Résumé
Biomass is a renewable resource, which can be transformed into useful chemical products. The effects of dilute hydrochloric acid on the hydrolysis of steam explosion pretreatment of corn straw were studied. This article developed the application research of ergosterol using corn straw hydrolysates as fer- mentation substrates. The results showed that when corn straw was hydrolyzed with 1.5% hydrochloric acid, temperature at 90?C, hydrolysis for 3 h and the corresponding solid to liquid ratio at 10%, the reducing sugar content can reached up to 53.3% and cellulose conversion efficiency was 79%. The optimal fermental pa- rameters were as follows: 6.0 oBx of corn straw hydrolysates, corn concentration steep water at 4%, pH 7.5, 10% of inoculation, 28?C cultivated for 32 h. Under these conditions, the yeast biomass up to 8.5 g/L and the ergosterol content up to 2.35%. The infrared spectrometer and the X-ray diffract meter used to characterize of crystallite structure.
Résumé
The ergosterols were produced from corn straw hydrolysates fermented by ergosterol yeast,which was obtained from protoplast electrofusion.The effects on the yield of ergosterol were studied in the condition of shaker,such as initial sugar concentration,nitrogen source,pH value and fermentation time.The technical conditions were optimized according to the DPS center-united experimental design principles and the method of response surface analysis with four factors and three levels.The results indicated that the four factors had significant correlation to ergosterol accumulation.The biomass and the ergosterol content could be up to 8.67g/L and 2.37% respectively after cultivated for 32h under optimal technical condition.The structure of ergosterol crystal was characterized by UV,IR and SEM.A new approach of biomass source application was presented.