● Microbes are present `color{Violet}"everywhere"` – in soil, water, air, inside our bodies and that of other animals and plants.

● They are present even at sites where `color{Violet}"no other life-form"` could possibly exist–sites:
`star` Deep inside the `color{Violet}"geysers"` (thermal vents) where the temperature may be as`color{Violet}"high"` as 100 degree C

`star` Deep in the `color{Violet}"soil"`

`star` Under the `color{Violet}"layers of snow"` several metres thick

`star` In highly `color{Violet}"acidic environments"`.

● Microbes are `color{Violet}"diverse"`–protozoa, bacteria, fungi and microscopic plants viruses, viroids and also prions that are proteinacious infectious agents.

● Microbes like `color{Violet}"bacteria"` and many `color{Violet}"fungi"` can be grow on `color{Violet}"nutritive media"` to form `color{Violet}"colonies"`, that can be seen with the `color{Violet}"naked eyes"`.

● Such `color{Violet}"cultures"` are useful in `color{Violet}"studies on micro-organisms"`.

● A common example in households is the production of `color{Violet}"curd from milk"`.

● Micro-organisms such as `color{Violet}"𝘓𝘢𝘤𝘵𝘰𝘣𝘢𝘤𝘪𝘭𝘭𝘶𝘴"` and others commonly called `color{Violet}"lactic acid bacteria (LAB)"` grow in milk and convert it to curd.

● During growth, the `color{Violet}"LAB produce acids"` that `color{Violet}"coagulate"` and partially digest the `color{Violet}"milk proteins"`.

● A small amount of curd added to the fresh milk as `color{Violet}"inoculum or starter"` contain `color{Violet}"millions of LAB"`, which at suitable temperatures multiply, thus converting `color{Violet}"milk to curd"`.

● It also improves its `color{Violet}"nutritional quality"` by increasing vitamin `B_12`.

● In our `color{Violet}"stomach"` too, the LAB play very beneficial role in `color{Violet}"checking"` `color{Violet}"disease causing microbes"`.

● The `color{Violet}"dough"`, which is used for making foods such as dosa and idli is also `color{Violet}"fermented by bacteria"`.

● The `color{Violet}"puffed-up appearance"` of dough is due to the production of `CO_2` gas.

● Similarly the dough, which is used for making `color{Violet}"bread"`, is fermented using baker’s yeast (`color{Violet}"𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴 𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦"`).

● A number of `color{Violet}"traditional"` drinks and foods are also made by `color{Violet}"fermentation"` by the microbes.

● `color{Violet}"Toddy"`, a traditional drink of some parts of `color{Violet}"southern India"` is made by fermenting `color{Violet}"sap from palms"`.

● Microbes are also used to `color{Violet}"ferment fish"`, `color{Violet}"soyabean"` and `color{Violet}"bamboo shoots"` to make foods.

● `color{Violet}"Cheese"`, is one of the oldest food items in which microbes were used.

● Different varieties of cheese are known by their `color{Violet}"characteristic texture"`, `color{Violet}"flavour and taste"`, the specificity coming from the microbes used.

● For example, the `color{Violet}"large holes"` in `color{Violet}"Swiss cheese"` are due to production of a large amount of `CO_2` by a bacterium named `color{Violet}"𝘗𝘳𝘰𝘱𝘪𝘰𝘯𝘪𝘣𝘢𝘤𝘵𝘦𝘳𝘪𝘶𝘮 𝘴𝘩𝘢𝘳𝘮𝘢𝘯𝘪𝘪"`.



● The `color{Violet}"Roquefort cheese"` are ripened by growing a specific fungi on them, which gives them a `color{Violet}"particular flavour"`.

● Even in industry, microbes are used to synthesise a `color{Violet}"number of products"` valuable to human beings.

● `color{Violet}"Beverages"` and `color{Violet}"antibiotics"` are some examples.

● Production on an `color{Violet}"industrial scale"`, requires growing microbes in very large vessels called `color{Violet}"fermentors"`.