Azadian Fatemeh, Badoei-Dalfard Arastoo, Namaki-Shoushtari Abdolhamid, Hassanshahian Mehdi
Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.
Mol Biol Res Commun. 2016 Sep;5(3):143-155.
A thermophilic strain AMF-07, hydrolyzing carboxymethylcellulose (CMC) was isolated from Kerman hot spring and was identified as based on 16S rRNA sequence homology. The carboxymethylcellulase (CMCase) enzyme produced by the was purified by (NH4)2SO4 precipitation, ion exchange and gel filtration chromatography. The purified enzyme gave a single band on SDS- PAGE with a molecular weight of 37 kDa. The CMCase enzyme was highly active and stable over broad ranges of temperature (40-80ºC), pH (6.0-10.0) and NaCl concentration (10-25%) with an optimum at 70ºC, pH 9.0 and 20% NaCl, which showed excellent thermostable, alkali-stable and halostable properties. Moreover, it displayed high activity in the presence of cyclohexane (134%) and chloroform (120%). Saccharification of rice bran and wheat bran by the CMCase enzyme resulted in respective yields of 24 and 32 g L-1 reducing sugars. The enzymatic hydrolysates of rice bran were then used as the substrate for ethanol production by . Fermentation of cellulosic hydrolysate using , reached maximum ethanol production about 0.125 g g-1 dry substrate (pretreated wheat bran). Thus, the purified cellulase from AMF-07 utilizing lignocellulosic biomass could be greatly useful to develop industrial processes.
从克尔曼温泉中分离出一株嗜热菌株AMF-07，该菌株能够水解羧甲基纤维素（CMC），并基于16S rRNA序列同源性对其进行了鉴定。通过硫酸铵沉淀、离子交换和凝胶过滤色谱法对该菌株产生的羧甲基纤维素酶（CMCase）进行了纯化。纯化后的酶在SDS-PAGE上呈现单一条带，分子量为37 kDa。CMCase酶在较宽的温度范围（40-80ºC）、pH范围（6.0-10.0）和NaCl浓度范围（10-25%）内具有高活性和稳定性，其最适温度为70ºC、最适pH为9.0、最适NaCl浓度为20%，表现出优异的热稳定性、碱稳定性和盐稳定性。此外，在环己烷（134%）和氯仿（120%）存在的情况下，它也表现出高活性。CMCase酶对米糠和麦麸的糖化作用分别产生了24 g L-1和32 g L-1的还原糖。然后，将米糠的酶水解产物用作酿酒酵母生产乙醇的底物。利用酿酒酵母对纤维素水解产物进行发酵，乙醇产量达到最大值，约为0.125 g g-1干底物（预处理麦麸）。因此，从嗜热栖热放线菌AMF-07中纯化得到的纤维素酶在利用木质纤维素生物质方面，对开发工业生产工艺可能非常有用。
