ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

5pBV6. Effects of acoustic cavitation on luminescent bacteria.

E. Carr Everbach

Inder R. S. Makin

Amy Cheng Vollmer

Dept. of Eng. and Biol., Swarthmore College, Swarthmore, PA 19081-1397

The interaction of intense ultrasound with bacteria has implications for improving fundamental understanding in biology and bioacoustics, as well as providing possible applications in water purification and medicine. An investigation will be presented of the effects of acoustic cavitation on E.coli bacteria that have been genetically engineered to emit visible light when subjected to physical or chemical stress. Genetic cloning techniques allow the placement of the lux gene, derived from luminescent marine microorganisms, at specific locations in bacterial DNA. Each placement location yields light production in proportion to the repair mechanism employed by the bacteria in response to specific kinds of stress (oxidative damage, DNA damage, membrane damage, protein damage, thermal damage, etc.). A 20-MHz passive acoustic detector [abstract, Huertas et al., 2856 (1994)] was used to quantify cavitational activity when bacteria were exposed to 1-MHz pulsed ultrasound. By comparing a measure of cavitational activity with light output from exposed bacteria that were presensitized to different kinds of damage, cavitational effects on both bacteria and mammalian cells can be better understood.