. Bacteria in relation to soil fertility. Soil microbiology; Bacteriology, Agricultural. SYMBIOTIC NITROGEN FIXATION 159 This fuel is silently passed down to those tiny dynamos, the bac- teria, which fill the nodules on all the roots. Here the carbohy- drates are burned, and the resulting energy used to cause the lazy nitrogen to join hands with hydrogen and oxy- gen. Some of the resulting protein is used in the construction of more bacterial cells, but most of it is passed on to the plant and then be- comes a part of its tissues and later its seeds. The bacteria probably receive this fuel in
. Bacteria in relation to soil fertility. Soil microbiology; Bacteriology, Agricultural. SYMBIOTIC NITROGEN FIXATION 159 This fuel is silently passed down to those tiny dynamos, the bac- teria, which fill the nodules on all the roots. Here the carbohy- drates are burned, and the resulting energy used to cause the lazy nitrogen to join hands with hydrogen and oxy- gen. Some of the resulting protein is used in the construction of more bacterial cells, but most of it is passed on to the plant and then be- comes a part of its tissues and later its seeds. The bacteria probably receive this fuel in the form of a soluble carbohydrate, but we do not under- stand the medium of ex- change used in payment. Is it a nitrite, a nitrate, an amino-acid, or a pro- tein? We only know it is a nitrogen-carrying compound which can be utilized by the plant in all of its constructive metabolism. The Nodules.—These small wart-like protuberances which occur only on the roots of infected legumes are the home of bacteria-like microorganisms called bacteroids. These get into the roots of the young, partly starved plants. As the tip of the root hairs of the legumes pushes itself out into the soil, it chances to come into intimate contact with the microbe. Some scientists believe that the organism is attracted to the plant by chemotaxis. They believe that the plant excretes a substance, probably a car- bohydrate, which passes into the soil solution and attracts the mo-. FiG. 33.—Nodules on soy beans. , sell and Hasting.) (After Rus-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Greaves, Joseph Eames, 1880-; Greaves, Ethelyn O. , joint author. New York, D. Van Nostrand Co.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbacteriologyagricult
