The third part of the developed program analyzed the spatial distribution of the biofilm. Characterizing spatial patterns can be complex, especially when dealing with continuous values like the biofilm spatial distribution rather that presence/absence data . For the characterization of the biofilm spatial distribution, the fractal dimension (FD) was chosen for it G-749 is a metric that has been extensively used to characterize spatial patterns . The FD has the advantage of synthesizing in a single value a geometrical property well suited to describe spatial patterns originated by organisms and other phenomena which are characterized by self-similar, scale-free behavior . The spatial pattern of the biofilm was considered as a three-dimensional (3D) surface, where the z-axis is cycads the amount of dye present on each pixel of the image. Furthermore, the 3D surface obtained as previously described is in turn proportional to the actual height of the biofilm in each pixel of the image if the concentration of dye is constant, due to Eq. (3). For such 3D surface, the FD can take a value between 2 and 3; FD would take values near 2 for smooth surfaces, such as a smooth paper, and would approach its maximum value of 3 if the surface increases in complexity and tends to “fill” the space, like a wrinkled paper. The FD was estimated by the box-counting method , which was implemented in MATLAB.