bacteria, starch, amylose, amylopectin, Corynebacterium kutscheri
Corynebacterium kutscheri required 10 days of growth on semisolid medium to accumulate intracellular starch, but when the same medium was used as a broth, only l day of growth was required. C. kutscheri synthesized starch when amylose was added to nutrient agar in the substrate, but did not do so when amylopectin was substituted for amylose. Dimethyl sulfoxide (DMSO) was superior to water as a cell wash for removing substrate starch from cells before chemical treatment to remove intracellular starch. Bacterial starch was extracted from C. kutscheri cells by destroying cell walls with lysozyme and sodium lauryl sulfate, removing cellular debris by centrifugation, and precipitating the starch from the supernatant with butanol. A qualitative method for the separation of this starch into amylose and amylopectin fractions is described. Use of DMSO in cell washes established that the bacterial starch molecule was too large to pass through the membrane of the bacterial cell because DMSO passes through the cell membrane and cells gave a positive test for starch after the treatment.
Proceedings of the Iowa Academy of Science
©1987 Iowa Academy of Science, Inc.
Dunleavy, J. M. and Gobelman-Werner, K. S.
"Method of Extracting Starch from Bacteria,"
Proceedings of the Iowa Academy of Science, 94(4), 107-110.
Available at: https://scholarworks.uni.edu/pias/vol94/iss4/4