Bacteria-algae association in batch cultures of phytoplankton from a tropical reservoir: the significance of algal carbohydrates

Autor(es)

Giroldo, Danilo ^[1] ; Ortolano, Pedro I. C. ^[2] ; Vieira, Armando A. H. ^[3]

Afiliação do(s) autor(es)

^[1] Universidade Federal de São Carlos (UFSCAR). Centro de Ciências Biológicas e da Saúde - Brasil

^[2] Universidade Federal de São Carlos (UFSCAR). Centro de Ciências Biológicas e da Saúde. - Brasil

^[3] Universidade Federal de São Carlos (UFSCAR). Centro de Ciências Biológicas e da Saúde. - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Freshwater Biology; v. 52, n. 7, p. 1281-1289, 2007.
• Área do conhecimento: Ciências Biológicas - Microbiologia
• Assunto(s): Fitoplâncton Cianobactérias Diatomáceas Simbiose

Resumo

The dissolved organic matter, especially carbohydrates, released by phytoplanktonic organisms may be ecologically important, through its influence on carbon cycling and microbial diversity. Here axenic cultures of three phytoplanktonic species, Cryptomonas tetrapyrenoidosa (Cryptophyceae), Staurastrum orbiculare (Zygnematophyceae) and Thalassiosira duostra (Bacillariophyceae), were inoculated with a microbial community from the same habitat in which the algae had been isolated (a tropical reservoir). Replicate cultures were not inoculated. 2. In both axenic and co-inoculated cultures, phytoplanktonic density and extracellular carbohydrate production were monitored microscopically and by high performance liquid chromatography with a pulse amperometric detector, respectively. Bacterial population density was also monitored by epifluorescence microscope in the microbial co-inoculated cultures. 3. Both bacterial and phytoplanktonic densities increased for 11 days in all cases. The use of extracellular carbohydrates by bacteria was also showed for all phytoplanktonic species. Of the three species of phytoplankton, only T. duostra had a faster population growth in the presence of bacteria, and reached a higher biomass than in axenic culture. (AU)

• Processo FAPESP: 99/07766-0 - Produção e destino dos polissacarídeos extracelulares de origem algal em um reservatório eutrofizado do rio Tietê (estudo de processo)
• Beneficiário: Armando Augusto Henriques Vieira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 00/07202-8 - Estudo das relações interespecíficas alga/bactéria vinculadas aos excretados algais de baixa massa molecular
• Beneficiário: Pedro Ivo Coelho Ortolano
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 99/01353-5 - Especificidade alga/bacteria vinculada a materia organica dissolvida excretada pelas algas planctonicas de agua doce.
• Beneficiário: Danilo Giroldo
• Modalidade de apoio: Bolsas no Brasil - Doutorado