Evening star. [volume] (Washington, D.C.) 1854-1972, 1905-04-09
BENEFICIAL BACTERIA
THEME OF LECTURE BY MR.. GEO.
F. MOORE.
Germs Which Are Essential to Human
Life-Discoveries Made by
Scientists.

which are beneficial and often essential to
human life was shown in a lecture delivered
yesterday afternoon under the auspices of
the Biological Society at the National Mu-
scum, by Mr.. George f. Moore. pathofo-
gist in the Department of Agriculture.
President Knowlton of the Biological So
ciety introduced the speaker, announcing
as his subject. Beneficial Bacterial The
important results obtained by using cul-
lures of these beneficial bacteria on sterile
ground was largely the subject of the
lecture.
Dr. Moore opened his lecture by telling
of the immense strides that have been made
in the study and uses of bacteria since
twenty-five years ago, when the exist
ence of the minute organisms was not gem
orally believed. He pointed out also that,
like many other families, bacteria were
more widely known by their evil members,
but as matter of fact. however, the large
proportion of them are beneficial to the hui
man race. as in the dairy industry, when
the bacteria are responsible for the sour
cream; in fax refinement and in many
other industries.
Nitrogen and nitroles, he said were es-
sential to all life. Should the supply of
nitrogen give out, life would soon be-
come extinct. And yet only few years
ago scientists and students of the problem
estimated that there would be nitrogen
famine in forty or fifty years. In that time
the supply of saltpeter. the source OF the
nitrogen in the air would be exhausted and
plants could not draw any nitrogen from
the air. The earth is full of nitrates, but
in it's normal condition it would never pro-
duce nitrogen for plant life. piece OF
meat, although rich in heterogeneous matter.
would never get into such a form as to be
available to supply plant life. Scientists
hpn hoo tn in
what provision has been made to supply the
loss. Continuing he said:
Found in the Soil.
1T was found by students of the problem
that there existed in the soil certain bac-
terra, which had the power of fixing nitro
gen. For instance it was found that when
a field has been left unused for few
years it is found much richer in nitrogen
at the end of that period than at the be-
ginning. Only minute portions of nitrogen
could be brought down from the air. 1t
was due to bacteria in the soil itself. Plant
life must depend on these bacteria for ex-
iStence.
Independent of these. it was found that
clusters of bacteria We're often gathered
on the roots of plants, particularly of the
legume species. such as beans, peas, pea
nuts, etc. The knots have been called
nodules. In many cases the nodules have
been found very numerously and large In
we find it filled with many tiny organisms.
When magnified these assume the known
forms of bacteria common to certain dis
eases. OF course, it was long time be-
fore it was known just to what these
nodules were due, but it is now recognized
that they are due to bacteria which gather
on the roots of these plants. By further
experiments it was found that wherever
these nodules are present the plants grew
much more luxurously, even without the
use of fertilizer. Thorough tests of this
We're made by planting the legume roots
in baked sand, to which no heterogeneous
to provide the plant with nitrogen. The
experiments successfully and conclusively
proved the ability of the bacteria of the
nodules to fix nitrogen.
THE next problem to be met with was
how to get the nodule bacteria into the
soil. OF course, the natural way would be
to transfer some of the soil rich in the bac-
terra to the sterile field There are many
objections to this method, chief of which
is that. with the soil and bacteria there
will also be transferred plant diseases.
Thus some artificial way had to be provid-
ed. German professor sought to solve
the problem by cultivating the bacteria in
tubes of heterogeneous jelly and then dis
tributing this in the soil. But the plan was
not successful.
Experiments along this line by the De-
partment of Agriculture showed also that
these cultures, when added to the soil did
not produce nodule. The cultures had been
grown in substance rich in heterogeneous
matter, and it was the idea of the expert
mentors that it was easy for the starting
bacteria to get nitrogen that they got lazy
and would not work when put in the soil.
So cultures were made in nitrogen-free
media, thus compelling the bacteria to draw
all their nitrogen from the air. When these
cultures were added to the soil nodules
We're always produced. Thus the problem
was solved.
Bacteria in Commercial Form.
Next the department had to find some
means of getting the bacteria to the farmer
in some practical and commercial form. 1t
was found that the cultures when made
could be dried and would revive after a
year, and 1t is in the form of dried bacteria
that this new fertilizer is furnished to the
farmer. In order that the experiments
tons, packages of salts and other foods
for the bacteria are sent with the bacteria.
The contents of the government packages
are mixed in a gallon of water and with
this water the seed is wet. When sown it
carries the bacteria with 1t, that when
the roots begin the bacteria can produce
the nitrogen producing nodules."
Dr. Moore stated that out of 5000 reports
on experiments made last year so per cent
were favorable, the failures being due to dis
obeying directions or similar causes.
President Knowlton announced that the
next lecture in the course would be given
next Saturday, on Bruno. the Black Bear
"A Story of the North Woods" by William
Lyman Underwood.