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Lei X, Cui G, Sun H, Hou S, Deng H, Li B, Yang Z, Xu Q, Huo X, Cai J. How do earthworms affect the pathway of sludge bio-stabilization via vermicomposting? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170411. [PMID: 38280597 DOI: 10.1016/j.scitotenv.2024.170411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 01/29/2024]
Abstract
The synergy effects between earthworms and microorganisms promote nitrogen mineralization and enhance stabilization of organic matters in a vermicomposting system. However, the stabilization pathways of vermicomposting in the system remain unknown. The aim of this study was to investigate the effect of earthworms on the stabilization pathway and associated microbial population of waste activated sludge recycled by vermicomposting. The treatment of sludge with and without earthworms was conducted at 20 °C for 60 days. The trends in organic matter (OM), dissolved organic carbon (DOC), NH4+-N, electrical conductivity (EC), microbial biomass carbon (MBC), and dehydrogenase activity (DHA) were similar in both systems over time. At the end of the treatment, OM and DOC were significantly lower (p < 0.05), and EC, NH4+-N, and NO3--N were significantly higher (p < 0.05) in the vermicomposting group than in the control. Based on the statistical results of principal component analysis (PCA), it was proposed that the stabilization pathway in both treatment systems required a sequence of reactions characterized by the degradation of organic matter, accumulation of dissolved organic carbon, ammonification, and nitrification. Vermicomposting led to greater abundance and diversity (Shannon index) of 16S rDNA microbial species, but more even distribution in microbial community composition (Simpson index) than the control. However, the opposite performance for 18S rDNA microbes was observed. Vermicomposting enhanced the abundance of microorganisms involved in organic matter degradation and nitrification, facilitating the conversion of organic matter and favoring the nitrification. In short, the pathway of sludge bio-stabilization is not altered regardless of the addition of earthworms or not, which enables us to better understand vermicomposting process of sludge.
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Affiliation(s)
- Xuyang Lei
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Guangyu Cui
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Hongxin Sun
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Suxia Hou
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Hongying Deng
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Bo Li
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Zhengzheng Yang
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Qiushi Xu
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Xueyu Huo
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
| | - Jiaxuan Cai
- Department of Resource and Environmental Engineering, Hebei Vocational University of Technology and Engineering, Hebei, Xingtai 054000, China
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Pratte ZA, Richardson LL. Microbiome dynamics of two differentially resilient corals. DISEASES OF AQUATIC ORGANISMS 2018; 131:213-226. [PMID: 30459293 DOI: 10.3354/dao03289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Coral bleaching and disease are 2 common occurrences that are contributing to global coral cover decline. Understanding the interactions between the coral animal and its microbial associates, and how they may change in the presence of stressors such as warming and acidification, is a crucial component to understanding both susceptibility and resistance to disease and bleaching. The coral Diploria labyrinthiformis has been shown to be more disease resistant than its relative Pseudodiploria strigosa, providing an ideal study system for disease resistance. In this study, we examined the bacterial communities of these 2 coral species on the Florida Reef tract every 6 mo for 18 mo (in situ sampling), and under experimental (laboratory) thermal and pH manipulation. The in situ sampling encompassed wide fluctuations in temperature, including an anomalously warm summer period. The laboratory experiments involved exposure to both increased temperature (31°C) and lowered pH (7.7). The in situ bacterial communities of both coral species were highly similar in the winter, but diverged during summer, with the D. labyrinthiformis bacterial community being more stable than that of P. strigosa. Differences in the bacterial community between the 2 coral species included 29 operational taxonomic units (OTUs) that were specific to D. labyrinthiformis in all seasons, while only 2 OTUs were specific to P. strigosa. The comparative stability of the D. labyrinthiformis microbiome, in addition to harboring a more specific microbiome, may be a key component of the relative disease resistance of this coral.
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Affiliation(s)
- Zoe A Pratte
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
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Tourova TP, Kovaleva OL, Gorlenko VM, Ivanovsky RN. Use of genes of carbon metabolism enzymes as molecular markers of Chlorobi phylum representatives. Microbiology (Reading) 2014. [DOI: 10.1134/s0026261714010159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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