Mixed glycerol and orange peel-based substrate for fed-batch microbial biodiesel production

Heliyon

卷:6

Maurizio Petruccioli¹  Eleonora Carota²  Silvia Crognale²  Alessandro D'Annibale³ 

[1] Department for Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, Via S. Camillo De Lellis snc, 01100, Viterbo, Italy;

[2] Corresponding author.;

关键词: Biotechnology;    Microbiology;    Waste treatment;    Green engineering;    Sustainable development;    Microbial biotechnology;   

DOI  :  

来源: DOAJ

【 摘 要 】

The aqueous extraction of orange peel waste (OPW), the byproduct of the juice extraction process generated annually in massive amounts (21 Mton), yields a carbohydrate-rich liquid fraction, termed orange peel extract (OPE). Several studies highlight that the combination of glycerol, a biodiesel byproduct, with carbohydrate mixtures might boost microbial lipid production. This study performed first a shaken flask screening of 15 oleaginous yeast strains based on their growth and lipid-producing abilities on OPE- and glycerol-based media. This screening enabled the selection of R. toruloides NRRL 1091 for the assessment of the process transfer in a stirred tank reactor (STR). This assessment relied, in particular, on either single- and double-stage feeding fed-batch (SSF-FB and DSF-FB, respectively) processes where OPE served as the primary medium and nitrogen-containing glycerol-OPE mixtures as the feeding one. The continuous supply mode at low dilution rates (0.02 and 0.01 h−1 for SSF-FB and DSF-FB, respectively) starting from the end of the exponential growth of the initial batch phase enabled the temporal extension of biomass and lipid production. The SSF-FB and DSF-FB processes attained high biomass and lipid volumetric productions (LVP) and ensured significant lipid accumulation on a dry cell basis (YL/X). The SSF-FB process led to LVP of 20.6 g L−1 after 104 h with volumetric productivity (rL) of 0.20 g L−1 h−1 and YL/X of 0.80; the DSF-FB process yielded LVP, rL and YL/X values equal to 15.92 g L−1, 0.11 g L−1 h−1 and 0.65, respectively. The fatty acid profiles of lipids from both fed-batch processes were not significantly different and resembled that of Jatropha oil, a vastly used feedstock for biodiesel production. These results suggest that OPE constitutes an excellent basis for the fed-batch production of R. toruloides lipids, and this process might afford a further option in OPW-based biorefinery.

【 授权许可】

Unknown