engleski

The role of structural features of algal cells on adhesion behavior at the interface

The structural features of the cell barrier significantly affect the life of unicellular microalgae and determine which niches in the ecosystem will cell occupy. The structural features, its composition, and surface properties of cell barriers are important for intercellular communication, as well as for the regulation of the transport of materials between the intracellular cytosol and the external environment. This study aimed to examine the effects of algal cell structural features on adhesion and spreading at a model charged interface. The used method was the electrochemical method of polarography and chronoamperometry at the dropping mercury electrode (DME). Due to the attractive interaction between the algal cell and charged electrode, the cell attaches, deforms, bursts, and spreads over the interface which can be recorded as an amperometric signal [1]. Each amperometric signal corresponds to the adhesion of a single organic particle from the suspension to the charged interface. Four unicellular algal cell species with distinctive barrier structures were selected as model organisms. Results show that Dunaliella tertiolecta, with a thin elastic plasma membrane and glycocalyx surface coat, and Prorocentrum micans, with a cellulose amphiesma adhere to and spread over a charged mercury interface at species-specific potential ranges which are registered as well-defined amperometric signals. Tetraselmis suecica, encased with a thin calcite incrustrated theca, and Cylindrotheca closterium, with an organosilicate cell wall, do not adhere to the charged interface and thus do not generate an amperometric signal. These differences in adhesion behavior of algal cells determined amperometrically are in agreement with reported cell nanomechanical properties. The elasticity of Dunaliella cells is about ten kPa [2]. Cylindrotheca cell elasticity is about three to four orders of magnitude higher, thus these cells behave as non-deformable at the interface [3]. Besides differentiation between soft vs. rigid cells, measured critical interfacial tensions of adhesion enable fine differentiation between soft algal cells and ghost vesicles. Taking into account that the electrochemical method at DME offers direct and fast, high-throughput differentiation of cells, this approach can help to better understand the behavior of algal cells at the complex interfaces in aquatic systems and serve for biotechnology needs.

algae, cell adhesion, surface properties

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