Erwinnia chrysanthemi. Transmission Electron Micrograph (TEM) of a single bacterium Erwinnia chrysanthemi. Long flagellae can be seen; shorter filaments known as pili are also visible on the cell wall. E.chrysanthemi is a Gram-negative rod- shaped bacillus bacteria of the Enterobacteriaceae group. In nature, it causes vascular wilting in a wide range of plants. In the laboratory, this bacteria is grown for the enzyme L-asparaginase which it contains. The enzyme is extracted from E.chrysanthemi and purified as a drug for acute lymphoblastic leukaemia (ALL). ALL is a cancer of white blood cells found largely in children. Magnification: x65,000 at 8x10 inch size.