Effects of pipe material on nitrogen transformation, microbial communities and functional genes in raw water transportation

2018 ◽  
Vol 143 ◽  
pp. 188-197 ◽  
Author(s):  
Hang Xu ◽  
Chenshuo Lin ◽  
Wei Chen ◽  
Zhen Shen ◽  
Zhigang Liu ◽  
...  
2021 ◽  
Author(s):  
Ikuro Kasuga ◽  
Hitomi Nakamura ◽  
Futoshi Kurisu ◽  
Hiroaki Furumai

Abstract Microbial regrowth in premise plumbing is a threat to water safety. Disinfectant residuals are often diminished during water transportation and stagnation, leading to the regrowth of opportunistic pathogens. Although microbial regrowth potential is mostly determined by water treatment, little is known about how each treatment step affects two key factors that contribute to microbial regrowth potential: biodegradable organic matter and microbial abundance. In this study, we operated annular reactors to evaluate the microbial regrowth potential of water shaped after each treatment step in a full-scale drinking water treatment plant with ozonation and biological activated carbon filtration. The assimilable organic carbon and total cell count (TCC) were stable at all treatment steps during the sampling period from July to October 2015. The assimilable organic carbon consumption and TCC net increase in the annular reactors indicated that apparent growth yields (cell number base) of microbial communities were different in each reactor. Regrowth potential evaluated by indigenous microbial community in finished water was reduced to 22% of that in raw water, while 75% of assimilable organic carbon in raw water remained in finished water. It suggested that treatment performance evaluated by indigenous microbial communities was better than that evaluated by assimilable organic carbon.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 865
Author(s):  
Lantian Su ◽  
Xinxin Liu ◽  
Guangyao Jin ◽  
Yue Ma ◽  
Haoxin Tan ◽  
...  

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions.


2021 ◽  
Author(s):  
Joel White ◽  
Lena Ström ◽  
Dag Ahrén ◽  
Janne Rinne ◽  
Veiko Lehsten

<p>Microbial communities of methane producing methanogens and consuming methanotrophs play an important role for the earths atmospheric methane budget. Despite their global significance, the functional potential of these communities is poorly understood. To investigate this, we applied the molecular technique, captured metagenomics, to identify the variability in functional diversity of microorganisms involved in the metabolism of methane<sub></sub>in an environmentally controlled laboratory study. Nine plant-peat mesocosms dominated by the sedge Eriophorum vaginatum, with varying coverage, were collected from a temperate natural wetland is Sweden and subjected to a simulated growing season. Samples for analysis of captured metagenomes were taken from the top, bottom and root adjacent zone at the end of the experiment. In addition, over the simulated season, measured gas fluxes of carbon dioxide (CO<sub>2</sub>) and CH<sub>4</sub>, δ<sup>13</sup>C of emitted CH<sub>4</sub> and the pore water concentration of dissolved methane and low molecular weight organic acids were recorded. The functional genes resulting from the captured metagenomes had a higher Shannon α-diversity in the root zone when compared to the bottom and top. Sequences coding for methane metabolism were significantly more diverse in the root and bottom zones when compared to the top. However, the frequency of Acetyl-CoA decarbonylase and methane monooxygenase subunit A were significantly higher in the high emitting methane flux category when compared to the medium and low emitting mesocosms. We conclude that captured metagenomic analyses of functional genes provides a good measure of the functional potential methanogenic and methanotrophic microbial communities. This technique can be used to investigate how methanogens and methanotrophs function in peatlands and thus, contribute to the concentration of atmospheric methane.</p>


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