Bioaugmentation and Biostimulation

Shu-Chi Chang, Ph.D., P.E., P.A.Assistant Professor1 and Division Chief2

1Department of Environmental Engineering2Division of Occupational Safety and Health,

Center for Environmental Protection and Occupational Safety and Health

National Chung Hsing University

Wednesday, May 23, 2007

Bioaugmentation (BA) Addition of microorganisms to enhance a specific

biological activity Has been demonstrated to be beneficial on PHCs and

chlorinated compounds. Mass transport: Microbial attachment and contaminant

mobility. Hard to discern effects of BA from simultaneous

biostimulation caused by nutrient addition. May be useful in case of pollutant toxicity of lack of

appropriate microorganisms Success relies on an understanding of (1) bioavailability

of contaminants, (2) survival and activity of added microorganisms or its genetic materials, and (3) general environmental conditions

Bioreactive Barriers

Need a side-by-side comparison of bioaugmentation and biostimulation

Dehalococcoids and Desulfuromonas were quantitatively monitored

Real-time PCR and Terminal Restriction Fragment Length Polymorphism were employed

Introduction

Dehalococcoids spp., Dehalococcoids ethenogens

DCE-cis TCE PCE,

Ethene TCE PCE,

EtheneVC, PCE

Desulfuromonas spp.

KB-1

Methods

Methods

Results

Results

Results

Results

Results

Results

Summary

Bioaugmentation is based on the ecological principle that natural microorganisms have not established a competitive 'niche' (function) for the contaminant. An inoculum has a high rate of success to establish as long as the contaminant is present, and the niche is unoccupied.

Requirement for some type of 'tracking mechanism' to establish that the degradation is due to biodegradative activity associated with the inoculum.

---> development of specific metabolic (e.g. Biolog), genetic (e.g. DNA and RNA probes) or physiological (e.g. FAME) fingerprints for the inoculum which can be recognized against 'autochthonous' microorganisms

---> development of bioluminescence probes; e.g luciferase genes coupled to biodegradative genes. Induction of the biodegradative enzymes by long chain aldehydes and alcohols will trigger luciferase expression:

ATP + NADH luciferase ADP + NAD+ +