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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 principal coordinates analysis (PCoA) plots of the bacterial communities in 20 independently-operated full-scale anaerobic digesters. Bray-Curtis distance was used for the PCoA analysis. Plots were ranked by (A) substrate type, and (B) free ammonia content (FA, mgl−1).
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Figure 1: The principal coordinates analysis (PCoA) plots of the bacterial communities in 20 independently-operated full-scale anaerobic digesters. Bray-Curtis distance was used for the PCoA analysis. Plots were ranked by (A) substrate type, and (B) free ammonia content (FA, mgl−1).

Mentions: Two potential clusters were observed by means of PCoA analysis of the bacterial communities (Figure 1A). Cluster 1 contained 8 samples exclusively from cattle manure digesters; Cluster 2 consisted of 12 samples originating from swine manure digesters. Approximately, PCo1 and PCo2 explained 45% of the total variations in the bacterial community structure among the digesters. The significant difference between the two potential clusters was verified with three nonparametric multivariate permutation tests (Adonis, F = 5.85, P = 0.001; ANOSIM, R = 0.77, p = 0.001; MRPP, δ = 0.64, P = 0.001). The results indicated that substrate type was likely to segregate bacterial communities in these anaerobic digesters. In addition, the segregation of bacterial communities within each cluster was also observed, suggesting that other parameters also contributed to the variations in the bacterial communities.


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 principal coordinates analysis (PCoA) plots of the bacterial communities in 20 independently-operated full-scale anaerobic digesters. Bray-Curtis distance was used for the PCoA analysis. Plots were ranked by (A) substrate type, and (B) free ammonia content (FA, mgl−1).
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: The principal coordinates analysis (PCoA) plots of the bacterial communities in 20 independently-operated full-scale anaerobic digesters. Bray-Curtis distance was used for the PCoA analysis. Plots were ranked by (A) substrate type, and (B) free ammonia content (FA, mgl−1).
Mentions: Two potential clusters were observed by means of PCoA analysis of the bacterial communities (Figure 1A). Cluster 1 contained 8 samples exclusively from cattle manure digesters; Cluster 2 consisted of 12 samples originating from swine manure digesters. Approximately, PCo1 and PCo2 explained 45% of the total variations in the bacterial community structure among the digesters. The significant difference between the two potential clusters was verified with three nonparametric multivariate permutation tests (Adonis, F = 5.85, P = 0.001; ANOSIM, R = 0.77, p = 0.001; MRPP, δ = 0.64, P = 0.001). The results indicated that substrate type was likely to segregate bacterial communities in these anaerobic digesters. In addition, the segregation of bacterial communities within each cluster was also observed, suggesting that other parameters also contributed to the variations in the bacterial communities.

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