The correct answer is: B. Tanning of leather
Bacteria are not involved in the tanning of leather. Tanning is a process of converting animal skin into leather. It involves a series of steps, including removing the hair and fat from the skin, treating it with a tanning agent, and drying and finishing it. The tanning agent is typically a natural substance, such as tannins from tree bark or oak galls, or a synthetic substance, such as chromium salts. The tanning agent helps to convert the skin into a durable material that can be used to make shoes, bags, furniture, and other items.
A. Sewage disposal is a process of treating wastewater so that it can be safely returned to the environment. It involves a series of steps, including screening, grit removal, primary treatment, secondary treatment, and disinfection. Bacteria are involved in the secondary treatment of sewage. In secondary treatment, bacteria break down organic matter in the wastewater. This helps to reduce the amount of pollutants in the wastewater.
C. Ripening of cheese is a process that involves the growth of bacteria on the surface of the cheese. These bacteria help to give cheese its characteristic flavor and texture. The type of bacteria that grows on cheese depends on the type of cheese and the conditions in which it is stored. For example, cheddar cheese is typically ripened with a strain of bacteria called Lactococcus lactis.
D. Preparation of silage is a process of preserving green forage crops for later use. It involves chopping the forage, packing it into a silo, and allowing it to ferment. Bacteria are involved in the fermentation process. These bacteria convert the sugars in the forage into lactic acid. This helps to preserve the forage and make it more digestible for livestock.