Assessment of Bacterial and Archaeal Community Structure in Swine Wastewater Treatment Processes

Abstract

Microbial communities from two field-scale swine wastewater treatment plants (WWTPs) were assessed by pyrosequencing analyses of bacterial and archaeal 16S ribosomal DNA (rDNA) fragments. Effluent samples from secondary (anaerobic covered lagoons and upflow anaerobic sludge blanket [UASB]) and tertiary treatment systems (open-pond natural attenuation lagoon and air-sparged nitrification-denitrification tank followed by alkaline phosphorus precipitation process) were analyzed. A total of 56,807 and 48,859 high-quality reads were obtained from bacterial and archaeal libraries, respectively. Dominant bacterial communities were associated with the phylum Firmicutes, Bacteroidetes, Proteobacteria, or Actinobacteria. Bacteria and archaea diversity were highest in UASB effluent sample. Escherichia, Lactobacillus, Bacteroides, and/or Prevotella were used as indicators of putative pathogen reduction throughout the WWTPs. Satisfactory pathogen reduction was observed after the open-pond natural attenuation lagoon but not after the air-sparged nitrification/denitrification followed by alkaline phosphorus precipitation treatment processes. Among the archaeal communities, 80% of the reads was related to hydrogeno-trophic methanogens Methanospirillum. Enrichment of hydrogenotrophic methanogens detected in effluent samples from the anaerobic covered lagoons and UASB suggested that CO2 reduction with H2 was the dominant methanogenic pathway in these systems. Overall, the results served to improve our current understanding of major microbial communities' changes downgradient from the pen and throughout swine WWTP as a result of different treatment processes.

Microbial community in a hydrogenotrophic denitrification reactor based on pyrosequencing

“…Firmicutes was reported to be predominant in biogas fermenter (Jaenicke et al 2011), fermentation liquor from rice straw (Zhao et al 2012), autotrophic denitrification biocathode (Xiao et al 2015), and swine WWTPs (Da Silva et al 2015). Lee et al enriched class Clostridia in phylum Firmicutes for bioelectrochemical denitrification.…”

“…It is known that Clostridia inhabit diverse anaerobic environments including soil, sediments, fresh water, and anaerobic digesters (Karanasios et al 2010), and some of them (e.g., Clostridium perfringens, Clostridium butyricum, Clostridium denitrificans, Clostridium aminobutyricum, and Clostridium tertium) are capable of denitrification (Hasan and Hall 1977;Lee et al 2013). Da et al investigated bacterial archaeal community and demonstrated that Firmicutes was predominant in swine wastewater treatment processes (Da Silva et al 2015).…”

Archaeal community structure and underlying ecological processes in swine manure slurry

“…Of the 122,321 sequences, around 98.8% sequences were classified up to phylum Euryarchaeota. Euryarchaeota are known to inhabit pig feces and mostly dominated by the methanogenic members of this phylum (Cardinali-Rezende et al 2012; Da Silva et al 2014).…”

“…During storage the swine manure slurry decomposes, and emits a considerable quantity of methane (EPA 2013), which is exclusively generated by methanogenic archaea (Whitman et al 2006). Over the past decade, several studies have characterized the archaeal community present in swine feces and stored manure slurry by using both cultivation-based (Miller et al 1986) and culture-independent methods (Whitehead and Cotta 1999; Mao et al 2011; Da Silva et al 2014). However, it is still not clear what underlying ecological processes are important in structuring the community composition of archaea in swine manure slurry.…”

Elimination of Antibiotic Multi-Resistant Salmonella Typhimurium from Swine Wastewater by Microalgae-Induced Antibacterial Mechanisms

“…However, most if not all of these approaches are not economically feasible. Therefore, biological anaerobic digestion followed by stabilization ponds are the most common treatment option adopted in swine farming worldwide [3,6,7]. Pathogen elimination can occur under thermophilic conditions, but not under mesophilic conditions that prevail in most digesters [8].…”