Utilizing microalgal hydrolysate from dairy wastewater-grown Chlorella sorokiniana SU-1 as sustainable feedstock for polyhydroxybutyrate and β-carotene production by engineered Rhodotorula glutinis #100-29

• Published in: Bioresource technology 2023-09, Vol.384, p.129277-129277, Article 129277
• Main Authors: Kusmayadi, Adi, Huang, Chi-Yu, Leong, Yoong Kit, Yen, Hong-Wei, Lee, Duu-Jong, Chang, Jo-Shu
• Format: Article
• Language: English
• Subjects: Acidic hydrolysis; beta Carotene; Biomass; Chlorella; Detoxification; Microalgae; Polyhydroxybutyrate; Rhodotorula; Wastewater; Yeast fermentation; β-carotene
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.129277

[Display omitted] •C. sorokinina SU-1 biomass as feedstock for producing PHB and β-carotene was evaluated.•Hydrolysis using 3% w/v sulfuric acid resulted in high reducing sugar yields.•The addition of 5% w/v activated carbon significantly reduced HMF inhibitor levels.•R. glutinis #100-29 fermentation yielded a high biomass concentration of 9.22 g/L.•PHB and β-carotene concentrations of 1.83 g/L and 134.2 mg/L, respectively, were achieved.•Detoxified microalgal hydrolysate has significant potential as sustainable feedstock. The objective of this study was to explore the potential of utilizing Chlorella sorokiniana SU-1 biomass grown on dairy wastewater-amended medium as sustainable feedstock for the biosynthesis of β-carotene and polyhydroxybutyrate (PHB) by Rhodotorula glutinis #100-29. To break down the rigid cell wall, 100 g/L of microalgal biomass was treated with 3% sulfuric acid, followed by detoxification using 5% activated carbon to remove the hydroxymethylfurfural inhibitor. The detoxified microalgal hydrolysate (DMH) was used for flask-scale fermentation, which yielded a maximum biomass production of 9.22 g/L, with PHB and β-carotene concentration of 897 mg/L and 93.62 mg/L, respectively. Upon scaling up to a 5-L fermenter, the biomass concentration increased to 11.2 g/L, while the PHB and β-carotene concentrations rose to 1830 mg/L and 134.2 mg/L. These outcomes indicate that DMH holds promise as sustainable feedstock for the production of PHB and β-carotene by yeast.