Lignocellulose-degrading Paenibacillus Isolates from Alaska Grassland

Abstract

Lignocellulose, consisting of lignin, hemicelluloses, and cellulose, is the major structural component of woody plants and non-woody plants such as grass. These chemical properties of the components make lignocellulose an attractive substrate of biotechnological value. As an effort to unearth new sources of cold-active lignolytic enzymes, we have screened Alaska grassland soils for the presence of bacteria with the activity of xylanase. Xylanases randomly cleave the ß 1,4 backbone of xylan, which constitutes the major component of hemicelluloses. Xylanase activity was initially measured as the size of the clear zones around colonies and, based on the size, a total of 100 bacterial colonies were selected. The 16S rDNA sequencing using the primers 27F and 1492R showed that 90 out of the 100 isolates belong to the genus Paenibacillus with various levels of 16S rDNA identity. Ten of the Paenibacillus isolates were found to grow well on different monomeric and dimeric components of lignocelluloses including vanilic acid, cinnamic acid, coumaric acid, and cellulobiose. Also, it is noteworthy that eight of the ten Paenibacillus isolates exhibit significant caseinase enzyme activity.strate of biotechnological value. As an effort to unearth new sources of cold-active lignolytic enzymes, we have screened Alaska grassland soils for the presence of bacteria with the activity of xylanase. Xylanases randomly cleave the ß 1,4 backbone of xylan, which constitutes the major component of hemicelluloses. Xylanase activity was initially measured as the size of the clear zones around colonies and, based on the size, a total of 100 bacterial colonies were selected. The 16S rDNA sequencing using the primers 27F and 1492R showed that 90 out of the 100 isolates belong to the genus Paenibacillus with various levels of 16S rDNA identity. Ten of the Paenibacillus isolates were found to grow well on different monomeric and dimeric components of lignocelluloses including vanilic acid, cinn