A comparative study on two yarrroiwia lipolytica strains for optimum citric acid production

摘要

The aim of this study was to investigate the influence of various carbon sources like glucose, glycerol, olive oil and different nitrogen sources including yeast extract, tripton, peptone, soybean and (NH4)2S04 with various concentrations on production of citric acid by two strains Yarrowia lipolytica DSM3286 and Yarrowia lipolytica Ml. Present results proved glucose and olive oil as the best carbon sources in media for citric acid production by these strains. Decreasing nitrogen rate is the most important factor influencing citric acid production by yeasts. Decreasing in (NH^SC^ from 0.5 g L-1 to 0.25 g L-1 in production media improved production of citric acid in Y. lipolytica DSM3286 (43.3 g L1) and Y. lipolytica M7 (55.5 g L1) to 56.09 g L1 and 65.12 g L1 alternatively. Also soybean (0.5 g L-1) for Y. lipolytica M7 and yeast extract (0.5 g L-1) for Y. lasipolytica DSM3286 were the suitable organic nitrogen sources in production media. This study characterized citric acid accumulation is a very complex process during which various metabolic and morphological changes take place in a complex form.