Abstract
This study presents the cultivation and monitoring of Scenedesmus abundans GH-D11 on a microbioreactor, which is compatible to commercially and readily available plate reader. The properties of cell, including microalgae cell density (O.D.682) and carotenoids (O.D.440), were determined by absorbance read by a plate reader during cultivation. Conventional screening methods for optimization of microalgae culture are time-consuming and complicated. Therefor, this research aims for developing prompt culture and rapid quantification of microalgae cellular contents using microbioreactor. In this study, the effects of nitrogen resource, pH, salinity stress and spectral light on microalgae cultivation are investigated. The results show microalgae were cultivated better, indicated by more carotenoids and cell density, by applying suitable nitrogen source, adjusting a suitable pH value and using suitable light source. Scenedesmus abundans had high cell density (biomass = 2.126 g/L after 96 hour of cultivation) and carotenoids (total carotenoids = 1.014 mg/L) with sucrose as carbon source and ammonia as nitrogen source. The suitable pH value is 7 for Scenedesmus abundas cultivation and any shift of pH value may decrease the cell density and carotenoids. Salinity stress also decreased the cell density and carotenoids.The cultivation with salinity stress had the low cell density (biomass = 2.087 g/L after 96 hour of cultivation) and carotenoids (total carotenoids = 0.3580 mg/L) compared to the cultivation without salinity stress (biomass = 2.437 g/L after 96 hour of cultivation, total carotenoids = 0.504 mg/L). From the experimental results of effects of spectral light on microalgae cultivation, green LED exhibited the highest cell density (biomass = 2.412 g/L after 96 hour of cultivation) and red LED exhibited the highest carotenoids (total carotenoids = 0.2185 mg/L).In summary, our microbioreactor provides not only fast and convenient way to determining microalgae cellular contents but also considerably decreases the amount of microalgae cell culture size for screening cultivation parameters.