家蚕肠道产酶菌的分离与筛选

Isolation and Screening of the Enzyme-producing Bacteria in the Intestine of Silkworm

探明家蚕肠道菌在食物消化过程中的作用,有助于微生态饲用添加剂的开发研究。从家蚕肠道中分离出30株菌株,并研究了它们的胞外淀粉酶、蛋白酶、纤维素酶和脂肪酶的产酶能力。在家蚕肠道中存在着可以分泌蛋白酶、淀粉酶、脂肪酶和纤维素酶的菌株。在分离到的30株肠道菌株中,产4种酶的有1株菌,产3种酶的有4株菌,产2种酶的有2株菌,产1种酶的有11株菌,不产酶的有12株菌。在产酶菌中,有9株菌株能分泌蛋白酶,能分泌脂肪酶和纤维素酶的各有7株菌,有8株菌株能分泌淀粉酶。家蚕肠道菌中的各种产酶菌高达60%,表明了肠道菌在家蚕食物消化过程中的重要性。

To understand the role of bacteria from the silkworm intestine in the digestion and assimilation of food, and to screen potential beneficial strains for the future applications in the silkworm rearing, 30 strains were isolated from the intestine of silkworm and their enzyme-producing capabilities were studied. Results showed that a strains were able to produce protease, 7 strains were able to produce either lipase and 7 strains produced cellulose, and 8 strains were able to produce amylase （8 stains） . Among the 30 isolates, 1 strain excreted all four enzymes, 4 strains excreted three kinds of enzymes, 2 strains excreted two kinds of enzymes, 11 strains excreted one enzyme, and other 12 strains didn＇t excret any enzyme. In other words, 60% of the isolates were capable of producing enzymes. Therefore, it can be concluded that bacteria in the intestine of silkworm play an important role in the digestion of food.