Quality assessment, safety evaluation, and microbiome analysis of night-soil compost from Lahaul valley of northwestern Himalaya

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The Himalayan dry toilet system prevalent in the northwestern Himalaya is a traditional practice of converting human faeces into a compost-like soil amendment. The current study evaluated night-soil compost (NSC) for agricultural use by assessing the compost quality, safety, and microbiome properties. Based on the fertility and clean indices determined by the fertility and heavy metal parameters, NSC was categorized as good quality compost with high fertilizing potential and moderate concentration of heavy metals. With respect to pathogens, the faecal coliform levels in the NSC were categorized as safe according to the U.S. Environmental Protection Agency standards. The bacterial community structure based on 16S rRNA gene amplicons revealed a diverse taxonomy with 14 phyla and 54 genera in NSC. Compared to publicly available 16S rRNA gene amplicon data, NSC exhibited predominant phyla (Proteobacteria, Bacteriodetes, Actinobacteria, and Firmicutes) similar to human faeces, cattle manure, food waste compost, vermicompost, and activated sludge. However, statistically, NSC was distinct at the genus level from all other groups. Additionally, pathogenic bacteria with antimicrobial resistance (AMR) genes in the NSC metagenome were determined by performing a standalone BLASTN against the PATRIC database. The analysis revealed 139 pathogenic strains with most pathogens susceptible to antibiotics, indicating lower AMR in the predicted strains. The phytotoxicity of NSC with Pisum sativum var. AS-10 seeds showed a germination index of > 85%, indicating NSC's non-harmful effects on seed germination and root growth. Overall, NSC from Himalayan dry toilets can be used as a soil amendment for food and non-food plants.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:149

Enthalten in:

Waste management (New York, N.Y.) - 149(2022) vom: 15. Juli, Seite 42-52

Sprache:

Englisch

Beteiligte Personen:

Borker, Shruti Sinai [VerfasserIn]
Thakur, Aman [VerfasserIn]
Khatri, Abhishek [VerfasserIn]
Kumar, Rakshak [VerfasserIn]

Links:

Volltext

Themen:

16S comparative metagenomics
Antimicrobial resistance genes
Compost indexing
Journal Article
Metals, Heavy
Pathogenicity
Phytotoxicity
RNA, Ribosomal, 16S
Soil

Anmerkungen:

Date Completed 09.08.2022

Date Revised 09.08.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.wasman.2022.06.003

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM342357328