Rye and Oat Agricultural Wastes as Substrate Candidates for Biomass Production of the Non-Conventional Yeast Yarrowia lipolytica

Abstract

The aim of this study was to test rye straw, rye bran and oat bran hydrolysates as substrates for growth of the yeast Yarrowia lipolytica, a microorganism known to have large biotechnological potential. First, after the combined process of acid-enzymatic hydrolysis, the concentration and composition of fermentable monosaccharides in the obtained hydrolysates were analyzed. Glucose was the main sugar, followed by xylose and arabinose. Rye bran hydrolysate had the highest sugar content—80.8 g/L. The results showed that this yeast was able to grow on low-cost medium and produce biomass that could be used as a feed in the form of single cell protein. The biomass of yeast grown in oat bran hydrolysate was over 9 g/L after 120 h, with the biomass total yield and total productivity values of 0.141 g/g and 0.078 g/h, respectively. The protein contents in yeast biomass were in the range of 30.5–44.5% of dry weight. Results obtained from Y. lipolytica cultivated in rye bran showed high content of exogenous amino acid (leucine 3.38 g, lysine 2.93 g, threonine 2.31 g/100 g of dry mass) and spectrum of unsaturated fatty acid with predominantly oleic acid—59.28%. In conclusion, these results demonstrate that lignocellulosic agricultural waste, after hydrolysis, could be efficiently converted to feed-related yeast biomass.

Application of a New Engineered Strain of Yarrowia lipolytica for Effective Production of Calcium Ketoglutarate Dietary Supplements

“…In the examined biomass, the total lipid content, the other factor affecting quality of biomass, reached 20.8% in the dry biomass weight ( Table 4 ), and was comparable to or even higher than the results presented for Y. lipolytica by other researchers, where the lipid content was in the range 6.5–20.3% [ 40 , 41 , 42 , 49 ]. It is worth noting that in the present study, the yeast was cultivated in conditions of high nitrogen availability, whereas lipid accumulation is favored when nitrogen is limited in the culture medium.…”

“…In the biomass, the limiting amino acids were methionine and cysteine, the pool of which reached 1.6 g/100 g of protein, corresponding to a chemical score of 28.1 and 94.1 calculated with respect to the FAO/WHO standards for whole egg and adult men’s requirements, respectively. The low sulfuric content of the Y. lipolytica yeast was also noted in previous reports [ 40 , 41 , 42 ]. For animal feed, the recommended level of sulfur amino acids is 3.5 g/100 g of protein [ 47 ].…”

“…The protein content of the biomass increased up to 29.9% with increased nitrogen availability in the culture where the C:N:P ratio reached 87:5:1 ( Table 2 ). In processes optimized for biomass production, and thus without limiting factors and with comparatively high nitrogen availability, the protein content in the dry matter of Y. lipolytica has ranged from over 30% up to 54% [ 40 , 41 , 42 , 43 ]. The literature reports that high carbon excess stimulated different processes performed with Y. lipolytica , e.g., erythritol [ 38 , 39 ], lipid [ 37 ] and citric acid [ 36 ] production, where a C:N ratio of about 87:1, 100:1 and 367:1 was applied, respectively.…”

Optimization of steam explosion parameters for improved biotechnological use of wheat straw

“…Others found a maximum biomass of 7.4 g L − 1 (reached after 144 h) for Y. lipolytica grown on wheat straw hydrolysate [51]. Conversely, when grown for 120 h on rye straw hydrolysate, it was 3.35 g L −1 [63]. Concluding, our results suggest that wheat straw pretreated by the strategy developed in our study could be efficiently bio-converted into valuable platform chemicals or biofuels.…”

Production of enriched in B vitamins biomass of Yarrowia lipolytica grown in biofuel waste

“…Hence, such the yeast is also called nutritional yeast. Noteworthy, Y. lipolytica can accumulate lipids intracellularly up to ≥40% of its cell dry weight or produce 30–50% protein of dried biomass ( Bellou et al, 2016 , Beopoulos et al, 2011 , Dourou et al, 2018 , Drzymała et al, 2020 , Jach et al, 2017 , Juszczyk et al, 2013 , Lopes et al, 2018 , Lopes et al, 2019 , Papanikolaou et al, 2001 , Papanikolaou et al, 2003 , Rywińska et al, 2013 ). Similar to animal cells, Y. lipolytica is also capable of vitamin B12 assimilation into its cells from biofuel waste acting as a substrate ( Jach et al 2020b ).…”