Effects of Inoculation of Thermotolerant Bacillus Strains on Lignocellulose Degradation

Thise study investigated the effect of three lignocellulolytic thermophilic Bacillus strains (F11, Q1, and FP4) on lignocellulose degradation, enzymatic activities, and microbial community structure in composting. The lignin degradation rate reached 36% in the presence of the inoculant, the hemicellulose degradation rate ranged from 43% (F11) to 51% (Q1), and cellulose degradation rates reached 57% in F11 and in FP4, which were significantly higher than the control (CK). The inoculation treatment could explain 28% of the lignin degradation for all three strains. The contribution of FP4 to hemicellulose and cellulose degradation was 30% and 20%, respectively. Compared to CK, lignin peroxidase activity in the water extract of the compost had increased by 66~145% for inoculation treatments, and manganese peroxidase and laccase activity increased by 114% and 78% for Q1. The inoculation stimulated the growth of indigenous bacteria with stronger lignocellulolytic enzyme-producing ability; such shifts in microbial communities were most likely responsible for the improved lignocellulose degradation.