Resumen
The aim of this work was to evaluate the formation of biofilm on abiotic surface and growth in culture medium with reduced water activity (Wa). Five endophytic isolates from sugarcane deposited at Microbiology Laboratory Microorganisms Bank (ISO1 and ISO2 belonging to the genre Herbaspirillum and ISO3, ISO4 and ISO5 of the genre Bacillus). For evaluation of the biofilm production, 100µL of each bacterial isolates were inoculated with 900µL of TSB +10% sucrose culture medium. After incubation at 40 °C for 96 hours, the cells were removed and each tube was washed twice with distillated water, followed by addition of 25 µL of crystal violet (0.1%), after 15 minutes of incubation at room temperature and washed two more times with distilled water. The bacterial isolates were inoculated in Petri dishes containing TSB culture medium and the diameter of colony was measured after 48 hours. The biofilm formation was quantified by the optical density (O.D.) at 540 nm. Growth was evaluated in TSA culture medium supplemented with sorbitol (405 gL-1) at 28 °C. All bacterial isolates tested were capable of producing biofilm at pH 7.5 and 5.5 and grow in medium with low Wa.