In the marine environment, the bacteria that colonize the surface of a seaweed affect its growth and development. In the laboratory, several seaweeds do not develop normal foliose thalli in axenic cultures, but adopt an atypical morphology. Adding certain bacteria to the culture, however, can result in reversion to the normal morphology. The aim of the present study was to examine the effects o...

The effects of age in culture and the type of medium used for induction of Acanthamoeba polyphaga (Ros) cysts on susceptibilities to polyhexamethylene biguanide (PHMB; 3 micro g/ml), chlorhexidine digluconate (30 micro g/ml), myristamidopropyl dimethylamine (20 micro g/ml), H(2)O(2) (3%), and two multipurpose contact lens solutions (MPS-1 and MPS-2, based on 1 micro g of PHMB per ml) were exami...

Saprophytic bacteria in cultures of the marine dinoflagellate Alexandrium catenella were removed to assess their effect on growth and paralytic shellfish poisoning toxin production of this dinoflagellate. The actual axenic status was demonstrated by the lack of observable bacteria both immediately after treatment and following extended incubation in the absence of antibiotics. Bacteria were mea...

Benthic diatoms and bacteria often co-operatively build up phototrophic epilithic biofilms. Studying the properties and contributions of the individual partners requires the establishment and maintenance of axenic cultures of the involved organisms. Axenification of biofilm organisms is often challenging, because bacteria as well as diatom cells are embedded in a matrix of extracellular polymer...

Interactions between phytoplankton and heterotrophic bacteria have been intensively studied, but many aspects of these interactions are still unknown because most of the studies were performed under non-axenic conditions. Therefore, we investigated the growth and release of dissolved organic matter of the marine diatom Thalassiosira rotula in axenic culture in comparison to T. rotula cultures i...