Thiobacillus is a group of bacteria helpful in carrying out:
Nitrates are reduced to gaseous compounds of nitrogen by Pseudomonas denitrificans, Thiobacillus denitrificans, Micrococcis denitrificans
Thiobacillus denitrificans is a bacteria invovled in denitrification. It's actions result in convesion of nitrates in soil to free atmospheric nitrogen.
Nitrogen fixationOption 2)
Chemoautotrophic fixationOption 3)