Morphology Characterization and Colonization of Selected Endophytic Streptomyces spp
All isolates grew vigorously on the four tested media (YMA, OA, YSA, and GAA) except isolate AB131-1, which was not able to grow on the GAA medium. Isolate AB131-1 showed the same color of aerial or substrate mycelium on all media, which was brown and cream, respectively (Table 3). The other isolates showed various colors of aerial or substrate mycelia, depending on the growth medium. The mycelium substrates of AB131-2 on media YMA, OA, and YSA were green bluish. On the GAA media, the mycelium arieal were grey, the mycelium substrates were brown, and there were none soluble pigments. LBR02 had brown mycelium aerial and substrates on YMA, OA, and YSA, and grey aerial and substrates on the GAA medium. Meanwhile, there were none soluble pigments in the YMA and GAA medium. Scanning electron microscope observations showed different types of Streptomyces spp. spore chain formations. LBR02 formed compact and closed spirals of spore chains, whereas AB131-1 and AB131-2 formed long and stretched spirals in two major types, open and loose ( Figure 2).