Antibiotic resistance genes and heavy metals in landfill: A review.

Landfill is reservoir containing antibiotic resistance genes (ARGs) that pose a threat to human life and health. Heavy metals impose lasting effects on ARGs. This review investigated and analyzed the distribution, composition, and abundance of heavy metals and ARGs in landfill.

Effects of tillage patterns and stover mulching on NO production, nitrogen cycling genes and microbial dynamics in black soil.

Stover-covered no-tillage (NT) is of great significance to the rational utilization of stover resources and improvement of cultivated land quality, and also has a profound impact on ensuring groundwater, food and ecosystem security. However, the effects of tillage patterns and stover mulching on soil nitrogen turnover remain elusive. Based on the long-term conservation tillage field experiment in the mollisol area of Northeast China since 2007, the shotgun metagenomic sequencing of soils and microcosm incubation were combined with physical and chemical analyses, alkyne inhibition analysis to elucidate the regulatory mechanisms of NT and stover mulching on the farmland soil nitrogen emissions and microbial nitrogen cycling genes.

The Utility of Electrochemical Systems in Microbial Degradation of Polycyclic Aromatic Hydrocarbons: Discourse, Diversity and Design.

Polycyclic aromatic hydrocarbons (PAHs), especially high molecular weight PAHs, are carcinogenic and mutagenic organic compounds that are difficult to degrade. Microbial remediation is a popular method for the PAH removal in diverse environments and yet it is limited by the lack of electron acceptors. An emerging solution is to use the microbial electrochemical system, in which the solid anode is used as an inexhaustible electron acceptor and the microbial activity is stimulated by biocurrent to ensure the PAH removal and avoid the defects of bioremediation.

[Relationships of soil physical and microbial properties with nitrous oxide emission under effects of freezing-thawing cycles].

Freezing-thawing cycles often occurs in the regions of mid-high latitude and high altitude. This process can affect soil physical and biological properties, e.g.

Nitrous oxide emission and reduction in a laboratory-incubated paddy soil response to pretreatment of water regime.

A laboratory incubation experiment was conducted to investigate nitrous oxide (N2O) emission and reduction in a paddy soil (Stagnic Anthrosol) response to the pretreatment of water regime. The paddy soil was maintained under either air-dried (sample D) or submerged (sample F) conditions for 110 d before the soil was adjusted into soil moisture of 20% , 40% , 60% , 80% and 100% water holding capacity (WH(-2)) respectively, and then incubated with or without 10% (v/v) acetylene for 138 h at 25 degrees C. At lower soil water content (< or = 60% WHC), N2O emission from the sample F was 2.