The present studies showed that the use of Gram’s iodine
remarkably enhances the sharpness of the clearance zone,
making the process for screening cellulase-producing
microorganisms easy, efficient, and rapid. Although the
new method is a qualitative assay, the greatest advantage
lies in its simplicity, quickness of performance, and
effectiveness for screening a large number of microorganisms.
Moreover, it avoids the use of toxic chemicals.