Accelerated lipid production from distillery wastewater by Rhodosporidium toruloides using an open-bubble-column reactor under non-aseptic conditions

• Published in: International biodeterioration & biodegradation 2019-09, Vol.143, p.104720, Article 104720
• Main Authors: Ling, Jiayin, Xu, Yanbin, Lu, Chuansheng, He, Peigen, Chen, Jinliang, Zheng, Li, Talawar, Manjunatha P., Xie, Guangyan, Du, Qingping
• Format: Article
• Language: English
• Subjects: Adaptability; Aeration; Air temperature; Biodiesel fuels; Biofuels; Bubble columns; Cell density; Chemical oxygen demand; Cultivation; Density; Distilleries; Distillery wastewater; Fungi; Lipid; Lipids; Non-aseptic; Nutrients; Oleaginous yeast; Open-bubble-column reactor; Organic chemistry; Phosphorus; Reaction time; Reactors; Renewable energy; Rhodosporidium toruloides; Sterilization; Wastewater
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2019.104720

It is an ideal and sustainable approach to recover renewable energy like biodiesel and to remove organic matters from wastewater simultaneously. However, the common demands of aseptic conditions and long reaction time limit the practical applications of this technology. In this study, lipid production by Rhodosporidium toruloides was investigated using distillery wastewater with an initial soluble chemical oxygen demand (SCOD) of 28,080–17,120 mg/L, an initial cell density of 0.5–2 × 108 cells/mL, and an aeration rate of 0.9–4.5 vvm (air volume/liquid volume/minute) in an open-bubble-column reactor at room temperature. The lipid production reached its peak of 1.92 ± 0.24 g/L in 12 h with a maximum lipid productivity of 160 mg/(L• h) achieved under the conditions: initial SCOD 20,315 mg/L, initial cell density 2 × 108 cells/mL and aeration rate 4 vvm, without external nutrients and sterilization. The associated removal efficiencies for SCOD, total phosphorus (TP) and total nitrogen (TN) were 71.82 ± 0.52%, 79.53 ± 1.77% and 54.39 ± 6.45%, respectively. Both contaminating bacteria and fungi were negligible throughout the cultivation period, suggesting that the studied process has good adaptability to full scale practical applications. •A new process for lipid production from real wastewater under open conditions.•Incubation time has been reduced to about 12 h under optimal conditions.•Lipid productivity increased from 17 to 160 mg/(L·h) after optimization.•Applicable to real distillery wastewater without sterilization and pH adjustment.•Contaminating microorganisms were negligible compared to the total biomass.