Screening of Bacteria as Antagonist against Xanthomonas oryzae pv. oryzae, the Causal Agent of Bacterial Leaf Blight of Paddy and as Plant Growth Promoter

Abstract

The aim of this study is to screen and characterize bacteria isolated from different sources that has potential as antagonistic bacteria against Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight of paddy and as a plant growth promoter. Ninety three bacteria were successfully isolated from different sources including compost, rhizosphere, water, roots and leaves from paddy field. By using chloroform vapours method, only 16 bacterial isolates showed positive antagonistic activity indicated by inhibition zone around bacterial colony against Xoo on nutrient agar plate. Twelve antagonistic bacteria were able to produce protease indicated by clear halo zone around bacterial colony on skim milk agar. Fourteen antagonistic bacteria were able to produce cellulase indicated by clear zone against red colour of congo red. Fifthteen antagonistic bacteria Original Research Article

Plant Growth-Promoting Bacteria as an Emerging Tool to Manage Bacterial Rice Pathogens

“…Other bacterial genera belonging to the phylum Proteobacteria ( Acinetobacter and Pantoea ) and Firmicutes ( Staphylococcus , Oceanobacillus , and Paenibacillus ) have been reported as PGPB and showed antagonistic effects against X. oryzae pv. oryzae [ 194 ]. Moreover, PGPB with antifungal and antibacterial activities were detected from endo- and rhizospheric bacteria isolated from Basmati rice [ 195 ].…”

Screening of Endophytic Bacteria as Biocontrol Agents Against Bacteria Leaf Blight (Xanthomonas oryzae)

“…Biological control of plant diseases can be defined as the process in which the pathogenic bacteria that caused plant disease will be inhibit or impacting their activities by one organism (Dicklow 2013). Endophytic bacteria have shown effective control of disease such as Bacillus sp., Acinetobacter sp., Bacillus licheniformis, and Pseudomonas putida (Palaniyandi Velusamy et al 2013), Burkholderia cepacia, Bacillus amyloliquefaciens, Staphylococcus warneri, Panteo vagans, Pantoea sp., Oceanobacillus oncorhynchi, and Paenibacillus cineris (Azman et al 2017).…”

“…The gene fragments of antagonistic endophytes were sequenced using universal primers pair 518F (5'-CCAGCAGCCGCGGTAATACG3') and 800R (5′TACCAGGGTATCTAATCC-3′) that was synthesised by MYTACG Bioscience Enterprise, Malaysia. The 50 μl of PCR reaction mixture contained 5X Green GoTaq (5 μl ), dNTPs (1 μl), Forward primer (1 μl), Reverse primer (1 μl , genomic DNA (2 μl), Taq Polymerase (0.5 μl) and nucleus free water (39.5 μl) modified from Azman et al (2017) method. Amplifications of gene was performed for 30 cycles in Eppendorf gradient thermal cyclers programmed (Kathleen 2006).…”

“…The pairwise alignment analysis of partial 16S rRNA gene sequences was performed on the MEGA X database (Kim et al 2012). The 16S rRNA gene sequences of known bacterial species were subjected to Basic Local Alighment Search Tool (BLAST) for identification and all obtained sequence were submitted to NCBI GenBank database (Azman et al 2017).…”

“…Cell suspensions containing 10 8 colony forming units (cfu) of Xanthomonas oryzae pv. oryzae using a spectrophotometer at 600 nm wavelength with 0.6 optical density volume was used (Azman et al 2017).…”