Biology ETDs

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This study was concerned with the sporicidal efficiency of dimethyl sulfoxide (DMSO), various disinfectants, and their combinations or complexes. Spores of Bacillus subtilis var. niger (globigii), Bacillus cereus, Bacillus subtilis (5230), and Bacillus stearothermophiluswere used to demonstrate the sporicidal activity of DMSO, phenol, Clorox, phenylmercuric nitrate, silver nitrate, Roccal, merthiolate, and iodine. Dimethyl sulfoxide has been shown in the past to enhance the penetration of neighboring substances which it encounters whether it be by the formation of a complex or by a reservoir effect in which DMSO causes a change in the osmotic concentrations on either side of a semipermeable barrier. The possibility that DMSO might enhance the sporicidal efficiency of one of the agents seemed likely. The action of the complexes seemed to be indirectly related to their ability to penetrate the spore core. The sporicidal efficiency of each combination was determined. Results indicated that each strain’s death rate is due to one or more of the following: (1) Effectiveness of DMSO alone, (2) effectiveness of the agent alone, (3) efficiency of a complex formed, (4) a partial, but additive effect of DMSO and the agent in the form of a combination, not a complex, (5) a partial, but reduced effect of DMSO or the agent in the form of a combination, not a complex. Silver nitrate, Clorox, and iodine proved to be efficient sporicides. Iodine with DMSO increased sporicidal activity, while the complex of Clorox reduced its efficiency drastically. All other disinfectants were favorable in action but inefficient. The author believes that other simple chlorine compounds complexed with DMSO might provide extremely efficient sporicides.



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Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

John William Beakley

Second Committee Member

Martin William Fleck

Third Committee Member

Gordon Verle Johnson

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Biology Commons