Functional Stability Of A Mixed Microbial Consortia Producing PHA From Waste Carbon Sources

Conference · Sat Apr 01 04:00:00 EST 2006

OSTI ID:911930

Thompson, David N; Coats, Erik R; Smith, William A; Loge, Frank J; Wolcott, Michael P

Polyhydroxyalkanoates (PHAs), naturally-occurring biological polyesters that are microbially synthesized from a myriad of carbon sources, can be utilized as biodegradable substitutes for petroleum-derived thermoplastics. However, current PHA commercialization schemes are limited by high feedstock costs, the requirement for aseptic reactors, and high separation and purification costs. Bacteria indigenous to municipal waste streams can accumulate large quantities of PHA under environmentally controlled conditions; hence, a potentially more environmentally-effective method of production would utilize these consortia to produce PHAs from inexpensive waste carbon sources. In this study, PHA production was accomplished in sequencing batch bioreactors utilizing mixed microbial consortia from municipal activated sludge as inoculum, in cultures grown on real wastewaters. PHA production averaged 85%, 53%, and 10% of the cell dry weight from methanol-enriched pulp-and-paper mill foul condensate, fermented municipal primary solids, and biodiesel wastewater, respectively. The PHA-producing microbial consortia were examined to explore the microbial community changes that occurred during reactor operations, employing denaturing gradient gel electrophoresis (DGGE) of 16S-rDNA from PCR-amplified DNA extracts. Distinctly different communities were observed both between and within wastewaters following enrichment. More importantly, stable functions were maintained despite the differing and contrasting microbial populations.

• Research Organization: Idaho National Laboratory (INL)
• Sponsoring Organization: DOE - NE
• DOE Contract Number: AC07-99ID13727
• OSTI ID: 911930
• Report Number(s): INL/CON-05-01051
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOREACTORS
BIOTECHNOLOGY
CARBON SOURCES
COMMERCIALIZATION
COMMUNITIES
DGGE
DNA
ELECTROPHORESIS
FUNCTIONALS
MUNICIPAL WASTES
POLYESTERS
PURIFICATION
REACTOR OPERATION
SLUDGES
STABILITY
THERMOPLASTICS
WASTES
activated sludge
denaturing gradient gel electrophoresis
feedstock
mixed consortia
polyhydroxyalkanoates
wastewater