TITLE:
Enrichment of nitrous oxide reducing bacteria from coastal marsh sediments
AUTHORS:
Khuong B. T. Nguyen, Dmitri Sobolev
KEYWORDS:
Nitrous Oxide Reduction; Salt Marsh; Denitrification; DGGE; Gammaproteobacteria
JOURNAL NAME:
Open Journal of Ecology,
Vol.3 No.4,
July
23,
2013
ABSTRACT: We attempted to recover organisms capable of respiratory
nitrous oxide reduction with acetate as an electron donor from a variety of
coastal marine sediments from Lavaca Bay area, Texas by use of liquid
enrichment cultures. Putative positive cultures were analyzed by amplifying
eubacterial and archaeal 16S rRNA gene fragments and analyzing their diversity
by separating them by a denaturing gradient gel electrophoresis (DGGE). No Archaea was detected in our enrichments;
however, positive enrichments from coastal salt marsh indicated the presence of
putative nitrous oxide reducing bacteria. DGGE patterns of the amplified DNA
were similar between enrichments, with ca. 7 obvious bands. The dominant bands
were tentatively identified as members of the Gammaproteobacteria class, closely related to various denitrifying
pseudomonads. Our results indicate that coastal marine environments may sustain
a nitrous oxide reducing community, although nitrous oxide reduction is
probably an opportunistic form of metabolism in that environment.