283509 Isolation of a Lignolytic Facultative Anaerobe From the Former Goldmine in Homestake,Lead,South Dakota

Wednesday, October 31, 2012: 4:55 PM
331 (Convention Center )
Rajneesh Jaswal, Rajesh V. Shende and Anuradha Shende, Chemical and Biological Engineering Department, South Dakota School of Mines and Technology, Rapid City, SD

The former goldmine at Homestake , Lead, South Dakota  had wooden support  infrastructure.  Some of  the wooden logs have  been decomposing in the water logged soil  since the mine closed in  2001.   The  hot ( between 40oC-43oC)  and humid mine conditions  devoid of sunlight mimic the   environment in a rain forest and has lead to rapid decomposition of the wooden logs. . Soil   underneath decomposing logs was collected to screen for lignin degrading anaerobes. Microflora from the soil was enriched on minimal media containing Kraft lignin as sole carbon source. The  soil cultures were incubated  under anaerobic conditions without shaking at 430C. After 5 successive transfers in 60 days,   a gram negative lignolytic bacteria was isolated. The bacteria was found to completely degrade Kraft lignin in 76 days. Lignin degradation was monitored by UV-Vis differential spectroscopy . The fermentation products formed were identified by GC-MS.   Succinic acid was identified as one of the products  formed within 48 hrs of inoculation. The 16S rRNA  sequence analysis classified this    microbe  as an  Enterobacter spp.  Results obtained from the  phylogenetic and FAME analysis  of this novel bacteria will be presented.  Degradation products obtained by fermentative action of this  bacteria on Kraft and other technical lignin  will be discussed . A hypothetical  lignin degrading pathway in this bacteria will be presented.

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See more of this Session: Fundamentals of Biomass Utilization
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