MODIFIED STAINING FOR OBSERVATION OF FLAGELLA IN Bacillus amyloliquefaciens BY OPTICAL MICROSCOPY

Background: Bacillus amyloliquefaciens is a plant growth-promoting rhizobacterium and produces several secondary metabolites with antimicrobial activity. One of its most important morphological characteristics is the presence of flagella. Currently the existing staining techniques for bacterial flagellar visualization have limitations; as increased time requirement and unstable reactions of the reagents. Objective: Therefore, the objective of this study was to describe a modification in the flagellar staining methodology, to visualize flagella in B. amyloliquefaciens bacteria by light microscopy. Methodology: Mordant was used (80 mL of 25% tannic acid solution and 15 mL of 2.5% chromium trioxide, it was mixed and left to rest for 5 days at 4 °C) and crystal violet, in bacterial colonies of 16, 18, 20, 22 and 24 h of growth. Results: After a growth period of 20-24 h, in bacterial cells of B. amyloliquefaciens, the presence of peritric flagella was observed (flagella distributed on the surface of the bacteria), which was possible through the modified flagellar staining technique developed. Implications: The correct, fast and practical visualization of bacterial flagella is important for morphological identification. Conclusion: In this research it was possible to demonstrate the visualization of bacterial flagella, with a modified technique and less manipulation of the bacteria.