Microbial protein production by Paecilomyces variotii cultivated in eucalyptus hemicellulosic hydrolyzate

The eucalyptus hemicellulose fraction was hydrolyzed by treating eucalyptus wood chips with 1•2% (w/v) sulfuric acid (wood to acid ratio of 1:3) at 150°C for 120 min. The hydrolyzate was used as substrate to grow Paecilomyces variotii IOC-3764 in a 7-l fermenter at 30°C; air 1•5 vvm; stirring 400 rpm. The kinetic parameters measured included maximum growth rate (μmax 0•10/h), yield (Yx/s 0•44 g/g), and productivity (Qx 0•26 g/l•h). The protein produced (34% of the biomass) contained all essential amino acids for animal feed.