Degradation of bacterial lipopolysaccharide by the slime mould Physarum polycephalum.

A strain of the acellular slime mould Physarum polycephalum degraded lipopolysaccharides (LPS) from a variety of bacteria. The anticomplementary (AC) activity of LPS was greatly reduced, as was the content of lauric, myristic, and palmitic acids, and the ability to sensitize erythrocytes to agglutination by antibody. These results indicate that Physarum has enzymes which reduce the lipid A moiety of LPS. In contrast, 2-keto-3-deoxy-D-manno-actanoic acid (KDO), immunodominant sugars, and beta-hydroxymyristic acid were scarcely affected. Both supernates and plasmodial extracts of Physarum had LPS-degradative activity and were able to attack both purified LPS and LPS in killed bacteria.