Identity and Potential Functions of Heterotrophic Bacterial Isolates from a Continuous-Upflow Fixed-Bed Reactor for Denitrification of Drinking Water with Bacterial Polyester as Source of Carbon and Electron Donor
A collection of 186 heterotrophic bacteria, isolated directly from a continuous-upflow fixed-bed reactor for the denitrification of drinking water, in which poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) granules acted as biofilm carrier, carbon source and electron donor, was studied with regar...
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Published in | Systematic and applied microbiology Vol. 24; no. 2; pp. 303 - 310 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Jena
Elsevier GmbH
01.07.2001
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | A collection of 186 heterotrophic bacteria, isolated directly from a continuous-upflow fixed-bed reactor for the denitrification of drinking water, in which poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) granules acted as biofilm carrier, carbon source and electron donor, was studied with regard to taxonomic affiliation and degradation and denitrification characteristics. Two granule samples were taken from a fully operating reactor for enumeration and isolation of heterotrophic bacteria. One sample was drawn from the lower part of the reactor, near the oxic zone, and the other sample from the upper, anoxic part of the fixed bed. Dominant colonies were isolated and the cultures were identified using fatty acid analysis and 16S rDNA sequencing. Their ability to degrade the polymer and 3-hydroxybutyrate and to denitrify in pure culture was assessed. The results show that high numbers of heterotrophic bacteria were present in the biofilms on the polymer granules, with marked differences in taxonomic composition and potential functions between the lower and upper part of the fixed bed. The majority of the isolates were Gram negative bacteria, and most of them were able to reduce nitrate to nitrite or to denitrify, and to utilize 3-hydroxybutyrate as sole source of carbon. Only two groups, one identified as
Acidovorax facilis and the other phylogenetically related to
Brevundimonas intermedia, could combine denitrification and utilization of poly(3-hydroxybutyrate) (PHB), and were found only in the upper sample. The other groups occurred either in the lower or upper part, or in both samples. They were assigned to
Brevundimonas,
Pseudomonas,
Agrobacterium,
Achromobacter, or
Phyllobacterium, or were phylogenetically related to
Afipia or
Stenotrophomonas. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0723-2020 1618-0984 |
DOI: | 10.1078/0723-2020-00037 |