FIG. 4.
Unique macroscopic and microscopic features distinguish the N. asteroides laboratory type strain ATCC 19247T. Colony morphology varied with medium after 7 days of incubation at 35°C. (A) Individual colonies were shiny, honey-colored, slightly elevated, and growing to a peak with an eroded surface texture on BAP. (B) Colonies were similar but cream colored on BCYE agar. (C) Colonies were white and dome shaped, with a buff velvety surface on 7H11 agar. (D) Mega-colonies after 4 days of incubation on SAB agar were coral colored, flat, and moderately ruffled. (E) Microscopically, aerial hyphae protruding from these large colonies had a bundled, pointed-end appearance. Note that all N. cyriacigeorgica strains differed from the N. asteroides species type strain in each of the above descriptions (compare with Fig. 3) as well as by urease activity and the ability to grow at 45°C (Table 3).