INBA   12521
INSTITUTO DE INVESTIGACIONES EN BIOCIENCIAS AGRICOLAS Y AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effect of captivity conditions on gut microbial community associated with the southern green stinkbug (Nezara viridula).
Autor/es:
MEDINA, V; SARDOY, P; PAGANO, E; MIYAZAKI, S; ZAVALA J.A.
Lugar:
Mar del Plata
Reunión:
Congreso; VII Congreso Argentino de Microbiología General ? SAMIGE,; 2012
Institución organizadora:
SAMIGE
Resumen:
Southern green stinkbug (Nezara viridula) is one of the most relevant pests of soybean crops, which feeds on the seeds in spite of their strong defenses against herbivory. The microbial community in the gut of stinkbugs may have a role in helping digestion and tolerance of chemical defenses of soybeans, such as protease inhibitors that decrease insect performance. The aim of this study was to describe the microbial communities present in the gut of adult southern greenstink bugs collected from their natural environment, and the effect of captivity on bacterial communities. Fifty percent of the bugs collected from soybean crops and neighboring areas were dissected, and the rest were held for rearing with artificial diet and dissected 15 days later. Insect dissections were carried out under sterile conditions, and guts were analyzed using culturing and non-culturing techinques. Cell counts and isolations, and 16S ribosomal sequencing were performed and communities and pure cultures were analyzed by (ARISA). In addition, proteolytic activity of pure bacterial cultures was assayed. In insects collected in their natural environment a transient flora with varying total bacterial count (from103 to 106 CFU/mg) was found, which included the presence of proteolytic spore-forming rods identified as Bacillus pumilus and other species, typical flora of host plants and soil and Gram ?  of the Enterobacteriaceae family. On the other hand, the bugs in captivity were more stable in bacterial counting (106 CFU/mg),  two enterobacteria of the genus Klebsiella sp. and Serratia marcescens were identified. Occasionally, Enterococcus faecium and Bacillus sp were also found in captivity. In addition, the CFU/mg of the entomopathogen Serratia marcescens, whose presence seems to be associated with insect stress generated by the captivity conditions, was reduced with the addition of 125 mg/l of streptomycin into the drinking water. ARISA profiles of the microbiome of the stinkbugs fed in captivity showed lower diversity, 3 to 4 OTUs (Operational Taxonomic Unit) compared to 6 to 10 OTUs found in those insects collected from soybean cultivars.The biodiversity of the microbiome of the bugs in their natural environment is more complex than in captivity conditions. These changes in biodiversity should be taken into account for studies on nutrition of these insects and its symbiotic relationships with intestinal microorganisms.