Experiment Station Record, Volume 95, July-December, 1946 Page: 31
xii, 1033 p. ; 24 cm.View a full description of this book.
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1946] AGRICULTURAL BOTANY 31
On the existence, morphology, nature, and functions of the cytoplasmic membrane
in the bacterial cell, G. KNAYSI. (Cornell Univ.). (Jour. Bact., 51
(1946), No. 1, pp. 113-121, illus. 14).-The study of spontaneously autolyzed cells
in cultures of Bacillus cereus and B. megatherizum rendered possible the isolation and
demonstration of the cytoplasmic membrane. The fact that this membrane is much
more resistant to autolysis than the cytoplasm proper indicates considerable chemical
or physicochemical differences between them. The cytoplasmic membrane stains
with dyes of the Sudan series and gives the Sharp test for proteins and a positive
Feulgen reaction; it consists principally of lipoids and proteins in a highly stable
chemical combination. The significance of the positive Feulgen reaction is discussed.
The internal surface of the cytoplasmic membrane is jagged and wavy;
besides surrounding the cytoplasm, it forms plane films which separate the cells into
compartments and which are potential places of cell division; it forms and eliminates
into the cytoplasm granules similar to itself in chemical composition; its demonstrated
roles are in cell division and in permeability. The thickness of the cytoplasmic
membrane was found to vary even in a single cell; in young cells of B. cereus it was
usually 0.21R to 0.35[i in thickness.
Studies on cellulose fermentation.-II, An anaerobic cellulose-decomposing
actinomycete, Micromonospora propionici n. sp., R. E. HUNGATE. (Wash. State
Col.). (Jour. Bact., 51 (1946), No. 1, pp. 51-56, illus. 2).--During studies of cellulose
decomposition (E. S. R., 92, p. 479).-in this case by termites-anaerobic shake tubes
of agar medium containing cellulose were inoculated with serial dilutions of the
crushed alimentary tract of a worker termite; several large clear spots developing
in the cellulose suggested the presence of an actinomycete and isolation indicated
it to be this new species of Micromzonospora. The further demonstration that it carried
on a propionic acid fermentation provides physiological evidence supporting the
hypothesis of an origin of the actinomycetes from the propionic acid bacteria.
Morphological characteristics of a purified thermophilic cellulose decomposing
culture, D. B. PRATT. (Purdue Univ.). (Ind. Acad. Sci. Proc., 54 (1944), pp.
75-78, illus. 1).-In culture tubes of ground up filter paper in peptone mineral salt
solution two zones of development appeared to function-one near the surface and
the other near the cellulose fibers at the bottom. At the top large uniform rods
developed; in the bottom, a more filamentous form. "Amorphous cocci" were
observed first at the bottom and later throughout the medium. Filaments bearing
a large terminal spore-atypical in staining reactions-were noted after 48 hr.; thus
the large oval body cannot properly be termed a spore. Observations of the development
of the culture indicated that the evolution of gas is responsible for the mixture
of types usually observed.
On the utilization and synthesis of sucrose and related compounds by some
microorganisms, M. DOUDOROFF. (Univ. Calif.). (Fed. Proc. [Fed. Amer. Socs.
Expt. Biol.], 4 (1945), No. 3, pp. 241-247).-A review (37 references) of the possible
mechanisms of sucrose synthesis in certain bacteria and the suggestion that they
might also apply to the problem of the production of polysaccharides and disaccharides
other than sucrose in both plants and animals. It is concluded that the key
to the formation of many disaccharides and polysaccharides appears near discovery,
but up to the present it has in most cases eluded a direct approach. The roles of
the exchange of phosphoric ester bonds for glycosidic linkages and of the exchange
of glycosidic bonds themselves have given a clue to the types of reactions to be
sought in carbohydrate syntheses. The mechanism of sucrose synthesis in plants
seems to be one of the most promising reactions for study, and its understanding
would contribute greatly to the elucidation of a number of related processes.
The inactivation of iron by 2,2'-bipyridine and its effect on riboflavin synthesis
by Clostridium acetobutylicum, R. J. HICKEY (Arch. Biochem., 8 (1945), No. 3,
pp. 439-447, illus. 1).-2,2'-Bipyridine proved capable of inactivating Fe in the
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U.S. Department of Agriculture. Agricultural Research Administration. Office of Experiment Stations. Experiment Station Record, Volume 95, July-December, 1946, book, 1948; Washington D.C.. (https://digital.library.unt.edu/ark:/67531/metadc5061/m1/43/: accessed April 18, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.