Monday, May 5, 2008
6-15

Alkaline active hemicellulases from bacteria isolated from an extremely alkaline lake ecosystem

Bradley A. Plantz1, Kenneth W. Nickerson1, Vicki L. Schlegel2, Julie Shaffer3, and Gautam Sarath4. (1) School of Biological Sciences, University of Nebraska, E149 Beadle Center, Lincoln, NE 68588, (2) Food Science and Technology, University of Nebraska, 326 Food Industry Complex, Lincoln, NE 68588, (3) Biological Sciences, University of Nebraska, Kearney, Bruner Hall of Sciences, Kearney, NE 68849, (4) Grain, Forage, and Bioenergy Research Unit, USDA-ARS, 314 Biochemistry Hall, UN-L East Campus, Lincoln, NE 68583-0737

Enzymes are critical for cost effective cellulosic ethanol production processes.  The complexity and diversity of lignocellulose requires ancillary enzymes beyond cellulases for complete hydrolysis of cellulose to fermentable sugars.  Enzymes that are optimally active above pH 9 are needed to complement alkaline pretreatment processes such as alkaline fiber explosion and alkali recirculation.  Nutrient cycling and geochemistry of a lake system located in the Nebraska Sandhills was used to predict the presence of alkaline active enzymes.  Extracellular hemicellulases have been isolated from no less than five species of Gram positive bacteria [Bacillus wakoensis, Bacillus okhensis (2 isolates), Bacillus alkalophilus (2 isolates), Jonsia sp. and Amphibacillus sediminsis] and two unidentified fungi.  Supernatants from cultures grown on xylan contain enzymes that are active from pH 6 - 12.  Growth profiles and zone of clearing assays indicate greater functional diversity between the isolates than is indicated by species identification.  We report on the ongoing efforts to characterize and identify the enzymes from these microbial cultures.

See more of Poster Session Two
See more of General Submissions

See more of The 30th Symposium on Biotechnology for Fuels and Chemicals (May 4 -- 7, 2008)