Diversity and Metabolic Potential of Earthworm Gut Microbiota in Indo-Myanmar Biodiversity Hotspot

Abstract

Earthworms are important members of the soil macrofauna that play a significant role in soil structure and fertility. However, there is scanty information on the earthworm gut microbial flora and their metabolic potential. In the present study, the diversity of the microbial community and their metabolic potential from the gut content of four different earthworm species from Indo-Myanmar Biodiversity Hotspot were collected and identified by standard methods. The microbial diversity and their metabolic potential were assessed by high throughput sequencing of V3-V4 region of 16S rRNA using Illumina technology. Analysis of microbial diversity was performed by QIIME software package v.1.8.0 with their metabolic potential by PICRUSt (v1.1) software package. A total of 3,36,047 processed sequences were obtained that generated 3686 operational taxonomic units (OTUs). Major bacterial phyla identified were Proteobacteria (47.1%), Firmicutes (38.9%), Actinobacteria (6.3%), Bacteroidetes (3.6%) and Cyanobacteria (1.1%). The abundant genera were Lysinibacillus (26.9%), Acinetobacter (21.2%), Pseudomonas (4.7%), Bacillus (3.8%), Staphylococcus (3.5%), Stenotrophomonas (1.1%) and Ralstonia (1%). The functional annotation of the metagenome revealed abundance of bacterial community associated with amino acid, carbohydrate as well as energy metabolism. Furthermore, the presence of enzymes involved in the process of denitrification and methanogenesis were also identified. This study gives insight into the gut microbial composition and their putative functional roles in the gut of tropical hilly earthworms. The study on forest and garden soil earthworm gut microbiomes might help us understand the role of these organisms in their respective ecosystems.

Gut microbiome reflect adaptation of earthworms to cave and surface environments

“…Higher proportions of metabolism-related genes were found in the gut of soil animal microbiota compared to other functions. It is evidenced soil animals are highly dependent on the metabolism genes from their gut microbiome for nutrient needs [ 32 , 33 ]. As the cave environment is deficient in food sources, when the earthworms are living in the caves, their gut might be stimulated to serve as a more efficient “nutrient factory” [ 12 ].…”

Lignans dramatically enhance the resistance of Fraxinus velutina Torr. by adjusting the dominant bacterium group of Agrilus planipennis Fairmaire

“…[35][36][37] Many studies have been published on the impact of insect intestinal microbial diversity on growth and development. 20,38,39 Research has shown that Burkholderia in the intestinal microbes of the Riptortus pedestris helped R. pedestris obtain more limited essential nutrients from food. 40 Moreover, they help R. pedestris to grow and reproduce quickly.…”

“…They mostly regulate insect feeding, but they can also influence specific physiological activities of insects 35–37 . Many studies have been published on the impact of insect intestinal microbial diversity on growth and development 20,38,39 . Research has shown that Burkholderia in the intestinal microbes of the Riptortus pedestris helped R. pedestris obtain more limited essential nutrients from food 40 .…”

Vermicast Analysis with the Earthworm Species Pheretima losbanosensis (Crassiclitellata: Megascolecidae): Bacterial Profiles for Potential Applications in Agriculture

“…The concentration of extracted DNA was measured using a NanoDrop spectrophotometer and submitted to Macrogen for next-generation sequencing (NGS). The V3-V4 hypervariable region of the 16S rRNA gene was sequenced using the Illumina MiSeq platform [4,36,37].…”