Effect of Multiple Inhibitions in Corncob Hydrolysate on the Lipid Production by Rhodotorula glutinis

Abstract Background: Converting wastewater sludge to lipid is considered as one of the best strategies of sludge management. The current problem of lipid production from wastewater sludge is the low yield (0.10-0.16 g lipid/g dry sludge) due to the low availability of easily uptaken materials (such as soluble monosaccharide and oligosaccharide) in sludge to oleaginous microorganism (Rhodotorula glutinis, Trichosporon oleaginosus, Lipomyces starkeyi). Pretreatments are efficient methods to improve sludge bioavailability. This study is aimed to achieve high lipid production from sludge and high sludge reduction. Results: In this study, it was observed that the soluble chemical oxygen demand (SCOD) had significantly increased after different pretreatment. The SCOD in the supernatant was increased from 32.64 to 180.25 mg/L, 924.16 mg/L, 1029.89mg/L and 3708.31 mg/L after acidic (pH 2 for 2 h), alkaline (pH 12 for 2 h), microwave irradiation (15 min with 5 min interval), and ultrasonication (30 min at 450 W and 20 kHz frequency with 5 s on and 2 s off mode) pretreatment, respectively. Pretreatments have also increased the release of total nitrogen (TN) and total phosphorus (TP) from solids. The sludge after different pretreatments were used as medium for lipid production, and the highest lipid content (36.67% g/g) was obtained in the fermentation with ultrasonication pretreatment sludge, and the sludge reduction was 63.10%. For other pretreatments, the lipid content and sludge reduction were 18.42% and 32.63% in acid pretreatment case, 21.08% and 36.44% in alkaline pretreatment case, and 26.31% and 43.03% in microwave pretreatment case, respectively.Conclusion: It was found that ultrasonication pretreatment was the most efficient way to increase the sludge biodegradability (SCOD) and to release TN and TP from solid phase to liquid phase. Pretreated sludge for lipid production achieved significant improvement in lipid yield and sludge reduction. Lipids produced from pretreated sludge were transesterified to biodiesel and the analysis showed that the biodiesel had a similar composition as commercial biodiesel. The study reveals that pretreatment on sludge is a promising method for enhancing biological sludge management efficiency.

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Mixed culture of oleaginous yeast Rhodotorula glutinis and microalga Chlorella vulgaris for lipid production from industrial wastes and its use as biodiesel feedstock

New Biotechnology ◽

10.1016/j.nbt.2011.01.004 ◽

2011 ◽

Vol 28 (4) ◽

pp. 362-368 ◽

Cited By ~ 96

Author(s):

Benjamas Cheirsilp ◽

Warangkana Suwannarat ◽

Rujira Niyomdecha

Keyword(s):

Mixed Culture ◽

Chlorella Vulgaris ◽

Oleaginous Yeast ◽

Lipid Production ◽

Rhodotorula Glutinis ◽

Industrial Wastes ◽

Biodiesel Feedstock

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Two-stage fermentation method for lipid production by Rhodotorula glutinis

Journal of Biotechnology ◽

10.1016/j.jbiotec.2010.08.385 ◽

2010 ◽

Vol 150 ◽

pp. 149-149 ◽

Cited By ~ 1

Author(s):

Hua Ye ◽

Yongqiang Zhu ◽

Feiyan Xue ◽

Tianwei Tan

Keyword(s):

Lipid Production ◽

Rhodotorula Glutinis ◽

Two Stage ◽

Fermentation Method

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Lipid Production for Microbial Biodiesel by the Oleagenious Yeast Rhodotorula glutinis Using Hydrolysates of Wheat Straw and Miscanthus as Carbon Sources

Waste and Biomass Valorization ◽

10.1007/s12649-014-9312-9 ◽

2014 ◽

Vol 5 (6) ◽

pp. 955-962 ◽

Cited By ~ 23

Author(s):

Benjamin Mast ◽

Nora Zöhrens ◽

Felix Schmidl ◽

Rafael Hernandez ◽

W. Todd French ◽

...

Keyword(s):

Wheat Straw ◽

Lipid Production ◽

Carbon Sources ◽

Rhodotorula Glutinis

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Lipid Production by Yeasts Growing on Commercial Xylose in Submerged Cultures with Process Water Being Partially Replaced by Olive Mill Wastewaters

Processes ◽

10.3390/pr8070819 ◽

2020 ◽

Vol 8 (7) ◽

pp. 819 ◽

Cited By ~ 1

Author(s):

Evangelos Xenopoulos ◽

Ioannis Giannikakis ◽

Afroditi Chatzifragkou ◽

Apostolis Koutinas ◽

Seraphim Papanikolaou

Keyword(s):

Lipid Production ◽

Rhodotorula Glutinis ◽

Cryptococcus Curvatus ◽

Submerged Cultures ◽

Batch Bioreactor ◽

Dry Cell Weight ◽

Olive Mill Wastewaters ◽

Blank Experiment ◽

Dry Cell ◽

Olive Mill

Six yeast strains belonging to Rhodosporidium toruloides, Lipomyces starkeyi, Rhodotorula glutinis and Cryptococcus curvatus were shake-flask cultured on xylose (initial sugar—S0 = 70 ± 10 g/L) under nitrogen-limited conditions. C. curvatus ATCC 20509 and L. starkeyi DSM 70296 were further cultured in media where process waters were partially replaced by the phenol-containing olive mill wastewaters (OMWs). In flasks with S0 ≈ 100 g/L and OMWs added yielding to initial phenolic compounds concentration (PCC0) between 0.0 g/L (blank experiment) and 2.0 g/L, C. curvatus presented maximum total dry cell weight—TDCWmax ≈ 27 g/L, in all cases. The more the PCC0 increased, the fewer lipids were produced. In OMW-enriched media with PCC0 ≈ 1.2 g/L, TDCW = 20.9 g/L containing ≈ 40% w/w of lipids was recorded. In L. starkeyi cultures, when PCC0 ≈ 2.0 g/L, TDCW ≈ 25 g/L was synthesized, whereas lipids in TDCW = 24–28% w/w, similar to the experiments without OMWs, were recorded. Non-negligible dephenolization and species-dependent decolorization of the wastewater occurred. A batch-bioreactor trial by C. curvatus only with xylose (S0 ≈ 110 g/L) was performed and TDCW = 35.1 g/L (lipids in TDCW = 44.3% w/w) was produced. Yeast total lipids were composed of oleic and palmitic and to lesser extent linoleic and stearic acids. C. curvatus lipids were mainly composed of nonpolar fractions (i.e., triacylglycerols).

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