N^+注入诱变选育改善豆粕饲用品质的菌种研究  

A Study on the Strain of Improved Feeding Quality of Soybean Mealby N^+ Implantation Mutation

作　　者：吴胜华 李吕木[1] 张邦辉[2] 袁航[3] 韩景华[1] 

机构地区：[1]安徽农业大学动物科技学院,安徽合肥230036 [2]安徽天邦饲料科技有限公司,安徽和县238200 [3]中国科学院离子束生物工程重点实验室,安徽合肥230031

出　　处：《激光生物学报》2009年第4期527-533,共7页Acta Laser Biology Sinica

基　　金：安徽省2007年重大科技专项(07010301019)

摘　　要：为了选育能够提高豆粕饲用品质的高效菌株,利用能降解胰蛋白酶抑制因子(trypsin inh ib itors,TI)的枯草芽孢杆菌进行N+注入诱变,挑选碱性蛋白酶高产菌株,按出发菌的优化发酵条件与出发菌分别进行豆粕固态发酵,比较其TI降解效果,同时采用L16(45)正交设计对诱变菌株发酵豆粕的接种量、料水比、温度、发酵时间和通气量五个因素进行优化。在诱变能量为15 keV,剂量为1.5×1015ions/cm2时,筛到一株高产碱性蛋白酶的菌株KY-103,其酶活由诱变前21.39 U/mL提高到103.07 U/mL,胰蛋白酶抑制因子的降解率由19.58%提高到36.24%,小肽含量也由4.27%提高到7.89%。综合考虑的最佳发酵条件为15%的接种量,料水比1∶1,通气量为60 g/500 mL,pH自然,在40℃下发酵96 h。此条件下胰蛋白酶抑制因子的降解率达43.92%,小肽含量达8.14%。结果提示,N+注入诱变可以获得改善豆粕饲用品质的高效枯草芽孢杆菌。In order to obtain the high-efficient bacteria that improved the feeding quality of soybean meal, Bacillus subtills with strong inhibitory activity against trypsin inhibitor （TI） of soybean meal was mutated by N^＋ implantation. The high-yield strain of alkaline proteinase was selected, and used for comparing solid-state fermentation of soybean meal with its starting bacteria by the optimization of fermentation conditions. Their degradation rates of TI were determined. At the same time, a L16 （45） orthogonal design was conducted to optimize the inoculum size, the ratio of material and water, temperature, fermentation time and ventilation 5 factors. In the mutation energy of 15 keV and dose of 1.5 × 10^15 ions/cm^2, a high-yield strain of the alkaline protcase KY-103 was screened and obtained, the enzyme activity was enhanced from 21.39 U/mL before mutation to 103.07 U/mL. The degradation rate of trypsin inhibitors was enhanced from 19.58 % to 36.24 %. The content of small peptide was enhanced from 4.27 % to 7.89 %. The best conditions for fermentation were ： the inoculation 15 %, the ratio of material and water 1 ： 1, the fermentation temperature 40 ℃, the fermentation time 96 h, the ventilation 60 g/500 mL, pH nature. The degradation rate of TI was 43.92 % ; the content of small peptide was 8.14 % under these conditions. The results showed that the high-efficient Bacillus subtilis can be achieved which improved the feeding quality of soybean meal by N^＋ implantation mutation.

关 键 词：枯草芽孢杆菌 氮离子 碱性蛋白酶 胰蛋白酶抑制因子 小肽 

分 类 号：Q691[生物学—生物物理学]