The Potential Plant Growth-Promoting Bacteria (PGPB) Consortia to Suppress the Growth of Xanthomonas oryzae pv. oryzae in vitro

Bacterial leaf blight (BLB) is one of the main diseases in rice plants caused by the pathogenic bacteria Xanthomonas oryzae pv. oryzae (Xoo). Plant Growth-Promoting Bacteria (PGBP) are a group of beneficial microorganisms that interact with plants. The interaction of PGPB with plants can act as a biocontrol agent against plant pathogens.This study aims to obtain a PGPB consortium that can potentially suppress the growth of Xanthomonas oryzae pv. oryzae in vitro. The PGPB isolates used were Stenotrophomonas pavanii KJKB 54, Stenotrophomona maltophilia LMTSA 54, Stenotrophomonas maltophilia LMB35, Bacillus cerereus AJ34, Serratia marcescens AR1, Ochrobactrum intermedium LMB1, Alcaligenes faecalis AJ14, and bacterial isolate Bacillus thuringiensis LmD13. Seven PGPB consortia were obtained which will be tested for their ability to suppress the growth of Xoo using an experimental method with a completely randomized design consisting of 8 treatments and 4 replications. The antagonist test of PGPB consortia against Xoo bacteria was carried out using the dual culture method. The result showed the consortium of Stenotrophomonas pavanii KJKB54+ Stenotrophomonas maltophilia LMTSA54+ Bacillus cereus AJ34+ Serratia marsescens AR1 cell consortium and supernatant had the highest potential to suppress Xoo. The antagonistic activities of the consortium were 58% and 52%. This consortium shows the ability to produce of protease enzyme, HCN and siderophores and can be developed as a biological agent against Xanthomonas oryzae pv. oryzae.