ISOLATION AND IDENTIFICATION OF AUTOTROPHIC AND HETEROTROPHIC BACTERIA FROM AN AUTOHYDROGENOTROPHIC PILOT-PLANT FOR DENITRIFICATION OF DRINKING-WATER

Citation
J. Vanbrabant et al., ISOLATION AND IDENTIFICATION OF AUTOTROPHIC AND HETEROTROPHIC BACTERIA FROM AN AUTOHYDROGENOTROPHIC PILOT-PLANT FOR DENITRIFICATION OF DRINKING-WATER, Systematic and applied microbiology, 16(3), 1993, pp. 471-482
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology,"Biothechnology & Applied Migrobiology
ISSN journal
0723-2020
Volume
16
Issue
3
Year of publication
1993
Pages
471 - 482
Database
ISI
SICI code
0723-2020(1993)16:3<471:IAIOAA>2.0.ZU;2-I
Abstract
The bacterial population of an autohydrogenotrophic pilot-reactor for denitrification of drinking water was characterized. Two samples were taken from the reactor under mesotrophic and psychrotrophic conditions , respectively. We purified 82 mesotrophs and 54 psychrotrophs. After screening by sodium dodecyl sulphate-polyacrylamide gelelectrophoresis of whole-cell proteins we obtained 30 and 36 different strains, respe ctively. These strains were identified by gaschromatographic fatty aci d analysis, phenotypic tests (API), DNA-rRNA hybridizations and % G+C determination. Furthermore, their autohydrogenotrophic and heterotroph ic denitrification capacities under mesotrophic or psychrotrophic cond itions were tested. Some of the mesotrophs were assigned to: Aeromonas hydrophila (5 strains), Acinetobacter johnsonii (3 strains), Comamona s acidovorans (2 strains) and Shewanella putrefaciens (1 strain). The following identifications were obtained at the genus level: Serratia s p. (2 strains), Pseudomonas sp. (possibly P. stutzeri, 4 strains, P. m endocina, 1 strain; P. syringae, 2 strains). Some of the psychrotrophs were assigned to: Shewanella putrefaciens (5 strains), Aeromonas hydr ophila (1 strain), Aeromonas sobria (1 strain) and Micrococcus lylae ( 1 strain). The following identifications were obtained at the genus le vel: Acinetobacter sp. (16 strains) and Pseudomonas sp. (P. aureofacie ns, 4 strains; P. syringae, 2 strains). The identification of the othe r strains was unreliable. Computer-assisted comparison of the individu al strain data showed that Aeromonas hydrophila, Shewanella putrefacie ns, Acinetobacter sp. and Pseudomonas sp. are present both in the meso trophic and the psychrotrophic sample. None of the isolates was capabl e of autohydrogenotrophic denitrification. Under heterotrophic conditi ons, 7 Pseudomonas members and one unidentified isolate showed complet e denitrification. This could indicate that the denitrification proces s in the reactor is not strictly autohydrogenotrophic or that the caus al organisms were not yet isolated. Due to the presence of opportunist ic human pathogens such as Aeromonas hydrophila, Shewanella putrefacie ns, Acinetobacter sp. and Serratia sp. this denitrification reactor ca n only be used as a pretreatment step, which should be followed by a d esinfection of the water.