Development of a circular oriented bioprocess for microbial oil production using diversified mixed confectionery side-streams

Tsakona, S., Papadaki, A., Kopsahelis, N., Kachrimanidou, V., Papanikolaou, S. and Koutinas, A. (2019) Development of a circular oriented bioprocess for microbial oil production using diversified mixed confectionery side-streams. Foods, 8 (8). 300. ISSN 2304-8158 doi: 10.3390/foods8080300

Abstract/Summary

Diversified mixed confectionery waste streams were utilized in a two-stage bioprocess to formulate a nutrient-rich fermentation media for microbial oil production. Solid-state fermentation was conducted for the production of crude enzyme consortia to be subsequently applied in hydrolytic reactions to break down starch, disaccharides, and proteins into monosaccharides, amino acids, and peptides. Crude hydrolysates were evaluated in bioconversion processes using the red yeast Rhodosporidium toruloides DSM 4444 both in batch and fed-batch mode. Under nitrogen-limiting conditions, during fed-batch cultures, the concentration of microbial lipids reached 16.6−17 g·L−1 with the intracellular content being more than 40% (w/w) in both hydrolysates applied. R. toruloides was able to metabolize mixed carbon sources without catabolite repression. The fatty acid profile of the produced lipids was altered based on the substrate employed in the bioconversion process. Microbial lipids were rich in polyunsaturated fatty acids, with oleic acid being the major fatty acid (61.7%, w/w). This study showed that mixed food side-streams could be valorized for the production of microbial oil with high unsaturation degree, pointing towards the potential to produce tailor-made lipids for specific food applications. Likewise, the proposed process conforms unequivocally to the principles of the circular economy, as the entire quantity of confectionery by-products are implemented to generate added-value compounds that will find applications in the same original industry, thus closing the loop.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/85370
Identification Number/DOI	10.3390/foods8080300
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Research Group
Uncontrolled Keywords	food-processing, circular economy, bioprocess development, Rhodosporidium toruloides, microbial oil, oleic acid
Publisher	MDPI
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