Characterization and molecular identification of dominant bacterial species of red soil and vermicompost made from Oryza sativa biomass

Abstract

The population of soil bacteria beneficial for plant growth is a direct indicator of soil health. A study was conducted in Bengaluru in 2024 to compare the bacterial population of red soil and vermicompost made from Oryza sativa biomass using the earthworm species Eudrilus eugeniae. In the red soil, six major bacterial species were identified using 16S rRNA technique belonging to the genera Pseudomonas and Stutzerimonas. These species were mainly chemoorganotrophs having ability to survive in low-nutrient soil. On the other hand, eight major bacterial species were identified in the vermicompost made from Oryza sativa biomass, belonging to the genus Lysinibacillus. Out of eight species, three species were found to be effective against agricultural fungal pathogens, two were known to produce plant-growth promoting substances, one was phosphate-solubilizer, one was helpful in bioremediation of heavy metal Cadmium and one species was low-boron-containing with unknown function. The results showed that vermicompost of Oryza sativa biomass contains many beneficial bacteria for plant growth and can be considered as a sustainable solution for improving soil health.