A large number of organic compounds can be decomposed by:

Explanation

Let's explain each option individually: a) Azotobacter: Azotobacter is a genus of free-living, nitrogen-fixing bacteria. While they play an essential role in nitrogen fixation by converting atmospheric nitrogen into a usable form for plants, they are not primarily known for their ability to decompose a large number of organic compounds. Their main significance lies in their contribution to nitrogen cycling and plant growth. b) Chemolithotrophs: This option is correct. Chemolithotrophs are organisms, including certain bacteria and archaea, that can decompose a large number of organic compounds using inorganic substances as a source of energy. These organisms derive their energy from the oxidation of inorganic compounds, such as ammonia, nitrite, sulfur, iron, or hydrogen, rather than organic carbon sources. They are essential players in various biogeochemical cycles, such as the nitrogen, sulfur, and iron cycles, as they help decompose and recycle a wide range of organic compounds in the environment. c) Mycoplasma: Mycoplasma is a genus of bacteria that are characterized by their small size and lack of a cell wall. While they can cause various diseases in animals and plants, they are not typically associated with decomposing a large number of organic compounds. Mycoplasma species are more commonly known for their parasitic or pathogenic nature. d) Pseudomonas: Pseudomonas is a diverse genus of bacteria that includes many species capable of breaking down a wide range of organic compounds. They are well-known for their metabolic versatility and ability to degrade various complex organic molecules, such as hydrocarbons, aromatic compounds, and pollutants. Some Pseudomonas species are valuable in bioremediation, where they help clean up environmental contamination by breaking down harmful substances. In summary, the correct answer is b) Chemolithotrophs. These organisms can decompose a large number of organic compounds using inorganic substances as a source of energy. While Pseudomonas can also decompose organic compounds, chemolithotrophs have a broader ability to break down various organic substances using inorganic compounds for energy.