Biotechnological Conversions of Mizithra Second Cheese Whey by Wild-Type Non-Conventional Yeast Strains: Production of Yeast Cell Biomass, Single-Cell Oil and Polysaccharides

The cultivation of oleaginous yeasts on various agro-industrial residues and the subsequent production microbial lipids (single-cell oils), which can be used as starting materials for synthesis both “second generation” biodiesel types oleochemicals, is considered one most important approaches Industrial Biotechnology, in terms circular economy green sustainable development. In this study, seven wild-type non-conventional yeast strains were evaluated their growth a semi-defined medium with cheese whey lactose sole carbon source. Five these further batch-cultivated into complex substrate that contained second whey, main by-product Mizithra manufacture, after centrifugation filtration without any extra mineral salts, carbon, or nitrogen source addition. All five grown produced mainly biomass to lesser extent other interesting metabolites, such polysaccharides. strain Cryptococcus curvatus ATCC 20509 highest total dry weight (TDW) amount (22.4 g/L), 3.4 g/L intra-cellular lipids, followed by C. NRRL Y-1511, 20.6 TDW 3.2 lipids. A novel, non-previously systematically studied strain, namely Papiliotrema laurentii Y-2536, significant quantities (22.0 g/L) and, interestingly, secreted exopolysaccharides. Fed-batch shake-flask pretreated pulse-supplemented condensed whey-derived lactose, led quantity 38.1 c. 57% w/w (lipids at concentration 21.7 produced). Cellular all microorganisms, stored triacylglycerols, variable fatty acids ?9C18:1, C16:0, ?9,12C18:2 C18:0, constituting perfect candidates biodiesel.