Influence of substrate concentration on microbial oil production by pseudozyma parantarctica CHC28 and its fatty acid characterization

Abstract

Microbial oil production by a novel oleaginous yeast Pseudozyma parantarctica CHC28 was studied using glucose as the main carbon source, in order to investigate its growth, oil production and fatty acid characterization among various glucose concentrations. Batch cultivations demonstrated that there was no significantly inhibitory effect at 100 g/L glucose. Moreover, the highest oil production and oil content of P. parantarctica CHC28 were obtained for 10.99 g/L and 49.66 %dry weight, respectively at 100 g/L glucose. During 120 and 150 g/L glucose, these values were not significantly increased. Furthermore, the fatty acid compositions of P. parantarctica CHC28 were also investigated in this study. The long-chain fatty acids (C16 to C18) were main fatty acids in all conditions, which were ranged between 86.62% and 90.79%. The short-chain fatty acids (carbon less than 14 atoms) were decreased while very long-chain fatty acid (carbon over than 20 atoms) were increased with increasing glucose level. The percentages of saturated (SFA), mono-(MUFA), poly-(PUFA), and total unsaturated fatty acid (TUFA) in crude oil were affected with the concentration of glucose (carbon source). The percentages SFA were significantly increased together with increasing of glucose level. The percentages of MUFA (C16:1 and C18:1 as main fatty acids) and PUFA were significantly decreased under high glucose concentration. Although high TUFA could lower the stability of fuel, the cultivation of P. parantarctica CHC28 under high carbon source could improve the stability of biodiesel.