This suggests that the medium is a desiccated exopolysaccharide glycocalyx known commonly as bacterial biofilm. (journals.plos.org)
A study in a close relative, Burkholderia thailandensis (Bth), showed that a quorum sensing mutant had marked differences in colony morphology, but other genes involved in exopolysaccharide production could also be necessary for morphotype switching. (jcvi.org)
They were forming complicated structures, cities of germs encased in a slippery substance the bacteria exude called an exopolysaccharide matrix. (discovermagazine.com)