abstract
Rhodotorula glutinis (R. glutinis) yeasts are natural sources of intracellular carotenoids such as beta-carotene, torularhodin, and torulene. Since these yeasts are constituted by a rigid cell-wall structure, the use of energy-saving and high-efficiency cell disruption procedures is critical for carotenoids recovery. A new technology using protic ionic liquids (PILs) was here evaluated as an alternative platform to permeabilize the R. glutinis cells and to improve the extraction of beta-carotene, torularhodin, and torulene. The cell disruption ability of 12 highly concentrated aqueous solutions of ammonium-based PILs was determined, evaluating the influence of the relative ion hydrophobicity, solid-liquid ratio, water content, and temperature. Carotenoid extraction yields increased with the hydrophobicity of the PILs (i.e., increase of alkyl chain length of the anion or cation), temperature (from 25 to 65 degrees C), and PIL concentration (from 75 to 90% v/v). Additionally, to demonstrate the potential of PILs in carotenoids recovery, solvent recycling and carotenoids polishing were carried out using a three-phase partitioning system. The results demonstrate that the use of PILs as cell-disrupting agents can be a simple, efficient, sustainable, and feasible method to recover intracellular carotenoids from microbial biomass.
keywords
AQUEOUS-SOLUTIONS; ORGANIC-SOLVENTS; BETA-CAROTENE; EXTRACTION; TEMPERATURE; FOOD; BIODEGRADABILITY; (ECO)TOXICITY; IMIDAZOLIUM; PERFORMANCE
subject category
Chemistry; Science & Technology - Other Topics; Engineering
authors
Mussagy, CU; Santos-Ebinuma, VC; Gonzalez-Miquel, M; Coutinho, JAP; Pereira, JFB
our authors
Jorge Fernando Brandão Pereira
PhD Studentacknowledgements
This research was supported by grants from the Ministry of Science and Technology, Higher and Technical Vocational Education Training of Mozambique (MCTESTP, Maputo, Mozambique) through the HEST Project, World Bank and the FAPESP (Sao Paulo Research Foundation Brazil) through project nos. 2014/19793-3, 2014/16424-7, 2014/01580-3, and 2017/50303-0. The authors also acknowledge the support from the CNPq (National Council for Scientific and Technological Development, Brazil) and the CAPES (Coordination of Superior Level Staff Improvement, Brazil), finance code 001. This work was partly developed in the scope of the project CICECO-Aveiro Institute of Materials POCI-01-0145FEDER-007679 (ref no. FCT UID/CTM/50011/2019) funded by FEDER through COMPETE2020, Programa Operational Competitividade e Internacionalizacao (POCI), and by national funds through FCT, Fundacao para a Ciencia e a Tecnologia.