Earthworms are an integral part of soil ecosystems, especially for their role in soil functions such as organic matter (OM) decomposition and nutrient cycling. Earthworms and microorganisms are interdependent, and a considerable portion of the contribution earthworms make to influencing OM fate is through interactions with microorganisms. However, the importance of the earthworm-associated microbiome is not fully understood, because it is difficult to separate the direct influence of the earthworms from the indirect influence of their microbiome. Here, we evaluated an antibiotic-based procedure for producing axenic ecologically-contrasting earthworm species (E. fetida, L. terrestris, A. chlorotica) as the first step towards soil studies aimed at understanding the importance of the earthworm microbiome for host health and function. Individual earthworms were exposed to antibiotics: cycloheximide (150 μg ml-1), ampicillin (100 μg ml-1), ciprofloxacin (50 μg ml-1), nalidixic acid (μg ml-1), and gentamicin (μg ml-1) either singly or in a cocktail via culture (96 h) in a semi-solid agar carrier. Compared to the non-antibiotic treated control, the cocktail (for all three species) and ciprofloxacin (for E. fetida and A. chlorotica) treatments significantly reduced (P<0.05) culturable microbial abundance on nutrient agar and potato dextrose agar. The microbial counts were reduced to below detection (<50 CFU individual-1) for E. fetida and A. chlorotica receiving the cocktail. Illumina 16S rDNA amplicon sequence analysis of culturable L. terrestris -associated bacteria showed that antibiotic treatment influenced community composition revealing putative sensitive (Comomonas, Kosakonia and Sphingobacterium) and insensitive (Aeromonas, Pseudochrobactrum) taxa. Overall, we report a rapid, with minimal earthworm- handling, process of creating axenic E. fetida and A. chlorotica individuals or L. terrestris with a suppressed microbiome as a tool to be used in future ecological studies of earthworm microbial interactions affecting host health and function.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.