caa a22 4500 605497745 CHVBK 20210128100542.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00253-014-6013-z doi (NATIONALLICENCE)springer-10.1007/s00253-014-6013-z The essential role of nitrogen limitation in expression of xplA and degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in Gordonia sp. strain KTR9 [Elektronische Daten] [Song-Hua Zhu, Jens Reuther, Jie Liu, Fiona Crocker, Karl Indest, Lindsay Eltis, William Mohn] Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a widely used explosive and a major soil and groundwater contaminant. Organisms such as Gordonia sp. KTR9, capable of degrading RDX and using it as an N source, may prove useful for bioremediation of contaminated sites. XplA is a cytochrome P450 monooxygenase responsible for RDX degradation. Expression of xplA in KTR9 was not induced by RDX but was strongly induced (50-fold) during N-limited growth. When glnR, encoding a regulatory protein affecting N assimilation in diverse Actinobacteria, was deleted from KTR9, the bacterium lost the ability to use nitrate, nitrite, and RDX as N sources. Deletion of glnR also abolished the inhibition of xplA expression by nitrite. Our results confirm the essential role of GlnR in regulating assimilation of nitrite, but there was no evidence for a direct role of GlnR in regulating XplA expression. Rather, the general availability of nitrogen repressed XplA expression. We conclude that the inability of the glnR mutant to use RDX as an N source was due to its inability to assimilate nitrite, an intermediate in the assimilation of nitrogen from RDX. Regulation of XplA does not seem adaptive for KTR9, but it is important for RDX bioremediation with KTR9 or similar bacteria. Springer-Verlag Berlin Heidelberg, 2014 RDX degradation nationallicence Metabolism nationallicence Gene expression/regulation nationallicence xplA nationallicence GlnR nationallicence Bacteria nationallicence Zhu Song-Hua Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut Reuther Jens Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut Liu Jie Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut Crocker Fiona Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, USA aut Indest Karl Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, USA aut Eltis Lindsay Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut Mohn William Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/1(2015-01-01), 459-467 0175-7598 99:1<459 2015 99 253 https://doi.org/10.1007/s00253-014-6013-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6013-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhu Song-Hua Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Reuther Jens Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Liu Jie Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Crocker Fiona Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, USA aut NATIONALLICENCE 700 1- Indest Karl Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, USA aut NATIONALLICENCE 700 1- Eltis Lindsay Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Mohn William Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/1(2015-01-01), 459-467 0175-7598 99:1<459 2015 99 253