家蝇纤维素酶的检测及酶活性与其发育的关系  

Detection of Cellulases and the Relationship Between Enzyme Activity and Development of Musca domestica

作　　者：胡蓉[1] 张姝[1] 吴建伟[1] 国果[1] 付萍[1] 

机构地区：[1]贵阳医学院基础医学院,贵阳550004

出　　处：《应用与环境生物学报》2013年第3期444-448,共5页Chinese Journal of Applied and Environmental Biology

基　　金：国家科技支撑计划项目(2011BAC06B12);国家自然科学基金项目(30960343);国家教育部博士点专项基金项目(2008-220);高校博士点学科专项科研基金;新教师类基金项目(20105215120001);贵州省教育厅培育项目(2009-0137)资助~~

摘　　要：为了解家蝇能否降解利用纤维素,采用DNSA法检测家蝇幼虫纤维素酶活性及酶学特性;并进一步研究纤维素酶活性与家蝇发育的关系.结果显示,在生长发育的不同时期,家蝇都具有滤纸酶活性,活性范围为0.85(±0.035)IU mg-1至10.45(±0.050)IU mg-1;家蝇纤维素酶的组成包含3种酶,即β-葡萄糖苷酶(β-glucosidase,BG)、内切β-1,4-葡聚糖酶(Endo-β-1,4 glucanase,EG)和外切β-1,4-葡聚糖酶(Exo-β-1,4-glucanase,CBH).在pH 5.6的条件下,这3种酶的最适反应温度和时间分别为50℃和60 min,在体外具有较强的热稳定性,50℃放置1 h后仍可保持较强的酶活性.纤维素酶活性随着家蝇的发育逐渐增高(P<0.05),卵的酶活性最低,成虫的酶活性最高,在最适反应条件下,成虫BG、EG和CBH的活性分别为(7.96±0.065)IU mg-1、(9.76±0.080)IU mg-1和(10.86±0.091)IU mg-1.这3种酶的活性在家蝇卵、幼虫、蛹和成虫4个发育阶段,均是CBH最高,BG最低.增加家蝇幼虫饲料中粗纤维的含量,3龄幼虫的纤维素酶活性明显提高(P<0.05),而平均体重和体长与对照组比无显著差异(P>0.05).研究表明家蝇具有完整的降解利用植物纤维素的酶系,其纤维素酶活水平与家蝇的发育密切相关.For understanding whether or not Musca domestica has an ability to hydrolyze cellulose, the activities and characteristics of cellulases from M. domestica were examined with the 3,5-dinitrosalicylic acid （DNSA） method. Then the composition and activity change of M. domestica cellulases were investigated during its development. The results showed that M. domestica in the different developmental stages had the filter paper enzyme activity, the activity-range being 0.85 （＋ 0.035） IU mgL to 10.45 （0.050） IU mg. The cellulase components included fl-glucosidase （BG）, endo-fl-l,4 glucanase （EG） and exo- fl-l,4-glucanase （CBH）, which were detected with the special substrate of 1% salicin, 1% carboxymethylcellulose （CMC） and 1% microcrystalline cellulose （MCC）, respectively. Under the condition of pH 5.6, for the three enzymes, the optimum reaction temperature and time were 50 ℃ and 60 min. They had good heat stability in vitro when being kept in 50 ℃ for 1 hour. Activity of the cellulases increased gradually with its development （P 〈 0.05）. The lowest enzyme activity showed in the ovule stage and the highest enzymatic activity in the imago stage. At the optimum reaction condition, the activities of BG, EG and CBH were 7.96 （＋ 0.065） IU mg, 9.76 （ 0.080） IU mg and 10.86 （ 0.091） IU mg respectively. The CBH activity was the highest, and the BG the lowest in M. domestica life cycle. With increasing crude fiber in the forage ofM. domestica larvae, cellulase activity of the third instar larvae was also increased （P 〈 0.05）, without a significant deviation of mean weight and stem length of the third instar larvae compared to the control group （P 〉 0.05）. The results suggested a complete enzyme system of cellulases in domestica and a close relationship between the enzyme activity level and the development of M. domestica. Fig 6, Tab 1, Ref 19 cellulase; fl-glucosidase; endo-fl-l,4 glucanase; exo-fl-l,4-glucanase; enzyme activity; development; Musca domestica

关 键 词：纤维素酶 Β-葡萄糖苷酶 内切β-1 4-葡聚糖酶 外切β-1 4-葡聚糖酶 酶活性 发育 家蝇 

分 类 号：Q966[生物学—昆虫学]