Microbial Diversity: Its Exploration and Need of Conservation - Applied Environmental Biotechnology: Present Scenario and Future Trends - page 44

considered in ecology. A number of major experi-
ments have recently shown that declining plant
diversity may impair plant biomass, primary
production and nutrient retention, and so many
ecosystem properties. Presently, the relationship
between biodiversity and ecosystem function-
ing in ecological and environmental sciences has
emerged as a central issue. Microorganisms are
invisible, less familiar and apparently considered
primarily as agents of disease and these may be
the few reasons for ignoring their management.
However, few experiments have directly
tested the consequences of changing the diver-
sity of ecosystem components other than plants,
and simultaneously manipulated the diversity
of primary producers (algae) and decomposers
(bacteria) in aquatic microorganisms and found
complex interactive effects of algal and bacte-
rial diversity on algal and bacterial biomass pro-
duction. Both algal and bacterial diversity had
significant effects on the number of the carbon
source used by bacteria, suggesting nutrient
cycling associated with microbial exploitation
of organic carbon source as the link between
bacterial diversity and algal production. There
are several explanations but the exact theory is
greatly missing.
Producers and decomposers are the two key
functional groups that form the basis of all eco-
systems interactions. Obviously, their diversity
might have major consequences on the function-
ing of ecosystems. Thus, it is now generally ac-
cepted that the extent of microbial diversity has
not been adequately characterized and there is a
huge mismatch between the knowledge of that
diversity and its importance in both ecosystem
process and economic development. Soil qual-
ity has been defined as the capacity of the soil
to function within ecosystem limitations to sus-
tain biological productivity, maintain environ-
mental quality, and promote plant and animal
health. Nutrient immobilization by decomposers
and competition for inorganic nutrients between
plants and decomposers are known to occur, but
at equilibrium, the two functional groups must
be limited by different factors in order to allow
their consistence and ecosystem persistence. Mi-
crobial diversity is an unseen national resource
that deserves greater attention. It is too small to

be seen and studied or valued. Microbial diver-
sity includes the spectrum of variability among
all types of microorganisms (bacteria, fungi, vi-
ruses, and many more) in the world and is greatly
changed by human intervention. Microorgan-
isms are the ubiquitous custodians of the Earth
occurring in all climate areas including Arctic
and Antarctic, the heat of geysers etc. They are
decomposers, converting nutrients in the organic
wastes from dead organisms into molecules that
are reused within ecosystems.

4.2 Microbes: Necessity of Life

Conserving microbial diversity will often, in
a practical sense, equate to the conservation of
the ecosystem microbial gene pool. From a ra-
tional point of view, the conservation of the gene
pool and microbial diversity itself equates to the
conservation of the physical and chemical con-
ditions within an environment that best support
the indigenous microbiota. Figure 4.1 clearly de-
picts the relationship between various microbial
species.

Extremophile Life Forms Majority of life
forms found in extreme environmental conditions
are microbes. These extreme physico-chemical
conditions may be pH, heat, salinity, pressure,
radiation, etc. These microbes can be character-
ized by using r-RNA comparative sequencing
technology. These microbes may be capable of
producing a wide array of enzymes in extreme
conditions which may be used in various indus-
trial applications such as lipase, protease, DNA
polymerase, etc (Tripathi et al. 2007 ). These
microorganisms hold many secrets such as
genetic instructions which make them able to
produce these enzymes in extreme conditions.

4.3 What Are the Drivers Causing

Decrease of Microbial
Biodiversity

The diversity of microscopic life forms (includ-
ing viruses, archaea, bacteria, and small eukary-
otic microorganism) are recently coming to light,