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7.1
Introduction
Microbes form the largest community of living organisms on the face of earth. They
are present in a wide range of places, from the gastrointestinal tract of animals to the
deepest sea vents, where complex life forms cease to exist. Presently, most of the
well-known commercial antibiotics, anticancer drugs, and industrial enzymes are
from microbes. Microorganisms have a genetic makeup that encodes a wide variety
of structurally diverse secondary metabolites which has led to the discovery of
many compounds of therapeutic potential. Work on microbes has fascinated
researchers for decades, and this fascination has only intensified in the recent years,
with evolving modern technologies taking the front seat in uncovering novel
microbes and their attributes. Microbes are omnipresent and can survive in a wide
range of environmental conditions and also give a helping hand to other organisms
to adapt to the stress in an environment in which they establish. This belief has
surged the interest in search for novel microbes in every corner on the face of earth
and the positive outcomes of such research studies have boosted this expedition to
continue for the many decades that are in store. Microbes are known to evolve more
efficiently than any other organism according to the demands of the environment or
in sync with the environmental stress factors. The evolution of modern medical
world and bio-based industries has a close association with the unicellular dynasty.
History stands proof that microbes have played a vital role in eradicating and controlling many human ailments and, at the same time, touching other arenas of agricultural and industrial importance. Biosynthesis of numerous valuable
pharmaceutical molecules, ranging from antibiotics; antitumor, anticancer, antiviral, antihypertensive, antiparasitic, antidiabetic, antioxidant, and immunological
agents; enzyme inhibitors; and hormones, now aids microbes as the smallest unit of
factories for mass production (Jeandet et al. 2013).
The search for drugs began late in the nineteenth century with the growing acceptance of the germ theory of disease. This has resulted in scientists putting a lot of
time and effort into searching for drugs that would kill pathogenic bacteria.
Alexander Fleming pioneered drug discovery from microbes way back in 1928,
when his Petri plate with Staphylococcus aureus was contaminated with a mold
leading to the inhibition of growth of the bacteria (Fleming 1929). The mold responsible for the action was Penicillium notatum which produced the component penicillin, which was later isolated, produced commercially, and was used as an antibacterial
agent during World War II. This work generated interest in naturally occurring substances, and research focused on finding more novel molecules was initiated. In the
early phase of microbial secondary-metabolite research, much focus was put on to
discover antimicrobials and enzymes. Later on, research organizations and pharmaceutical industries extended their search beyond antifungal, antibacterial, and antiviral agents and looked for therapeutic compounds that have value in other clinically
relevant diseases (Cardenas et al. 1998; Schwartsmann et al. 2002). The horizon of
microbial research spread out in search of immunosuppressants, anticancer drugs,
enzyme inhibitors, insecticides, antiparasitics, and other pharmacologically relevant
agents.
V.M. Dan and R. Sanawar
7.1
Introduction
Microbes form the largest community of living organisms on the face of earth. They
are present in a wide range of places, from the gastrointestinal tract of animals to the
deepest sea vents, where complex life forms cease to exist. Presently, most of the
well-known commercial antibiotics, anticancer drugs, and industrial enzymes are
from microbes. Microorganisms have a genetic makeup that encodes a wide variety
of structurally diverse secondary metabolites which has led to the discovery of
many compounds of therapeutic potential. Work on microbes has fascinated
researchers for decades, and this fascination has only intensified in the recent years,
with evolving modern technologies taking the front seat in uncovering novel
microbes and their attributes. Microbes are omnipresent and can survive in a wide
range of environmental conditions and also give a helping hand to other organisms
to adapt to the stress in an environment in which they establish. This belief has
surged the interest in search for novel microbes in every corner on the face of earth
and the positive outcomes of such research studies have boosted this expedition to
continue for the many decades that are in store. Microbes are known to evolve more
efficiently than any other organism according to the demands of the environment or
in sync with the environmental stress factors. The evolution of modern medical
world and bio-based industries has a close association with the unicellular dynasty.
History stands proof that microbes have played a vital role in eradicating and controlling many human ailments and, at the same time, touching other arenas of agricultural and industrial importance. Biosynthesis of numerous valuable
pharmaceutical molecules, ranging from antibiotics; antitumor, anticancer, antiviral, antihypertensive, antiparasitic, antidiabetic, antioxidant, and immunological
agents; enzyme inhibitors; and hormones, now aids microbes as the smallest unit of
factories for mass production (Jeandet et al. 2013).
The search for drugs began late in the nineteenth century with the growing acceptance of the germ theory of disease. This has resulted in scientists putting a lot of
time and effort into searching for drugs that would kill pathogenic bacteria.
Alexander Fleming pioneered drug discovery from microbes way back in 1928,
when his Petri plate with Staphylococcus aureus was contaminated with a mold
leading to the inhibition of growth of the bacteria (Fleming 1929). The mold responsible for the action was Penicillium notatum which produced the component penicillin, which was later isolated, produced commercially, and was used as an antibacterial
agent during World War II. This work generated interest in naturally occurring substances, and research focused on finding more novel molecules was initiated. In the
early phase of microbial secondary-metabolite research, much focus was put on to
discover antimicrobials and enzymes. Later on, research organizations and pharmaceutical industries extended their search beyond antifungal, antibacterial, and antiviral agents and looked for therapeutic compounds that have value in other clinically
relevant diseases (Cardenas et al. 1998; Schwartsmann et al. 2002). The horizon of
microbial research spread out in search of immunosuppressants, anticancer drugs,
enzyme inhibitors, insecticides, antiparasitics, and other pharmacologically relevant
agents.
V.M. Dan and R. Sanawar