Medium #2 is defined (**could add nacl and h2o or glucose and it would still be defined) and minimal because it contains only biochemical ingredients whereas 1 has the exception of yeast extract. It contains the minimal necessity for the bacteria"s growth and only the aerobic etpum grew. Medium #1 is complex (inclusion of 2 extracts- yeast and tryptone) because the components include yeast extract and carbon energy sources. It is also rich because it allows growth for both the aerobic and anaerobic etpum. Possible to be minimal and defined because it doesn"t grow in just any condition- anaerobic did not grow. [lab: given that polyurethane is a huge polymer (mw. Polyurethanase is a secreted enzyme by the microbe in order to break down polyurethane. Since the polymer is an important source of energy for the organism, it needs to be broken down in order for etpum"s growth.