Simultaneous Lipid and Carotenoid Production via Rhodotorula paludigena CM33 Using Crude Glycerol as the Main Substrate: Pilot-Scale Experiments

Abstract

Rhodotorula paludigena CM33 is an oleaginous yeast that has been demonstrated to accumulate substantial quantities of intracellular lipids and carotenoids. In this study, crude glycerol, a by-product of biodiesel production, was used as a carbon source to enhance the accumulation of lipids and carotenoids in the cells. The culture conditions were first optimized using response surface methodology, which revealed that the carotenoid concentration and lipid content improved when the concentration of crude glycerol was 40 g/L. Different fermentation conditions were also investigated: batch, repeated-batch, and fed-batch conditions in a 500 L fermenter. For fed-batch fermentation, the maximum concentrations of biomass, lipids, and carotenoids obtained were 46.32 g/L, 37.65%, and 713.80 mg/L, respectively. A chemical-free carotenoid extraction method was also optimized using high-pressure homogenization and a microfluidizer device. The carotenoids were found to be mostly beta-carotene, which was confirmed by HPLC (high pressure liquid chromatography), LC-MS (liquid chromatography-mass spectrometry), and NMR (nuclear magnetic resonance). The results of this study indicate that crude glycerol can be used as a substrate to produce carotenoids, resulting in enhanced value of this biodiesel by-product.

Current Advances in Carotenoid Production by Rhodotorula sp.

“…The authors reported an increase in carotenoid production of 42% in fed-batch culture. Sriphuttha et al [88] demonstrated a 12-fold increase in carotene production with the fed-batch strategy compared to batch.…”

Enhanced high β-carotene yeast cell production by Rhodotorula paludigena CM33 and in vitro digestibility in aquatic animals

“…The strain Rhodotorula paludigena CM33, first isolated from castor seeds ( Ricinus communis ) 8 , has been identified for its significant lipid synthesis and carotenoid production capabilities 14 . Prior research by Sriphuttha et al 5 has extensively studied its effects on the growth, gene expression, intestinal microbial composition, disease resistance, and meat quality of whiteleg shrimp ( Litopenaeus vannamei ), demonstrating its potential as a probiotic supplement in shrimp feed.…”