Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.


Plastic-Devouring Bacteria Could Keep Soda Bottles Out of Landfills

80beatsBy Eliza StricklandSeptember 23, 2008 2:01 AM


Sign up for our email newsletter for the latest science news


Researchers have discovered new strains of Pseudomonasbacteria that feed on the PET plastic used in drink bottles, and turn it into a more valuable, biodegradable form of plastic. The discovery suggests a way to keep billions of pounds of discarded plastic out of landfills; a 2006 study [pdf] found that less than 25 percent of PET plastic is currently recycled because the industry doesn't have enough use for the end product.

Getting high-quality material — such as plastics suitable for packaging food or beverages —- back out of recycled plastic is more expensive than making virgin PET, so most plastic bottles are recycled into lower-grade, and less valuable, plastic. But there’s only so much demand for lower-grade plastics, says microbiologist and coauthor Kevin O’ Connor.... “The problem is that the market [for recycled PET] is saturated” [Science News].

The researchers knew that heating PET plastic in the absence of oxygen produces a substance called terephthalic acid, which some bacteria feed on. They also know that other bacteria produce a high quality plastic called PHA that could have numerous applications in medicine--because PHA plastic is biodegradable, it's ideally suited for sutures, wound dressings, and various implants. The researchers hoped to find a bacteria that fed on terephthalic acid and produced PHA plastic, so they collected soil bacteria from a bottle processing plant. As reported in their paper, published in Environmental Science and Technology [subscription required], after

48 hours they screened each culture for PHA. Three cultures, all similar to known strains of Pseudomonas, accumulated detectable quantities of the valuable plastic. The next step is to improve the efficiency of the process, says O'Connor. "A quarter to a third of each cell is filled with plastic – we want to increase that to 50 to 60%" [New Scientist].

Image: flickr/fhemerick

3 Free Articles Left

Want it all? Get unlimited access when you subscribe.


Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%


Already a subscriber? Register or Log In