Final answer:
After co-incubating strains A and B overnight, plating and incubation could reveal distinct bacterial colonies. Sub-culturing onto a TSA plate could allow for separation into pure cultures. Observations post-incubation are essential to confirm successful isolation.
Step-by-step explanation:
Mixing Strain A with Strain B
When you mix strain A and B in the same culture and allow them to co-incubate overnight under suitable growth conditions, the result could be a mixed culture with both bacterial populations. If you then take a sample from this mixed culture, plate it, and incubate it, you may observe distinct colonies of each strain, assuming they have different morphological characteristics. To create a pure culture of each bacterium from the mixed culture, a single colony representing each strain can be sub-cultured to separate halves of a TSA plate. After incubation, you should be able to determine if you have successfully isolated each bacterium into two pure cultures based on their distinctive growth patterns and characteristics.
To further validate the separation, you might use selective media like Blood Agar Plate and Bile Esculin Agar plate to emphasize the differences between Gram-positive and Gram-negative bacteria. Observing the growth on these plates after incubation should reveal distinct reactions that help in identifying and confirming the separation of the cultures.
Laboratory observations are crucial and can only be made after the cultures have had sufficient time to grow. These observations will include the size, shape, color, and other morphological details of the bacterial colonies that can help in distinguishing between them.