Improvement of medium composition and cultivation conditions for growth and lipid production by Crypthecodinium cohnii

WOS: 000423282700009In this study, glycerol was used as an alternative carbon supply in the growth medium of Crypthecodinium cohnii. Concentration of other nutrients was optimized by using response surface methodology (RSM) for the growth and lipid production by microalgae. As a result, when using yeast extract, there was no need using glutamic acid and sodium beta-glycerophosphate in the growth medium. Additionally, it was revealed that there was a reduced growth by C. cohnii with a certain yeast extract concentration. The optimum sea salt concentration in the medium was determined as 16 g L-1. In the optimized medium, the highest biomass productivity and total lipid content achieved were 1.0 g L(-1)d(-1) and 30 % of dry weight basis, respectively. The yield coefficient of YX/S on glycerol obtained in this study was between 0.30-0.48 (w w(-1)). The effect of mechanical agitation on the growth and lipid production by C. cohnii was investigated in a 2 L stirred tank bioreactor. Nile red based flourescence intensity measurements during bioreactor productions revealed that lipid production by C. cohnii continued even after cells entered the stationary phase. The docosahexaenoic acid proportion increased until the beginning of stationary phase (5rd day) at 150 rpm agitation rate in bioreactor