Estimation of periphytic photosynthesis efficiency using the Fluorescence Monitoring System: response of FMS parameters on light intensity, temperature, and chlorophyll concentrations

The development of methods in measuring the photosynthesis process is now increasingly widespread, especially to get a more efficient method and fast. Photosynthetic efficiency of micro-algae periphytic has been estimated under the influence of light intensity and temperature by using the fluorescence monitoring system.The measurement on a colonized substrate by the saturation pulse method has been conducted using a FMS1 (Fluorescence Monitoring Systems, Hansatech). Measurement of the fluorescence parameters was conducted every week on algal periphyton which was cultivated on the artificial substrate during for 5 weeks under light and temperature conditions. The result show that fluorescence maximal value (Fm) increase linearly with chlorophyll a concentrations. For 20°C (experiments where the biomass reached higher values), up to 100 mg chlorophyll a.m-2 the change in Fm is approximately linear. After, the response of Fm is hyperbolic, suggesting a saturation law. Our results clearly show that the FMS may be satisfactorily used to measure in vivo chlorophyll a fluorescence of periphyton in laboratory conditions.The instrument is simple to use, with convenient software control, especially when used in PC mode.