The
major
interests
of
microbiologists
during
the
time
of
Pasteur
Were
the
characterization
of
infectious
agents,
study
of
immunity,
prevention
and
cure
of
diseases
and
the
analysis
of
chemical
activities
of
microorganisms.
During
the
20th
century,
microorganisms
have
contributed
a
great
deal
to
the
development
of
other
sciences
such
as
biochemistry,
genetics
and
in
general,
contemporary,
biology.
The
discovery
of
cell
free
alcoholic
fermentation
by
Buchner
was
the
beginning
of
the
use
of
micro
organisms
in
understanding
metabolic
processes.
A
few
years
later,
similarities
were
found
between
microbial
and
animal
nutrition.
Vitamins
required
in
traces
by
animals
were
found
to
be
chemically
identical
with
the
growth
factors
required
by
bacteria
and
yeast.
Detailed
study
of
the
role
of
these
growth
promoting
factors
(vitamins)
showed
their
indispensable
role
in
cell
metabolism.
