Microbes in Human Welfare - Role and Uses

Can you imagine that you remain surrounded by trillions of ultra-minute organisms all the time? These are microscopic entities which are nearly invisible to your naked eyes. We refer to them as microorganisms. And since they are present almost everywhere, including the land you walk on, the water you drink, and the air you breathe; thus, they form a crucial component of the biological system.

We can categorize the microbes around us into two primary types- good microbes and bad microbes. This implies that neither all microbes are good nor all are harmful. Here, we will discuss about the microbes that don’t cause any infection in the human body but are helpful to us in one way or another.

Role of Microbes in Human Welfare

Microorganisms have the unique ability to survive in conditions where no other living entity could possibly exist. Some of them can tolerate temperatures as high as 1000^oC, extreme acidic pH, several snow layers etc. This ability makes them a potential candidate for producing materials that require harsh conditions.

The microbes actively contribute to every sector, from our houses to large-scale industries. Pharmaceutical, food and beverages, and sewage treatment plant exploit the microbial fauna to obtain the desired product. They play a significant part in environmental balance by serving the role of decomposers.

Also, microbes work as biofertilizers and biocontrol agents in the agriculture sector. The generation of biogas using microbes has proven to be one of the successful applications of the present era. Nowadays, microbes are extensively used in the research and development segment, for instance, in genetic engineering. Of the above-mentioned versatile nature, it is clear that the microbes are vigorously contributing to the welfare of the human race.

Microbes in Human Body

There is a variety of microbial fauna naturally existing inside the human body. Generally, they are present in the gut region, where they aid the proper breakdown of the food as well as other digestive actions.

One most common and essential gut bacteria are Escherichia coli (E. coli). They help in the proper digestion of the food and extraction of nutrients from it. They establish their colonies inside the gut in such a way that no harmful bacteria can occupy the space to grow. Also, E. coli produces B complexes inside the body, particularly vitamin B 12.

Bifidobacteria are also naturally occurring microbial fauna of the human body. Their location is mainly in the intestinal region. They function in the breakdown of the food particles left by the stomach digestion.
For this reason, they prevent the health issues like constipation and diarrhoea and keep your gut healthy. However, their only side effect is the production of gas while working. So, whenever you feel gassy, understand that Bifidobacteria is working properly.

Microbes in Household Products

The household products obtained by the use of microbes are curd, bread, toddy, cheese, etc. The most common example is milk comprising lactic acid bacteria (LAB) or Lactobacillus. This bacteria naturally exist in the milk and aids the curd formation. While growing, the LAB produces acid that coagulates or digests the milk proteins, transforming them into its healthier and nutritive version, i.e., curd.

The curd not only tastes well or is healthy, but also it acts as a probiotic, increasing the production of good bacteria in the stomach. It also facilitates the production of vitamin B 12.

Fermented food Items

The fermented food items like Idli, Dosa, Dhokla, bread, cheese etc., contain useful and healthy microbes.

Toddy

It is a traditional south Indian fermented drink made from fermented palm sap. The fermentation is carried out with the help of naturally occurring bacteria in palm sap.

Idli and Dosa

These fermented food items are light on your stomach and easily digestible. It is because of the healthy bacteria Leuconostoc. Leuconostoc naturally occurs in the batter made from rice and dal. The microbe will multiply itself, releasing carbon dioxide providing fluffy appearance to the batter.

Bread

Baker’s yeast, i.e., Saccharomyces cerevisiae, helps in the bread-making process. During bread making, yeast secretes three enzymes:

Amylase: Breakdown starch (amylose)
Maltase: Acts on Maltose sugar
Zymaze: Causes fermentation

These three enzymes break substrate material taken and release lots of CO₂ during digestion. Release CO₂ raises the dough, making it soft and fluffy. We refer to this process as leavening.

Cheese

A variety of cheese is available with different textures, colours, tastes and aromas. Some are hard, sour and grainy, while others are soft, bland and smooth. It relies on the type of microbial species as well as the type of substrate used.

Swiss Cheese: It comprises big holes produced due to the release of carbon dioxide gas during the fermentation. Bacteria named Propionibacterium sharmanii help in making swiss cheese.

Roquefort Cheese: Also known as blue cheese. A fungus Penicillium roquefortii produces this cheese using sheep milk as a substrate.

Microbes in Industrial Products

Currently, industries concerning fermented food, beverages, medicines etc., actively use microbes to manufacture products that are consumable to humans and valuable to industries. Such a large-scale production requires an equally large volume of microbial culture.

Organic Acids

Citric acid: Used as preservatives. Produced by Aspergillus niger.
Lactic acid: Helps in curdling of milk. Done by Lactobacillus.
Butyric acid: Produces rancid butter. Aided by Clostridium butylicum.
Gluconic acid: Acts as a calcium source for lactating mothers, including cows. Produced by Aspergillus.
Acetic acid: Also known as vinegar. Produced by Acetobacter acetii. Used as a preservative.

Fermented Beverages

Since ancient times, brewer’s yeast, i.e., Saccharomyces cerevisiae contributed to the preparation of several fermented beverages from fruits and malted cereals. Based on the fermentation process and the raw substrate used, you can categorize them as distilled and non-distilled.

Antibiotics

Antibiotics are the ones that cease the growth of infectious pathogens either by attenuating or killing them. In 1992, while working with the culture of streptococcus, Alexander Flemming noticed a green mould growing over the culture plate. This mould was secreting some chemical that inhibited the growth of bacteria. Later he concluded that the mould was Penicillium notatum and named the secretion as penicillin.

Several microbes contribute to antibiotic production:

Eubacteriales: Around 70% of them are obtained from Bacillus (B. subtilis–Bacitracin) and Pseudomonas species.
Fungi: Most common example is Penicillium (P. notatum, P. crysogenum).
Actinomycetales (Ramified): Includes Streptomyces, Micromonospora and Streptosporangium. S. griseus produces more than 40 types of antibiotics, such as Azithromycin, Chloramphenicol, Streptomycin etc.

Enzymes

Lipases: The lipases are used in detergents and soaps against the lipids. Extracted from Candida lipolytica and Geotrichum candidum.
Amylases: Helps in amylose digestion. Produced by Rhizopus, Aspergillus and Bacillus.
Streptokinases: Used rarely as a clot buster in blood vessels. Produced by Streptococcus.
Pectinases and Proteases: Used as a clearing agent in juices and beverages. Obtained from Byssochlamys fulvo, Aspergillus niger, and some Bacillus species.

Microbes in Biofuel Production

Biofuels are those renewable fuel materials obtained from biomass over a short span. They are very effective in curbing the pollution problems due to the combustion of fossil fuels.

Biogas and ethanol are the most successful biofuels obtained by using microorganisms.

Ethanol Production

Ethanol is produced by using the edible parts of the plants as a raw substrate. It may involve sugar cane, kernels, sugar beets etc. . The sugar (mainly glucose) gets broken down or fermented during the production process by microbial culture. The process is aided by Saccharomyces cerevisiae culture. The yeast consumes the sugar particles and releases ethanol as a by-product.

Microbes in Biogas Production

Biogas is one of the most common biofuels used around us. Biogas is actually a mixture of various gases such as methane, carbon dioxide, hydrogen sulphide, and carbon monoxide. Aerobic combustion of these gases releases energy which is used as a biofuel.

Biogas production involves the anaerobic breakdown of organic matter by using microbes. Bacteria involved in this process are methanogens. Examples of some methanogens are methanococcus, methanobacillus, methanobacterium etc.

They can be found in the rumen part of cattle stomach and are excreted as dung (cattle excreta). Thus, cattle dung is ideal for biogas production as it contains plenty of methanogens.

Microbes as Biocontrol Agents

The use of chemical pesticides, weedicides and insecticides has led to the degradation of soil quality. They kill both harmful and useful organisms. Using microbes as biocontrol agents is a natural method to get rid of pests and insects via conventional predation.

For instance, Baculoviruses are excellent biocontrol agents. It only attacks arthropods and causes no harm to other useful organisms.

Similarly, Bacillus thuringiensis is a bacteria cable of killing caterpillars and insect larvae.

Fungus Trichoderma in the plant’s root helps control many plant pathogens.

Microbes as Biofertilizers

The excessive use of chemical fertilizers in the last few years is responsible for land pollution and soil destruction. Thus, nowadays, professionals highly emphasize on the use of natural fertilizers.

Cyanobacteria, fungi, and bacteria are the microbial sources of biofertilizers.

For instance, Rhizobium bacteria naturally occurs in the root nodules of leguminous plants. It fixes the atmospheric nitrogen, thereby enhancing the soil’s nitrogen content. Similarly, Azotobacter and Azospirillum are also free-living nitrogen-fixing bacteria of the soil.

Cyanobacteria like Anabaena, Nostoc, Oscillatoria etc., also help fix nitrogen.

The fungal association in roots, i.e., mycorrhiza, benefits the soil by enhancing its nutrient content.

Frequently Asked Questions (FAQs)

Q. Why the concept of biofertiliser is not very popular?
The main reason behind this is unawareness, lack of technological advancement, financial issues etc.

Q. Why do we distil a few fermented drinks?
The distillation of the fermented drinks makes them more concentrated.

Q. Is it possible to use microbes as an energy source?
Yes, some of them are consumable with very high nutritional value. For instance, spirulina, a single cell protein, is an excellent source of multiple nutrients.

Q. Which enzyme is present in the detergents and soaps that help remove stains? Do microbes produce them?
The detergents and soaps contain lipase enzymes that work against the oils and lipids and remove the stains. And yes, microbes like Geotrichum candidum and Candida lipolytica are its good sources.