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A biochemical study of streptococci, with special emphasis on the determination of their chemical composition ... by Frances Krasnow ...

01 Jan 1922-

AboutThe article was published on 1922-01-01 and is currently open access. It has received 1 citation(s) till now.

Summary (1 min read)

INTRODUCTION

  • The chief purposes pervading researches on the streptococci are two: (i) to get a sound basis for the classification of the different types and (2) to understand the role they play in the general processes of nature.
  • The authors have undertaken the work to be detailed here.
  • This is not the first study on bacterial composition, also known as 2. HISTORICAL.
  • 75 grams of Bacto-veal in 1000 cc. of tap water were heated in the Arnold sterilizer for two hours and filtered through filter paper, also known as (a) Sugar-free broth.

3. PREPARATION OF THE REAGENTS USED IN THE DETERMINATION OF HYDROGEN-ION CONCENTRATIONS:

  • All the slants were formed by equal amounts of medium.
  • The data tabulated below indicate the results obtained for one series.
  • Medium (c) Constancy in composition of medium:.
  • To insure absolute constancy in the composition of the medium a stock infusion was prepared from one large shipment of fresh hashed liver (200 pounds).
  • This was estimated as the quantity large enough to cover the needs of the entire investigation.

2. CULTURES:

  • (a) Preparation of cultures for mass growing: Jablons liver peptone broth (58) was used for the cultivation of the test organisms preliminary to mass growing.
  • This medium attracted their attention because it contained the same ingredients as the solid medium selected, thus favoring exceptional uniformity in the metabolic reactions of the bacteria throughout the entire experimental period.
  • That the bouillon supported hardy development may be proven by the following experiments comparing it with other good liquid media: (i) Huntoon broth ( 56) and (2) Rosenow broth (59) .
  • The test media were inoculated with one loopful of culture from the seed tubes, kept at room temperature for 60 hours and then incubated for 24 hours at 37 C.
  • The results tabulated represent the reactions given by all the organisms.

VII. SUMMARY OF CONCLUSIONS.

  • It becomes apparent, therefore, that the total amounts of protein material in the different organism varies but slightly.
  • This indicates no striking variations in the quantity of nucleoprotein (the P from the phosphatide being very small in amount).
  • The percentages obtained by drying the material at 100 C. are higher than those obtained by drying the substances in vacuo.
  • These vary greatly for the different types of streptococci.
  • The percentage of lipins is lowest in the indifferent type and highest in the green-producing type, the hemolytic type taking a position between these two.

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1922


A Biochemical
Study
of
Streptococci
With
Special
Emphasis
on
the
Determination
of
Their Chemical
Composition
DISSERTATION
Submitted
in
partial
fulfillment of
the
requirements
for
the
degree
of
Doctor
of
Philosophy
in
the
Faculty
of
Pure
Science
of
Columbia
University
By
FRANCES
KRASNOW,
B.S.,
A.M.
NEW YORK
CITY
1922


A
Biochemical
Study
of
Streptococci
With
Special
Emphasis
on
the
Determination of
Their Chemical
Composition
DISSERTATION
Submitted
in
partial
fulfillment of
the
requirements
for
the
degree
of
Doctor of
Philosophy
in
the
Faculty
of Pure Science
of
Columbia
University
By
FRANCES
KRASNOW,
B.S.,
A.M
NEW YORK
CITY
1922

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