Microbial Oil Production under Optimum Condition by Oleaginous Yeast
Dalia M. Mohammed
Department of Agricultural Microbiology, National Research Center, Egypt.
Fatma H. Abd El Zaher *
Department of Agricultural Microbiology, National Research Center, Egypt.
Enass A. Hassan
Department of Agricultural Microbiology, Faculty of Agriculture, Ain Shams University, Egypt.
H. K. El Maksoud
Department of Agricultural Microbiology, National Research Center, Egypt.
E. M. Ramadan
Department of Agricultural Microbiology, Faculty of Agriculture, Ain Shams University, Egypt.
*Author to whom correspondence should be addressed.
Abstract
Two oleaginous yeast strains identified as Issatchenkia orientalis D5 and Candida tropicalis S5 were evaluated for oil production under optimized growth factors. Both strains were inoculated in 2L of optimal fermentation broth medium for 9 days. Sample was taken periodically (24 hrs.), The data exhibited that cell biomass was gradually increased along with time sample to reach maximum values of cell dry weight (11.22 & 13.30 gL-1) after 8 and 9 day at consumed sugar equal to 79.52 and 156.29 gL-1 for Candida and Issatchenkia. It was found that Candida gave the highest values of lipid weight, lipid content, lipid yield, conversion coefficient and lipid productivity after 6 days being 2.16 gL-1, 34.17%, 2.70%, 2.73% and 0.36 gL-1/day, while Issatchenkia recorded the highest lipid concentration and lipid yield after 4 days of the fermentation period being 3.24 gL-1 and 2.06%. The specific growth rate, doubling time, multiplication rate and number of generation were 0.317 day-1, 2.18 days, 0.458 day-1 and 1.37 for Candida and reached to 0.275 day-1, 2.52 days, 0.396 day-1 and 0.793 for Issatchenkia. The data proved that the strains Issatchenkia orientals and Candida tropicalis could be used as feedstock producers for microbial lipid production.
Keywords: Oleaginous yeast, fermentation, microbial lipid.