Open AccessPhylogenetic and metabolic diversity of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX)‐transforming bacteria in strictly anaerobic mixed cultures enriched on RDX as nitrogen source
Author(s) -
Zhao JianShen,
Spain Jim,
Hawari Jalal
Publication year - 2003
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1016/s0168-6496(03)00216-2
Subject(s) - clostridia , biology , clostridium , microbiology and biotechnology , obligate anaerobe , bacteria , methanogen , desulfovibrio , enrichment culture , nitrite , anaerobic bacteria , nitrogen , food science , environmental chemistry , chemistry , nitrate , organic chemistry , ecology , genetics
Five obligate anaerobes that were most closely related to Clostridium bifermentans , Clostridium celerecrescens , Clostridium saccharolyticum , Clostridium butyricum and Desulfovibrio desulfuricans by their 16S rRNA genes sequences were isolated from enrichment cultures using hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) as a nitrogen source. The above isolates transformed RDX at rates of 24.0, 5.4, 6.2, 2.5, 5.5 μmol h −1 g (dry weight) of cells −1 , respectively, to nitrite, formaldehyde, methanol, and nitrous oxide. The present results indicate that clostridia are major strains responsible for RDX removal, and all isolates seemed to mainly transform RDX via its initial reduction to MNX and subsequent denitration. Since clostridia are commonly present in soil, we suggest that they may contribute to the removal of RDX in the subsurface (anoxic) soil.