Domestication of Chlorella protothecoides for High Tolerance to Sugarcane Bagasse Hydrolysate Using a Fibrous-bed Bioreactor
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Chlorella protothecoides can rapidly utilize fermentable sugars in sugarcane bagasse hydrolysate (SCBH), but its cell growth is inhibited by by-products in the hydrolysate. In this study, to enhance the heterotrophic growth capability in high-concentration SCBH, C. protothecoides was cultured in a fibrous-bed bioreactor (FBB). The preparation and components of SCBH, seed culture by batch-fed fermentation, cell immobilization in FBB, and cell domestication in SCBH medium in an FBB were systemically studied. The results showed that after acid hydrolysis and enzymolysis, the main components of SCBH were glucose, xylose, acetic acid, cellobiose, and arabinose with concentrations of 18.40, 16.17, 6.13, 5.10, and 2.29 g/L, respectively. The cell density was up to 12.37 g/L for batch-fed cultures in Basal medium after 117 hours in a fermenter. The immobilized cell bed formed when the medium was recycled for 33 hours after connecting the fermenter with the FBB. Then, the Basal medium was replaced with SCBH medium, and the concentration of the SCBH medium was gradually increased to domesticate the immobilized cells. A highly tolerant strain, which grew heterotrophically in SCBH medium containing 35 g/L glucose, was isolated from the fibrous bed, while the wild-type strain was unable to grow.