Spatial and temporal analysis of estuarine bacterioneuston and bacterioplankton using culture-dependent and culture-independent methodologies
- 326 Downloads
Bacterioneuston may play a key role in water–air exchange of gases and in processing organic matter and pollutants that accumulate at the sea-surface microlayer (SML). However, the phylogenetic diversity of bacterioneuston has been poorly characterized. We analyzed 24 samples each from the SML and underlying water (UW) at three sites in the Ria de Aveiro estuary, Portugal. Cultivation and culture-independent techniques were used to compare bacterioneuston and bacterioplankton. Culturable heterotrophic bacteria were enriched in the SML. The culturable community was dominated by Psychrobacter and Acinetobacter. The presence of high numbers of Psychrobacter was a notable result. Differences were confined to a few genera overrepresented in UW samples (Kocuria, Agrococcus and Vibrio). 16S rDNA DGGE profiles were highly stable in terms of number and position of bands between sampling sites and dates but cluster analysis revealed a slight tendency for grouping according to sampled layer. SML-specific DGGE bands affiliated with Actinobacteria, Cyanobacteria, Gammaproteobacteria and Bacteroidetes. Low similarity between nucleotide sequences of DGGE-bands and previously reported sequences suggest the occurrence of SML-specific populations. Enrichment of SML for Pseudomonas and Aeromonas was questioned and the diversity of both communities was analyzed. Consistent differences between SML and UW aeromonads communities were not identified. In terms of Pseudomonas, a culturable operational taxonomic unit was consistently overrepresented within SML samples. Taken together, our results indicate that the similarity between SML and UW communities depends on spatial and temporal factors.
KeywordsPhylogenetic diversity biofilm Sea-surface microlayer Estuary DGGE
This work was financed by the Fundacão para a Ciência e a Tecnologia (FCT) through grants SFRH/BPD/65820/2009 (CSO), SFRH/BD/64057/2009 (JSNA) and SFRH/BPD/21384/2005 (IH) and by the European Union Program of High Level Scholarships for Latin America––Program Alβan––through grant E07D403901BR (JSNA). The authors wish to thank Ângela Cunha and Adelaide Almeida for technical support (sampling device, conductivity meter, etc.). We are also grateful to A. Moura (Department of Biology, University of Aveiro) for reviewing English style and grammar.
- Clarke KR, Gorley RN (2001) PRIMER v5: User manual/tutorial. PRIMER-E, Plymouth, p 91Google Scholar
- Coelho FJRC, Sousa S, Santos L, Santos AL, Almeida A, Gomes NCM, Cunha A (2010) PAH Degrading bacteria in an estuarine system. Studies on environmental chemistry-biological responses to contaminants. In: Hamamura N, Suzuki S, Mendo S, Barroso CM, Iwata H, Tanabe S (eds) Interdisciplinary studies on environmental chemistry-biological responses to contaminants. Center for Marine Environmental Studies, Ehime University, Japan, Department of Biology, University of Aveiro, Portugal, pp 77–87Google Scholar
- Keddy PA (2000) Wetland ecology: principles and conservation. Cambridge University Press, Cambridge, pp 3–77Google Scholar
- Lane DJ (1991) 16S/23S rRNA Sequencing. In: Stackebrandt E, Goodfellow M (eds) Nucleic acid techniques in bacterial systematics. John Wiley and Sons, New York, pp 115–175Google Scholar
- Liss PS, Watson AJ, Bock EJ, Jahne B, Asher WE, Frew NM, Hasse L, Korenowski GM, Merlivat L, Philips LF, Schluessel P, Woolf DK (1997) Physical processes in the microlayer and the air–sea exchange of trace gases. In: Liss PS, Duce RA (eds) The sea surface and global change. Cambridge University Press, Cambridge, pp 1–34CrossRefGoogle Scholar
- Maki JS (2002) Neuston microbiology: life at the air–water interface. In: Bitton G (ed) Encyclopedia of environmental microbiology. John Wiley and Sons, New York, pp 2133–2144Google Scholar
- Naumann E (1917) Beiträge zur Kenntnis des Teichnannoplanktons. II. Über das Neustons des Süsswasser. Biologie Zentralbl 37:98–106Google Scholar
- Tamaki H, Sekiguchi Y, Hanada S, Nakamura K, Nomura N, Matsumura M, Kamagata Y (2005) Comparative analysis of bacterial diversity in freshwater sediment of a shallow eutrophic lake by molecular and improved cultivation-based techniques. Appl Environ Microbiol 71:2162–2169PubMedCrossRefGoogle Scholar