David A. Lach

Publication Date


Document Type


First Advisor

Vary, Patricia S.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Bacillis Megaterium; Bacterial genetics; Microbial mutation


Several different morphogenic mutants of Bacillus megaterium QM B1551 were isolated and characterized phenotypically. These included 24 germination defective mutants as well as 6 sporulation defective mutants. In addition, several abnormally pigmented mutants and a protease deficient mutant were isolated. One of the sporulation defective mutants was also defective in the location of division site along cell length and designated as div-1. Morphological studies including light microscopy and scanning and transmission electron microscopy of the mutant revealed that it was a filamentous, minicell-producing mutant which also accumulated poly-B-hydroxybutyrate (PHB). Assayed PHB levels of the mutant were 34-fold higher than in the parent strain at 48 hrs of growth. The mutant showed similarities to the divIVA mutants of B. subtilis. MP13 cotransductional mapping of the div-1 locus revealed a new linkage group for B. megaterium consisting of div-1 and the pyrBCDF loci. The mutant was also found to be sensitive to UV irradiation. Several conditional germination mutants were also isolated which were defective in response to various initiation agents of this strain. These mutants should prove useful in the further study of sporulation and germination in this species.


Bibliography: pages [112]-138.


vii, 138 pages




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