Beating biofilms

Slimy colonies of microbes steadfastly sticking to equipment and piping systems are the bane of food processors. They are notoriously hard to eliminate but a novel solution is coming.

Biofilms usually present with a tough surface which disinfectants and antibiotics can’t readily penetrate. Now a research team led by University of Illinois at Urbana-Champaign scientists has found a novel way to infiltrate biofilms and kill them off. And it is based on tiny bubbles!

The researchers are loading diatoms, the tiny skeletons of algae, with hydrogen peroxide and tiny oxygen-generating sheets of manganese oxide. Inside the hollow, highly porous and rod-shaped diatoms the hydrogen peroxide and manganese oxide nanosheets react and produce oxygen. The diatoms have a lot of surface area where the bubbles of oxygen can form and a channel for the bubbles to escape. The result is a flourish of microbubbles that flow through the tiny channel, propelling the rigid diatoms forward with enough force to break up the surface and internal structure of the biofilms. Once the diatoms break through to the internal structure of the biofilm, they continue to expel bubbles and facilitate the entry of hydrogen peroxide, which is an effective disinfectant against bacteria and fungus.

The researchers believe that their success is a result of a decision to focus on the mechanical aspects of biofilm destruction, not the chemical aspects of simply killing microbes.

The team’s work has been published in ACS Applied Materials and Interfaces. The paper ‘Diatom microbubbler for active biofilm removal in confined spaces’ is available online and from the U. of I. News Bureau. DOI: 10.1021/acsami.8b08643

Image credit: ©stock.adobe.com/au/Kateryna_Kon