Novel microbial consortium formulation as plant growth promoting bacteria (PGPB) agent

PGPB enhance plant growth through nitrogen fixation, IAA production, phosphorus and pottasium solubilization. PGPB as biofertilizer provide an alternative for chemical fertilizer to reduce environmental damage. PGPB in consortium could be more effective instead of single strain inoculant. The aim of this study is to investigate compatibility, design soil bacteria consortium isolated from rubber-Canna intercropping plantation and evaluate the consortium's potential as biofertilizer. Functional roles of PGPB was tested such as nitrogen fixation, potassium and phosphate solubilization, and IAA production. Detection of pathogenic bacteria was tested by Blood Agar method. Compatibility test was performed by cross streak method. Bacteria were identified using sequencing of 16srRNA gene and verified using BLAST to database of NCBI. The results showed that among 19 bacterial isolates, all showed the nitrogen-fixing activity, G5 had the highest phosphorus and potassium solubilization index, whereas Citrobacter braakii strain 167 produced the highest IAA concentration. Compatibility analysis showed that Citrobacter freundii strain LMG 3246, Citrobacter braakii strain DSM 17596 and G5 are compatible as a bacteria consortium and may developed as biofertilizer. This study found a possible new and beneficial biofertilizer formulation to enhance plant growth and to reduce the application of chemical fertilizer.

Automated summary

This study aimed to investigate the compatibility of soil bacteria consortium, design and evaluate its potential as biofertilizer. The results showed that Citrobacter braakii strain DSM 17596, G5 and LMG 3246 were identified as a compatible bacteria consortium for potential development as biofertilizer.