The aim of the present study was to examine different yeast species ability to utylise glycerol in the pH range from 3.5 to 6.5. Growth kinetics and yield biomass of selected yeast strains in stirred tank reactor on pH 3.5-4.0 media with raw glycerol from a bio-diesel production unit was investigated, also. An automated turbidimetry, Bioscreen C, was used to monitor yeast growth on pure glycerol in the pH range from 3.5 to 6.5. The growth of the yeast was kinetically monitored throughout the incubation period and various growth curves parameters were used as quantitative indicators of yeast growth. Yarrowia lipolytica ATCC 8661 UV’1 strain growth parameters were the highest values and was not dependent on the pH media (ΔOD = 1,70-1,75 i WEW = 3077-3360). Biomass production processes were cerried out with the best growing strains at the pH 3.5-4.0 (Y. lipolytica ATCC 8661 UV’1, Candida robusta ATCC 60 559, C. utilis ATCC 60 558 and C. tropicalis ATCC 60 557). Technological parameters (biomass yield, protein content, productivity and total yield) showed that the best biomass producer from raw glycerol was Y. lipolytica ATCC 8661 UV’1 strain.

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