Modeling hexanal production in oxido-reducing conditions by the yeast Yarrowia lipolytica

Optimization and scaling up of a biotechnological synthesis of natural green leaf volatiles using Beta vulgaris hydroperoxide lyase

“…Regarding the cost of the extracting medium, the antibiotics and inductor, the scaling-up of this production was not performed at 100 L. A further alternative is the use of excreted HPL produced by eukaryotes strains, this new protocol suppress the necessity of enzymatic extraction but in these conditions HPL activity produced remains often very low e.g. under 1 kat/mL [31][32][33].…”

Selected dehydrogenases in Yarrowia lipolytica JMY 861: their role in the synthesis of flavor compounds

“…Strain and culture conditions. The genotype of the yeast strain JMY 861 of Y. lipolytica, expressing a 6-His-tagged (N-terminal) green bell pepper HPL is described by Bourel et al 3) This strain was grown, as described by Santiago-Gómez et al, 8) on YTGA medium (5 g of yeast extract/L, 10 g of tryptone/L, 10 g of glucose/L, and 15 g of agar/L) at 27°C for 48 h. The biomass was harvested and inoculated, with an optical density (OD) at λ 600 of 0.2, in 100 mL of YTG medium (5 g of yeast extract/L, 10 g of tryptone/L, and 10 g of glucose/L), with continuous shaking at 140 rpm, using an orbital shaker incubator (New Brunswick Scientific Co., Inc.; Edison, NJ) at 27°C. After 24 h of pre-culture, the biomass was inoculated, with an initial OD at λ 600 of 4, into YTO medium, composed of 10 g of olive oil/L, 5 g of yeast extract/L yeast, 10 g of tryptone/L, 5.3 g of NH 4 Cl/L, and 1% (v/v) Tween-80, to induce the expression of HPL.…”

“…ALDHs catalyze, in the presence of water, the irreversible oxidation of aldehydes into their corresponding carboxylic acids, 1) with the concomitant reduction of NAD + and/or nicotinamide adenine dinucleotide phosphate (NADP + ). The volatile C 6 -aldehydes and their corresponding C 6 -alcohols are major contributors to the characteristic "green odor" of plants, 6) where they are commonly used to enhance or to reconstitute the "fresh green odor" of processed foods 8) as well as in the cosmetic and personal care sectors. 9) However, the use of ADHs and ALDHs in industrial applications is limited because of the high cost of the nicotinamide cofactors.…”

Development of redox potential-controlled schemes for very-high-gravity ethanol fermentation

“…Moreover, the external redox potential reflects the net balance of intracellular reducing equivalents (De Graef et al, 1999) that relates to energy and material metabolism (Johannes et al, 1986), and is one of the few available and manipulable parameters that can be implemented into a fermentation process. Maintaining the redox potential within a proper range could alter internal NADH/NAD + redistribution, which can redirect the yeasts' intracellular metabolic flow towards the production of desired metabolites: 1,3-propanediol (Du et al, 2006), xylitol (Sheu et al, 2004), citric acid (Berovic and Cimerman, 1982), hexanal (Santiago-Gómez et al, 2009), and so on. By correlating a particular redox potential with a particular dissolved oxygen level, it would be possible to maintain a desired dissolved oxygen level to increase yeast ethanol production (Yu et al, 2007).…”