Microbiology laboratory homework 6
Please use the following diagram to answer questions # 1 through 4
Based on their oxygen requirement, bacteria can be classified into five major groups.
1-Which tube indicates the growth of an obligate aerobe?
2-Which tube might indicate an organism like E.coli (facultative)?
3-Which tube indicates Clostridium growing?
4-Which tube might indicate the presence of Helicobacter pylori?
5- True or False
A disinfectant should be used after a spill, before the start of a lab period and after all work
is completed.
6- True or False
In exercise #21 Fluid Thioglycollate medium is a rich medium used to support the growth
of only anaerobic bacteria.
7- True or False
A selective medium consists of organic compounds and inorganic ions whose composition
is known.
8- True or False
The purpose of the gas generator envelope in the gas pak anaerobic jar system is to
generate oxygen gas and carbon dioxide. The oxygen gas reacts with oxygen to create an
anaerobic condition.
9--True or False
Chemolitotrophs are organisms that can oxidize inorganic ions such as Iron and Nitrates
and obtain energy from them.
10-Some bacteria can grow by respiratory means if oxygen is available. But if oxygen is not
available they can also grow using fermentation. These bacteria are best classified as
a) obligate aerobes
b) obligate anaerobes
c) facultative anaerobes
d) none of the above
11-True or false
Clostridium is classified as a microaerophile.
12- Pseudomonas Aeruginosa is a
e) gram negative rod
f) gram positive rod
g) gram positive cocci
h) gram negative cocci
13- State a specific result that will indicate that our anaerobic jar was successful in what we
aimed at accomplishing in lab (cultivating anaerobes).