Raw Glycerol as Substrate for the Production of Yeast Biomass

Abstract

The possibility of using raw glycerol as a substrate for yeast biomass production as a source of proteins was investigated. Biomass concentration, protein content and total protein content of four yeasts (Yarrowia lipolytica NRRL YB-423, Candida lipolytica NRRL Y-1095, Candida utilis NRRL Y-900 and Candida rugosa NRRL Y-95) were determinate, comparing analytical grade glycerol and raw glycerol. Y. lipolytica NRRL YB-423 has been selected as promising for cultivation in a raw glycerol-based medium, mainly due to the higher biomass concentration in relation to the other strains. For this strain, four different culture media were tested. The best results were obtained with 50 g/L glycerol, 5.5 g/L ammonium phosphate, 5.5 potassium dihydrogen phosphate, 1 g/L ammonium sulphate, 0.25 g/L magnesium sulphate, 0.021 g/L calcium chloride dehydrate, 1 g/L yeast extract, 1 g/L peptone, pH adjusted to 5.5. In these conditions, it was possible to obtain 17.8 ± 0.6 g/L maximum biomass concentration, 18.2 ± 1.0% protein content and 3.1 ± 0.1 g/L total protein production. These results represent a 1.2-fold increase in biomass concentration, a 1.5-fold increase in protein content and a 1.9-fold increase in total protein production in relation to the results obtained with the previously medium composition.

Single cell protein production by Wickerhamomyces anomalus CCC32 using crude glycerol

“…The results obtained with W. anomalus CCC32 in mineral medium as nitrogen sources, are comparable to those obtained by yeasts using high cost media such as yeast extract and peptone, which were among 17-22 g L −1 , on average (GALVANO et al, 2011;TACCARI et al, 2012;SANTOS et al, 2013). In addition, the mineral medium provided for W. anomalus CCC32 growth favored high biomass yield (20 g L −1 ) in about half the time when compared with other yeast strains.…”

Production of Added-Value Chemical Compounds through Bioconversions of Olive-Mill Wastewaters Blended with Crude Glycerol by a Yarrowia lipolytica Strain

“…To this end, crude glycerol could be considered as an alternative carbon source rather than a waste. It could be used as a valuable substrate for microorganisms, with various applications in industry [31], since a plethora of microbial compounds (such as 1,3-propanediol, hydrogen, propanoic acid, trehalose, single cell oil, n -butanol, glyceric acid, citric acid, ethanol, polyunsaturated fatty acids, biopolymers) can be produced [23,32]. The rationale behind the use of crude glycerol and OMW blends as substrate is to partially or fully replace process tap water in concentrated glycerol dilution by utilizing a wastewater stream.…”

Biocontrol and Probiotic Function of Non-Saccharomyces Yeasts: New Insights in Agri-Food Industry

“…PMKT binds linear (1→6)-β-d-glucans in the cell wall and Cwp2p plasma membrane receptor of sensitive yeasts, leading to alterations in ionic exchange via plasma membrane [ 60 ]. PMKT2, a protein with an apparent molecular mass of 30 kDa, binds mannoproteins and induces cell cycle blockage in the early S-phase of sensitive yeasts and stimulates markers of cellular apoptosis such as the cytochrome c release, DNA strand breaks, metacaspase activation and production of reactive oxygen species at a low dose [ 61 ]. The killer activity of P. membranifaciens was exploited in winemaking to control the B. bruxellensis economic relevant spoilage yeast using mixed fermentation with S. cerevisiae and B. bruxellensis (inoculum ratio of 1:1).…”