Can Milk be used as a Universal Medium for cell culture ?

Daily live of a biotechnologist deals with media preparation and cell culturing in general. Then many times a thought pop up in our mind why do we prepare so many media? What is it’s use ? Why can’t there be a single media for all? Can there be universal media?

source :- giphy.com

First we need to understand what is a media and why it is important ?

The most basic need of any living form on the earth is food and nobody can survive without it although some animals go in hibernation but they cannot live in that state for long.

Media provides this very need for the microbes ,so it is like a party hall full of food and nutrients for microbes and there next generations to grow and populate . In addition to that we provide them full space and ambient temperature to grow , it’s an ideal life for them .

But what is there eating buffet ?

we all have some favourite dish that we want to eat and some that we don't like on our plate. Microbes also behaves the same they do not eat everything and have some hot favourites while reject the other.

Let’s see more on what they eat in real?

1. Carbohydrates:- The main source of energy is carbohydrates and is added to culture media to increase the rate of growth of organisms in glucose.
2. Proteins/peptides/amino acids:-we all know that proteins is the building block of every organism and proteins are indeed made up of amino acids. Therefore it is basic need for their development and growth.

3. Essential metals and minerals:- Minerals like calcium, magnesium, iron, trace metals: phosphates, sulphates etc. are important for their growth too and required in different amounts. They are the

• macro-components (gm/litre): Na, K, Cl , P, S, Ca, Mg, Fe.
• micro-components (microgram/litre): Zn, Mn, Br, B, Cu, Co, Mo, V, Sr.

4. Vitamins :- Many vitamins are essential for growth and proliferation of cells. Vitamins cannot be synthesized in sufficient quantities by cells and are therefore important supplements required in tissue culture.

now we have a brief idea on the necessary food items they want.

Ideal Home Environment for Cells?

see cell also grow faster and healthier in their favourable conditions , They also want some luxury in their life and we provide cells with all the luxury that they want.

1. Buffer- It is important that the pH of a culture medium is poised around the optimum necessary for growth of the desired micro-organisms. eg:- phosphates, acetates etc. Some indicators are also used to check the exact pH of the media eg:- phenol red, bromo-cresol purple, fuchsin, etc. that change colours at critical pH values.
2. Controlled Temperature:- An ideal temperature for most of the cells would be around 37 deg Celsius. For this purpose have huge machines called the incubators.
3. Osmolarity:-is a measure of the osmotic pressure of a solution, it must be should be similar to the osmolality of the natural environment of the cells. eg:- 260 to 320 mOSM/kg. is the most used range of osmolarity in vertebrate cell lines.
4. Gel:-It mostly acts like the bed for microbes to grow. Agar gel is mostly used . Its inertness to microbial action, the unique setting and melting temperatures (38°C and 84°C respectively) the high gel strength which allows low concentrations of agar to be used, its clarity and low toxicity have contributed to its wide popularity with microbiologists. Its ability to retain its gel structure at 60°C makes agar of special value to culture media which have to be incubated at this temperature to isolate thermophilic organisms.

CONCLUSION

Milk is a highly nutritious growth medium for many microorganisms as it is rich in carbohydrates, fat, casein, protein, vitamins, and minerals and ticks all requirement but if asked the basic question as to why we need growth medium then , it is mostly for monitoring the growth of specific organism but if we use a universal medium every organism could grow in it and thus don’t satisfies the basic need of specificity :- we can’t use a universal media .

Yeasts, moulds and a broad spectrum of bacteria can grow in milk, particularly at temperatures above 16°C. But some microorganisms are unable to grow well in this medium when specific enzymes required for lactose metabolization process are lacking.

But an important point to remember , Raw milk does not undergo the pasteurization process to kill off potentially pathogenic bacteria, and therefore may pose the risk of food poisoning. as milk provides such a nutritious environment for bacteria to grow, pathogenic organisms can multiply rapidly in these medium.

Also store you milk in cold that will stop the growth of microbes and stay safe.