IGEM:IMPERIAL/2009/Degradation

Right, colanic acid can be depolymerased by enzymes called colanases. These are naturally produced by both phages and other gut microflora such as citrobacter:
 * James Field 15:33, 20 August 2009 (EDT):

http://www3.interscience.wiley.com/cgi-bin/fulltext/120077585/PDFSTART

http://www.brenda-enzymes.org/php/result_flat.php4?ecno=3.2.1.38

http://books.google.com/books?id=rneYX9h99VwC&lpg=PA400&ots=TLnAFo33pr&dq=colanic%20acid%20phage%20cleavage&lr=&pg=PA402#v=onepage&q=colanic%20acid%20phage%20cleavage&f=false