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| Author(s): |
Aline Bartelochi Pinto
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Rio Claro. 2016-07-19. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro |
| Defense date: | 2016-05-16 |
| Advisor: | Ana Júlia Fernandes Cardoso de Oliveira; Marcelo Antônio Amaro Pinheiro |
| Abstract | |
Intertidal rocky shores biofilm is a tridimensional structure composed, mainly, by bacteria, cyanobacteria, diatoms, protozoans and macroalgae spores immersed in a mucopolysaccharides matrix. Thus, biofilm is an important food source for some species and has direct influence on the community structure of rocky shores although, due to difficulties in its sampling and quantification, has being given little attention. The present study aimed to evaluate the influence of organic contamination on biofilm composition and diversity of microbiota (cyanobacteria, heterotrophic bacteria) and microphytoplancton (diatoms and nanoheterotrophs) from rocky shores under different conditions as well as differences according to zonation (meso and infralittoral) and wave impacts (moderately exposed and sheltered). Therefore, 4 rocky shores from Ubatuba city (Sao Paulo, Brazil) were sampled during low tide, in georeferenced points from meso and infralittoral. Samples destined to quantification by epifluorescence were placed in vials with formaldehyde at 5% final concentration, for fixation of microorganisms while those intended for the isolation were placed in vials with sterile and filtered seawater. At each sampling point were recorded temperature, dissolved oxygen (DO) and photosynthetic pigment (chlorophyll a). The results suggest that there are differences between the analyzed beaches and in relation to the parameters assessed within a beach which indicates that both zonation and wave impact on rocky shores influence the structure of microbial community present in its biofilm. The presence of faecal indicators both in water and biofilm samples shows an impact by domestic effluents in the evaluated beaches and that biofilms can act as a protective microenvironment for microorganisms in intertidal systems. Although this may offer advantages for ecosystems productivity, it can be a problem for environment and public health since they can also accumulate pathogenic microorganisms and, similarly to what happens in other types of biofilms, can become potential sources of environment, biota and humans contamination. The present study was founded by FAPESP proc nº 2011/22781-9 (AU) | |