Characterization of the actinomycetes Based on their
growth in ISP media and morphological observations, the 70 isolates were grouped into Streptomycetes and non-Streptomycetes
(rare). Streptomycetes isolates appeared as leathery colonies with
abundant spores (powdery) and varied in their growth pattern in
the ISP media, showing light yellow to brown substrate mycelia,
aerial mycelia as white, off-white, greenish white and light brown
in colour with the presence or absence of diffusible pigments (data
not shown). Thirty-two isolates were identified as Streptomyces sp.
based on prominent fragmented substrate mycelia, multiple spore
chains and spores which were oval to round in shape, majorly of
smooth surface. Non-Streptomycete isolates produced white to
yellow spores, light to dark orange in colour colonies and yellow to
red, round, convex and opaque colonies which did not show any
visible sporulation to naked eye. Micromonospora spp. were 14 in
number with non-fragmented substrate mycelia. There were no
prominent aerial mycelia and single spherical spores (w1 mm) were
observed onto the substrate mycelia, typical characteristic of genus
Micromonospora (17). Nocardiopsis isolates were 19 and they had
long branched substrate hyphae which were fragmented and
aerial hyphae had smooth non-motile, rod shaped long spore
chains, suggesting them to belong to the genera Nocardiopsis (12).
Five Kocuria isolates were identified based on their non-spore
forming coccoid cells which were of w1e1.5 mm in diameter and
were arranged in pairs or in clusters, typical morphology of
genera Kocuria (18). Based on these observations, the isolates
were grouped into four different genera. Fig. 2 shows the
percentage of different genera among the isolates. Streptomyces
spp. was the most predominant group contributing 46% of the
total isolates, followed by Nocardiopsis spp. (27%),
Micromonospora spp. (20%) and Kocuria spp. (7%).