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VEPANATION AND MANAGE

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1900,

J52
THESIS
The object of this investim tion wis to daetermine the hest media
For the yeast, und the best method of minarins the veast.

A. Yeterminition of Best Meciz«,

The object of experiments Vos. lyf onda 3 wis to determine the val-
us of super in voast, In erneh of these experiments, the batter wes

2

put into a storrile elas

on
wd

fPruit jer nd covered with sterile cotton-

wool.

(l). “A thin batter was mete of flaur ond boilins poti:.to wat7r, to

which « “leishmen voust @.k9? was udded after the batter had become
9

cool. This batter wis kept at um tomperature of 26 C. A mold “ormed

on this bitter bit no fermentation was evident. A repetition of

this experiment produced the sume result.

(2) A better wis m.fe os in (1) with the acdition of one tex-
spoon*ul of cane supir to one-hil? pint of the batter. In this esse
Formentation wis actives at tho end of twelve nours,

In the above experiments no d*finite amomnt of flour ene votato
,
water wes used ane. thr conditions unter which the bitters were kept,
yeriec, In tne fo llowine expe riment,a cefinite emount of “lour
and potato water wes used ond the batters were kept under the Sime
condition:.
(3s. (2) A b%etter was maecc of one-fourth cup flour and one enp

boiling potito w.tor,und when ecol, th? batter wis inoculated with

wy

an’ tublespoontful of yeast from (2). fo) A batter was made as in
fi.) to which was udved one te spoon*ul of suse.r. After twelve hours,

'n’ @howed no fermentation while in !b) the fermentation was eetiv.

The results o®* these experiments show that sueor is essential

94646
for tne repia fermentation of the yeort plant

The next experiment

wis to eetermine thr efFfeet of Aif*™ rent emounts

of surir,

(4) A bitter was made of potato wrteor ant Flour und 50e7 of this

butter w.s put into euch of nine Evlonzneyor flasks which hit heen

previously pluers* "rith cotton wool unt sterilizer
thren FPlasks were added 4ems.,.

Ll l/s ems.,l pm.,1/2 9m.,0rme.

Flasks w.s inoculeted with

a Fleishmien yvonst cake, The F

3 1/2 ens sugar showed ictine

flasks conteainine 3 epms., 2

pure

lusks which conteines the 4 ems.anc

ry fe

Sum.p reepectivoly.

LFS og 4S ems, ’

in fry heat To

©\ fey wr cy
owe 1/ wom Ss e939 OTN Ss e 9

wey UY
0 6) ve
as 4 wa

£ tr
‘ oY SM
a O Py a

culture of yeast isolated from

fermentation after trelve hourss th?

we

aod
L/k oms'p, 1 1/2 ems.,end 1 em. showed

Permentition after twenty-four hours, bit the flasks containine

Vem. and O om, sum:r showe?t no fermentation at the end of one

week, Thus, the ferment ition

contained the most sug ir,

(5) In this expcrinent, the

potato wetor in the media,

(i) A thin batter was m.ce of Flour,

Toms. Ssumar, This flask wis

7

object wis

most r pid in tho

flasks which

to detormine the value of

Clear boilins water, ond

inoculated,when cool,with one tea-

spoonful of a pure youst batter m.de from a TPleishman ye st cuka,

(%) A thin batter was m.ce

Toms, suger, This batter wa

of flour, boilins potato waiter and

ao
a

inoculated with

that uscd in (4) and both flasks were kent et

tiie

the

Some heutter as

same temperature.

The fermentation in (5) was netive after twenty-four hours ‘ut no

fermentation was apparent in

(ea) until thre fifth coy after inocu-

lation. Thus,thne potnto wator is fF vornuhle Tor the revid fermnenta-

ion of thr vyeust,.
(%) The ohjeet of this “xovriment was to determine the value of
flour in the meric. One hundred fifteen eroams potito were boiled
in on? liter of water until tender, the pot.ito wis removed, put
throurh a sieve and thon mixed erin with the water in which the
pot: tors were boiled.

(&) A butter wis m.de of 1 1/2 ems. flour, 1 Ve pos. supgor and
20ce¢c. of the potato water, This batter wos inoculateda,whien cool,
with © pure culture of youst isolated from a Fleishman cee, This
bitter showed fermoent:tion after four devs,

(b) A batter was made of 1 V2 pres, snare ond 50 @0, of” the
Yoilins noteto weter, When cool, this batter wes inocnl.ted from
the seme cultures es (a). This showed no ferment: tion until the
Sixth any,

(ec). A batter was mate of 1 1/2 ome. flour. 1 1/2 pms. suger and
"QO ce, Clrkr boilins water. Yhon cool, this butter was ..1ls90 ine¢u-
lited from the sime culture as (i). This showed no “ermentation
at tne end of the eiehth dav.

In this exoeriment, sterile flisks were used end the different
Flasks of bitter were all rept unedor the seme concitions., Th refors,
these experiments show tht poti.to woter end fbour torether are more
Povorahble for the rapid fPermenti.tion o° yeast thon Pither - lone,
and that the potato writer alone is mor? © vornh le thin flour.

Th. following t hie jie & Sumervy of PxovTriments hearing on th

first part of the investisa:tion.
"No. “lour

Ll InerFinitc.

>)

>?

4(1L)Inde finite

(2) 0”

(Sj

(A) 0

(GU)

'6) 2

(T) 0”

(os) ”

(9)

Bt)»
,

ft teaspoonful

 

 

 

 

Seay
Water Remarks,

ee te a ee

Water

 

In?e*init?. None No fermentiition.

»? One tsp. Permenti tion ufter 12 hours.

Mts Pe)No fermentation aftor

Ly hours,

lL ep.

od One tsp. {h)FPerments tion -ctive after
12 hours.
Indefinite. ‘k PMs, Veementation oftor 12 hours.

” 4 Lf mos, Veemontethon, 24 hours in
yy Fy 269,7,

) } 3 ris,

) & 1/2 ome,

” © eras.

” 1 1/2 ers,

? lo oem.

” 1/2 ono fernent tion after lo week,

” Orn, “o fermentition after Lowest,
Indefinite.7 ems. Fermontiution, fifth day.

” Tomme, Fermentation «fter £4 hours,
a

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Creir

Pot:.to
Watep Weiter, Surir, Rem.r’s,
No. “lour, a ee a
B.li)l sk ems. m9 ec. 1 i/o ems. Showed ferment:.tion
after & avys,
(4) SO ec, 1 f/f ems ,Permentation, sixth & y.
fe) Ll Usk ens, "O ee, Lie ens.No fermenti: tion at ene
of ePimhth wy.
RB. Moamirement of Ya ost,
The secant part of th investigation war to determin? practice: 1

met.oc for %eepins yeost
yOouSt in e@eans wis first t

(1)

ons fron this « colony o”

ordinary wort, Attor fern

the yvenst ons tronsferre4

”
nr
t

Eo a? Flour, suger ond h

A wort @meolutin plat.

pur’. The ordinervy mothed of kceepine

EPs Y

4
uf

Xow wt From a Fleishmen yeast

yest wos isolated in a test tube of

5
YON
bet

ontition } cessed in the treet tit,

7
Y

Q
>

to a Pestrur "le of wort. A hatter wes

N
s

oiline poti to w.ter., This hetter wes nut

into © onc-quert eloss “mit Por which ht heen vreviously steril-
iret in storm for three-fourths hor. The pore strain wie cemorvec
Prom th: cover ond thea metellic part perfor tet to oanit fir.
After pinecine the cover on the eon, the top o* the ean wes coverces
With storile cotton and then tty whole wes sterilized in steam

Pop one-hil? hour. When the bitter h.c beeome ecol, thr yvenst trom
the Pustour *lass wos sav eal Anos week Loetor, this eon owes opened
one i: portion of the b.tter wes removed by manns of « strrile

+)

a

Nn ‘

spoon for inoculition

of the S8eeond ey, A

oF Wetter,
(- ‘
° sO . ys. 3 YF t . Yr ca gn rR t aye + tie are ~ yr re oc £ re - f ‘e by .
or LC rose 0 Ol om, ‘ Me - tt L "1: ‘ . 1 () i show : ‘ M4. oo ’ ry us Lt ‘ t Vy ery : a 4 rom } a

4

teria, One woek later, another examin tion was veto whieh showed
the presence of mole and heetorie., At this time tho hotter gore
of’ no stron otor, but two weeks Loter, © stronme cei otor wees
eivern oF TP ant the bh. tter was covered with mold,

Pl) One woo after the first b tter wes mide, co second hotter
wie mm Ae, pre inte a sterile jer, covered ant sterilized in the
seme munnor ac the first ».tter but was inoculated with ove treble
spoon*nl of th better which td heen taken from the first jar.
arter tyvo months this jor wes opened and tie batter was :.pparent-
ly in root condition; but a microscopic ?ximiniution showes tht
Miecteria weer prosent,

Experiments (1) and (2) were repeated three times and in evry
ese the bh.tter became contamineted in rerovine the br tter for
tie sesond inoculation,

oe In this expveriment, the Brlenmeyer Flasks were used, The
STeskys were etoenaned, plusrr aA with cotton-wool,:ne sterilized in
Ary heat at a temnerature o7 140 4. for one hour. A better was
mide of Flour, sue r,enr hoiline potuto writer, ane a ereall «mount
of tre latter was pinced in each Tiask. Thos: flisks of better
were then sterilize?t in stoum for Tifteen minutes for three suc-
erssive Cove hefore inoculation. A pure culture of yeast from a
Wleishcan eno owes used for inoculation. Among thirty of thes»
flasks, four heeaame contumin:ted bot thoes four had been oponed

sover.d tines for ss xamine tion. In sch of these four fliusks, the

osor of Spoilea yoast”? wos strons ont a mold hed formed on three
y@)

tion “or

or small

VW 4 co &8Pen J
til ar Wed
woulA al.

’

WeySR Ho

sterile

Wier, CO

tin n
vea

Treas

ate
i ee
'

v. 4¢

. »,~wWw r / po es yee ,° : Soytie.
ot pretienhin to keep voesct pure by tiie oreine-
* s . . =) + va > “y
a? yoenst beceme:s contaminetec¢ in resovine & por-

oN ‘ ay yo) . . : ? . ya) .
soon spoils. Inster:7 of ans, Melen-ecyor Plisks

bottles m.y be used. A Oetter cen he mace ond

tioee Flosks or bottles, thorourhly steril-

O) inoculated with & pure culture of voeust. In

>

Sf conle be kept vurc in incefinite time and

rer. ay Por us.
ROOM USE ONLY
 

 

 

 
 
 

 

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