scholarly journals Characteristics of the community-structure of A2O processes under different temperature conditions in plateau areas

2020 ◽  
Author(s):  
Yongchen Zong ◽  
Yuanwei Li ◽  
Decai Huang ◽  
Kaiyue Hao ◽  
Guanghua Lu

Abstract Background: In this study, laboratory-scale A2O wastewater treatment was performed in Linzhi at an altitude of 3000 meters. Water temperatures were maintained at four operating conditions (25°C, 20°C, 15°C, and 10°C). Sludge in the aerobic tank was assessed by 16SrRNA sequencing and composition analysis. The Phylum, Class, Order, Family, Genus, and Species of the sludge were also confirmed.Results: The bacteria within the sludge showed significant differences at varying temperatures (P<0.05). A significant correlation between the bacteria numbers in anaerobic tanks and anoxic tanks also occurred. Indicators of community richness, community uniformity, community diversity and other areas showed differences. Significant differences in bacteria abundance were also observed and differed to those of previously reported superior community categories and proportions. T-tests were used to identify temperature-sensitive community at each level. Correlation analysis of environmental factors and colony structure further confirmed the association between temperature and colony structure (P<0.05). The removal rates of TP, TN, NH3-N, and COD were all affected by the sample community structure. The variety of colony structure include nitrifying bacteria, denitrifying bacteria, phosphorus accumulating bacteria and other bacterial differed, but their proportions were relatively low. Heatmaps were used to identify species sensitive to temperature, TP, TN, NH3-N, COD at the species level.Conclusions: Amongst the common dominant bacteria at the species level, Bacteroidetes_bacterium_OLB10 was significantly related to temperature. Other common dominant bacteria that were related to temperature metagenome_g__Gordonia, unclassified_f__Burkholderiaceae, uncultured_bacterium_g__norank_f__Saprospiraceae.

2013 ◽  
Vol 777 ◽  
pp. 213-220 ◽  
Author(s):  
Lu Zhou ◽  
Ge Li ◽  
Hang Sik Shin ◽  
Li Li Jiang ◽  
Guo Feng Fang ◽  
...  

To investigate nutrient removal and biological community structure in wastewater treatment system under different ratio of C/N/P, hybrid biofilm reactor (HBR) and sequencing batch reactor (SBR) in lab scale were set up. Results showed that both HBR and SBR achieved the best removal efficiency of nitrogen and phosphorus when C/N/P=100/6.25/1. With the rise of C/N/P from 50/6.25/1 to 100/6.25/1, the removal efficiencies of NH3-N were greater than 93% in three phases of both reactors; the efficiencies of TN were increased from 65% to 79% in SBR while these values at HBR were from 73% to 86%; the efficiencies of TP were increased from 42% to 93% in SBR while these values at HBR were from 32% to 93%. Microbial community structure response to different C/N/P was determined by PCR-DGGE technology. Similarity coefficient was lowest and denitrifying phosphate accumulating bacteria became dominant bacteria in SBR when C/N/P was 100/6.25/1. There were many functional bacteria in HBR, such as bacteria for removing nutrients (Uncultured BacteroidetesFJ828150), bacteria for removing organic (Uncultured Saprospiraceae) bacteria for removing nitrogen (Ferribacterium sp.), and nitrifying bacteria (Uncultured Nitrospira sp.) which became dominant bacteria. Because of microbial diversity index of biofilm was up to 3.3, similarity coefficient was as low as 43.4%.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1938
Author(s):  
Han Aricha ◽  
Huasai Simujide ◽  
Chunjie Wang ◽  
Jian Zhang ◽  
Wenting Lv ◽  
...  

Mongolian cattle from China have strong adaptability and disease resistance. We aimed to compare the gut microbiota community structure and diversity in grazing Mongolian cattle from different regions in Inner Mongolia and to elucidate the influence of geographical factors on the intestinal microbial community structure. We used high throughput 16S rRNA sequencing to analyze the fecal microbial community and diversity in samples from 60 grazing Mongolian cattle from Hulunbuir Grassland, Xilingol Grassland, and Alxa Desert. A total of 2,720,545 high-quality reads and sequences that were 1,117,505,301 bp long were obtained. Alpha diversity among the three groups showed that the gut microbial diversity in Mongolian cattle in the grasslands was significantly higher than that in the desert. The dominant phyla were Firmicutes and Bacteroidetes, whereas Verrucomicrobia presented the highest abundance in the gut of cattle in the Alxa Desert. The gut bacterial communities in cattle from the grasslands versus the Alxa Desert were distinctive, and those from the grasslands were closely clustered. Community composition analysis revealed significant differences in species diversity and richness. Overall, the composition of the gut microbiota in Mongolian cattle is affected by geographical factors. Gut microbiota may play important roles in the geographical adaptations of Mongolian cattle.


2018 ◽  
Vol 16 (6) ◽  
pp. 914-920 ◽  
Author(s):  
Qing Wu ◽  
Shuqun Li ◽  
Xiaofei Zhao ◽  
Xinhua Zhao

Abstract The abuse of antibiotics is becoming more serious as antibiotic use has increased. The sulfa antibiotics, sulfamerazine (SM1) and sulfamethoxazole (SMZ), are frequently detected in a wide range of environments. The interaction between SM1/SMZ and bacterial diversity in drinking water was investigated in this study. The results showed that after treatment with SM1 or SMZ at four different concentrations, the microbial community structure of the drinking water changed statistically significantly compared to the blank sample. At the genus level, the proportions of the different bacteria in drinking water may affect the degradation of the SM1/SMZ. The growth of bacteria in drinking water can be inhibited after the addition of SM1/SMZ, and bacterial community diversity in drinking water declined in this study. Furthermore, the resistance gene sul2 was induced by SM1 in the drinking water.


2013 ◽  
Vol 726-731 ◽  
pp. 1621-1627 ◽  
Author(s):  
Zhu Chen ◽  
Ying Liu ◽  
Liang Zi Liu ◽  
Xiao Jing Wang ◽  
Zhi Pei Liu ◽  
...  

The success of a recirculating aquaculture system (RAS) greatly depends on the structure, dynamics and activities of microbial community. Heterotrophic bacteria as the major members play various roles. The heterotrophic bacterial community structure in threestaged biofilters was studied using four different media. 228 isolates belonging to 77species were obtained and affiliated toGammaproteobacteria,Alphaproteobacteria,Bacteroidetes,Firmicutes,ActinobacteriaandBetaproteobacteria.Gammaproteobacteriawas the predominant group. The concurrence was found between potential pathogens (VibrioandShewanella) and probiotics (BacillusandPseudomonas). On the basis of community diversity index, we could infer that differences existed between stages, and the diversity index increased along the biofilters. A comprehensive understanding of microbial community in RAS will be in favor of utilization of microbial resources and optimizing the culture systems' operation.


2019 ◽  
Vol 30 (12) ◽  
pp. 1950104 ◽  
Author(s):  
Haijuan Yang ◽  
Jianjun Cheng ◽  
Mingwei Leng ◽  
Xing Su ◽  
Wenbo Zhang ◽  
...  

Communities in networks expose some intrinsic properties, each of them involves some influential nodes as its cores, around which the entire community grows gradually; the more the common neighbors that exist between a pair of nodes, the larger the possibility of belonging to the same community; the more the neighbors of any one node belong to a community, the larger the possibility that node belongs to that community too. In this paper, we present a novel method, which makes full utilization of these intrinsic properties to detect communities from networks. We iteratively select the node with the largest degree from the remainder of the network as the first seed of a community, then consider its first- and second-order neighbors to identify other seeds of the community, then expand the community by attracting nodes whose large proportion of neighbors have been in the community to join. In this way, we obtain a series of communities. However, some of them might be too small to make sense. Therefore, we merge some of the initial communities into larger ones to acquire the final community structure. In the entire procedure, we try to keep nodes in every community to be consistent with the properties as possible as we can, this leads to a high-quality result. Moreover, the proposed method works with a higher efficiency, it does not need any prior knowledge about communities (such as the number or the size of communities), and does not need to optimize any objective function either. We carry out extensive experiments on both some artificial networks and some real-world networks to testify the proposed method, the experimental results demonstrate that both the efficiency and the community-structure quality of the proposed method are promising, our method outperforms the competitors significantly.


2017 ◽  
Vol 262 ◽  
pp. 38-42 ◽  
Author(s):  
Mariette Smart ◽  
Robert J. Huddy ◽  
Catherine J. Edward ◽  
Charl Fourie ◽  
Trust Shumba ◽  
...  

In the commercial BIOX® process, an acidophilic mixed bacterial and archaeal community dominated by iron and sulphur oxidising microorganisms is used to facilitate the recovery of precious metals from refractory gold-bearing sulphidic mineral concentrates. Characterisation of the microbial communities associated with commercial BIOX® reactors from four continents revealed a significant shift in the microbial community structure compared to that of the seed culture, maintained at SGS (South Africa). This has motivated more detailed study of the microbial community dynamics in the process. Microbial speciation of a subset of the BIOX® reactors at Fairview mines (Barberton, South Africa) and two laboratory maintained reactors housed at Centre for Bioprocess Engineering Research, University of Cape Town, has been performed tri-annually for three years by quantitative real-time polymerase chain reaction. The laboratory BIOX® culture maintained on Fairview concentrate was dominated by the desired iron oxidiser, Leptospirillum ferriphilum, and sulphur oxidiser, Acidithiobacillus caldus, when operated under standard BIOX® conditions. Shifts in the microbial community as a result of altered operating conditions were transient and did not result in a loss of the microbial diversity of the BIOX® culture. The community structure of the Fairview mines BIOX® reactor tanks showed archaeal dominance of these communities by organisms such as the iron oxidiser Ferroplasma acidiphilum and a Thermoplasma sp. for the period monitored. Shifts in the microbial community were observed across the monitoring period and mapped to changes in performance of the commercial process plant. Understanding the effect of changes in the plant operating conditions on the BIOX® community structure may assist in providing conditions that support the desired microbial consortium for optimal biooxidation to maximize gold recovery.


2011 ◽  
Vol 250-253 ◽  
pp. 3228-3231 ◽  
Author(s):  
Da Hua Jiang ◽  
An Gui Li ◽  
Fa En Shi ◽  
Zhi Hua Wang

For particular commercial kitchen, using CFD software to build model according to the actual operation condition uttermost, adopting the exhaust system of up-suction hood, the effect of exhaust airflow rate on working temperature,velocity,CO2 concentration at main site in commercial kitchen is studied. According to the common four calculation methods of airflow rate of exhaust hood, the simulation results shows 4.81 m3/s of exhaust system can realize eliminating harmful gas quickly and effectively, IAQ is good relatively. Based on of it, additional airflow rate can not improve emissions effect and operating conditions obviously, whereas it can be detrimental to save energy. The simulation results help design exhaust system.


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