RESEARCH NEEDS FOR BIOAUGMENTATION - Bioaugmentation for Groundwater Remediation - page 327

CHAPTER 12
RESEARCH NEEDS FOR BIOAUGMENTATION
Laura A. Hug, 1 Elizabeth A. Edwards, 1 Helen Vrionis 1 and David W. Major 2
1 University of Toronto, Toronto, Ontario, Canada; 2 Geosyntec Consultants Inc.,
Guelph, Ontario, Canada
12.1 INTRODUCTION
Successful bioaugmentation depends on an ability to identify and monitor the organisms,
proteins and genes needed for biodegradation, as well as the biomarkers of other organisms
upon which they rely or with whom they compete. Innovations in biotechnology are leading to
a better understanding of microbial communities and their environments. New technologies
such as metagenome sequencing, transcript profiling, shotgun proteomic analysis, metabolic
modeling and synthetic biology are allowing researchers to study the important functional
and regulatory elements in complex microbial systems. These technologies will enable more
accurate predictions of bioremediation outcomes. Such basic scientific understanding will
become critical for developing successful bioaugmentation inocula, assessing the need for
bioaugmentation at specific sites and obtaining regulatory approval for bioaugmentation in
many jurisdictions.
Buoyed by the stunning example of a successful merger of basic science and practical
application represented by the Dehalococcoides ( Dhc ) story for chlorinated ethene bioaug-
mentation, researchers are pursuing additional discoveries and developments that will have
practical applications for bioremediation. Examining specifically why bioaugmentation can
work so well for chlorinated ethenes, but yet has offered little added benefit for petroleum
hydrocarbon remediation, will hopefully provide clear direction for future approaches. This
chapter describes some of these promising research directions and identifies some of the
current research needs in basic science at various scales. Some specific examples illustrating
research needs directly targeted to extending the application of bioaugmentation to broader
environments and new contaminants are described.
12.2 RESEARCH NEEDS IN BASIC SCIENCE
As the previous chapters have shown, several different bioaugmentation approaches can
be successful. One lesson from these approaches is that the better the understanding of the
microorganisms at the heart of the process, the more effective the implementation will be.
There are four scales at which basic science is critical to a better understanding of bioaugmen-
tation: (1) at the molecular scale, particularly at the levels of gene regulation and the enzymatic
mechanism for dechlorination; (2) at the organismal scale, such as in the detailed understanding
of an isolated culture; (3) at the community scale, understanding microbial community dynam-
ics and interspecies connections; and (4) at the environment, ecosystem or field scale, where
community dynamics interact with the physical and chemical environment and issues of
partitioning and transport come into play.