Integrated cascade biorefinery processes for the production of single cell oil by Lipomyces starkeyi from Arundo donax L. hydrolysates

Giant reed (Arundo donax L.) is a promising source of carbohydrates that can be converted into single cell oil (SCO) by oleaginous yeasts. Microbial conversion of both hemicellulose and cellulose fractions represents the key step for increasing the economic sustainability for SCO production. Lipomyces starkeyi DSM 70,296 was cultivated in two xylose-rich hydmlysates, obtained by the microwave-assisted hydrolysis of hemicellulose catalysed by FeCl3 or Amberlyst-70, and in two glucose-rich hydrolysates obtained by the enzymatic hydrolysis of cellulose. L. starkeyi grew on both undetoxified and partially-detoxified hydrolysates, achieving the lipid content of 30 wt% and yield values in the range 15-24 wt%. For both integrated cascade processes the final production of about 8 g SCO from 100 g biomass was achieved. SCO production through integrated hydrolysis cascade processes represents a promising solution for the effective exploitation of lignocellulosic feedstock from perennial grasses towards new generation biodiesel and other valuable bio-based products.

Automated summary

This study explored the microbial conversion method of giant reed into single cell oil, achieving the production of SCO from biomass by cultivating oleaginous yeast in xylose-rich or glucose-rich hydrolysates. Integrated cascade processes showed promising potential for effective utilization of lignocellulosic feedstock from perennial grasses to produce biodiesel and other bio-based products.