title: Valorisation of side streams from wheat milling and confectionery industries for consolidated production and extraction of microbial lipids.
abstract: Crude enzymes produced via solid state fermentation (SSF) using wheat milling by-products have been employed for both fermentation media production using flour-rich waste (FRW) streams and lysis of Rhodosporidium toruloides yeast cells. Filter sterilization of crude hydrolysates was more beneficial than heat sterilization regarding yeast growth and microbial oil production. The initial carbon to free amino nitrogen ratio of crude hydrolysates was optimised (80.2g/g) in fed-batch cultures of R. toruloides leading to a total dry weight of 61.2g/L with microbial oil content of 61.8% (w/w). Employing a feeding strategy where the glucose concentration was maintained in the range of 12.2-17.6g/L led to the highest productivity (0.32 g/L·h). The crude enzymes produced by SSF were utilised for yeast cell treatment leading to simultaneous release of around 80% of total lipids in the broth and production of a hydrolysate suitable as yeast extract replacement.
authors.affiliation: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
authors.forename: Sofia
authors.initials: S
authors.lastname: Tsakona
authors.affiliation: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
authors.forename: Argyrios G
authors.initials: AG
authors.lastname: Skiadaresis
authors.affiliation: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kopsahelis
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading RG6 6AD, UK.
authors.forename: Afroditi
authors.initials: A
authors.lastname: Chatzifragkou
authors.affiliation: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
authors.forename: Seraphim
authors.initials: S
authors.lastname: Papanikolaou
authors.affiliation: Department of Chemical Engineering, University of Patras, 26504 Patras, Rio, Greece.
authors.forename: Ioannis K
authors.initials: IK
authors.lastname: Kookos
authors.affiliation: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece. Electronic address: akoutinas@aua.gr.
authors.forename: Apostolis A
authors.initials: AA
authors.lastname: Koutinas
mesh_terms: D008055:Lipids / Q000737:chemistry*; D009584:Nitrogen; D045483:Rivers; D014908:Triticum / Q000737:chemistry*; D064091:Waste Disposal Facilities; D015003:Yeasts
chemical_list: D008055:Lipids; D009584:Nitrogen
keywords: Bioprocess development; Enzymatic cell lysis; Food waste valorisation; Microbial oil; Rhodosporidium toruloides