Jianxin Sun and Jeffrey Chalmers. Chemical and Biomolecular Engineering, the Ohio State University, 140 W 19th Ave, Rm125A, Columbus, OH 43210
Bacillus is a genus of rod-shaped, Gram-positive bacteria, either obligate or facultative aerobic. Bacillus forms spores when facing environmental stresses, and spores of some species are found to oxidize Mn(II) to Mn3O4 and MnO2 enzymatically. While much literature exists describing the heat resistance and other properties of spores, our laboratory was the first to observe spores’ intrinsic magnetism. This magnetism, however, is highly related to some factors in fermentation. In this study, physical conditions were manipulated to optimize the magnetism of Bacillus spores. The concentration of Mn in the culture seems to be the most important factor while the sporulation time and oxygen availability do not affect the magnetism significantly. Antifoaming surfactant was not used in the fermentation, since magnetism will be mostly removed. Upscale fermentation was also studied to further explore the factors described above.
