On Monday mornings, machinists often are greeted at work by the horrible stench of rotten eggs. The fumes, which can be toxic as well as smelly, come from anaerobic bacteria that grow in a factory's metalworking fluids during the weekend.

And there are other problems too.

"If the microorganisms grow to high levels, the lubricant properties of the metalworking fluids will be lost and bacteria in the mist produced by machine tools may be a health hazard for workers," says Robert Vinopal, an associate professor of molecular and cell biology.

Enter pyrithione, a biocide (bacteria killer) developed by Stamford's Olin Chemicals in the 1950s. The product kills or inhibits the growth of bacteria, fungi and algae, and is widely used in metalworking fluids and other applications. But Olin didn't know why it worked.

If they could figure that out, Vinopal says, "then Olin could put it to better use, and then they would feel more comfortable about using it in new applications."

So Olin enlisted Vinopal's help. And help them he did, with the assistance of two graduate students supported by Olin through the Center for Grinding Research and Develop-ment.

He found that pyrithione disrupts the energy of cells and at the same time it causes cells to leak metal ions they need to grow. Because he could figure this out, Vinopal was able to help Olin develop ways to make pyrithione effective at lower concentrations. Some of his work with Olin led to a U.S. patent issued to the University last year.

"Bob has changed the way we think about our biocides," says Jon Geiger, group leader of biotechnology and microbiology at the Olin Research Center in Cheshire. "It has made us more analytical in approaching biocide use with our customers. It also made our approach to new product development more scientific and more productive. I think that our interaction with Bob should be a model of how UConn's talented faculty can help make Connecticut industry more competitive. His insight, broad knowledge of the field of bacterial physiology, and creative approach to understanding problems provided the useful consultation that made, and continues to make, a significant impact on our growth."

Commercial applications
Vinopal's clear understanding of the effect microorganisms have on metalworking fluids enticed Triton Thalassic Tech- nologies Inc. of Ridgefield to approach him about a product the company hoped would also curb bacterial growth. Triton has invented an advanced ultraviolet light source and fluid treatment system that destroys and controls the regrowth of bacteria and other microorganisms in a wide variety of mainly opaque fluids.

"Bob helped us verify that without any chemical biocide additive, we could effect a reduction of the bacteria in the fluid," says Barry Ressler, Triton's chairman and chief executive officer. "Second, the fluid would retain its original performance characteristics, and third and most important, we were not creating mutations or any UV (ultraviolet) resistance strains that could multiply and prove our system ineffective."

Vinopal's work also has given Triton other areas to explore in the future. Ressler hopes to examine whether high-intensity UV will be applicable to opaque fluids other than those used in the metalworking industry. Also, this unique ultraviolet system could be used on recirculating systems like aquaculture farms that have been resistant in the past because of the fear that ultraviolet light would generate mutations.

"Our experience with Bob has been extremely rewarding, and has certainly given us incentive to look for future funding with the University and Bob as a participant," Ressler says.