Ur answer is number 2 i'm almost sure of i
It oxidies iron and inorganic sulfur compounds. The oxidation process can be harmful, as it produces sulfuric acid, which is a major pollutant. It has been suggested that T. ferrooxidans forms a symbiotic relationship with members of the genus Acidiphilium, a bacterial capable of iron reduction. Other species of Thiobacillus grow in water and sediment; there are both freshwater and marine strains.
The bacteria are usually found in rivers, canals, mine drainage effluents and mining areas. So there may be some source of these bacilli near their house.They require inorganic sources to grow and contain an enzyme called ferrous oxidase that allows them to metabolize iron.
<span>They eat iron pipes corroding the pipes leading into households and produce a thick slime layer biofilm.</span>
Creating or controlling a situation by causing something to happen rather than responding to it after it has happened.
I’m unsure how to answer this because I don’t know
How much bacteria there was
What bacteria it was
And what the conditions of the bacteria are
This chart is from Dr. Jason from the math forum
http://mathforum.org/library/drmath/view/64555.html hope this helps!