In the semi-solid medium, δ-endotoxin productionwas about 862μg/mLsubstrate, which presented a 30.2% increasefrom the equivalent volume of the solid-state sample and a 73.8% increasefrom the equivalent volume ofthe submerged sample. Moreover, results showed that the semi-solidstate samples have higher utilization rates of reducing sugar(in Fig.1 (a)), larger number of spores, and higherentomotoxicity (in Fig.1 (b)), which indicated that thesemi-solidstate system exhibits better availabilitythan the solid-state system15and is mainly characterized byhighmass-transfer efficiency,uniform physicochemical