Structure of the peptidoglycans of Moraxella glucidolytica and Moraxella lwoffi grown on hydrocarbons

Abstract

The peptidoglycans of Moraxella glucidolytica and Moraxella lwoffi grown on aliphatic hydrocarbons were isolated. They contained muramic acid, glucosamine, alanine, D-glutamic acid and mesodiaminoimelic acid in a molar ratio of about 0.5:0.5:1.6:1.0:1.0 (M. glucidolytica) and 0.8:0.7:1.3:1.0:1.0 (M. lwoffi). The peptidoglycans were lysozyme-resistant. However, when treated with formanide, they could be partially degraded by lysozyme. The fragments were purified and their structure determined. In both strains, the peptide subunits consisted mainly of tripeptides (L-Ala-D-Glu-meso-DAP) and tetrapeptides (L-Ala-D-glu-meso-DAP-D-Ala), most of them being directly cross-linked. It is concluded that in both strains the primary structures of the peptidoglycans are closely related.