TY - JOUR
T1 - Bacterial community and nitrogen fixation in the red turpentine beetle, dendroctonus valens LeConte (Coleoptera: Curculionidae: Scolytinae)
AU - Morales-Jiménez, Jesús
AU - Zúñiga, Gerardo
AU - Villa-Tanaca, Lourdes
AU - Hernández-Rodríguez, César
N1 - Funding Information:
We thank Esperanza Martínez-Romero and Marco Rogel for their technical assistance with the acetylene reduction assay, and Francisco Bonilla, Marco Espinal, Fernanda López, Arturo Vera, Javier Zavala for support in insect collection. Also, we thank Hugo Ramírez Saad and Félix Garrido for their technical assistance with DGGE. This work was supported by grants CGPI20060532 and CGPI20070651, IPN, and CONAFOR 2002 C01-6020. Jesús Morales-Jiménez thanks to CONACyT and PIFI, IPN, for scholarships.
PY - 2009/11
Y1 - 2009/11
N2 - The red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae: Scolytinae), colonizes all pines species within its native range throughout North and Central America. Recently, this species was accidentally introduced to China, where it has caused severe damage in pine forests. It belongs to a group of beetles that spend most of their lives between the tree bark and sapwood, where it feeds on phloem: a poor substrate with very low nutritional value of nitrogen and toxic properties due to its high content of secondary defensive compounds. The aim of this study was to characterize the bacterial community of the D. valens gut by culture-dependent and -independent methods. Polymerase chain reaction denaturing gradient gel electrophoresis and ribosomal gene library analyses revealed that species diversity in the D. valens gut was relatively low, containing between six and 17 bacterial species. The bacterial community associated with larvae and adults was dominated by members of the following genera: Lactococcus, Acinetobacter, Pantoea, Rahnella, Stenothrophomonas, Erwinia, Enterobacter, Serratia, Janibacter, Leifsonia, Cellulomonas, and Cellulosimicrobium. The members of the last four genera showed cellulolytic activity in vitro and could be involved in cellulose breakdown in the insect gut. Finally, nitrogen fixation was demonstrated in live larvae and adults; however, capacity of nitrogen fixing in vitro was not found among enterobacterial species isolated in nitrogen-free media; neither were nifD nor nifH genes detected. In contrast, nifD gen was detected in metagenomic DNA from insect guts. The identification of bacterial species and their potential physiological capacities will allow exploring the role of gut symbiotic bacteria in the adaptation and survival of D. valens in a harsh chemical habitat poor in nitrogen sources.
AB - The red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae: Scolytinae), colonizes all pines species within its native range throughout North and Central America. Recently, this species was accidentally introduced to China, where it has caused severe damage in pine forests. It belongs to a group of beetles that spend most of their lives between the tree bark and sapwood, where it feeds on phloem: a poor substrate with very low nutritional value of nitrogen and toxic properties due to its high content of secondary defensive compounds. The aim of this study was to characterize the bacterial community of the D. valens gut by culture-dependent and -independent methods. Polymerase chain reaction denaturing gradient gel electrophoresis and ribosomal gene library analyses revealed that species diversity in the D. valens gut was relatively low, containing between six and 17 bacterial species. The bacterial community associated with larvae and adults was dominated by members of the following genera: Lactococcus, Acinetobacter, Pantoea, Rahnella, Stenothrophomonas, Erwinia, Enterobacter, Serratia, Janibacter, Leifsonia, Cellulomonas, and Cellulosimicrobium. The members of the last four genera showed cellulolytic activity in vitro and could be involved in cellulose breakdown in the insect gut. Finally, nitrogen fixation was demonstrated in live larvae and adults; however, capacity of nitrogen fixing in vitro was not found among enterobacterial species isolated in nitrogen-free media; neither were nifD nor nifH genes detected. In contrast, nifD gen was detected in metagenomic DNA from insect guts. The identification of bacterial species and their potential physiological capacities will allow exploring the role of gut symbiotic bacteria in the adaptation and survival of D. valens in a harsh chemical habitat poor in nitrogen sources.
UR - http://www.scopus.com/inward/record.url?scp=73349105940&partnerID=8YFLogxK
U2 - 10.1007/s00248-009-9548-2
DO - 10.1007/s00248-009-9548-2
M3 - Artículo
C2 - 19543937
SN - 0095-3628
VL - 58
SP - 879
EP - 891
JO - Microbial Ecology
JF - Microbial Ecology
IS - 4
ER -