耐高温淀粉酶产生菌筛选与发酵条件优化

耐高温淀粉酶产生菌筛选与发酵条件优化(8300字)
摘  要：从浏阳河畔土壤中分离到两株能分泌耐高温淀粉酶的细菌YY-2和YJ-4，形态学分析表明，YY-2菌株为革兰氏阳性芽孢短杆菌，YJ-4菌株为革兰氏阳性球菌。YY-2菌株在3%麸皮，pH 7的条件下，37 ℃发酵48 h产酶效率最高，酶活力达到798 U/mL；YJ-4菌种在3% 麸皮，pH 5的条件下，40 ℃发酵48 h产酶效率最高，酶活力达到674 U/mL。酶学特性研究表明，YY-2菌产生的淀粉酶最适反应温度为90 ℃，该酶的分子量为30.8 kDa；YJ-4菌产生的淀粉酶最适反应温度为80 ℃，该酶的分子量约为61.0 kDa。
关键词：耐高温淀粉酶；筛选；发酵条件优化

Screening of Thermo-stable Amylase Producing Strains and Optimization of Fermentation Conditions
Abstract：Two strains named YY-2 which secreted thermo-stable amylase were secreted from soil near Liuyang River．Morphology analyses indicated that Strain YY-2 was bacillus bacterium while YJ-4 was coccus．Both of them were Gram-positive spore bacteria．Fermentation Conditions studies showed strain YY-2 thermo-stable amylase activity reached 798 U/mL，under condition wheat-bran 3%，pH 7.0，37 ℃ for 48 hours，while strain YJ-4 thermo-stable amylase activity reached 674 U/mL，under condition wheat-bran 3%，pH 5.0，40 ℃ for 48 hours．Enzymology characteristic studies showed that the amylase by YY-2 had a optimal temperature 90 ℃，molecular weight 30.8 kDa；While YJ-4 had a optimal temperature 80 ℃，molecular weight 60.0 kDa．

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Key words: Thermo-stable amylase；Screening；Optimization of fermentation conditions
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目    录
摘要    1
关键词    1
1 前言    2
1.1 耐高温淀粉酶研究的背景和意义    2
1.2 耐高温淀粉酶国内外研究现状    2
1.3 耐高温淀粉酶的优点    2
1.4 耐高温淀粉酶的应用    2
2 材料与方法    3
2.1 材料    3
2.1.1 菌种来源    3
2.1.2 实验仪器及设备    3
2.1.3 试剂及培养基    3

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2.2 方法    3
2.2.1 耐高温淀粉酶产生菌的初筛    4
2.2.2 耐高温淀粉酶产生菌的复筛    4
2.2.3 DNS法检测耐高温淀粉酶活性    4
2.2.4 淀粉酶耐热性检测    5
2.2.5 菌种革兰氏染色和芽孢染色    5
2.2.6 发酵条件优化    5
2.2.7 耐高温淀粉酶聚丙烯酰胺凝胶电泳    6
3 结果与分析    6
3.1 菌种筛选    6
3.1.1 初筛时能产生耐高温淀粉酶的细菌    6
3.1.2 DNS法检测耐高温淀粉酶活性    7
3.2 菌种YY-2 和YJ-4产生的淀粉酶耐热性检测    7
3.3 对菌种YY-2和YJ-4形态分析    8
3.4 耐高温淀粉酶发酵条件的优化    9
3.5 耐高温淀粉酶聚丙烯酰胺凝胶电泳    11
4 结论    13
参考文献    13
致谢    15