Hint: Lactic acid bacteria or LAB are a group of microorganisms that are involved in the production of lactic acid They are present in the substances of milk like curd, yoghurt, cheese, etc. They are mostly widely used in household conversion of milk to curd. They are also known to decompose plants and their products.
Complete Answer: Lactic acid bacteria are gram positive staining bacteria. They are generally rod shaped or sometimes spherical shaped bacteria. They are acidophilic. They are friendly bacteria present in different tissues of humans. They decompose milk and produce curd by coagulating the proteins in the milk. Thus, widely used in the dairy industry. They are used in the fermentation industry also to ferment certain substances such as cheese, yogurt etc. Even some types of beer and wine are made using fermentation of LAB. In probiotics i.e, giving microorganisms as supplements or in food for better health for humans, they are widely used. They are given to relieve symptoms of gastric trouble and irritable bowel Syndrome. In the fertilization of the crops also, lactic acid bacteria are used as they are found to solubilize phosphate, and nitrogen fixation on Citrus. Hence, for crop fertilization they can be used.
Note: Most commonly known Lactic acid bacteria is lactobacillus. Though there are many uses of the LAB, they also can cause some harmful effects in our body- they are known to cause the decaying of teeth by producing plaque. Hence, they are known as the oral bacteria that cause dental cavities.