Study on degradation of cellulose from steam-blasted reed straw by solid-state fermentation with mixed bacteria
In order to improve the utilization rate of reed straw,three strains of prion-producing Candida(CR1,CR2 and CR3),one strain of Bacillus subtilis(KC),one strain of Saccharomyces cerevisiae(NJ)and one strain of Lactobacillus plantarum(ZR)were used for single-bacterial solid-state fermentation,and CR1,CR2 and CR3 strains with high nitrogen tolerance were induced and screened.On this basis,the single-factor test method was used to screen and optimize the strain combination,strain proportion,composite bacteria inoculated amount,nitrogen source type,etc.,to explore their influence on the solid-state fermentation of reed straw with mixed bacteria.The results showed that the CR3 strain was more tolerant to high nitrogen,and the CR3 bacterial concentration was≥107 CFU/mL after liquid(2.5%urea)cultivation.The optimal strain combination and ratio was CR3∶NJ∶ZR=2∶1∶1,the inoculum amount of the composite bacteria was 15%,and urea was the optimal nitrogen source,and the content of crude protein and true protein under these conditions was 14.15%and 9.74%,respectively,which were 76.65%and 67.35%higher than before fermentation.The degradation rates of cellulose and hemicellulose were 21.07%and 27.30%,respectively,which were 68.56%and 167.65%higher than before fermentation.The study indicates that solid-state fermentation with mixed bacteria can increase the crude protein content and reduce the crude fiber content of reed straw.
solid-state fermentation with mixed bacteriasteam blastingreed strawhigh nitrogen inductioncellulose