Evaluation of Nitrogen Removal Process by Degradation Kinetics, Microbial Composition, and Functional Gene Expression in an Aerobic Fluidized Bed Biofilm Reactor at Different Carbon to Nitrogen (C:N) Ratios

2021 ◽  
Author(s):  
Jiehui Ren ◽  
Wen Cheng ◽  
Meng Jiao ◽  
Ting Meng ◽  
Taotao Lv ◽  
...  
Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2630
Author(s):  
Yi Ding ◽  
Hong You ◽  
Wei Sun ◽  
Zhansheng Guo ◽  
Junxue Mei ◽  
...  

In this study, the biological fluidized bed system was used to treat seafood processing wastewater. The sludge was collected from the secondary sedimentation tank of a municipal wastewater treatment plant and acclimated for 200 days before the experiment. The treatment efficiencies of simulated seafood processing wastewater by biological fluidized bed system with different sludge concentrations, different hydraulic retention times (HRTs) and different bio-carriers were studied. The results showed that the removal efficiency of nitrogen and phosphorus increased with the increasing sludge concentration and by extending hydraulic retention time, and the higher removal efficiency of nitrogen and phosphorus could be obtained with the higher specific surface area of the bio-carrier. The nitrogen removal process analysis showed that the nitrification and denitrification activity of sludge could be changed with different operation conditions resulting in different nitrogen removal efficiency in the biological fluidized bed system. This was mainly because the change tendency of the ammonia nitrogen oxidizing process, nitrite oxidizing process, nitrite reduction process and nitrate reduction process was different with different operation conditions in a high salinity environment. Theoretically, the difference of the inhibitory effect of a high-salt environment on different nitrification and denitrification processes could be used to realize shortcut nitrification denitrification by controlling a certain operation condition.


2011 ◽  
Vol 378-379 ◽  
pp. 428-432
Author(s):  
Yu Qin ◽  
Jing Song Guo ◽  
Fang Fang

PCR-DGGE was applied to analyze the relationship between pH and the microbial community structure of Sequence Batch Biofilm Reactor (SBBR) autotrophic nitrogen removal process. The reactor was possessed of a high nitrogen removal efficiency at pH=8.0 where the similarity of microbial community structure between active sludge and biofilm samples was the lowest about 84.6% and the richness of bacterial community was the most abundant in biofilm compared with other pH conditions. pH=7.0 was good for the microbes in active sludge but unfavorable for anaerobic bacteria. At pH=9.0, the effects were presented with both bacterial activities and microbial community structure and when pH=6.0 the amount of microbial types dramatically dropped


2018 ◽  
Vol 21 (2) ◽  
pp. 74-83
Author(s):  
Tzu-Hung Hsiao ◽  
Yu-Chiao Chiu ◽  
Yu-Heng Chen ◽  
Yu-Ching Hsu ◽  
Hung-I Harry Chen ◽  
...  

Aim and Objective: The number of anticancer drugs available currently is limited, and some of them have low treatment response rates. Moreover, developing a new drug for cancer therapy is labor intensive and sometimes cost prohibitive. Therefore, “repositioning” of known cancer treatment compounds can speed up the development time and potentially increase the response rate of cancer therapy. This study proposes a systems biology method for identifying new compound candidates for cancer treatment in two separate procedures. Materials and Methods: First, a “gene set–compound” network was constructed by conducting gene set enrichment analysis on the expression profile of responses to a compound. Second, survival analyses were applied to gene expression profiles derived from four breast cancer patient cohorts to identify gene sets that are associated with cancer survival. A “cancer–functional gene set– compound” network was constructed, and candidate anticancer compounds were identified. Through the use of breast cancer as an example, 162 breast cancer survival-associated gene sets and 172 putative compounds were obtained. Results: We demonstrated how to utilize the clinical relevance of previous studies through gene sets and then connect it to candidate compounds by using gene expression data from the Connectivity Map. Specifically, we chose a gene set derived from a stem cell study to demonstrate its association with breast cancer prognosis and discussed six new compounds that can increase the expression of the gene set after the treatment. Conclusion: Our method can effectively identify compounds with a potential to be “repositioned” for cancer treatment according to their active mechanisms and their association with patients’ survival time.


Author(s):  
Gabriela Bonassa ◽  
Alice Chiapetti Bolsan ◽  
Camila Ester Hollas ◽  
Bruno Venturin ◽  
Daniela Candido ◽  
...  

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jie Xu ◽  
Rongying Xu ◽  
Menglan Jia ◽  
Yong Su ◽  
Weiyun Zhu

Abstract Background Dietary fibers are widely considered to be beneficial to health as they produce nutrients through gut microbial fermentation while facilitating weight management and boosting gut health. To date, the gene expression profiles of the carbohydrate active enzymes (CAZymes) that respond to different types of fibers (raw potato starch, RPS; inulin, INU; pectin, PEC) in the gut microbes of pigs are not well understood. Therefore, we investigated the functional response of colonic microbiota to different dietary fibers in pigs through metatranscriptomic analysis. Results The results showed that the microbial composition and CAZyme structure of the three experimental groups changed significantly compared with the control group (CON). Based on a comparative analysis with the control diet, RPS increased the abundance of Parabacteroides, Ruminococcus, Faecalibacterium and Alloprevotella but decreased Sutterella; INU increased the relative abundance of Fusobacterium and Rhodococcus but decreased Bacillus; and PEC increased the relative abundance of the Streptococcus and Bacteroidetes groups but decreased Clostridium, Clostridioides, Intestinibacter, Gemmiger, Muribaculum and Vibrio. The gene expression of CAZymes GH8, GH14, GH24, GH38, GT14, GT31, GT77 and GT91 downregulated but that of GH77, GH97, GT3, GT10 and GT27 upregulated in the RPS diet group; the gene expression of AA4, AA7, GH14, GH15, GH24, GH26, GH27, GH38, GH101, GT26, GT27 and GT38 downregulated in the INU group; and the gene expression of PL4, AA1, GT32, GH18, GH37, GH101 and GH112 downregulated but that of CE14, AA3, AA12, GH5, GH102 and GH103 upregulated in the PEC group. Compared with the RPS and INU groups, the composition of colonic microbiota in the PEC group exhibited more diverse changes with the variation of CAZymes and Streptococcus as the main contributor to CBM61, which greatly promoted the digestion of pectin. Conclusion The results of this exploratory study provided a comprehensive overview of the effects of different fibers on nutrient digestibility, gut microbiota and CAZymes in pig colon, which will furnish new insights into the impacts of the use of dietary fibers on animal and human health.


2021 ◽  
Author(s):  
Chao Jin ◽  
Jiali Xing ◽  
Zijian Chen ◽  
Yabing Meng ◽  
Fuqiang Fan ◽  
...  

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