Agricultural Research Journal

Vermiwash, a liquid extract derived from vermicompost, plays a crucial role in organic farming, which is integral to sustainable agriculture. This study aimed to isolate and characterize plant-beneficial microbial strains from vermiwash and evaluate their potential as plant growth-promoting rhizobacteria (PGPR). Using standard microbiological techniques, bacterial colonies were isolated from vermiwash samples, resulting in the identification of twelve distinct strains (VW1 to VW12). These strains were subjected to biochemical characterization, including analysis of cell wall composition and various metabolic tests. The isolated strains were assessed for key plant growth-promoting traits, such as indole-3-acetic acid (IAA) production, ammonia synthesis, and phosphate solubilization. Additionally, their biocontrol capabilities were evaluated through amylase and cellulase activity assays and by testing their antagonistic effects against the fungal pathogen Aspergillus niger. Based on these qualitative assessments, strains VW-1, VW-4, and VW-9 were selected for further investigation in seed germination studies using Vigna radiata seeds. Furthermore, different concentrations of vermiwash extract (10%, 20%, and 30%) were tested to evaluate their impact on seed germination. Results indicated that both the vermiwash extract and the bacterial strains enhanced seedling growth, with notable improvements in hypocotyl and root length. Among the strains tested, VW-9 demonstrated superior performance in promoting shoot and root elongation compared to other microbial treatments and the control, highlighting its potential as an effective PGPR. Phylogenetic analysis identified strain VW-9 as Bacillus zanthoxyli (accession number PP694489). These findings suggest that the application of vermiwash, enriched with beneficial microorganisms, can serve as an effective bioinoculant in crop cultivation, supporting eco-friendly agricultural practices.