the riverbank sediment.

Microbial assemblages in water hyacinth silages with different initial moistures.

Making silage is a green process to use the fast-growing water hyacinth (Eichhornia crassipes) biomass. However, the high moisture (∼95%) of the water hyacinth is the biggest challenge to making silage while its effects on fermentation processes are less studied. In this study, water hyacinths silage with different initial moistures were conducted to investigate the fermentation microbial communities and their roles on the silage qualities.

An overview of the direct and indirect effects of acid rain on plants: Relationships among acid rain, soil, microorganisms, and plants.

Acid rain (AR) causes numerous environmental problems and complex negative effects on plants globally. Many studies have previously reported on direct effects of AR or its depositional substances on plant injury and performance. However, few studies have addressed the indirect effects of AR on plants as mediated by soil microorganisms and the abiotic environment of the soil rhizosphere.

Cable bacteria accelerate the anaerobic removal of pyrene in black odorous river sediments.

Cable bacteria play an essential role in biogeochemical processes in sediments by long-distance electron transport (LDET). A potential relationship has been found between cable bacteria and organic contaminant removal; however, the mechanisms remain unclear. In this study, the response of cable bacteria to pyrene was investigated in sediments with and without pyrene, and the effect of cable bacteria on pyrene removal was explored by connecting and blocking the paths of cable bacteria to the suboxic zones.

Risk control and assessment of sulfide-rich sediment remediation by controlled-release calcium nitrate.

Nitrate stimulation is widely used in sediment remediation to eliminate sulfides, degrade organic pollutants and immobilize phosphorus. However, the environmental risks of nitrate escape and the subsequent release of pollutants (e.g.

Water quality drives the distribution of freshwater cable bacteria.

Cable bacteria are a group of recently found filamentous sulfide-oxidizing Desulfobulbaceae that significantly impact biogeochemical cycling. However, the limited understanding of cable bacteria distribution patterns and the driving force hindered our abilities to evaluate and maximize their contribution to environmental health. We evaluated cable bacteria assemblages from ten river sediments in the Pearl River Delta, China.

sp. nov. and sp. nov., isolated from landfill leachate of a domestic waste treatment plant.

Two strains designated as c1 and c7, were isolated from the landfill leachate of a domestic waste treatment plant in Huizhou City, Guangdong Province, PR China. The cells of both strains were aerobic, rod-shaped, non-motile and formed yellow colonies on Reasoner's 2A agar plates. Strain c1 grew at 10-42 °C (optimum, 30 °C), pH 4.

Pyrethroid bioaccumulation in wild fish linked to geographic distribution and feeding habit.

The accumulation of pyrethroid insecticides in aquatic food webs has attracted increased research attention. Fish are key species in aquatic food webs, directly connecting invertebrates and human consumption. However, little is known about the bioaccumulation of pyrethroids in wild fish species.

Microorganisms in sediment microbial fuel cells: Ecological niche, microbial response, and environmental function.

A sediment microbial fuel cell (SMFC) is a device that harvests electrical energy from sediments rich in organic matter. SMFCs have been attracting increasing amounts of interest in environmental remediation, since they are capable of providing a clean and inexhaustible source of electron donors or acceptors and can be easily controlled by adjusting the electrochemical parameters. The microorganisms inhabiting sediments and the overlying water play a pivotal role in SMFCs.

Synergistic interactions of Desulfovibrio and Petrimonas for sulfate-reduction coupling polycyclic aromatic hydrocarbon degradation.

Microbial sulfate-reduction coupling polycyclic aromatic hydrocarbon (PAH) degradation is an important process for the remediation of contaminated sediments. However, little is known about core players and their mechanisms in this process due to the complexity of PAH degradation and the large number of microorganisms involved. Here we analyzed potential core players in a black-odorous sediment using gradient-dilution culturing, isolation and genomic/metagenomic approaches.

sp. nov., isolated from freshwater sediment.

A Gram stain-positive, non-spore-forming, non-motile and rod-shaped actinomycete, strain 5221, was isolated from the sediment of a river collected at Ronggui in the Pearl River Delta, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain formed a distinct lineage within the genus and had the highest sequence similarity to Tp12 (96.7 %), followed by 2C6-41 (96.

sp. nov., sp. nov., sp. nov. and sp. nov., isolated from a subtropical stream in PR China and proposal to reclassify as comb. nov.

Five Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile strains (FT50W, FT80W, FT92W, FT94W and FT135W) were isolated from a subtropical stream in PR China. Comparisons based on 16S rRNA gene sequences showed that strains FT50W, FT94W and FT135W take strain Sac-22, and strains FT80W and FT92W take strain DCY83 as their closest neighbour in the phylogenetic trees, respectively. The G+C contents of strains FT50W, FT80W, FT92W, FT94W and FT135W were 63.

Linking microbial community and biological functions to redox potential during black-odor river sediment remediation.

The black-odor phenomenon in polluted urban rivers is a serious environmental problem that has received increasing attention in the recent years. The low redox potential (less than - 100 mV) in the sediment is considered to be the key factor causing the occurrence of black-odor phenomenon. Here, we studied the structure and function of the microbial community during the remediation of urban rivers.

sp. nov., sp. nov., sp. nov. and sp. nov., isolated from subtropical streams in China.

Six Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile strains (FT9W, FT25W, FT26W, FT109W, FT134W and CY42W) were isolated from subtropical streams in China. Comparisons based on 16S rRNA gene sequences showed that the six strains shared similarities of less than 98.1 % with other species within the family and formed two separately distinct clades in phylogenetic trees.

Ciceribacter ferrooxidans sp. nov., a nitrate-reducing Fe(II)-oxidizing bacterium isolated from ferrous ion-rich sediment.

A nitrate-reducing Fe(II)-oxidizing bacterial strain, F8825, was isolated from the Fe(II)-rich sediment of an urban creek in Pearl River Delta, China. The strain was Gram-negative, facultative chemolithotrophic, facultative anaerobic, non-spore-forming, and rod-shaped with a single flagellum. Phy-logenetic analysis based on 16S rRNA gene sequencing indicated that it belongs to the genus Ciceribacter and is most closely related to C.

sp. nov., sp. nov. and sp. nov., isolated from a subtropical stream in China.

Four strains assigned the names FT13W, FT14W, FT58W and FT68W were isolated from a subtropical stream in PR China. All the strains were Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile with flagella. Comparisons based on 16S rRNA gene sequences showed that strains FT13W, FT14W, FT58W and FT68W belonged to genus and shared 16S rRNA gene similarities in the range of 98.

Interactions of PAH-degradation and nitrate-/sulfate-reducing assemblages in anaerobic sediment microbial community.

Nitrate and sulfate are electron acceptors (EAs) for biodegradation of polycyclic aromatic hydrocarbons (PAHs) in anaerobic sediments. The efficiency of PAHs biodegradation depends on the strength of the interactions between PAH-degradation and EA-reduction assemblages. However, these interactions are less studied.

Effects of Flavin-Goethite Interaction on Goethite Reduction by S12.

Flavin mononucleotide (FMN) and riboflavin are structurally similar flavins, except for the presence of a phosphate group on the FMN molecule. They are used by a variety of electroactive bacteria as extracellular electron shuttles in microbial Fe reduction and inevitably interact with Fe (hydr)oxides in the extracellular environment. It is currently unknown whether flavin/Fe (hydr)oxide interaction interferes with extracellular electron transfer (EET) to the mineral surface.

Application of independent immobilization in benzo[a]pyrene biodegradation by synthetic microbial consortium.

Bioaugmentation is an effective approach to remove the benzo[a]pyrene (BaP) from the environment, while its effect depends on the functional stability of the inoculated microorganisms. The aim of this study is to develop an approach on reducing the mutual exclusion of bacteria in the synthetic consortium in BaP degradation. Eight BaP-degrading bacterial strains were isolated from an enrichment with BaP as the sole carbon source.

Functional response of sediment bacterial community to iron-reducing bioaugmentation with Shewanella decolorationis S12.

Bioaugmentation with exogenously functional microbes is a widely used technology in bioengineering and environmental remediation. Generally, the colonization of inoculated bacteria is considered to be the determining factor in technical success. However, increasing reports have shown that bioaugmentation was still effective when the colonization of inoculated bacteria was unsuccessful.

Response of environmental variables and microbial community to sodium percarbonate addition to contaminated sediment.

Sodium percarbonate (SPC) is a common reagent used for in situ remediation of contaminated soil. Current studies focus on the effects of SPC on pollutant removal; however, a knowledge gap exists for the biochemical process following SPC addition. In this study, a microcosm batch experiment was conducted to investigate the residual effect caused by different doses of SPC addition on native microbial communities, as well as on the environmental variables of contaminated sediments.

Enhanced phenanthrene degradation in river sediments using a combination of biochar and nitrate.

Polycyclic aromatic hydrocarbons (PAHs) pollution in urban river sediments is a serious problem to ecological systems and human health. We examined novel remediation approaches, using a biochar amendment combined with bioaugmentation or/and nitrate stimulation, to degrade phenanthrene in sediment. Biochar amendment combined with nitrate stimulation enhanced phenanthrene degradation by 2.

The Role of Enriched Microbial Consortium on Iron-Reducing Bioaugmentation in Sediments.

Microbial iron reduction is an important biogeochemical process and involved in various engineered processes, including the traditional clay dyeing processes. Bioaugmentation with iron reducing bacteria (IRB) is generally considered as an effective method to enhance the activity of iron reduction. However, limited information is available about the role of IRB on bioaugmentation.