Degradation of organic pollutants by methane grown microbial consortia
UNSPECIFIED. (2005) Degradation of organic pollutants by methane grown microbial consortia. BIODEGRADATION, 16 (5). pp. 435-448. ISSN 0923-9820Full text not available from this repository.
Official URL: http://dx.doi.org/10.1007/s10532-004-4721-2
Microbial consortia were enriched from various environmental samples with methane as the sole carbon and energy source. Selected consortia that showed a capacity for co-oxidation of naphthalene were screened for their ability to degrade methyl-tert-butyl-ether ( MTBE), phthalic acid esters (PAE), benzene, xylene and toluene (BTX). MTBE was not removed within 24 h by any of the consortia examined. One consortium enriched from activated sludge ("AAE-A2''), degraded PAE, including ( butyl-benzyl) phthalate (BBP), and di-( butyl) phthalate ( DBP). PAE have not previously been described as substrates for methanotrophic consortia. The apparent K-m and V-max for DBP degradation by AAE- A2 at 20 degreesC was 3.1 +/- 1.2 mg l(-1) and 8.7 +/- 1.1 mg DBP ( g protein x h)(-1), respectively. AAE- A2 also showed fast degradation of BTX ( 230 +/- 30 nmol benzene ( mg protein x h)(-1) at 20 degreesC). Additionally, AAE- A2 degraded benzene continuously for 2 weeks. In contrast, a pure culture of the methanotroph Methylosinus trichosporium OB3b ceased benzene degradation after only 2 days. Experiments with methane mono-oxygenase inhibitors or competitive substrates suggested that BTX degradation was carried out by methane-oxidizing bacteria in the consortium, whereas the degradation of PAE was carried out by non-methanotrophic bacteria co-existing with methanotrophs. The composition of the consortium ( AAE- A2) based on polar lipid fatty acid (PLFA) profiles showed dominance of type II methanotrophs ( 83 - 92% of biomass). Phylogeny based on a 16S-rRNA gene clone library revealed that the dominating methanotrophs belonged to Methylosinus/Methylocystis spp. and that members of at least 4 different non-methanotrophic genera were present ( Pseudomonas, Flavobacterium, Janthinobacterium and Rubivivax).
|Item Type:||Journal Article|
|Subjects:||T Technology > TP Chemical technology|
|Journal or Publication Title:||BIODEGRADATION|
|Official Date:||October 2005|
|Number of Pages:||14|
|Page Range:||pp. 435-448|
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