Record Details
Field | Value |
---|---|
Title | Stimulatory effect of trace elements on cellulose digestion by washed suspensions of rumen microorganisms |
Names |
Martinez, Andres
(creator) Church, D. C. (advisor) |
Date Issued | 1969-05-09 (iso8601) |
Note | Graduation date: 1969 |
Abstract | The object of the present study was to investigate the stimulatory or inhibitory effects of barium, boron, bromine, cadmium, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, nickel, rubidium, selenium, strontium, vanadium, and zinc upon in vitro rumen microbial activity as measured by the amount of cellulose digested. Washed suspensions of rumen microorganisms were prepared by centrifuging intact rumen fluid at 1500 rpm (365 x g) for two minutes and immediately centrifuging the resulting supernatant at 8500 rpm for 20 minutes. The resulting sediment, consisting primarily of bacterial cells, was resuspended in a M/15 phosphate buffer and again centrifuged at 8500 rpm for 20 minutes. The twicewashed cells of rumen microorganisms were then incubated at 39°C for 24 hours in a medium containing 0, 2 percent purified cellulose (Solka-Floc); M/15 phosphate buffer and basal mineral media in a 1 to .1 ratio; and the element being tested. Ten levels of each of the 18 elements were added separately to the incubation media. Each concentration of the test element was duplicated in each of three trials (that is, six observations per concentration) yielding a total of 1296 observations during an eightmonth period. The elements and concentrations (in ppm) found to be stimulatory to cellulose digestion included: (P = 01) I, 20; Mn, 5-20; Mo, 30-70; (P = . 05) Co, 3; Fe, 3-5; Rb, 20; Zn, 5-7; (P = 10) Cd, 5; (P = . 20) Cr, 2, and Sr, 10-15. Depression of cellulose digestion (P = . 05) occurred at the following levels (in ppm): Ba, 30; B, 300; Cd, 10; Cr, 7; Co, 7; Cu, 1; F, 0.5; Fe, 100; Mn, 100; Ni, 0. 5; Se, 7; Sr, 200; V, 5, and Zn, 20. Bromine concentrations of 1 to 1000 ppm had no effect on cellulose digestion. Levels up to 1000 ppm I, 500 ppm Mo, and 1000 ppm Rb had no significant detrimental effect on cellulose digestion under the conditions tested. |
Genre | Thesis/Dissertation |
Topic | Rumen |
Identifier | http://hdl.handle.net/1957/46876 |