prokaryotic microorganisms in their natural habitats - soil

Question 1

what are the benefits of bacteria in soil?

Answer 1

bacteria are involved in the nitrogen cycle, the carbon cycle and the sulphur cycle.

Question 2

what are the bacteria involved in the nitrogen cycle?

Answer 2

aerobic bacteria such as azotobacter, azospirilium, cyanobacteria anabaena, and nostoc are involved in nitrogen fixation.
rhizobium, bradyrhizobium, and azorhizobium, are nitrogen fixers
anaerobic bacterium such as clostridium species, are nitrogen fixers.
nitrosomnas and nitrobacter are involved in nitrification.
bacillus, pseudomonas, spirllum, and thiobacillus are involved in denitrification.

Question 3

what are the bacteria involved in the carbon cycle?

Answer 3

algae (cyanobacteria) and green & purple sulphur bacteria fix or incorporate carbon dioxide (CO2) into organic matter using energy from sunlight.
thiobacillus and beggiatoa also fix CO2 into organic matter.

Question 4

what are the bacteria involved in the sulphur cycle?

Answer 4

thiobacillus are Gram-negative motile rods found in mud, sewage, bogs, mining drainage, and brackish springs. thiobacillus oxidise elemental sulphur, sulphides, and thiosulphate into sulphates - and gain energy in the process.

Question 5

what bacteria causes tetanus?

Answer 5

tetanus is caused by clostriduim tetani which produces a toxin that causes painful muscle contractions.

Question 6

symptoms of tetanus.

Answer 6

tetanus often causes a person’s neck and jaw muscles to lock making it hard to open the mouth or swallow.

Question 7

what bacteria causes gangrene?

Answer 7

gangrene is caused by clostridium perfringens which gather in an injury or surgical wound that has no blood supply. the bacterial infection produces toxins that release gas and cause tissue death.

Question 8

what bacteria causes anthrax?

Answer 8

anthrax is caused by the Gram-positive rod bacillus anthracis.

Question 9

symptoms of anthrax.

Answer 9

the symptoms of anthrax depend on the type of infection and can take anywhere from 1 day to more than 2 months to appear.
symptoms include: a group of small blisters or bumps that may itch, fever and chills, chest discomfort, shortness of breath, and in severe cases death.