Dynamics of bacterial and archaeal communities along the composting of tannery sludge

Abstract

The process of composting has been proposed as a biological alternative to improve the quality of tannery sludge (TS) by the action of microbial communities. However, there is limited knowledge about the dynamic of these microbial communities during the composting process. This study assessed the responses of bacterial and archaeal communities during TS composting using the 16S rRNA sequencing. The composting process occurred within 90 days, and samples of compost were collected on day 7 (d7; mesophilic stage), 30 (d30; thermophilic stage), 60 (d60; cooling stage), and 90 (d90; maturation stage). The results showed a succession of microbial phyla during the composting with enrichment of Synergistetes, WS1, and Euryarchaeota at the mesophilic stage, while at the thermophilic stage, there was an enrichment of Hydrogenedentes, WPS-2, Chloroflexi, and Deinococcus-Thermus. At the cooling stage, there was an enrichment of Kiritimatiellaeota, and at the maturation stage, there was an enrichment of Entotheonellaeota, Dadabacteria, Nitrospirae, Dependiatiae, and Fibrobacteres. When analyzing the drivers influencing microbial communities, Cr and pH presented more negative correlations with general phyla. In contrast, S, C, K, temperature, and N presented more positive correlations, while Ni, Cd, and P showed fewer correlations. According to niche occupancy, we observed a decreased proportion of generalists with a consequently increased proportion of specialists following the composting process. This study showed that different stages of the composting present a specific microbial community structure and dynamics, which are related to some specific composting characteristics.

Effects of High Pharmaceutical Concentrations in Domestic Wastewater on Membrane Bioreactor Treatment Systems: Performance and Microbial Community

“…Acidobacteria are closely associated with the degradation of organic compounds [ 40 ], with the relative abundance of Acidobacteria increasing initially in both MBR systems, before finally decreasing. In addition, by the 180th day, the relative abundances of Nitrospirae and Kiritimatiellaeota had increased in the MBRe system compared to the MBRc system, which was associated with nitrogen removal [ 41 , 42 ]. However, following the addition of pharmaceuticals, the relative abundance of Planctomycetes decreased in the anoxic and aerobic tanks by 16% and 54% compared to the MBRc system, which may be due to some pharmaceuticals, such as carbamazepine, being toxic to these bacteria [ 39 ].…”

Exploration of the Vermiculite-Induced Bacterial Community and Co-Network Successions during Sludge–Waste Mushroom Co-Composting

“…This was due to the fact that vermiculite promoted Bacillus , Pseudoxanthomonas , Saccharomonospora , Streptomyces , Ochrobactrum , and Nonomuraea, mentioned above. As demonstrated by Yin et al (2019), the breakdown of lignocellulose is positively influenced by carbohydrate metabolism, and composting maturation is closely linked to the metabolism of amino acids [ 41 ]. So, the KEGG metabolic pathway analysis indicated that vermiculite promoted the degradation of organic matter (carbohydrate and amino acid metabolisms) in composting and composting maturity.…”

Archaeal and Extremophilic Bacteria from Different Archaeological Excavation Sites

“…Thus, Dadabacteria are an indicator for pollution and are probably related to the degradation of aromatic compounds [ 40 , 41 ]. In addition to Archaea and other bacteria, an enrichment of Dadabacteria was reported to be found in recent tannery sludge [ 42 ]. This observation can be confirmed by the results reported here which connect the abundance of Dadabacteria with the comparatively high abundance of Archaea in a historical tannery area.…”