scholarly journals Optimization of carbon source efficiency for lipid production with the oleaginous yeast Saitozyma podzolica DSM 27192 applying automated continuous feeding

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Olga Gorte ◽  
Michaela Kugel ◽  
Katrin Ochsenreither
Keyword(s):  
Carbon Source ◽  
Process Optimization ◽  
Oleaginous Yeast ◽  
Lipid Production ◽  
Lipid Productivity ◽  
Sugar Uptake ◽  
Plant Oils ◽  
Microbial Lipids ◽  
Batch Phase ◽  
Xylonic Acid

Abstract Background Biotechnologically produced microbial lipids are of interest as potential alternatives for crude and plant oils. Their lipid profile is similar to plant oils and can therefore be a substitute for the production of biofuels, additives for food and cosmetics industry as well as building blocks for oleochemicals. Commercial microbial lipids production, however, is still not profitable and research on process optimization and cost reduction is required. This study reports on the process optimization using glucose or xylose with the unconventional oleaginous yeast Saitozyma podzolica DSM 27192 aiming to reduce the applied carbon source amount without sacrificing lipid productivity. Results By optimizing the process parameters temperature and pH, lipid productivity was enhanced by 40%. Thereupon, by establishing a two-phase strategy with an initial batch phase and a subsequent fed-batch phase for lipid production in which a constant sugar concentration of about 10 g/L was maintained, resulted in saving of ~ 41% of total glucose and ~ 26% of total xylose. By performing the automated continuous sugar feed the total sugar uptake was improved to ~ 91% for glucose and ~ 92% for xylose and thus, prevented waste of unused carbon source in the cultivation medium. In addition, reduced glucose cultivation resulted in to 28% higher cell growth and 19% increase of lipid titer. By using xylose, the by-product xylonic acid was identified for the first time as by-product of S. podzolica. Conclusions These findings provide a broad view of different cultivation process strategies with subsequent comparison and evaluation for lipid production with S. podzolica. Additionally, new biotechnological characteristics of this yeast were highlighted regarding the ability to produce valuable organic acids from sustainable and renewable sugars.

scholarly journals Expression of VHb Improved Lipid Production in Rhodosporidium toruloides

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4446
Author(s):  
Shuang Wang ◽  
Rasool Kamal ◽  
Yue Zhang ◽  
Renhui Zhou ◽  
Liting Lv ◽  
...  
Keyword(s):  
Parental Strain ◽  
Oleaginous Yeast ◽  
Lipid Production ◽  
Culture Conditions ◽  
Rhodosporidium Toruloides ◽  
High Cell Density Culture ◽  
Limiting Factor ◽  
Microbial Lipids ◽  
Aeration Conditions ◽  
Engineered Strain

The oleaginous yeast Rhodosporidium toruloides has emerged as a robust host for production of microbial lipids as alternative biofuel feedstocks. Oxygen supply is a limiting factor for microbial lipid production, as lipid biosynthesis is highly oxygen-demanding. Vitreoscilla hemoglobin (VHb) is a protein capable of promoting oxygen delivery for anabolism. In this study, we developed R. toruloides with VHb expression for improved lipid production. The VHb expression cassette was integrated into the R. toruloides chromosome via the Agrobacterium-mediated transformation. In shake flask cultures, the engineered strain 4#-13 produced 34% more lipids than the parental strain did. Results obtained under reduced aeration conditions in 3 L bioreactor showed that lipid titer and lipid yield of the engineered strain 4#-13 were 116% and 71%, respectively, higher than those of the parental strain. Under high cell density culture conditions, the engineered strain 4#-13 grew faster and produced 72% more lipids. Our results demonstrated that the VHb gene is functional in R. toruloides for promoting lipid production. The strains described here may be further engineered by integrating extra genetic parts to attain robust producers for more valuable products. This should improve the economics of microbial lipids to facilitate a sustainable production of biodiesel and other lipid-based biofuels.

scholarly journals Microbial lipid production from crude glycerol and hemicellulosic hydrolysate with oleaginous yeasts

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mikolaj Chmielarz ◽  
Johanna Blomqvist ◽  
Sabine Sampels ◽  
Mats Sandgren ◽  
Volkmar Passoth
Keyword(s):  
Carbon Source ◽  
Crude Glycerol ◽  
Paper Industry ◽  
Lipid Production ◽  
Microbial Lipids ◽  
Hemicellulose Hydrolysate ◽  
Lipid Concentration ◽  
Oleaginous Yeasts ◽  
Glycerol Conversion ◽  
Fermentation Time

Abstract 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 measured average biomass and lipid concentration were achieved with R. toruloides in 10% HH medium mixed with 55 g/L CG—19.4 g/L and 10.6 g/L, respectively, with a lipid yield of 0.25 g lipids per consumed g of carbon source. Fatty acid composition was similar to other R. toruloides strains and comparable to that of vegetable oils. Conclusions There were big strain differences in the ability to convert CG to lipids, as only few of the tested strains were able to grow. Lipid production rates and yields showed that mixing GC and HH have a stimulating effect on lipid accumulation in R. toruloides and R. glutinis resulting in shortened fermentation time to reach maximum lipid concentration, which provides a new perspective on converting these low-value compounds to microbial lipids.

scholarly journals Enhanced inhibitor tolerance and increased lipid productivity through adaptive laboratory evolution in the oleaginous yeast Metshnikowia pulcherrima

2020 ◽  
Author(s):  
Robert H. Hicks ◽  
Yuxin Sze ◽  
Christopher J. Chuck ◽  
Daniel A. Henk
Keyword(s):  
Formic Acid ◽  
Oleaginous Yeast ◽  
Lipid Production ◽  
Dry Weight ◽  
Lipid Productivity ◽  
Adaptive Laboratory Evolution ◽  
Stirred Tank Bioreactor ◽  
Inhibitor Tolerance ◽  
Laboratory Evolution ◽  
Wide Range

AbstractMicrobial lipid production from second generation feedstocks presents a sustainable route to future fuels, foods and bulk chemicals. The oleaginous yeast Metshnikowia pulcherrima has previously been investigated as a potential platform organism for lipid production due to its ability to be grown in non-sterile conditions and metabolising a wide range of oligo- and monosaccharide carbon sources within lignocellulosic hydrolysates. However, the generation of inhibitors from depolymerisation causes downstream bioprocessing complications, and despite M. pulcherrima’s comparative tolerance, their presence is deleterious to both biomass and lipid formation. Using either a single inhibitor (formic acid) or an inhibitor cocktail (formic acid, acetic acid, fufural and HMF), two strategies of adaptive laboratory evolution were performed to improve M. pulcherrima’s fermentation inhibitor tolerance. Using a sequential batch culturing approach, the resulting strains from both strategies had increased growth rates and reduced lag times under inhibiting conditions versus the progenitor. Interestingly, the lipid production of the inhibitor cocktail evolved strains markedly increased, with one strain producing 41% lipid by dry weight compared to 22% of the progenitor. The evolved species was cultured in a non-sterile 2L stirred tank bioreactor and accumulated lipid rapidly, yielding 6.1 g/L of lipid (35% cell dry weight) within 48 hours; a lipid productivity of 0.128 g L-1 h-1. Furthermore, the lipid profile was analogous to palm oil, consisting of 39% C16:0 and 56% C18:1 after 48 hours.

scholarly journals Proteome analysis of xylose metabolism inRhodotorula toruloidesduring lipid production

2019 ◽  
Author(s):  
Ievgeniia A. Tiukova ◽  
Jule Brandenburg ◽  
Johanna Blomqvist ◽  
Sabine Samples ◽  
Nils Mikkelsen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Source ◽  
Growth Phase ◽  
Exponential Growth ◽  
Lipid Production ◽  
Proteome Analysis ◽  
Exponential Growth Phase ◽  
Sugar Uptake ◽  
Beta Oxidation

AbstractBackgroundRhodotorula toruloidesis a promising platform organism for production of lipids from lignocellulosic substrates. Little is known about the metabolic aspects of lipid production from the lignocellolosic sugar xylose by oleaginous yeasts in general andR. toruloidesin particular. This study presents the first proteome analysis of the metabolism ofR. toruloidesduring conversion of xylose to lipids.ResultsR. toruloidescultivated on either glucose or xylose was subjected to comparative analysis of its growth dynamics, lipid composition, fatty acid profiles and proteome. The maximum growth and sugar uptake rate of glucose-grownR. toruloidescells were almost twice that of xylose-grown cells. Cultivation on xylose medium resulted in a lower final biomass yield although final cellular lipid content was similar between glucose- and xylose-grown cells. Analysis of lipid classes revealed the presence of monoacylglycerol in the early exponential growth phase as well as a high proportion of free fatty acids. Carbon source-specific changes in lipid profiles were only observed at early exponential growth phase, where C18 fatty acids were more saturated in xylose-grown cells. Proteins involved in sugar transport, initial steps of xylose assimilation and NADPH regeneration were among the proteins whose levels increased the most in xylose-grown cells across all time points. The levels of enzymes involved in the mevalonate pathway, phospholipid biosynthesis and amino acids biosynthesis differed in response to carbon source. In addition, xylose-grown cells contained higher levels of enzymes involved in peroxisomal beta-oxidation and oxidative stress response compared to cells cultivated on glucose.ConclusionsThe results obtained in the present study suggest that sugar import is the limiting step during xylose conversion byR. toruloidesinto lipids. NADPH appeared to be regenerated primarily through pentose phosphate pathway although it may also involve malic enzyme as well as alcohol and aldehyde dehydrogenases. Increases in enzyme levels of both fatty acid biosynthesis and beta-oxidation in xylose-grown cells was predicted to result in a futile cycle. The results presented here are valuable for the development of lipid production processes employingR. toruloideson xylose-containing substrates.

Microbial lipid production by oleaginous yeast Cryptococcus sp. in the batch cultures using corncob hydrolysate as carbon source

2015 ◽  
Vol 72 ◽  
pp. 95-103 ◽  
Author(s):  
Yi-Huang Chang ◽  
Ku-Shang Chang ◽  
Ching-Fu Lee ◽  
Chuan-Liang Hsu ◽  
Cheng-Wei Huang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Oleaginous Yeast ◽  
Lipid Production ◽  
Microbial Lipid ◽  
Batch Cultures ◽  
Corncob Hydrolysate ◽  
Microbial Lipid Production

scholarly journals Identifying carbohydrate-active enzymes of Cutaneotrichosporon oleaginosus using systems biology

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tobias Fuchs ◽  
Felix Melcher ◽  
Zora Selina Rerop ◽  
Jan Lorenzen ◽  
Pariya Shaigani ◽  
...  
Keyword(s):  
Carbon Source ◽  
Molecular Mechanisms ◽  
Oleaginous Yeast ◽  
Consensus Sequence ◽  
Lipid Production ◽  
Carbon Sources ◽  
Cellular Growth ◽  
Biomass Waste ◽  
Systematic Analysis ◽  
Wide Range

Abstract Background The oleaginous yeast Cutaneotrichosporon oleaginosus represents one of the most promising microbial platforms for resource-efficient and scalable lipid production, with the capacity to accept a wide range of carbohydrates encapsulated in complex biomass waste or lignocellulosic hydrolysates. Currently, data related to molecular aspects of the metabolic utilisation of oligomeric carbohydrates are sparse. In addition, comprehensive proteomic information for C. oleaginosus focusing on carbohydrate metabolism is not available. Results In this study, we conducted a systematic analysis of carbohydrate intake and utilisation by C. oleaginosus and investigated the influence of different di- and trisaccharide as carbon sources. Changes in the cellular growth and morphology could be observed, depending on the selected carbon source. The greatest changes in morphology were observed in media containing trehalose. A comprehensive proteomic analysis of secreted, cell wall-associated, and cytoplasmatic proteins was performed, which highlighted differences in the composition and quantity of secreted proteins, when grown on different disaccharides. Based on the proteomic data, we performed a relative quantitative analysis of the identified proteins (using glucose as the reference carbon source) and observed carbohydrate-specific protein distributions. When using cellobiose or lactose as the carbon source, we detected three- and five-fold higher diversity in terms of the respective hydrolases released. Furthermore, the analysis of the secreted enzymes enabled identification of the motif with the consensus sequence LALL[LA]L[LA][LA]AAAAAAA as a potential signal peptide. Conclusions Relative quantification of spectral intensities from crude proteomic datasets enabled the identification of new enzymes and provided new insights into protein secretion, as well as the molecular mechanisms of carbo-hydrolases involved in the cleavage of the selected carbon oligomers. These insights can help unlock new substrate sources for C. oleaginosus, such as low-cost by-products containing difficult to utilize carbohydrates. In addition, information regarding the carbo-hydrolytic potential of C. oleaginosus facilitates a more precise engineering approach when using targeted genetic approaches. This information could be used to find new and more cost-effective carbon sources for microbial lipid production by the oleaginous yeast C. oleaginosus.

Biophotolysis-based hydrogen and lipid production by oleaginous microalgae using crude glycerol as exogenous carbon source

2017 ◽  
Vol 42 (4) ◽  
pp. 1970-1976 ◽  
Author(s):  
Dennapa Sengmee ◽  
Benjamas Cheirsilp ◽  
Thanwadee Tachapattaweawrakul Suksaroge ◽  
Poonsuk Prasertsan
Keyword(s):  
Carbon Source ◽  
Crude Glycerol ◽  
Lipid Production ◽  
Oleaginous Microalgae ◽  
Exogenous Carbon Source
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