Abstract
This study investigated the potential of oleaginous yeast Rhodotorula glutinis utilizing pulp and paper wastewater effluents as cultivation media for the sustainable production of microbial lipids as biodiesel feedstock. R. glutinis is oleaginous yeast, which has the ability to produce significant quantities of intercellular lipids in the form of triacylglycerols. Yeast lipids are a promising potential feedstock for biodiesel production due to similar fatty acid composition to plant oils. The effect of various carbon sources on biomass production, lipid accumulation, substrate utilization, and fatty acid composition using R. glutinis in the pulp and paper wastewater media was studied. The pulp and paper wastewater was supplemented with glucose, xylose, and glycerol as carbon sources under nitrogen-limited conditions. The maximum lipid productions of 1.3 - 2.9 g•L–1, which corresponded to the intracellular lipid contents of 8% - 15% cell dry weight (CDW), were obtained under various carbon substrates. A kinetic study of the batch fermentation was performed in a 3 L aerobic batch fermenter to describe the cell growth, lipid accumulation, and substrate utilization process, and the kinetic parameter was estimated. The fatty acid profile of oleaginous yeast was rich in palmitic, oleic, and linoleic acids and comparable to vegetable oils. Thus, the results of this study indicated that pulp and paper wastewater could be used to produce lipids as biodiesel feedstock.
Highlights
The utilization of biodiesel has greatly increased over the past two decades due in part to concerns about the environmental consequences of fossil fuel combustion, the low lubricity quality of ultralow sulfur diesel, and the rapid rises in crude oil prices that can occur
It was hypothesized that the oleaginous yeast R. glutinis can produce microbial lipids from pulp and paper wastewaters amended with carbon sources, which can be further converted to biodiesel
A maximum lipid content of 15% ± 0.92% cell dry weight (CDW) was obtained when glycerol was used as a substrate, which could be attributed to the highest lipid accumulation
Summary
The utilization of biodiesel has greatly increased over the past two decades due in part to concerns about the environmental consequences of fossil fuel combustion, the low lubricity quality of ultralow sulfur diesel, and the rapid rises in crude oil prices that can occur. It has been shown that these microorganisms utilize glucose, xylose, glycerol, food industry waste [4], and N-acetylglucosamine (GlcNAc) [5] for the production of lipids. Glucose is one of the most common carbon substrates for producing microbial biomass and lipids, which has been extensively investigated for use by different oleaginous microorganisms [6] [7]. The depolymerization of cellulose and hemicellulose in lignocellulosic material results in a carbon source containing glucose and xylose; thusly the co-fermentation of mixed sugars must be explored for effective lipid production. Glycerol is another carbon source, which can be used as a substrate for lipid production. 1 kg of glycerol could be obtained for 3.78 liters of produced biodiesel [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
