摘 要：本文分别以玉米秸秆、小麦秸秆和杨树木屑为原料，研究了一株密孔菌在发酵不同农业废弃物时漆酶的活性。结果表明：农业废弃物对密孔菌产漆酶具有良好的诱导效果，且以玉米秸秆的效果最佳，漆酶酶活可达40。92U·mg protein-1。Cu2+的存在或浓度变化显著影响密孔菌产酶，当添加0。02%Cu2+时，菌株在小麦秸秆和木屑培养基上产酶活分别达到41。24U·mg protein-1和57。13U·mg protein-1；当Cu2+浓度为0。04%时，菌株在玉米秸秆培养基上分泌漆酶酶活达到峰值94。92U·mg protein-1。pH值对密孔菌产漆酶有明显影响，在中酸性环境中菌株产漆酶酶活较高。菌株在小麦秸秆和玉米秸秆培养基上发酵产酶的最适温度较高，分别为35℃和40℃，且在整个发酵周期能维持较高较稳定的酶活水平。因此，密孔菌有很好产漆酶和降解农作物秸秆的能力，可用于农作物秸秆处理。93175

毕业论文关键词：密孔菌，固态发酵，农业废弃物，漆酶

Abstract:The aim of this study is to investigate laccase production by Pycnoporus in solid-stage fermentation using different agricultural residues, such as corn stalk, wheat straw and poplar sawdust。 The results reveled that agricultural residues can induce Pycnoporus to produce laccase and corn stalk showed the highest effect with production of 40。92 U•mg protein-1。 Moreover, the concentration of Cu2+ has a significant effect on laccase production and the production could reach 41。24U•mg protein-1 and 57。13U•mg protein-1 using wheat straw and poplar sawdust as medium with 0。02% Cu2+; the production of laccase could reach 94。92U·mg protein-1 using corn stalk as medium with 0。04% Cu2+。 Lassase production was affected by pH obviously and the activity of laccase was higher in neutral and acid environment。 The optimum temperature for Pycnoporus to produce laccase in wheat straw medium and corn stalk medium was 35°C and 40°C, respectively。 Moreover, laccase activity could maintain a high and stable level during the whole fermentation period。 The results from this study indicate that Pycnoporus has a high efficacy in producing laccase and degrading crop straw, which can be used in the treatment of crop straw。源F于K优B尔C论V文N网WwW.youeRw.com 原文+QQ752^018766

Keywords:Pycnoporus,solid state fermentation,agricultural wastes,laccase

目 录

1 前言 6

2 材料方法 6

2。1 菌种 6

2。2 试剂和仪器 6

2。3 培养基 7

2。4 方法 7

2。4。1 发酵培养 7

2。4。2 粗酶液获取 7

2。4。3 可溶性蛋白测定 8

2。4。4 酶活测定方法 8

3 结果 8

3。1 不同农业废弃物对密孔菌漆酶活性的影响 8

3。2  Cu2+对密孔菌漆酶活性的影响 8

3。3 发酵料初始pH对密孔菌漆酶活性的影响 10

3。4 培养温度对密孔菌漆酶活性的影响 12

讨 论 14

参考文献 15

致 谢 18

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