| Abstract |
Sugarcane bagasse is a potential raw material for microbial lipid production by oleaginous yeasts. Due to the limited sugar concentrations in bagasse hydrolysate, increasing carbon
the concentration is necessary in order to improve lipid production. We aimed to increase carbon
concentration by incorporating glycerol as a co-substrate into unconcentrated bagasse hydrolysate
in the cultivation of Rhodotorula glutinis TISTR 5159. Cultivation in hydrolysate without nitrogen
supplementation (C/N = 42) resulted in 60.31% lipid accumulation with 11.45 ± 0.75 g/L biomass.
Nitrogen source supplementation increased biomass to 26.29 ± 2.05 g/L without losing lipid accumulation at a C/N of 25. Yeast extract improved lipid production in the hydrolysate due to high growth
without altering the lipid content of the cells. Mixing glycerol up to 10% v/v into the unconcentrated
hydrolysate improved biomass and lipid production. A further increase in glycerol concentrations
drastically decreased growth and lipid accumulation by the yeast. By maintaining C/N at 27 using
yeast extract as the sole nitrogen source, hydrolysate mixed with 10% v/v glycerol resulted in the
highest lipid yield, at 19.57 ± 0.53 g/L with 50.55% lipid content, which was a 2.8-fold increase
compared to using the hydrolysate alone. In addition, yeast extracts were superior for promoting
growth and lipid production compared to inorganic nitrogen sources. |
Publication
Journal Publication
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