Question

Discuss briefly the role of microbes in household products.

Answer 1

We use microbes or products derived from them everyday.

• Curd: Micro-organisms such as Lactobacillius and others commonly called lactic acid bacteria grow in milk and convert it into curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. The starter or inoculum contains millions of LAB, which at suitable temperatures multiply, thus converting milk to curd.
• Cheese: It is one of the oldest food item in which microbes were used. Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity is determined by the microbes used. For example, large holed Swiss cheese is ripened with the help of bacterium called Propionibacterium shermanii. Roquefort cheese are ripened by fungi Penicillium roqueforti.
• Bread: Bread is prepared from dough, which is fermented using Baker’s yeast (Saccharomyces cerevisiae). Puffed-up appearance of dough is due to production of $C{O}_2$ during fermentation. $C{O}_2$ gas along with ethyl alcohol evaporate during baking, making bread porous and soft.
• Dosa and Idli: The fermented preparation of rice and black gram, prepared by using bacteria.
• Toddy: A traditional drink of some parts of southern India, is made by fermenting sap from palm known as Caryota urens.
• Other foods: Microbes are also used to ferment fist, soyabean and bambo-shoots to make foods.