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Substrate Type and Free Ammonia Determine Bacterial Community Structure in Full-Scale Mesophilic Anaerobic Digesters Treating Cattle or Swine Manure.

Li J, Rui J, Yao M, Zhang S, Yan X, Wang Y, Yan Z, Li X - Front Microbiol (2015)

Bottom Line: Syntrophic metabolism by Proteobacteria, Chloroflexi, Synergistetes and Planctomycetes are likely inhibited when FA content is high.The core communities were best characterized by phylum Firmicutes, wherein Clostridium predominated overwhelmingly.These findings extend our current understanding of the bacterial assembly in full-scale manure anaerobic digesters.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences Sichuan, China ; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences Sichuan, China.

ABSTRACT
The microbial-mediated anaerobic digestion (AD) process represents an efficient biological process for the treatment of organic waste along with biogas harvest. Currently, the key factors structuring bacterial communities and the potential core and unique bacterial populations in manure anaerobic digesters are not completely elucidated yet. In this study, we collected sludge samples from 20 full-scale anaerobic digesters treating cattle or swine manure, and investigated the variations of bacterial community compositions using high-throughput 16S rRNA amplicon sequencing. Clustering and correlation analysis suggested that substrate type and free ammonia (FA) play key roles in determining the bacterial community structure. The COD: [Formula: see text] (C:N) ratio of substrate and FA were the most important available operational parameters correlating to the bacterial communities in cattle and swine manure digesters, respectively. The bacterial populations in all of the digesters were dominated by phylum Firmicutes, followed by Bacteroidetes, Proteobacteria and Chloroflexi. Increased FA content selected Firmicutes, suggesting that they probably play more important roles under high FA content. Syntrophic metabolism by Proteobacteria, Chloroflexi, Synergistetes and Planctomycetes are likely inhibited when FA content is high. Despite the different manure substrates, operational conditions and geographical locations of digesters, core bacterial communities were identified. The core communities were best characterized by phylum Firmicutes, wherein Clostridium predominated overwhelmingly. Substrate-unique and abundant communities may reflect the properties of manure substrate and operational conditions. These findings extend our current understanding of the bacterial assembly in full-scale manure anaerobic digesters.

No MeSH data available.


Related in: MedlinePlus

The heatmap showing the correlations of relative abundance of various phyla (A) and genera (B) with available operational parameters. The phyla and genera with average relative abundances of higher than 0.1% and 0.3%, respectively, were listed. SRT, sludge retention time; T, digester temperature; COD, chemical oxygen demand; FA, free ammonia; C:N, ratio of COD/. **p < 0.01, *p < 0.05.
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Figure 4: The heatmap showing the correlations of relative abundance of various phyla (A) and genera (B) with available operational parameters. The phyla and genera with average relative abundances of higher than 0.1% and 0.3%, respectively, were listed. SRT, sludge retention time; T, digester temperature; COD, chemical oxygen demand; FA, free ammonia; C:N, ratio of COD/. **p < 0.01, *p < 0.05.

Mentions: Correlation analysis of the bacterial community compositions with most available operational parameters showed that biogas production, temperature, COD and phosphate did not significantly correlate to the relative abundances of any dominant phyla (Table S5). However, FA positively correlated with the relative abundance of phylum Firmicutes, and negatively correlated to Proteobacteria, Chloroflexi, Synergistetes, and Planctomycetes (Figure 4A). Sludge pH and usually showed same correlation patterns with these phyla as those of FA. Sludge pH and SRT were also significantly correlated with the relative abundance of Acidobacteria. C:N was positively correlated with the relative abundances of phyla Synergistetes and Actinobacteria (p < 0.01).


Substrate Type and Free Ammonia Determine Bacterial Community Structure in Full-Scale Mesophilic Anaerobic Digesters Treating Cattle or Swine Manure.

Li J, Rui J, Yao M, Zhang S, Yan X, Wang Y, Yan Z, Li X - Front Microbiol (2015)

The heatmap showing the correlations of relative abundance of various phyla (A) and genera (B) with available operational parameters. The phyla and genera with average relative abundances of higher than 0.1% and 0.3%, respectively, were listed. SRT, sludge retention time; T, digester temperature; COD, chemical oxygen demand; FA, free ammonia; C:N, ratio of COD/. **p < 0.01, *p < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663275&req=5

Figure 4: The heatmap showing the correlations of relative abundance of various phyla (A) and genera (B) with available operational parameters. The phyla and genera with average relative abundances of higher than 0.1% and 0.3%, respectively, were listed. SRT, sludge retention time; T, digester temperature; COD, chemical oxygen demand; FA, free ammonia; C:N, ratio of COD/. **p < 0.01, *p < 0.05.
Mentions: Correlation analysis of the bacterial community compositions with most available operational parameters showed that biogas production, temperature, COD and phosphate did not significantly correlate to the relative abundances of any dominant phyla (Table S5). However, FA positively correlated with the relative abundance of phylum Firmicutes, and negatively correlated to Proteobacteria, Chloroflexi, Synergistetes, and Planctomycetes (Figure 4A). Sludge pH and usually showed same correlation patterns with these phyla as those of FA. Sludge pH and SRT were also significantly correlated with the relative abundance of Acidobacteria. C:N was positively correlated with the relative abundances of phyla Synergistetes and Actinobacteria (p < 0.01).

Bottom Line: Syntrophic metabolism by Proteobacteria, Chloroflexi, Synergistetes and Planctomycetes are likely inhibited when FA content is high.The core communities were best characterized by phylum Firmicutes, wherein Clostridium predominated overwhelmingly.These findings extend our current understanding of the bacterial assembly in full-scale manure anaerobic digesters.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences Sichuan, China ; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences Sichuan, China.

ABSTRACT
The microbial-mediated anaerobic digestion (AD) process represents an efficient biological process for the treatment of organic waste along with biogas harvest. Currently, the key factors structuring bacterial communities and the potential core and unique bacterial populations in manure anaerobic digesters are not completely elucidated yet. In this study, we collected sludge samples from 20 full-scale anaerobic digesters treating cattle or swine manure, and investigated the variations of bacterial community compositions using high-throughput 16S rRNA amplicon sequencing. Clustering and correlation analysis suggested that substrate type and free ammonia (FA) play key roles in determining the bacterial community structure. The COD: [Formula: see text] (C:N) ratio of substrate and FA were the most important available operational parameters correlating to the bacterial communities in cattle and swine manure digesters, respectively. The bacterial populations in all of the digesters were dominated by phylum Firmicutes, followed by Bacteroidetes, Proteobacteria and Chloroflexi. Increased FA content selected Firmicutes, suggesting that they probably play more important roles under high FA content. Syntrophic metabolism by Proteobacteria, Chloroflexi, Synergistetes and Planctomycetes are likely inhibited when FA content is high. Despite the different manure substrates, operational conditions and geographical locations of digesters, core bacterial communities were identified. The core communities were best characterized by phylum Firmicutes, wherein Clostridium predominated overwhelmingly. Substrate-unique and abundant communities may reflect the properties of manure substrate and operational conditions. These findings extend our current understanding of the bacterial assembly in full-scale manure anaerobic digesters.

No MeSH data available.


Related in: MedlinePlus