Question

-03] What is the advantage of growing bacteria on solid media?- 4. [CH-09-04] Describe bacterial morphology, oxygen and temperature requirements of Bacillus subtilis- 5. [CH-09-05] Describe bacterial morphology, oxygen and temperature requirements of Staphylococcus epidermidis 6. [CH-09-06] Colony size, color, and shape are critical of bacterial growth description. At least three other crucial factors - not description of the organism itself- typically included when describing bacterial growth. What are they and why are they important? 7. [CH-09-07] What steps should be taken before attempting to light Bunsen burner?- 8. [CH-09-08] If the flame is yellow what does this indicate? What adjustments must be made?- 9. [CH-09-09j Suppose you cough on plate and there is no growth after incubation. It is highly unlikely your cough was sterile. Suggest at least two reasons why no growth was recovered on the plate- 10.[CH-09-10] If you found the colony to be a mixture of organisms, what could you do to isolate them as pure cultures?-

Answer 1

Ans 3) The advantage of growing bacteria on solid media is that it does not submerge and gets a strong base to grow upon. The agar or other solid based media tend to support better growth as the microbes are able to form colonies. It helps in adding all the essential nutrients to the culture and hence is able to support better growth through individual colony formation. The microbial growth can well spread due to the strong base.

Ans 4)The Bacillus subtilis is a rod shaped gram positive aerobic bacteria which is even catalase positive. They are majorly found in soil as well as within the gastrointestinal tract of some animals and humans. They are aerobic bacteria and hence require oxygen for their growth. The optimum growth temperature for the Bacillus subtilis species is around 25 – 35 degrees celcius and they fall under the mesophilic range of temperature.

Ans 5) The staphylococcus epidermis bacteria is a gram positive bacteria and they majorly form the part of human skin flora. They are coagulase negative and cocci in shape and are known to interrupt the innate defense system of the host. They are facultative anaerobe which means that are able to grow in presence of oxygen and produce ATP but are able to switch their mechanism as soon as there is no oxygen available. They have a wide range of temperature in which they can grow and the optimal range is from 30 to 37°C.