helpful bacteria

helpful bacteria

Can we survive without bacteria? Could bacteria survive without us? No and yes. No, we could not survive without bacteria. And yes, bacteria could survive without us.


Bacteria can be used to make cheese from milk. The bacteria turn the milk sugars into lactic acid. The acid is what causes the milk to curdle to form cheese. Bacteria are also involved in producing other foods. Yogurt is made by using bacteria to ferment milk ( Figure 1.1). Fermenting cabbage with bacteria produces sauerkraut. Yogurt is made from milk fermented with bacteria. The bacteria ingest natural milk sugars and release lactic acid as a waste product, which causes proteins in the milk to form into a solid mass, which becomes the yogurt.



In the laboratory, bacteria can be changed to provide us with a variety of useful materials. Bacteria can be used as tiny factories to produce desired chemicals and medicines. For example, insulin, which is necessary to treat people with diabetes, can be produced using bacteria. Through the process of transformation, the human gene for insulin is placed into bacteria. The bacteria then use that gene to make a protein. The protein can be separated from the bacteria and then used to treat patients. The mass production of insulin by bacteria made this medicine much more affordable. During transformation, bacteria can take up any DNA from the environment. Therefore, transformation allows scientists to insert any DNA into a bacteria, potentially producing many different proteins. This makes the bacteria greatly useful to people.


Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells!


Bacteria are important in practically all ecosystems because many bacteria are decomposers. They break down dead materials and waste products and recycle nutrients back into the environment. The recycling of nutrients, such as nitrogen, by bacteria, is essential for living organisms. Organisms cannot produce nutrients, so they must come from other sources. We get nutrients from the food we eat; plants get them from the soil. How do these nutrients get into the soil? One way is from the actions of decomposers. Without decomposers, we would eventually run out of the materials we need to survive. We also depend on bacteria to decompose our wastes in sewage treatment plants.

instructional diagrams

No diagram descriptions associated with this lesson


we need bacteria to survive.

-->  a. true

b. false

in your gut, bacteria cells outnumber your own cells.

-->  a. true

b. false

during fermentation, bacteria turn milk sugars into

a) carbon dioxide.

b) oxygen.

-->  c) lactic acid.

d) glucose.

bacteria have been used to produce human versions of

a) lactic acid.

-->  b) insulin.

c) nitrogen.

d) yogurt.

fermentation occurs in the absence of oxygen. fermentation allows glycolysis, the first step of cellular respiration, to continue, producing 2 atp in the process. lactic acid is produced in certain types of fermentation. what is the waste product in this process?

a) glucose

-->  b) lactic acid

c) oxygen

d) atp

what process is used when placing a foreign gene into bacteria?

-->  a) transformation

b) transduction

c) transcription

d) translation

decomposers help recycle nutrients so organisms can use them. decomposers include scavengers like vultures, as well as many types of worms, fungi and bacteria. what nutrient does bacteria recycle?

a) vitamin c

b) vitamin d

c) magnesium

-->  d) nitrogen

diagram questions

No diagram questions associated with this lesson