Catalysis

Biology

Yield (engineering)

Metallurgy

Materials science

Biochemistry

Nitrogen

Food science

Biodiesel

Paleontology

Organic chemistry

Xylitol

Glycerol

Biodiesel production

Bioconversion

Bioprocess

Arabitol

Chemistry

Fermentation

Carbon Resources Conversion

The purpose of this research was the bioconversion of biodiesel-derived glycerol to arabitol through the adoption of sustainable bioprocessing. Arabitol production by Debaryomyces prosopidis FMCC Y69 was significantly affected by initial glycerol concentrations. The highest arabitol concentration of 45.5 g/L was achieved in the case of 120 g/L initial glycerol combined with the highest yield (0.379 g arabitol/g initial glycerol). The yeast strain showed a non-typical oleaginous behavior with low accumulation of lipids (up to 20.9% w/w) despite nitrogen-limited condition that prevailed in the fermentation media. Endopolysaccharides (IPs) were considerably high with a yield on the produced dry cell weight (YIPs/X) (=40.9% w/w) when 85 g/L of glycerol was utilized as the starting material. The fermentation efficiency was further improved when the optimal carbon to nitrogen (C/N) ratio was applied. More specifically, arabitol production was maximized (reaching 56.5 g/L) at a C/N ratio of 158 moles/moles while yield and productivity were also enhanced with respective values of 0.48 g arabitol/g consumed glycerol and 0.112 g/L.h. The increase in C/N ratios led to a decrease in cell dry weight (DCW) concentrations, which is rationally associated with decreased nitrogen availability in the growth medium. YIPs/X values were remarkably high (23.1–26.1% w/w) at the end of each fermentation with the highest concentration in absolute values of 7.3 g/L achieved at the lowest C/N ratio employed (i.e., 79 moles/moles). This study demonstrated the efficient arabitol production along with other value-added metabolites, such as IPs and cellular lipids, implementing biotechnology and renewable resources and thus contributing to the development of circular economy technologies.

Sustainable arabitol production by a newly isolated Debaryomyces prosopidis strain cultivated on biodiesel-derived glycerol