Casablanca (1942, black and white, Hollywood movie) lovers may recognize the paraphrase of just one of the many famous lines in the movie. However, this ‘shocking’ news has more to do with preventing bacteria from congregating on surfaces according to a Jan. 12, 2014 news item by Alexander Chilton on Azonano (Note: Links have been removed),
Researchers at Rensselaer Polytechnic Institute and Cornell University have devised a new nanoscale surface which uses an electrochemical anodization process in order to prevent the surface attachment of bacteria.
The research published in the Biofouling journal focuses on the formation of nanoscale pores which alter the surface energy and electrical charge of a metal surface. A repulsive force is exerted on the bacterial cells, which prevents the attachment of bacteria and the formation of a biofilm. The size of the nanoscale pores formed can be as small as 15 nanometers.
The application of the anodization process to aluminum created a nanoporous surface, known as alumina. This surface proved effective in preventing the attachment of two popular bacterial species: Listeria monocytogenes and Escherichia coli O157:H7.
Krishna Ramanujan’s Jan. 9, 2015 article for Cornell University’s Chronicle explains why the scientists are excited about the anodization technique,
“It’s probably one of the lowest-cost possibilities to manufacture a nanostructure on a metallic surface,” said Carmen Moraru, associate professor of food science and the paper’s senior author. …
Finding low-cost solutions to limiting bacterial attachments is key, especially in biomedical and food processing applications. …
Anodized metals could be used to prevent buildups of biofilms – slick communities of bacteria that adhere to surfaces and are tricky to remove – in biomedical clean rooms and in equipment parts that are hard to reach or clean, Moraru said.
There are other strategies for limiting bacterial attachment to surfaces, including chemicals and bactericides, but these have limited applications, especially when it comes to food processing, Moraru said. With food processing, surfaces must meet food safety guidelines and be inert to food that they may contact.
Here’s a link to and a citation for the paper,
Alumina surfaces with nanoscale topography reduce attachment and biofilm formation by Escherichia coli and Listeria spp. by Guoping Feng, Yifan Cheng, Shu-Yi Wang, Lillian C. Hsu, Yazmin Feliz, Diana A. Borca-Tasciuc, Randy W. Worobo, & Carmen I. Moraru. Biofouling: The Journal of Bioadhesion and Biofilm Research Volume 30, Issue 10, 2014 pages 1253-1268 DOI: 10.1080/08927014.2014.976561 Published online: 27 Nov 2014
This article is open access.