Production of carotenoids by Rhodotorula glutinis MT-5 in submerged fermentation using the extract from waste loquat kernels as substrate

BACKGROUND: The aim of present study was to investigate the feasibility of the hydrolysate extracts from waste loquat kernels as substrate in submerged culture of yeast Rhodotorula glutinis MT‐5 for carotenoid production. RESULTS: Loquat kernel was found to have high protein (22.5%) and total carbohydrate (71.2%) contents. Dried and powdered loquat kernels were subjected to acid hydrolysis with 2 mol L^?1 HCl. The hydrolysate obtained was used for the preparation of loquat kernel extract and detoxified loquat kernel extract. The detoxification of hydrolysate was performed with Ca(OH)₂. Among the 10 R. glutinis isolates, the MT‐5 was found to be best in order to produce carotenoid using the extract as substrate. Production media prepared with detoxified loquat kernel extract or loquat kernel extract gave maximum biomass concentrations of 12.64 and 11.37 g L^?1, and maximum carotenoid concentrations of 72.36 and 62.73 mg L^?1, respectively. CONCLUSION: This study has provided effective processes for the conversion of waste material of plant origin to the extracts which are very rich in term of total fermentable sugar. The practicability of the extracts as fermentation substrate was proven in carotenoid production. To the best of our knowledge, this is the first report on use of this waste material as a substrate in yeast fermentations. Copyright © 2011 Society of Chemical Industry