The Gram stain is a differential stain, which allows most bacteria to
be divided into two groups, grampositive bacteria and gram-negative
bacteria. Morphological characters of isolates were observed by
smears from colonies up to 10 days, stained by Gram’s method as
described by Hucker and Conn (1923).Microscopic characterization was done by cover slip culture
method (Kawato and Sinobu, 1959). The mycelium structure, color
and arrangement of conidiospore and arthrospore on the mycelium
were observed through the oil immersion (1000×, Olympus)
microscope. The observed structure was compared with Bergey’s
manual of Determinative Bacteriology, ninth edition (2000) and the
organism was identified. Colonies were identified on the basis of
their colony morphology and color (Shirling and Gottlieb, 1966).
Color of aerial mycelium was determined from mature, sporulating
aerial mycelia of the actinomycetes colonies on starch-casein agar
media (Pridham, 1964).