title: Uncovering the cultivable microbial diversity of costa rican beetles and its ability to break down plant cell wall components.
abstract: Coleopterans are the most diverse insect order described to date. These organisms have acquired an array of survival mechanisms through their evolution, including highly efficient digestive systems. Therefore, the coleopteran intestinal microbiota constitutes an important source of novel plant cell wall-degrading enzymes with potential biotechnological applications. We isolated and described the cultivable fungi, actinomycetes and aerobic eubacteria associated with the gut of larvae and adults from six different beetle families colonizing decomposing logs in protected Costa Rican ecosystems. We obtained 611 isolates and performed phylogenetic analyses using the ITS region (fungi) and 16S rDNA (bacteria). The majority of fungal isolates belonged to the order Hypocreales (26% of 169 total), while the majority of actinomycetes belonged to the genus Streptomyces (86% of 241 total). Finally, we isolated 201 bacteria spanning 19 different families belonging into four phyla: Firmicutes, α, β and γ-proteobacteria. Subsequently, we focused on microbes isolated from Passalid beetles to test their ability to degrade plant cell wall polymers. Highest scores in these assays were achieved by a fungal isolate (Anthostomella sp.), two Streptomyces and one Bacillus bacterial isolates. Our study demonstrates that Costa Rican beetles harbor several types of cultivable microbes, some of which may be involved in symbiotic relationships that enable the insect to digest complex polymers such as lignocellulose.
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica; Departamento de Bioquímica, Universidad de Costa Rica, San Pedro de Montes de Oca, Costa Rica.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Vargas-Asensio
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica; Departamento de Bioquímica, Universidad de Costa Rica, San Pedro de Montes de Oca, Costa Rica; Centro de Investigación en Estructuras Microscópicas (CIEMIC), Universidad de Costa Rica, San Pedro de Montes de Oca, Costa Rica.
authors.forename: Adrian
authors.initials: A
authors.lastname: Pinto-Tomas
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rivera
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica.
authors.forename: Myriam
authors.initials: M
authors.lastname: Hernandez
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica.
authors.forename: Carlos
authors.initials: C
authors.lastname: Hernandez
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica.
authors.forename: Silvia
authors.initials: S
authors.lastname: Soto-Montero
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica.
authors.forename: Catalina
authors.initials: C
authors.lastname: Murillo
authors.affiliation: Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: David H
authors.initials: DH
authors.lastname: Sherman
authors.affiliation: Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica; Escuela de Química & Centro de Investigación en Productos Naturales (CIPRONA), Universidad de Costa Rica, San Pedro de Montes de Oca, Costa Rica.
authors.forename: Giselle
authors.initials: G
authors.lastname: Tamayo-Castillo
mesh_terms: D039903:Actinobacteria / Q000145:classification* / Q000201:enzymology / Q000302:isolation & purification; D000818:Animals; D001420:Bacteria, Aerobic / Q000145:classification* / Q000201:enzymology / Q000302:isolation & purification; D002473:Cell Wall / Q000378:metabolism*; D001517:Coleoptera / Q000033:anatomy & histology / Q000145:classification / Q000382:microbiology*; D003364:Costa Rica; D004269:DNA, Bacterial / Q000032:analysis; D004271:DNA, Fungal / Q000032:analysis; D005658:Fungi / Q000145:classification* / Q000201:enzymology / Q000302:isolation & purification; D007422:Intestines / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D059828:Plant Cells / Q000378:metabolism*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004271:DNA, Fungal