Seasonal variation and ecological risk assessment of dissolved organic matter in a peri-urban critical zone observatory watershed.

Peri-urban ecosystems are among the most intensive areas in terms of competition between different ecosystem components. Dissolved organic matter (DOM) plays a significant role in aquatic carbon cycling. The chemical composition of DOM and associated potential ecological risks in peri-urban aquatic ecosystems are poorly understood.

[Fluorescence Characteristics and Influencing Factors of Dissolved Organic Matter (DOM) in Water and Sediment of Urban Watershed: A Case Study of Xiaojia River in Ningbo City].

Rapid urbanization has a significant impact on dissolved organic matter (DOM) in water and sediment; thus, it is important to explore the distribution characteristics and influencing factors of DOM in watersheds. Xiaojia River is a typical urban area in Beilun District of Ningbo City, Yangtze River Delta. The spectral characteristics of DOM in the water and sediment in this river were studied to examine their sources and characteristics.

Variation in quantity and chemical composition of soil dissolved organic matter in a peri-urban critical zone observatory watershed in Eastern China.

Soil organic matter plays a fundamental role in terrestrial ecosystems. However, little is known about the spectral characteristics and fluorescent components of soil dissolved organic matter (DOM) in peri-urban ecosystems and their influencing factors. In this study, we used the fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC) to characterize soil DOM in a peri-urban Critical Zone Observatory watershed in Eastern China.

Electron Communication of Bacillus subtilis in Harsh Environments.

Elucidating the effect of harsh environments on the activities of microorganisms is important in revealing how microbes withstand unfavorable conditions or evolve mechanisms to counteract those effects, many of which involve electron transfer phenomena. Here we show that the non-acidophilic and non-thermophilic Bacillus subtilis is able to maintain activity after being subjected to extreme temperatures (100°C for up to 8 h) and acidic environments (pH = 1.50 for over 2 years).

[Characteristics of Dissolved Organic Matter (DOM) and Relationship with Dissolved Heavy Metals in a Peri-urban and an Urban River].

Dissolved organic matter (DOM) is ubiquitous in the aquatic environment, playing an important role in the fate of heavy metals in aquatic systems. In this study, we characterized the DOM and heavy metals and their distribution in a peri-urban river and an urban river in Ningbo city. In addition, the relationship between DOM and dissolved heavy metals was also determined.

[Fluorescent Dissolved Organic Matter and Its Correlation with Water Quality in a Urban River: A Case Study of the Lujiang River in Beilun, Ningbo].

Excitation-emission matrix fluorescence spectroscopy combined with fluorescence regional integration (FRI) analysis were adopted to analyze the water samples collected from the Lujiang River, which flows through the rapidly urbanizing areas of Beilun, Ningbo, in order to illuminate the composition and characteristics of the spatial distribution of fluorescent dissolved organic matter (FDOM), and further to explain its correlation with water quality in the urban river. The results showed that FDOM was composed of tyrosine-like, tryptophan-like, soluble microbial by-product-like, fulvic-like, and humic-like materials, and FDOM was dominated by protein-like components, accounting for 83.8% of the total fluorescence intensity, while humic-like components accounted for much less.

Draft Genome Sequence of Desulfitobacterium hafniense Strain DH, a Sulfate-Reducing Bacterium Isolated from Paddy Soils.

Desulfitobacterium hafniense strain DH is a sulfate-reducing species. Here, we report the draft genome sequence of strain DH, with a size of 5,368,588 bp, average G+C content of 47.48%, and 5,296 predicted protein-coding sequences.

Effects of bio-Au nanoparticles on electrochemical activity of Shewanella oneidensis wild type and ΔomcA/mtrC mutant.

Both Shewanella oneidensis MR-1 wild type and its mutant ΔomcA/mtrC are capable of transforming Au(III) into Au nanoparticles (AuNPs). Cyclic voltammetry reveals a decrease in redox current after the wild type is exposed to Au(III) but an increase in oxidation current for the mutant. The peak current of the wild type is much higher than that of the mutant before the exposure of Au(III), but lower than that of the mutant after the formation of AuNPs.