Experiment Station Record, Volume 94, January-June, 1946 Page: 30
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30 EXPERIMENT STATION RECORD [Vol. 94
incomplete nutrient such as a synthetic medium without a source of available
energy, but they germinate readily in the presence of the necessary nutrients,
even when the environment is unsuited to further growth. It is concluded that
in this strain endospores are formed most readily by healthy cells faced with
starvation in the presence of 02. There are 20 references.
Strain specificity and production of antibiotic substances, V, VI. (N. J. Exj;t.
Stas.). (Natl. Acad. Sci. Proc., 31 (1945), Nos. 6, pp. 157-164; 7, pp. 208-214).
V. Strain resistance of bacteria to antibiotic substances, especially to streptomycin,
S. A. Waksman, H. C. Reilly, and A. Schatz.-In continuation (E. S. R.,
93, p. 549), different strains of the same bacterial species were found to vary greatly
in their responses to streptomycin. The ratio of sensitivity to a given preparation
varied for Escherichia coli from 100 to 10' units (average 35); for Proteus vulgaris,
75 to 10 units (average 35); for Staphylococcus aureus, 20 to 75 units (average 34);
and for Bacillus subtilis, 30 to 250 units (average 109). A streptomycin-resistant
strain of P. vulgaris also exhibited a certain degree of resistance to streptothricin
but none at all to clavacin. A strain of S. aureus that was made only slighty resistant
to streptomycin showed no resistance to streptothricin. Several highly resistant
strains of S. aureus gave no evidence of increase in resistance to clavacin
or to an antibiotic substance isolated from a spore-forming soil bacterium, and
only a trace to streptothricin. There are 15 references.
VI. Strain variation and production of streptothricin by Actinoimyces lavendulae,
S. A. Waksman and A. Schatz.-Different cultures of A. lavendulae varied greatly
in capacity to produce streptothricin. Active cultures were found to give variants
differing morphologically, culturally, and physiologically from the parent strain.
Variants free of aerial mycelium failed to produce streptothricin. There are 19
references.
Mycology presents penicillin, C. THOM (Mycologia, 37 (1945), No. 4, pp. 460475).-Following
a historical presentation-the first 10 yr., the Fleming organism
comes to America, and penicillin comes to America-the author presents data on
current knowledge of Penicillium notatun-its aerobic nature, ventilation of cultures,
its behavior in pure culture, variability, selected strains, the culture medium, temperature
relations, penicillin production as marking a physiological stage of the
colony, and submerged cultures.
Quantitative action of penicillin inhibitor from penicillin-resistant strains of
staphylococci, W. W. SPINK and V. FERRIS (Science, 102 (1945), No. 2644, pp.
221-223, ills. 2).-Data are presented as showing that one of the mechanisms by
which staphylococci develop resistance to penicillin is the production by the organisms
of a potent inhibitor. That this is not the only mechanism involved is indicated by
the fact that staphylococci which have become resistant in vitro do not yield a
demonstrable inhibitor. It is believed that changes in bacterial metabolism are
involved in both instances. An elapse of time proved essential for the inhibitor from
staphylococci to overcome the antibacterial action of penicillin. With increasing
amounts of inhibitor, the antistaphylococcic effect of penicillin was more promptly
overcome, whereas decreasing quantities of inhibitor required increasing periods of
time to inhibit the penicillin.
Kojic acid and the antibiotic action of species of Aspergillus, A. H. COOK
and M. S. LAcEY (Nature [London], 155 (1945), No. 3948, pp. 790-791).-The
authors deem it evident from their cultural and chemical studies of A. parasiticusalong
with tests against a range of gram-positive and gram-negative bacteria-that
even though kojic acid is produced, only a part of the antibacterial activity can
be ascribed to this compound. Clearly at least two antibiotics were produced in
these experiments, the speed of their production apparently depending on the availability
of the carbohydrate nutrient; it is also believed possible that more than two
antibiotics were synthesized.
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U.S. Department of Agriculture. Agricultural Research Administration. Office of Experiment Stations. Experiment Station Record, Volume 94, January-June, 1946, book, 1947; Washington D.C.. (https://digital.library.unt.edu/ark:/67531/metadc5062/m1/41/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.