Which of the following statements is incorrect?

Methanogens are found in the human intestine and aid in the digestion of fibrous components of food.

The correct answer is Option (1) - Methanogens are not present in the human intestine.

They are present in the guts of ruminant animals, such as cattle, sheep, and goats. They also exist in some other anaerobic environments, such as swamps, marshes, and sewage treatment plants.

The other statements are all correct.

Methanobacterium and other rumen bacteria produce enzymes called cellulases, which can break down cellulose into simpler sugars that can be further metabolized by the microorganisms in the rumen. The breakdown of cellulose by these bacteria is a crucial step in the digestion of plant material.

Methanogens play a significant role in the digestion and nutrition of cattle. Methanogens are a type of microorganism that inhabit the rumen, a specialized chamber in the digestive system of ruminant animals such as cattle. Methanogens, along with other rumen microorganisms, contribute to the breakdown of complex carbohydrates into simpler molecules that can be absorbed and utilized by the animal. This symbiotic relationship between cattle and methanogens allows ruminants to derive energy from plant material that is otherwise indigestible for many other animals.

The excreta (dung) of cattle, commonly referred to as gobar, contains a significant amount of bacteria, including methanogenic bacteria. These bacteria are responsible for the production of biogas, which is commonly known as gobar gas.