舍雷肽酶是一种来自粘质沙雷氏菌(Serratia marcescens)的碱性蛋白酶，具有良好的抗炎和抗肿胀作用，应用于临床疾病的治疗已有多年。为了获得产酶活力高、传代稳定且不产灵菌红素的舍雷肽酶发酵生产菌株，以1株分离自家蚕(Bombyx mori)肠道，产舍雷肽酶的粘质沙雷氏菌LL-413为出发菌株，用紫外线和微波连续诱变，经过筛选，获得了2株产酶能力高，不产灵菌红素，且传代稳定的突变株MW-9和MW-14菌株，产酶活力分别达到982 U/mL和956 U/mL，是原始菌株的1.98倍和1.92倍。

Serrapeptase is a kind of alkaline protease from Serratia marcescens. Due to its excellent anti-inflammatory and anti-swelling function, serrapeptase has been applied to treat some diseases in clinical for many years. In order to obtain strains with the characteristics of fine hereditary stability and prodigiosin negative for high-yield production of serrapeptase, a strain isolated from the intestine of silkworm (Bombyx mori), S. marcescens LL-413 was mutated by ultraviolet and microwave continuously. As results, 2 strains, designated as MW-9 and MW-14, were selected out. Their productivity of serrapeptase was 982 U/mL and 956 U/mL, which respectively was 1.98 and 1.92 times higher than that of the original strain.