This document provides an introduction to microbiology, including: 1. Microbiology is the study of microorganisms like bacteria, fungi, algae, protozoa, and viruses. These microbes can survive in many environments and have high adaptability. 2. The field involves studying microbes' structure, reproduction, metabolism, classification, effects on other organisms, and reactions to physical/chemical agents. It can be divided into areas like bacteriology, mycology, and virology. 3. Important developments include Antony van Leeuwenhoek first observing microbes in 1674 using self-made microscopes and later researchers like Pasteur and Koch discovering causative agents of diseases and

1. Pharmaceutical
Microbiology &
Biotechnology-I
Introduction and scope
of Microbiology
Vishvajitsinh Bhati

2.  Microbiology is the — ‘scientific study of the
microorganisms’.
In fact, microorganism invariably refers to the minute
living body not perceptible to the naked eyes, especially a
bacterium or protozoon.
 Microbiology is the specific branch of ‘biology’
that essentially deals with the elaborated investigation
of ‘microscopic organisms’ termed as microbes, that
are composed of only one cell. These are typically
either unicellular or multicellular microscopic
organisms that are distributed abundantly both
in the living bodies of plants and animals and also in the air,
water, soil, and marine kingdom.
 Interestingly, each and every microbe essentially
bear both specific and special characteristic features
that enable it to survive adequately in a wide spectrum
of environments, such as : streams, ponds, lakes,
rivers, oceans, ice, water-bornepipes, hot-springs,
gastro-intestinal tract (GIT),roots of plants, and even
in oil wells. In general, the microorganisms are usually

3. characterized by very typical and extremely high
degree of adaptability. Microbes are invariably
distributed over the entire biosphere, lithosphere,
hydrosphere, and above all the atmosphere.
 One may also define microbiology as — ‘the
study of living organisms of microscopic size, that
include essentially bacteria, fungi, algae, protozoa and
the infectious agents at the very borderline of life
which are broadly known as viruses.
 It is mainly concerned with a variety of vital and
important aspects, such as : typical form, inherent
structure, reproduction, physiological characteristics,
metabolic pathways (viz., anabolism, and catabolism),
and logical classification. Besides, it includes the study
of their :
• Distribution in nature,
• Relationship to each other and to other living organisms,
• Specific effects on humans, plants, and animals, and
• Reactions to various physical and chemical agents.
The entire domain of microbiology may be judiciously sub-
divided into a plethora of diversified,

4. well-recognized, and broadly accepted fields, namely :
Bacteriology : the study of organism (bacteria),
Mycology : the study of fungi,
Phycology : the study of algae,
Protozoology : the study of protozoans, and
Virology : the study of viruses.
 Advantages : The advantageous fields of
microbiology are essentially the ones enumerated
below :
1. Aero-Microbiology — helps in the overall
preservation and preparation of food, food-pronediseases,
and their ultimate prevention.
2. Beverage Microbiology — making of beer, shandy,
wine, and a variety of alcoholic beverages e.g., whisky,
brandy, rum, gin, vodka. etc.
3. Exomicrobiology — to help in the exploration of life
in the outerspace.
4. Food Microbiology — making of cheese, yogurt.
5. Geochemical Microbiology — to help in the study of
coal, mineral deposits, and gas formation, prospecting the

5. deposits of gas and oil, coal, recovery of minerals from low-
grade ores.
6. Industrial Microbiology — making of ethanol, acetic
acid, lactic acid, citric acid, glucose syrup, high-fructose
syrup.
7. Medical Microbiology — helps in the diagnostic
protocol for identification of causative agents of various
human ailments, and subsequent preventive measures.
8. Pharmaceutical Microbiology — making of life-
saving drugs, ‘antibiotics’ e.g., penicillins,
ampicillin, chloramphenicol, ciprofloxacin, tetracyclines,
streptomycin.
9. Soil and Agricultural Microbiology — helps in the
maintenance of a good farm land by
keeping and sustaining a reasonable and regular presence of
microbes in it.
10. Waste-Treatment Microbiology — treatment of
domestic and industrial effluents or wastes
by lowering the BOD and COD.
 Disadvantages : The apparently
disadvantageous and detrimental manner whereby the

6. microorganisms may exhibit their effects are, namely
disease-producing organisms viz., typhus fever caused
by Rickettsia prowazekii, malaria caused by
Plasmodium falciparum ; food-spoilage microbes ; and
a host of organisms that essentially deteriorate
materials like optical lenses (in microscopes and
spectrophotometers), iron-pipes, and wood filings.
HISTORICAL DEVELOPMENT OF
MICROBIOLOGY
The Microscope :-
 The evolution of microscope gathered momentum
in the year 1674, when a Dutch cloth merchant Antony
van Leeuwenhoek first of all had a glimpse at a drop of
lake-water via a lens made of glass that he had ground
himself. Through this simple device using a
magnifying lens Leeuwenhoek first and foremost ever
had an ‘amazing sight’ of the most fascinating world
of the microbes.
 Later on, Leeuwenhoek critically and explicitly
described the finer details of a plethora of

7. microorganisms viz., protozoa, algae, yeast, and
bacteria to the august Royal Society of London (UK)
in a series of letters. It is worthwhile to mention here
that the entire description was so precise and accurate
that as to date it is now quite possible to assign them
into each particular genera without any additional
desription whatsoever.
 The earlier observations of microorganisms were
made duly by several researchers chronologically as
given below :
 Roger Bacon (1220–1292): first ever postulated
that a disease is caused by invisible living
creatures.
 Girolamo Fracastoro (1483–1553) and Anton von
Plenciz (1762) : these two reseachers also
made similar observations, assertions, and suggestions but
without any experimental concrete evidences/
proofs.
 Athanasius Kircher (1601–1680) : made reference
of these ‘worms’ that are practically invisible the
naked eyes and found in decaying meat, milk,
bodies, and diarrheal secretions. Kircher was, in fact,

8. the pioneer in pronouncing the cognizance and
significance of bacteria and other microbes in
disease(s).
 Antony van Leeuwenhoek (1632–1723): initiated
the herculian task of ‘microscope making’ through
his inherent hobby of ‘lens making’. During his
lifespan stretching over to 89 years he meticulously
designed more than 250 microscopes ; of which the
most powerful one could magnify about 200-300
times only. However, these microscopes do not have
any resemblance to the present day ‘compound light
microscope’ that has the ability to even magnify
from 1,000-3,000 times.

9.  JOHN TYNDALL (1820 – 1893) In 1876
discoveredthat there were two different types of
bacteria.
a) Heatsensitive or heat labile forms (vegetativecells)
easilydestroyed by boiling
b) Heat resistanttypes known as an endospore Tyndall
demonstratedthat alternateprocess of heating &
cooling if repeatedfive times,can kill all the
endospores.
This is known as Sterilizationprocess or Tyndallization
Pharmaceutical Microbiology
 The remarkable and spectacular breakthroughs
accomplished by Pasteur, Koch, Jenner, and a host of
others more or less paved the way towards several
miraculous discoveries in curing fatal and dreadful
human ailments thereby minimising their immense

10. sufferings. Many meaningful and wonderful researches
also led to the discovery of a good number of causative
agents of diseases and altogether newer techniques for
diagnosis, which ultimately rendered the diagnosis of
these ailments rather rapid and precise.