Soil serves as the major habitat of micro and macrofauna that shows mutualistic interaction with one another. The interaction between earthworms (macrofauna) and the microbial community has gained global attention because earthworms, along with their gut symbionts, synergistically and significantly modify soil structure. Isolation and characterization of gut wall associated culturable bacteria of Metaphire posthuma was studied to know the interaction between earthworm and soil microbial communities. The endogeic earthworm species Metaphire posthuma (Vaillant) was used in the present study because of its wide diversity and easy availability in various land-use patterns of Punjab, India. Based on ribotyping, eight bacteria were identified: Bacillus firmus (2 isolates), B. safensis, B. drentensis, B. amyloliquefaciens, Sphingomonas roseiflava, Brevundimonas diminuta, and Comamonas terrigena. During the BLAST analysis, all bacterial isolates showed 100% query coverage with more than 99.5% identity. Phylogenetic study of the bacterial isolates proved that the species belonging to Bacillus genus were within the same clade, while S. roseiflava, Brevundimonas diminuta, and C. terrigena were in another clade sharing a common ancestor. The present study will help to facilitate the use of earthworm as a carrier of various beneficial microbes specially bacteria for the dispersal (egested in the cast) in various land use patterns. These beneficial microbes can be used for the organic matter decomposition present in the soil and promotes sustainable agriculture.
Singh et al. (Thu,) studied this question.