MICROBES IN HUMAN WELFARE

Microbes can be any organisms which are smaller in size and that are invisible to the naked eyes since the size is 0.1 millimeter or maybe less than that

We can only see them under the microscope

The inhabitants in soil and all types of water and almost are present everywhere including the air the dust particles outside of a body etc

Microbes can come under various groups of organisms such as bacteria protozoa fungi etc

Most of the microbes can be grown artificially on a culture media such as Agar

Under God they will exist as colony and colony can be seen without the microscope with our naked eyes, we have mostly studied microorganisms with respect of infection and as a causative agent of various diseases but there are some microorganisms which can be beneficial to the human and they can help human to acquire or to produce very useful and indeed important products which can be used for the personal use of human

In this chapter we are going to talk about the microorganisms which are very much important for the processes that are useful in homes, industries, agriculture and sewage treatment.

I.                    Microbes in household products

a.       Dairy products: we are almost familiar with a bacteria called Lactobacillus species which belongs to a group called lactic acid bacteria we are usually added to milk and there is a sugar present in the milk called lactose sugar which is converted into lactic acid by these bacteria. This lactic acid produced by Lactobacillus causes coagulation or aggregation of the milk protein named Casein. This acid is reason for the curdling of milk. The lactic acid bacteria is present in inoculum or starter used in production of curd or cheese or yogurt

                                                               i.      Curd: In India the curd is prepared by mixing or inoculating skimmed and cream milk the small portion of Lactobacillus acidophilus. The bacteria require somewhere around 40⁰ C as its environmental temperature. if you see the nutritional value of curd, it has lots of organic acids as well as vitamins which also includes B12. curd is believed to improve the digestive system

 

                                                             ii.      yoghurt: yoghurt is prepared from the milk by curdling it with the help of Streptococcus thermophilus and lactobacillus bulgaricus these are the two strains used for preparation of yoghurt. yogurt contains the flavour of lactic acid and acetaldehyde

 

                                                           iii.      buttermilk: it is prepared with the help of inoculation of Streptococcus cremoris, lactobacillus acidophilus

                                                           iv.      Cheese: one of the oldest milk products in which microbes are employed to produce commercially. Whey from milk is used to prepare the cheese. There are several varieties of cheese present all over the world. Few are mentioned below:-

1.       Swiss cheese is made with help of Propionibacterium sharmanii

2.       Roquefort cheese is produced with the microbe called Penicillium roqueforti ( a fungus)

3.       Camembert cheese employes Penicillium camemberti.

b.       Bread : Baker’s yeast which is nothing but Saccharomycese cerevisiae which is added to the flour and kneaded.  Left for few hours which causes the flour to swell up due to production of carbon dioxide gas by Yeast. This phenomenon is referred as leavening. Enzymes like maltase, amylase and zymase are responsible for leavening

c.       Dosa uppma and idli are also prepared  by fermentation where the airborne bacteria like Leuconostoc , Streptococcus sp.  Plays the crucial role

d.       Toddy: it’s a traditional drink of some parts of South India. It’s prepared by fermentation of sap from the palm trees. It can be fermented using yeast to form a beverage which can have up to 6% of alcohol

e.       Probiotics : These are certain types of heath drinks which has live bacteria or yeast. These microbes can provide useful products to the gut and help creating good environmental condition in gut by overcoming harmful bacteria.

They include microbes like – Lactobacillus sp, Streptococcus sp, Bacillus subtilis, Bifidibacterium bifidum Saccharomyces boulardii

 

II.                   MICROBE IN INDUSTRIES

In industries microorganisms are grown in a large vessels called as fermenters. Going to discuss in this chapter about the commercial production of numerous alcohol drinks chemicals and antibiotics

Fermented beverages

                Saccharomyces cerevisiae which is also called as Brewer’s yeast, has been used from the olden times for preparation of alcoholic drinks from the malted cereals and fruit juices.

Various types of drinks are made based on the raw material and the fermentation techniques used for example without distillation wine and beer and with distillation whiskey rum and Brandy is prepared.

Antibiotics and vaccines

·         The first antibiotic which was synthesized was penicillin

·         The antibiotic was discovered by Alexande Flemming in a fungus named Penicillium nonatum

·         It was extracted and developed by Howard Florey and Ernest Chain

·         During World War II, it was used for treating American troops. For their research, in 1945, Florey, Chain and Fleming won the Nobel Prize. 

Various antibiotics and their sources are listed below

ANTIBIOTIC	SOURCE MICROBE	DISEASE TREATED
Bacitracin	Bacillus subtilis	Syphilis, Reticulosis, or Lymphonema
Streptomycin	Streptomyces griseus	Meningitis, Tuberculosis, Pneumonia, and Local Infection
Chloromycetin	Streptomyces venezuelae	Typhoid
Erythromycin	Streptomyces erythreus	Diphtheria, Typhoid, Whooping cough
Gentamicin	Micromonospora purpureae	Works well against Gram (+) bacteria
Tetracycline	Streptomyces aureofaciens	Urinary and intestinal tract infections, acne, and conjunctivitis

 

• At present day there are varieties of synthetic antibiotics produced. 
• Vaccines are simply weak or attenuated part of the disease causing pathogen and usually used to elicit the immune response in an individual
• Edward Jenner created the very first smallpox vaccine.
• Several vaccines are produced for viral diseases. The common example are Polio, Measles, DPT, Pneumococcal, Hepatitis-A and B, Influenza etc

Chemicals and Enzymes 

Plenty of organic acids and chemicals are formed using microorganisms. Examples include: 

·         Citric acid:  the source organism is Aspergillus niger. Citric Acid is used as a flavoring agent and preservative in food products. In products like beverages, soft drinks, Citric Acid can be found. It is also used in making candies due to its sourness

• Acetic acid: Acetobacter aceti is the source organism. Used to prepare vinegar in food industries. Used in Photographic films and textiles
• Lactic acid: Lactobacillus is the source Microbe. It is also used for the synthesis of lactic acid polymers that are recently being used as biodegradable plastics.
• Butyric acid: The source organism is Clostridium butylicum.  Important raw material in the manufacture of esters of lower alcohols which are used as flavouring agents
• Ethanol: Saccharomyces cerevisiae source organism for ethanol synthesis commercially. Ethanol is used as solvent.Used in medicine preparation and drug manufacturing. Used as disinfection agent. Used as a feul additive (gasohol)

Enzymes are usually formed by microorganisms and can be utilized for different purposes at the commercial level.

·         For instance, Streptococcus synthesises an enzyme called streptokinase that can be used to eliminate clots from the blood vessels. It is sort of clot buster

·         Lipases: Enzymes that can digest lipids, are used in detergents and oily stain removal processes.

·         Proteases and pectinases: These enzymes are used for the clarification of bottled juices.

·         Several bioactive molecules are developed and can be used for different purposes. 

·         Cyclosporin A: It is obtained from the Trichoderma polysporum (fungus). It is an immune system suppressor, widely used in patients with organ transplants so that there immune system won’t identify any foreign organ. 

·         Statins: They are made with Monascus purpureus (yeast). It reduces cholesterol levels in the blood by inhibiting cholesterol synthesis.

III. Microbes in Human Welfare - Sewage Treatment

Till the time of disposal it is important to monitor the wastewater, as it contains organic matter and pathogenic harmful bacteria. To achieve this, sewage treatment plants (STPs) are used. Microbes (heterotrophic) that are naturally found in sewage water are utilized.

Primary treatment: First step is to carry out Filtration and sedimentation to expel floating debris and grit, that is, soil and small pebbles, respectively. Primary sludge is the solid which settles down, and the supernatant liquid is the primary effluent.

Secondary treatment: it's far every now and then known as biological treatment. In wide aeration tanks, the increase of aerobic microbes is stimulated by way of mechanically agitating the effluent and pumping it into the air. This reduces the want for biochemical oxygen demand for (BOD). BOD represents the rate of microorganisms taking over oxygen and suggests the organic count content material located in the sample.

            The effluent is authorized to build up inside the settling tank after a extensive reduction of BOD. The sediment of bacterial flocs (bacterial mass developing a mesh-like structure in aggregate with fungal filaments) and is classed as activated sludge.

           The activated sludge is digested right into a digester with anaerobic sludge. This allows a number of the sludge to transfer back to the aeration tank and acts as inoculum. Biogas (a combination of gases released from digested sludge, like methane, CO2, and H2S) can be used as fuel. 

            The secondary effluent is poured into ponds and waterways. by pouring handiest filtered wastewater into them, our rivers can be stored much less polluted. To end this, the Government has released the action plan for the Ganga and Yamuna.

IV. MICROBES IN THE PRODUCTION OF BIOGAS 

Biogas is a mixture of gases (containing predominantly methane) produced by the microbial

activity. Certain micro organism grow anaerobically on cellulosic components and produce large

amount of methane along with CO2 and H2 which are collectively called as methanogens.

     One common methanogen is Methanobacterium

These bacteria are commonly found in the anaerobic sludge during sewage treatment and in the rumen of cattle to digest cellulose in the food of the cattle , thus the excreta of cattle, commonly called gobar can be used for generation of biogas, commonly called gobar gas.

Biogas plant

·  The biogas plant consists of a concrete tank (10-15 feet deep) in which bio-wastes are collected and a slurry of dung is fed.

·  A floating cover is placed over the slurry, which keeps on rising as the gas is produced in the tank due to the microbial activity.

·   The biogas plant has an outlet, which is connected to a pipe to supply biogas to nearby houses.

·   The spent slurry is removed through another outlet and may be used as fertilizer. o The biogas thus produced can be used for cooking and lighting.

·   IARI (Indian Agricultural Research Institute) and KVIC (Khadi and Village Industries Commission) put a great deal of effort into advancing biogas technology.

 

V. Biocontrol of Diseases and Pests

• Chemical pesticides and insecticides destroy species which are both dangerous and useful. A appropriate method of biocontrol may be established by using and implementing the natural predation and interacting networks.

• Ladybugs and dragonflies help to combat mosquitoes and aphids.

• Bacillus thuringiensis is used for the care of insect larvae and caterpillars. several plant life can be genetically engineered, and the toxin coding gene may be inserted into the plant genome. for instance, Bt-cotton is pest-resistant.

• Trichoderma (a fungus) is used for biocontrol of various pathogens on plants. The fungus generally habitats within the roots.

• Nucleopolyhedrovirus genus baculoviruses are exceptional agents of biocontrol. Arthropods are targeted, however they are harmful to vegetation and different species like birds, fish, and mammals. 

VI. Biofertilizers

• The overuse of chemical fertilizers is associated with contamination and adverse effects. it's far strongly recommended to use the microorganisms as biofertilizers.

• The primary sources of biofertilizers are fungi, bacteria, and cyanobacteria.

• The root nodules of leguminous plants produce rhizobium. They update or replace nitrogen inside the surroundings. alternatively growing leguminous flowers assist to growth soil nitrogen content material.

• Azotobacter and Azospirillum are nitrogen-fixing, free-living bacteria found in the soil.

• The mycorrhizal fungal association also enriches soil nutrient content. For the plant, Glomus genus fungi devour phosphorus.

• Such symbiotic relationships benefit not only from enriching the nutrient content but also from resistance to disease and tolerance to drought and salinity.

• Some cyanobacteria can absorb nitrogen from the atmosphere. These include Nostoc, Anabaena, and Oscillatoria. Cyanobacteria are normally used as a biofertilizer in paddy-fields. Blue-green algae are autotrophic in marine and terrestrial ecosystems and are observed everywhere. with the aid of adding natural count number, they raise the fertility factor of the soil.