The Glenwood post., 1909-09-11

Typical Lactic Acid Bacteria.
the milk with the hair, bits of feces
and dust that fall into the milk in
the barn.
Milk is an excellent medium for the
growth of Tactic acid bacteria, and un
der favorable temperature conditions
they multiply with astonishing rapid
ity.
The acidity of the milk is SO close
ly connected with the life processes of
this group of bacteria that it may be
taken as rough measure of their de-
velopment. The acid, as fast as it is
formed, unites chemically with the
casein, which exists as very fine par
ticles suspended in the milk serum.
When the acid reaches certain per
cent. the acid casein is precipitated
and the milk is said to have "curdled"
of "clabbered" This result may be
fastened by heating II milk or cream
that is slightly sour is added to hot
coffee, or is otherwise heated, 1t cur
dies
Milk which has undergone a strict
curd, free from gas bubbles and with
small amount of whey on the sur
face. When shaken the curd breaks
up into small particles which settle
slowly, leaving clear whey. The milk
should have pleasant acid taste. So
far as is known, none of the products
of the bacteria of this group Is of a
poisonous nature.
Some of the bacteria commonly
classed with Tactic acid bacteria form
acids other than Tactic, together with
large quantities of gas. Milk curdled
by bacteria of this class shows gas
bubbles and has disagreeable taste.
The Tactic acid bacteria not only are
able to grow In an acid medium, but to
a certain point the acid is favorable
influence. Many bacteria however,
find the acid detrimental to their de-
velopment and are not able to grow
long in milk in competition with lac
tic acid bacteria When the milk be-
gins to taste sour the growth of nearly
all nonacid-forming bacteria is
checked. The activity of the Tactic
acid bacteria themselves is checked
and finally ceases entirely when the
acid reaches certain concentration
which varies with different varieties.
Consequently sour milk usually con
tains nearly pure culture of one or
at most two or three closely related
varieties of bacteria.
While the Tactic acid bacteria are
considered very beneficial in butter
and cheese making, they are undesir>
able bacteria from the standpoint
Of the milk dealer or consumer. 1t
Is almost out of the question absolute
ly to prevent their presence in milk,
but the initial number may be much
reduced by observing few simple
rules of cleanliness in handling the
milk. Every precaution which re
duces the amount of dirt in milk re
duces the number of bacteria CORE
spondingly. The important factors here
are freedom from dust at time of milk
ing, brushing the cows, Wping the I'D
ders, and small-mouthed milk pals.
1t is also of great importance to cool
the milk as soon as possible after
milking to below the temperature at
which Tactic acid bacteria grow rapid.
ly. This temperature is controlled by
practical conditions, such as the tenn
perature of the water. available for
cooling, but 1t should not be higher
than 90 degrees Fahrenheit
Breeding geese must not be fat.
They should have corn In limited
quantities only during cold weather.
and then at night. Oats stepped in
warm water makes better feed. 1t
should be fed In v-shaped troughs.
Plenty of vegetable food, such as cab.
bage, boiled potatoes and clover,
should be supplied until the grass
hogina fO grow and the hirda ua 80