an organism that does not require a growth factor is called
Growth factors are organized into three categories. Some bacteria (e.g. E. coli) do not require any growth factors: they can synthesize all essential purines, pyrimidines, amino acids and vitamins, starting with their carbon source, as part of their own intermediary metabolism.
Observe for growth or no growth around the disks. Organisms that require only X-Factor will grow only in the area of the X- and XV-Factor Disks. Organisms that require only V-Factor, will grow only in the areas of the V- and the XV-Factor Disks. If both X- and V-Factors are required, the organism will grow only in the area of the XV-Factor Disk. In cases where slight growth occurs around the V-Factor Disk, the growth must be at least equal in amount to that around the XV-Factor Disk before the organism can be considered H. parainfluenzae .