%0 Journal Article %A Kennedy, Lynn %A Mcdowell, Kenneth %A Sutherland, Ian W. %T Alginases from Azotobacter species %D 1992 %J Microbiology, %V 138 %N 11 %P 2465-2471 %@ 1465-2080 %R https://doi.org/10.1099/00221287-138-11-2465 %I Microbiology Society, %X Alginate lyases (alginases) have been prepared from strains of Azotobacter vinelandii and Azotobacter chroococcum in which they were located in the periplasm. The enzymes are present in wild-type strains of each species and in mutants failing to encyst or produce bacterial alginate. The lyases have been partially purified by ion exchange chromatography and by affinity chromatography on a matrix prepared from poly-D-mannuronic acid. Although several bacterial and algal alginate preparations were degraded by the enzymes, highest activity was found on poly-D-mannuronic acid or on algal alginates with high mannuronic acid content. The major product from enzymes of either bacterium was an unsaturated uronic acid, when either alginates or poly-D-mannuronic acid were used as substrates. When tested against a series of algal alginates of increasing D-mannuronic acid content, the enzyme activity was highest against alginates of high D-mannuronic acid content, indicating that the enzymes are endo-D-mannurono-lyases. The alginases from the two bacterial species are not identical in their substrate specificity although both show the same generalized type of action. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-138-11-2465