石油降解菌XD-1产表面活性剂的性能

从含油废水中筛选分离到1株原油降解菌XD-1,鉴定为假单胞菌（Pseuomonas sp.）.初步实验表明菌XD-1具有较强的产表面活性剂乳化原油的作用,对该菌的产表面活性剂性能进行了研究.实验证明,菌XD-1所产表面活性剂为脂肽类物质,菌在生长对数期产表面活性剂,表面活性剂的产生为生长相关型;充足的碳源是产表面活性剂的必需条件,菌利用原油为碳源时能持续大量地产表面活性剂;原油和尿素为产表面活性剂的最适碳源和氮源,菌XD-1产表面活性剂的最佳营养培养基组成为葡萄糖10 g,尿素4 g,磷酸二氢钾1 g,微量元素液4 mL,水1 L,pH 8.0.     

Effects of bedform migration on nutrient fluxes at the sediment–water interface: a theoretical analysis

Environmental Fluid Mechanics - Nutrient fluxes at the sediment–water interface are essential for water quality and aquatic ecosystems. In this study, a unified expression for the sediment...     

Recent advances in antimony removal using carbon-based nanomaterials: A review

• The synthesis and physicochemical properties of various CNMs are reviewed. • Sb removal using carbon-based nano-adsorbents and membranes are summarized. • Details on adsorption behavior and mechanisms of Sb uptake by CNMs are discussed. • Challenges and future prospects for rational design of advanced CNMs are provided. Recently, special attention has been deserved to environmental risks of antimony (Sb) element that is of highly physiologic toxicity to human. Conventional coagulation and ion exchange methods for Sb removal are faced with challenges of low efficiency, high cost and secondary pollution. Adsorption based on carbon nanomaterials (CNMs; e.g., carbon nanotubes, graphene, graphene oxide, reduced graphene oxide and their derivatives) may provide effective alternative because the CNMs have high surface area, rich surface chemistry and high stability. In particular, good conductivity makes it possible to create linkage between adsorption and electrochemistry, thereby the synergistic interaction will be expected for enhanced Sb removal. This review article summarizes the state of art on Sb removal using CNMs with the form of nano-adsorbents and/or filtration membranes. In details, procedures of synthesis and functionalization of different forms of CNMs were reviewed. Next, adsorption behavior and the underlying mechanisms toward Sb removal using various CNMs were presented as resulting from a retrospective analysis of literatures. Last, we prospect the needs for mass production and regeneration of CNMs adsorbents using more affordable precursors and objective assessment of environmental impacts in future studies.     

New insights into different surfactants’ impacts on sludge fermentation: Focusing on the particular metabolic processes and microbial genetic traits

• The promoting effects for VFA generation follow the order of APG>SDBS>HTAB. • Surfactants improve the WAS solubilization/hydrolysis and acidification processes. • The VFA promotion is associated with surfactants’ distinctive characteristics. • Surfactants induce the enrichment of functional bacteria for VFA biosynthesis. • The vital genes for substrates delivery, metabolism, and VFA yields are upregulated. Surfactants were expected to exhibit positive effects on the waste activated sludge (WAS) disposal. However, the systematic comparison of different categories of surfactants on the WAS fermentation and the functional mechanisms, especially microbial metabolic traits, have not yet been precisely explored. This study revealed the positive effects of different surfactants on the volatile fatty acid (VFA) production, which followed the order of alkyl polysaccharides (APG)>sodium dodecylbenzene sulfonate (SDBS)>hexadecyl trimethyl ammonium bromide (HTAB). Mechanistic exploration found that the presence of different surfactants improved solubilization and hydrolysis steps, and then contributed to the subsequent acidification with different efficiencies. The functional microorganisms associated with VFA generation were enriched in surfactant-conditioned reactors. Metagenomic analysis further indicated that the key genes involved in the particular process of VFA generation were over-expressed. The simultaneous bioavailable substrate improvement, functional bacterial enrichment, and metabolic activity upregulation induced by different surfactants jointly contributed to VFA promotion during WAS fermentation. This study could provide a comprehensive realization of surfactants’ impacts on the WAS fermentation process, and more importantly, it reminded the public to discern the distinct interplaying effects induced by different chemicals in regulating the WAS disposal and resource recovery.     

Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic and bacteriological investigation in Escherichia coli

• Water-dispersible nano-pollutions exhibit type-specific toxic effects on E. coli. • Global metabolite profiling was used to characterize metabolic disruption patterns. • Key dysregulated metabolites responsive to nano-pollution exposures were found. • Amino acid metabolism and purine metabolism are perturbed at nano-pollutions. Incomplete separation and recycling of nanoparticles are causing undesirable nanopollution and thus raising great concerns with regard to nanosafety. Since microorganisms are important regulator of physiological processes in many organisms, the interaction between nanopollution and microbial metabolomics and the resultant impact on the host’s health are important but unclear. To investigate how typical nanopollution perturbs microbial growth and metabolism, Escherichia coli (E. coli) in vitro was treated with six water-dispersible nanomaterials (nanoplastic, nanosilver, nano-TiO₂, nano-ZnO, semiconductor quantum dots (QDs), carbon dots (CDs)) at human-/environment-relevant concentration levels. The nanomaterials exhibited type-specific toxic effects on E. coli growth. Global metabolite profiling was used to characterize metabolic disruption patterns in the model microorganism exposed to different nanopollutants. The percentage of significant metabolites (p<0.05, VIP>1) accounted for 6%–38% of the total 293 identified metabolites in each of the nanomaterial-contaminated bacterial groups. Metabolic results also exhibited significant differences between different nanopollutants and dose levels, revealing type-specific and untypical concentration-dependent metabolic responses. Key metabolites responsive to nanopollution exposures were mainly involved in amino acid and purine metabolisms, where 5, 4, and 7 significant metabolic features were included in arginine and proline metabolism, phenylalanine metabolism, and purine metabolism, respectively. In conclusion, this study horizontally compared and demonstrated how typical nanopollution perturbs microbial growth and metabolomics in a type-specific manner, which broadens our understanding of the ecotoxicity of nanopollutants on microorganisms.     

Occurrence,distribution, sources,and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in multi environmental media in estuaries and the coast of the Beibu Gulf,China: a health risk assessment through seafood consumption

Environmental Science and Pollution Research - The coastal zone is a crucial transitional area between land and ocean, which is facing enormous pressure due to global climate change and...     

Alkyl polyglycosides enhanced the dark fermentation of excess sludge and plant waste to produce hydrogen: performance and mechanism

Environmental Science and Pollution Research - Alkyl polyglycosides (APG), a biodegradable biosurfactant, have been widely used in environmental pollution control. However, the application of APG...     

Investigation of indole biodegradation by Cupriavidus sp. strain IDO with emphases on downstream biotransformation and indigo production

Environmental Science and Pollution Research - Indole, as a typical N-heterocyclic aromatic pollutant, poses risks to living things; however, indole-biotransformation mechanisms remain...     

Vitamin D mediates the association between acrylamide hemoglobin biomarkers and obesity

Environmental Science and Pollution Research - Mediation analysis aims to discover the role of intermediate variables from exposure to disease. The current study was performed to evaluate how...