RESUMEN
Bacillus amyloliquefaciens SQR9 is a plant growth-promoting rhizobacterium (PGPRs) that forms biofilm on the roots of plants and protects them from a variety of pathogens. In this study, we reported the effect of root exudates produced by cucumber (Cucumis sativus L.) at different developmental stages on the biochemical composition of the biofilm matrix of SQR9. The results showed that the amino acids present in the root exudates of cucumber were responsible for triggering biofilm formation of SQR9. In addition, when root exudates harvested at different growth phases of cucumber were used as carbon sources for biofilm formation, the resulting biofilm matrixes differed both quantitatively and qualitatively. The biofilm matrix was mostly composed of amino groups observed by confocal laser scanning microscope (CLSM) hence the proteins formed the major component of the resulting extracellular polymeric substances (EPS). The potential use of amino acid-based dietary supplements to control biofilm formation in the plants may be a viable option to improve agricultural productivity by recruiting beneficial association with PGPRs in the manufacture of bio fertilizers or bio controls.