Effects of ammonia fiber explosion treatment on activity of endoglucanase from Acidothermus cellulolyticus in transgenic plant
Effects of ammonia fiber explosion treatment on activity of endoglucanase from Acidothermus cellulolyticus in transgenic plant
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DOI：
10.1385/abab:116:1-3:1183
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发表时间：
2004-03-01
影响因子：
3
通讯作者：
Sticklen, M
中科院分区：
文献类型：
--
作者：
Teymouri, F;Alizadeh, H;Sticklen, M
影响木质纤维素生物转化经济可行性的一个关键参数是大量生产廉价和高活性的纤维素酶。降低酶成本的一个有希望的方法是用这些酶的基因转化植物，从而在植物中产生所需的纤维素酶。在生物转化过程中，从植物中提取和回收活性蛋白质或释放活性纤维素酶可能会对木质纤维素转化的整体经济性产生重大的积极影响。通过热处理和氨水处理，分别研究了氨纤维爆炸(AFEX)前处理参数(处理温度、含水率和氨负荷)对植物产生的异源纤维素酶活性的影响。最后，我们通过AFEX过程研究了所有这些变量的影响。植物材料包括表达纤维素酶E1的转基因烟草植株。测定了未处理和AFEX处理烟叶中的E1活性，以探讨处理对该酶活性的影响。AFEX处理的转基因烟草样品与未处理的样品相比，观察到的最大活性保留率约为35%(在60℃，氨负荷0.5：1，水分40%的情况下)。基于这些发现，我们认为AFEX预处理不是从转基因植物中释放纤维素酶的合适选择。
A critical parameter affecting the economic feasibility of lignocellulosic bioconversion is the production of inexpensive and highly active cellulase enzymes in bulk quantity. A promising approach to reduce enzyme costs is to genetically transform plants with the genes of these enzymes, thereby producing the desired cellulases in the plants themselves. Extraction and recovery of active proteins or release of active cellulase from the plants during bioconversion could have a significant positive impact on overall lignocellulose conversion economics. The effects of ammonia fiber explosion (AFEX) pretreatment variables (treatment temperature, moisture content, and ammonia loading) on the activity of plant-produced heterologous cellulase enzyme were individually investigated via heat treatment or ammonia treatment. Finally, we studied the effects of all these variables in concert through the AFEX process. The plant materials included transgenic tobacco plants expressing E1 (endoglucanase from Acidothermus cellulolyticus). The E1 activity was measured in untreated and AFEX-treated tobacco leaves to investigate the effects of the treatment on the activity of this enzyme. The maximum observed activity retention in AFEX-treated transgenic tobacco samples compared with untreated samples was approx 35% (at 60degreesC, 0.5:1 ammonia loading, and 40% moisture). Based on these findings, it is our opinion that AFEX pretreatment is not a suitable option for releasing cellulase enzyme from transgenic plants.