@article{fdi:010062375,
  title = {{C}ontribution of white grubs ({S}carabaeidae : {C}oleoptera) to {N}2{O} emissions from tropical soils},
  author = {{M}ajeed, {M}. {Z}. and {M}iambi, {E}. and {B}arois, {I}. and {R}andriamanantsoa, {R}. and {B}lanchart, {E}ric and {B}rauman, {A}lain},
  editor = {},
  language = {{ENG}},
  abstract = {{S}oil biological processes that produce greenhouse gases, such as {N}2{O}, are more intense in tropical soils because of the warm and humid climate; however, the role played by the wide diversity of fauna in these soils in soil {N}2{O} production is still poorly understood. {T}his study attempts to assess the role of scarabaeid grubs ({C}oleoptera), a major faunal group in tropical soils, in emissions of atmospheric {N}2{O}. {I}t was hypothesized that (i) the guts of these grubs are important sites of {N}2{O}-genesis, since they present environmental conditions (anoxia, high labile {C} and {N} mineral contents) that are suitable for {N}2{O} production; and (ii) rates of {N}2{O} emissions will vary according to the density of gut microbial communities that are involved in {N}2{O} emission (i.e. ammonia-oxidizers and denitrifiers). {T}hrough laboratory microcosm experiments, in vitro emissions of {N}2{O} were determined directly from live grubs of different scarabaeid species (collected from tropical soils of {M}adagascar and {M}exico) and from their surrounding parent soils. {Q}uantitative {PCR} was used to determine the abundance of the total bacterial community (using the 16{S} r{RNA} gene) as well as the ammonia-oxidizing (bacterial {AOB} and archaeal {AOA}) and denitrifying (nir{K}, nir{S} and nos{Z}) microbial communities in the grub guts and surrounding soils. {T}he mineral {N} contents of grub guts and parent soils were also determined using a continuous flow analysis technique. {A}ll of the studied grub species emitted significantly higher {N}2{O} than the parent soils and presented a high gut ammonium to nitrate ratio (16:1). {T}heir guts harbor a higher density of total bacterial (4.5-fold) and nitrite reductase (nir{K}) genes (1.5-fold) than the parent soils. {H}owever, with the exception of nir{K}, the relative and absolute abundances of all ammonia-oxidizer and denitrifier genes were higher in soils than in the grub gut environment. {T}he average gene abundance of {AOA} was 10-fold higher than that of its bacterial counterpart ({AOB}). {E}mission of {N}2{O} from grubs correlated significantly with the gene abundance of their gut ammonia-oxidizers ({AOA} and {AOB}) and denitrifiers (nir{S}), but not with mineral {N} contents. {B}ased on average biomass values, these scarabaeid grubs are estimated to contribute between 0.2 and 1.8% of total soil {N}2{O} emissions in tropical areas.},
  keywords = {{T}ropical soils ; {N}2{O} emissions ; {G}ut microbiota ; {F}unctional nitrogen genes ; {D}enitrification ; {M}ineral nitrogen ; {MADAGASCAR} ; {MEXIQUE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{S}oil {B}iology and {B}iochemistry},
  volume = {75},
  numero = {},
  pages = {37--44},
  ISSN = {0038-0717},
  year = {2014},
  DOI = {10.1016/j.soilbio.2014.03.025},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062375},
}