| 摘要: |
| 【目的】选育锰过氧化物酶（MnP）活力高的诱变菌株，研究其在秸秆木质素降解中的作用。【方法】利用合适的紫外诱变剂量处理哈茨木霉WRF-2的孢子悬液，通过初筛和复筛，选出1株产锰过氧化物酶能力强的突变菌株，并对突变菌株产生的MnP酶学性质及突变菌株粗酶液对玉米秸秆中木质素的降解效果进行分析。【结果】将哈茨木霉WRF-2孢子悬液在紫外光照射90 s后稀释10-4倍，经初筛和复筛获得了1株遗传性状稳定的正突变菌株0202。与出发菌株WRF-2相比，0202菌株的MnP活力提高了169.59%，木质素过氧化物酶（LiP）活力提高了17.98%。酶学性质测定结果表明，0202菌株的MnP底物作用的最适温度为40 ℃，最适pH为3.0，在pH 2.5～3.5以及温度50 ℃以下MnP活力稳定。Cu2+、Mn2+、Mg2+、Ca2+对0202菌株的MnP活力有促进作用，Fe2+ 、Zn2+则对其有抑制作用。用0202发酵后粗酶液处理玉米秸秆48 h后，木质素降解率达到了23.64%。【结论】获得了MnP活力高的突变菌株0202，其木质素降解酶系为LiP-MnP型，其对玉米秸秆中木质素的降解效果明显提高。 |
| 关键词: 紫外诱变 木质素分解菌 突变菌株；锰过氧化物酶 木质素降解 |
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| 基金项目:国家科技支撑计划项目（2007BAD41B02）；农业部农村能源建设项目；中国农业科学院作物科学研究所中央级公益性科研院所基本科研业务费专项 |
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| Breeding of high activity manganese peroxidase strain and preliminary investigation the enzymatic characteristics |
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| Abstract: |
| 【Objective】The study was to screen a high yield manganese peroxidase strain and to study its effects on lignin degradation of straw.【Method】A high yield ideal strain with the method of using suitable dose of UV to the spores suspension was obtained,meanwhile the manganese peroxidase characteristics of the mutant strain was investigated and the effect of lignin degradation of maize straw with the crude enzyme from mutant strain was determined.【Result】The spores suspension of initial strain (Trichoderma harizianum) were irradiated 90 s by UV treatment,and a positive mutation strain (0202) was obtained after screening.It was determined as a genetic stable high yield strain.The MnP activity was greatly increased by 169.59% more than its initial strain and the LiP activity was raised by 17.98%.The properties of MnP were researched and the results showed that the optimum temperature and pH of the MnP activity were 40 ℃ and 3.0.Moreover,the enzyme activity was stable within pH range of 2.5-3.5 under 50 ℃.Among different metal ions,the MnP activity was enhanced by Cu2+,Mn2+,Mg2+,Ca2+,whereas it was inhibited by the metal ions Fe2+,Zn2+ The lignin of corn straw was reduced by 23.64% after using its crude enzyme in 48 h.【Conclusion】High yield manganese peroxidase strain 0202 was obtained and its ligninolytic enzyme was LiP MnP.The raised MnP activity can increase lignin degradation rate of maize straw. |
| Key words: ultraviolet irradiation lignin decomposing fungi mutant strain manganese peroxidase lignin degradation |
