Bioaugmentation of butane-utilizing microorganisms to promote cometabolismof 1,1,1-trichloroethane in groundwater microcosms

Citation
P. Jitnuyanont et al., Bioaugmentation of butane-utilizing microorganisms to promote cometabolismof 1,1,1-trichloroethane in groundwater microcosms, BIODEGRADAT, 12(1), 2001, pp. 11-22
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biotecnology & Applied Microbiology
Journal title
BIODEGRADATION
ISSN journal
0923-9820 → ACNP
Volume
12
Issue
1
Year of publication
2001
Pages
11 - 22
Database
ISI
SICI code
0923-9820(2001)12:1<11:BOBMTP>2.0.ZU;2-L
Abstract
The transformation of 1,1,1-trichloroethane (1,1,1-TCA) in ioaugmented and non-augmented microcosms was evaluated. The microcosms contained roundwater and aquifer materials from a test site at Moffett Field, Sunnyvale, CA. Th e initial inoculum for bioaugmentation was a butane-utilizing enrichment fr om the subsurface of the Hanford DOE site. The non-augmented microcosm requ ired 80 days of incubation before butane-utilization was observed while the augmented microcosms required 3 days. Initially the augmented microcosms w ere effective in transforming 1,1,1-TCA, but their transformation ability d ecreased after prolonged incubation. The non-augmented microcosms initially showed limited 1,1,1-TCA transformation but improved with time. After 440 days, both the non-augmented and augmented microcosms had similar transform ation yields (0.04 mg 1,1,1-TCA/mg butane) and had similar microbial compos ition (DNA fingerprints). Subsequent microcosms, when bioaugmented with a H anford enrichment that was repeatedly grown in 100% mineral media, did not effectively grow or transform 1,1,1-TCA under groundwater nutrient conditio ns. Microcosm tests to study the effect of mineral media on transformation ability were performed with the Hanford enrichment. Microcosms with 50% min eral media in groundwater most effectively utilized butane and transformed 1,1,1-TCA, while microcosms with groundwater only and microcosms with 5% mi neral media in groundwater lost their 1,1,1-TCA transformation ability. DNA fingerprinting indicated shifts in the microbial composition with the diff erent mineral media combinations. Successful bioaugmentation was achieved b y enriching butane-utilizers from Moffett Field microcosms that were effect ive in groundwater with no mineral media added. The results suggest that su ccessful in-situ bioaugmentation might be achieved through the addition of enriched cultures that perform well under subsurface nutrient conditions.