Furthermore, the method was also validated by using the
standard cellulase form A. niger (Fig. 5). It was observed
that plates flooded with Gram’ iodine after incubation also
showed distinct, clear, and prominent zone in 3 to 5 minutes,
whereas the plates flooded with HAB or with Congo
red plus 1 M NaCl showed hazy zones after 30 to 40
minutes of incubation. The new method worked well with
bacteria, actinomycetes, and fungi; hence, it can be
employed for screening a large number of microorganisms
with greater throughput.