Question

A Thiobacillus is a group of bacteria helpful in carrying out.
A) Nitrogen fixation
B) Chemotrophic fixation
C) Nitrification
D) Denitrification

Answer 1

Hint: The cycle is a biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil, to the organism and back to the atmosphere again.

Complete answer: Nitrogen undergoes various sorts of transformation before it is utilized by plants. Denitrification is the process in which the nitrogen compound makes its way back into the atmosphere by converting nitrate into gaseous nitrogen. It is the final step which occurs in the absence of oxygen and it is carried out by the denitrifying bacterial species. Thiobacillus denitrificans is chemoautotrophic bacteria that denitrify nitrate during oxidation of compounds. Thiobacillus denitrificans is a chemolithoautotrophic, facultative anaerobe bacterium. It is most popular for its capacity to couple the oxidation of inorganic sulfur mixes, (for example, hydrogen sulfide and thiosulfate) to denitrification. It is a characteristic specialist for intrinsic bioremediation of groundwater dirtied with nitrate. Likewise, it has been utilized in designed water treatment frameworks for nitrate evacuation. Its capacity to do nitrate-subordinate Fe(II) oxidation under anaerobic conditions could impact metal and radionuclide transport in the subsurface, as ferric iron-containing minerals that might be shaped, particularly iron(III) oxides, are notable for their capacity to adsorb hefty metals and radionuclides, for example, uranium.
Thus, the correct answer is option D.

Additional information: The other steps involved in the nitrogen cycle are nitrogen fixation, nitrification, assimilation and ammonification. In assimilation, the nitrogen compounds are absorbed by the plants from their roots.

Note: Ammonium is thought to be preferred source of fixed oxygen for phytoplankton because its assimilation does not involve a redox reaction and therefore requires very little energy. Nitrogen fixation is essential for the plants in the synthesis of proteins and other important compounds.