The Remediation Technology Summit

February 26-28, 2019

Colorado Convention Center
Denver, CO

SAB RemTECspainJim C. Spain
Professor Emeritus, Georgia Institute of Technology
Research Professor, University of West Florida

Jim Spain joined the School of Civil and Environmental Engineering at the Georgia Institute of Technology at the beginning of 2005. Dr. Spain received his PhD in microbiology from The University of Texas at Austin and a BS in Biology from the University of Texas at Arlington. He studied the biodegradation of pesticides in the marine environment for five years as a post-doctoral fellow and research scientist at the U.S. Environmental Protection Agency Marine Environmental Research Laboratory.

Prior to joining Georgia Tech Dr. Spain directed the Environmental Biotechnology research program at the Air Force Research Laboratory in Panama City, Florida where he studied the biodegradation of synthetic organic compounds in the environment. His research interests in environmental biotechnology include: discovery and construction of bacteria for degradation of substituted aromatic compounds; physiological and ecological factors controlling microbial processes; and discovery of biocatalysts for green chemistry synthesis of novel materials. He works at the interface between basic microbiology research and practical applications to solve environmental problems.

Dr. Spain is a former editor for Applied and Environmental Microbiology and has published over 130 peer reviewed papers, several books, and numerous book chapters on the biodegradation and biosynthesis of organic compounds. He has served on review committees for the EPA, DoE, NIEHS, and DoD and on the editorial boards of a variety of journals.

PLATFORM PRESENTER - Biological Treatment: Strength in Small Packages

Biodegradation of Dichloronitrobenzenes

Dichloroanilines- key feedstocks for synthesis of diuron and other herbicides- are produced by reduction of dichloronitrobenzenes (DCNB). Despite the fact that it is a major contaminant at chemical manufacturing sites there are no reports of DCNB biodegradation. Therefore, such sites are not candidates for bioremediation. We used selective enrichment with samples from a contaminated site in Brazil to isolate bacteria able to mineralize either 2,3-dichloronitrobenzene or 3,4-dichloronitrobenzene. Both isolates released nitrite during growth on the respective DCNB isomers under aerobic conditions. The genome sequence of Acidovorax sp. 3050 revealed the presence of nitroarene dioxygenase genes, which would be consistent with initial attack by a dioxygenase analogous to the initial steps in degradation of nitrobenzene and dinitrotoluenes. Enrichments from the contaminated site were used as inoculum in a fluidized bed bioreactor (FBR) to determine whether mixtures of the contaminants of concern including 3,4-DCNB, 2,3-DCNB, 1,2-dichlorobenzene, and chlorobenzene could be biodegraded simultaneously. Biodegradation of the mixtures was complete even when the reactor was operated at high flow rates. The results indicate clearly that DCNB isomers are candidates for natural attenuation/bioremediation. Current efforts are directed toward evaluation of the distribution of the bacteria at the contaminated site to enable design of the remediation strategy.