Bioemulsifier production by an oleaginous yeast Rhodotorula glutinis IIP30 (original) (raw)
Process Biochemistry, 2018
Lipid was produced by Rhodosporidiobolus fluvialis DMKU-SP314 from a mixture of low-cost substrates: sugarcane top hydrolysate (STH) and biodiesel-derived crude glycerol. The optimized lipid production medium for shaking flask cultivation contained STH supplemented with 59 g/L crude glycerol, 0.21 g/L soybean powder, 0.9 g/L (NH 4) 2 SO 4 , 0.4 g/L KH 2 PO 4 , 2.0 g/L MgSO 4 •7H 2 O and pH 6.1 (C/N ratio 60), while the optimal cultivation temperature was 28°C. Batch cultivation in a 2 L stirred-tank fermenter at an agitation speed of 300 rpm and an aeration rate of 2 vvm achieved the maximum lipid quantity of 18.2 g/L, which was 75.0% of dry biomass (24.3 g/L biomass), after 240 h of cultivation. These represent a 5.4-fold and 1.7-fold improvement in the lipid concentration and lipid content, respectively, compared to non-optimized shaking flask cultivation. Under optimal conditions, the lipid produced had a high monounsaturated fatty acid content (36.6% of oleic acid), which is suitable for biodiesel production. Thus, R. fluvialis DMKU-SP314 is capable of producing large quantities of lipid from low-cost raw materials in a process that can be readily scaled up for industrial production.
Energy, 2013
This study investigated the production of microbial lipids for biodiesel production and high-value carotenoids by Rhodotorula glutinis combined with the use of brewery wastewater as carbon source for three treatments: (raw wastewater) WW raw , (glucose supplemented raw wastewater) WW glu and a (synthetic sugar medium) WW synth . The collected brewery effluents showed high contents of sugars (maltose 24.34 g L À1 ; glucose 5.77 g L À1 ), but the low utilization of maltose led to a limitation of carbon in WW raw and WW glu . Since nitrogen was still available, carbon was channeled into cell growth instead of lipid formation, reaching an overall biomass production of 5.22 g L À1 , 7.38 g L À1 , and 9.55 g L À1 , respectively. Carotenoids were synthesized in all treatments with total average carotenoid contents between 0.6 and 1.2 mg L À1 and with high proportions of b-carotene (w50%) in the wastewater treatments. Suboptimal culture conditions (pH; aeration) have been identified as obstacles for higher lipid and carotenoid yields. Nevertheless, brewery wastewaters can be considered as carbon source for microbial fermentation, since they can be assumed to be an adequate source of nitrogen and other nutrients, whereas the utilization of maltose needs to be increased to achieve considerable amounts of lipid and carotenoid production.
Rhodotorula glutinis T13 as a potential source of microbial lipids for biodiesel generation
Journal of Biotechnology, 2021
Single cell oils (SCO) are a promising source of oils that could be exploited in different industrial areas. SCO for biodiesel production circumvents the controversy food vs. fuel, does not require large land areas for culture, and is independent of climate and seasonal variations, among other advantages in comparison to vegetable oils. In this study, a red yeast isolated from a mountain water source, identified as Rhodotorula glutinis T13, showed high potential for lipid production (40% w/w) with suitable growth parameters, yields, and fatty acids profile. Yeast lipids showed a high content of unsaturated fatty acids (56.44%; C18:1, C18:2), and the fuel properties (cetane number, iodine value, density, kinematic viscosity, etc.) of yeast oil analysed were in good agreement with international biodiesel standards. The results show that R. glutinis T13 can be used in the future as a promising microorganism for the commercial production of biodiesel.
New bioemulsifiers produced by Candida lipolytica using D-glucose and babassu oil as carbon sources
Brazilian Journal of Microbiology, 2003
Candida lipolytica IA 1055 produced extracellular biosurfactants with emulsification activity by fermentation using babassu oil and D-glucose as carbon sources. Natural seawater diluted at 50% supplemented with urea, ammonium sulfate, and phosphate was used as economic basal medium. The best results were achieved with the YSW-B2 medium, which contained urea, ammonium sulfate, and babassu oil and with YSW-B3 medium, which contained urea, ammonium sulfate, phosphate, and babassu oil, kept under fed batch fermentation for 60 hours with 5% of babassu oil. For the two media, the maximum specific growth rates were 0.02 h -1 and 0.04 h -1 ; the generation times were 34.6 h -1 and 17.3 h -1 , and the emulsification activities were 0.666 and 0.158 units, respectively. The molecules of these new bioemulsifiers were contituted of carbohydrates, proteins and lipids.
Lipids of oleaginous yeasts. Part II: Technology and potential applications
European Journal of Lipid Science …, 2011
The process of lipid accumulation in the oleaginous yeasts cultivated in various fermentation configurations when either sugars and related compounds or hydrophobic substances are used as substrates is presented and kinetic models describing both de novo and ex novo lipid accumulation are analyzed. Technological aspects related with single cell oil (SCO) produced by oleaginous yeasts are depicted. The influence of culture parameters upon lipid production process is presented. Lipid production has been studied in batch, fed-batch, and continuous cultivation systems using yeasts belonging to the species Lipomyces starkeyi, Rhodosporidium toruloides, Apiotrichum curvatum, Candida curvata, Cryptococcus curvatus, Trichosporon fermentans, and Yarrowia lipolytica. The potentiality of yeasts to produce SCO as starting material of 2nd generation biodiesel is indicated and discussed. Of significant importance is also the utilization of yeast lipids as substitutes of high added value exotic fats (e.g., cocoa butter). Lipid produced by the various yeasts presents, in general, similar composition with that of common vegetable oils being composed of unsaturated fatty acids, whereas cocoa butter is principally composed of saturated fatty acids, consequently the various strategies that are followed in order to increase the cellular saturated fatty acid content of the yeast lipid are presented and comprehensively discussed.
3 Biotech, 2017
Rhodotorula kratochvilovae (syn, Rhodosporidium kratochvilovae) SY89, an oleaginous yeast, isolated from Ethiopian soil, was grown under nitrogen-limited media. The capacity this with respect to biomass production, lipid yield and lipid content was evaluated. The influence of inoculum size, carbon sources, variations in glucose concentration, nitrogen sources, C/N ratio, pH, temperature, agitation, and aeration rate and incubation period were investigated. Inoculum size of 10% v/v, glucose as a carbon source at 50 g/L glucose, 0.50 g/L yeast extract and 0.31 g/L (NH4)2SO4, C/N ratio of 120, pH 5.5, incubation temperature of 30 °C, 225 rpm, 0.2 as aeration ratio and 144 h of incubation were found to be optimum conditions for lipid production. Then the yeast was grown in a batch bioreactor by combining the different optimized parameters together. Under the optimized conditions, the yeast gave maximum biomass (15.34 ± 1.47 g/L), lipid yield (8.60 ± 0.81 g/L) and lipid content (56.06 ± ...
Microbial lipid production from crude glycerol and hemicellulosic hydrolysate with oleaginous yeasts
Biotechnology for Biofuels
Background Crude glycerol (CG) and hemicellulose hydrolysate (HH) are low—value side-products of biodiesel transesterification and pulp—and paper industry or lignocellulosic ethanol production, respectively, which can be converted to microbial lipids by oleaginous yeasts. This study aimed to test the ability of oleaginous yeasts to utilise CG and HH and mixtures of them as carbon source. Results Eleven out of 27 tested strains of oleaginous yeast species were able to grow in plate tests on CG as sole carbon source. Among them, only one ascomycetous strain, belonging to Lipomyces starkeyi, was identified, the other 10 strains were Rhodotorula spec. When yeasts were cultivated in mixed CG/ HH medium, we observed an activation of glycerol conversion in the Rhodotorula strains, but not in L. starkeyi. Two strains—Rhodotorula toruloides CBS 14 and Rhodotorula glutinis CBS 3044 were further tested in controlled fermentations in bioreactors in different mixtures of CG and HH. The highest m...
Bioprocess and Biosystems Engineering, 2012
Microbial lipid produced using yeast fermentation with inexpensive carbon sources such as lignocellulosic hydrolyzate can be an alternative feedstock for biodiesel production. Several inhibitors that can be generated during acid hydrolysis of lignocellulose were added solely or together into the culture medium to study their individual inhibitory actions and their synergistic effects on the growth and lipid accumulation of oleaginous yeast Rhodosporidium toruloides. When the inhibitors were present in isolation in the medium, to obtain a high cell biomass accumulation, the concentrations of formic acid, acetic acid, furfural and vanillin should be lower than 2, 5, 0.5 and 1.5 g/L, respectively. However, the synergistic effects of these compounds could dramatically decrease the minimum critical inhibitory concentrations leading to significant growth and lipid production inhibitions. Unlike the above-cited inhibitors, sodium lignosulphonate had no negative influence on biomass accumulation when its concentration was in the range of 0.5-2.0 g/L; in effect, it was found to facilitate cell growth and sugar-to-lipid conversion. The fatty acid compositional profile of the yeast lipid was in the compositional range of various plant oils and animal tallow. Finally, the crude yeast lipid from bagasse hydrolyzate could be well converted into fatty acid methyl ester (FAME, biodiesel) by enzymatic transesterification in a tert-butanol system with biodiesel yield of 67.2% and lipid-to-biodiesel conversion of 88.4%.
Optimization of Lipid Production by Oleaginous Yeast Using Response Surface Methodology
2014
The effects of growth parameters of Rhodotorula graminis TISTR 5124 in batch fermentation were studied and optimized for lipid production by using response surface methodology via a BoxBehnken Design. Values of the fermentation parameters affecting the lipid production were varied as follows: carbon sources (glucose, glucose and glycerol and glycerol), temperatures (28, 30, and 32 o C) and shaking speeds (150, 200, 250 rpm). Fermentation was carried out in 100 mL Erlenmeyer flasks with a 24 h cultivation time. After eliminating insignificant terms, we found that a good fit (R 2 = 0.7555) for lipid production was given by the quadratic regression relationship:Lipid = (4.00* Temperature)- (4.75*Carbon) + (0.70*Shaking speed) – (0.02*Temperature*Shaking speed) -116.0. The results showed that lipid production was significantly influenced by carbon source (p < 0.0001). For the range of conditions studied, we found that the highest yield of lipid was 17.40 g/L, which was obtained using...
Effect of pH on lipid accumulation by an oleaginous yeast: Rhodotorula glutinis IIP30
World Journal of Microbiology & Biotechnology, 1992
Maximum lipid production (66% w/w dry wt) inRhodotorula glutinis IIP-30 utilizing glucose in a fed-batch fermentation under N-limiting conditions at 30°C, was at pH 4. At pH 3, 5 and 6, the lipid contents were 12%, 48% and 44%, respectively. There was only a small change in the fatty acid profile over the pH range examined, although the ergosterol content decreased by a third as the pH increased.