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dc.contributor.advisorMontalvo-Rodríguez, Rafael R.
dc.contributor.authorCouto-Rodríguez, Mara
dc.date.accessioned2018-06-03T23:06:59Z
dc.date.available2018-06-03T23:06:59Z
dc.date.issued2009
dc.identifier.urihttps://hdl.handle.net/20.500.11801/678
dc.description.abstractSea grass beds are considered a vital component of marine ecosystems, which serve as a nutrient source for many marine organisms, while also providing a critical habitat for many endangered species. In Puerto Rico sea grass bed communities are beneficial to different marine ecosystems, though this habitat has been threatened by developmental projects, pollution and global warming which consequently are causing its decay. The scope of this research project was to determine the prokaryotic endophytic diversity of T. testudinum beds and to establish differences in community structure of four geographical areas in Puerto Rico that have been exposed to different anthropogenic impacts. The objectives were addressed by culture dependent and culture independent techniques. A total of 1,279 strains were recovered from surface sterilized leaves. Phylogenetic analysis revealed the prevalence of gamma-Proteobacteria (Enterobacter (5%), Pseudomonas(1%) and Cobetia(4%), Actinobacteria (Cellulosimicrobium, Nesterenkonia and Micrococcus (1%)), and the Firmicutes (Bacillus(55%), Geobacillus(<1%), Staphylococcus(18%) and Halobacillus(11%). Furthermore the complexity and diversity patterns of the prokaryote community associated with total DNA extracted was evaluated based on Terminal Fragment Length Polymorphism (TRFLP) profiles and the analysis of clone libraries of PCR amplified 16S rRNA genes. TRFLP patterns revealed shared similarities in community structure as well as unique patterns for each sampling site, while the analysis of 16S rRNA clone libraries revealed the dominance of alpha-Proteobacteria, gamma Proteobacteria, epsilon-Proteobacteria and Firmicutes. Staphylococcus isolates predominated in Buyé Beach (39%) in contrast to the reduced community at the other sites (< 7%). In addition, Bacillus isolates were predominant in all sites, excluding Buyé which confirms the unfavorable influence of higher impact to this site, since members of Bacillus are recognized for establishing beneficial associations with terrestrial plants. Culture independent techniques revealed low diversity of TRF’s and shifts of predominant OTU’s for Buyé clone libraries. Statistical analysis confirmed that this site is significantly different from the others, suggesting that Buyé higher levels of impact are causing alterations to the basal endophytic communities. By knowing the assemblages of these endophytes is setting bases for the development of new strategies for restoration programs to address the decay of sea grasses.
dc.description.abstractLas praderas de hierbas marinas son un componente vital del ecosistema marino, sirviendo como fuente de nutrientes para muchos organismos marinos, y también proveen un habitat crítico para especies en peligro de extinición. En Puerto Rico las praderas de hierbas marinas son beneficiosas para diferentes ecosistemas marinos, pero este habitat ha sido amenazado por el desarrollo de proyectos, la contaminación y calentamiento global, causando como consecuencia su decaimiento. El enfoque de este proyecto de investigación consistió en determinar la diversidad de endófitos procariotas asociados a las praderas de Thalassia testudinum y establecer la estructura de comunidades de cuatro areas geográficas de Puerto Rico que están expuestas a diferentes impactos antropogénicos. Los objetivos fueron realizados por técnicas dependientes de cultivo e independiente de cultivo. Se obtuvo un total de 1,279 cepas de hojas esterilizadas superficialmente. Análisis filogenéticos demostraron la prevalencia de gamma-Proteobacteria (Enterobacter (5%), Pseudomonas(1%) y Cobetia(4%), Actinobacteria (Cellulosimicrobium, Nesterenkonia y Micrococcus (1%)), y Firmicutes (Bacillus(55%), Geobacillus(<1%), Staphylococcus(18%) and Halobacillus(11%). Tambien los patrones de diversidad y complejidad de la comunidad procariota asociada al DNA total extraído fue evaluado por perfiles de “Terminal Fragment Length Polymorphism” (TRFLP) y análisis de bibliotecas de clones del gen 16S rRNA amplificadas por PCR. Los patrones de TRFLP demostraron similaridades compartidas en la estructura de la comunidad, como también patrones únicos por cada area de muestreo, mientras que el análisis de las bibiliotecas de clones de 16S rRNA demostraron la dominancia de alpha-Proteobacteria, gamma Proteobacteria, epsilon- Proteobacteria y Firmicutes. Cepas de Staphylococcus fueron las predominantes en Buyé Beach (39%), en contraste con la reducida comunidad presente en las otras areas (< 7%). En adición, las cepas de Bacillus predominaron en todas las áreas, excluyendo a Buyé confirmando la desfavorable influencia del impacto en este lugar, ya que los miembros de Bacillus se reconocen por establecer asociaciones beneficiosas con plantas terrestres. Las técnicas independientes de cultivo revelaron baja diversidad de TRF’s y cambios en la predominancia de OTU’S para las librerias de clones en Buyé. El análisis estadístico confirma que este lugar es significativamente diferente a las demás areas, sugiriendo que los niveles elevados de impacto en Buyé están causando alteraciones a la comunidad endófita basal. El conocer la composición de estos endófitos está sentando las bases para desarrollar nuevas estrategias para programas de restauración enfocados en prevenir el decaimiento de las hierbas marinas.
dc.description.sponsorshipSea Grant at the University of Puerto Rico-Mayagüez Campusen_US
dc.language.isoenen_US
dc.subjectSea grass bedsen_US
dc.subjectT. testudinum bedsen_US
dc.subjectPuerto Rico sea grass bed communitiesen_US
dc.subjectProkaryotic endophytic diversityen_US
dc.subject.lcshEndophytic fungi--Variation--Puerto Ricoen_US
dc.subject.lcshTurtle grass--Microbiology--Puerto Ricoen_US
dc.subject.lcshEcological assessment (Biology)--Puerto Ricoen_US
dc.subject.lcshProkaryotes--Variation--Puerto Ricoen_US
dc.subject.lcshMicrobial diversity--Puerto Ricoen_US
dc.titleEndophytic prokaryotic diversity associated with sea grass beds of Thalassia testudinum from Cabo Rojo, Lajas, and Vieques, Puerto Ricoen_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2009 Mara Couto Rodríguezen_US
dc.contributor.committeeMaldonado Ramírez, Sandra L.
dc.contributor.committeeAcosta Mercado, Dimaris
dc.contributor.committeeRodríguez Minguela, Carlos
dc.contributor.representativeGrove, Kurt
thesis.degree.levelM.S.en_US
thesis.degree.disciplineBiologyen_US
dc.contributor.collegeCollege of Arts and Sciences - Sciencesen_US
dc.contributor.departmentDepartment of Biologyen_US
dc.description.graduationYear2009en_US


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