Piriya P Sobana, Vasan P Thirumalai, Padma V S, Vidhyadevi U, Archana K, Vennison S John
Department of Biotechnology, Anna University of Technology, Tamil Nadu, Tiruchirappalli 620024, India.
Biotechnol Res Int. 2012;2012:817549. doi: 10.1155/2012/817549. Epub 2012 Jul 20.
The ethanol fermenting genes such as pyruvate decarboxylase (pdc) and alcohol dehydrogenase II (adh II) were cloned from Zymomonas mobilis and transformed into three different cellulolytic bacteria, namely Enterobacter cloacae JV, Proteus mirabilis JV and Erwinia chrysanthemi and their cellulosic ethanol production capability was studied. Recombinant E. cloacae JV was found to produce 4.5% and 3.5% (v/v) ethanol, respectively, when CMC and 4% NaOH pretreated bagasse were used as substrates, whereas recombinant P. mirabilis and E. chrysanthemi with the same substrates could only produce 4%, 3.5%, 1%, and 1.5 % of ethanol, respectively. The recombinant E. cloacae strain produced twofold higher percentage of ethanol than the wild type. The recombinant E. cloacae strain could be improved further by increasing its ethanol tolerance capability through media optimization and also by combining multigene cellulase expression for enhancing ethanol production from various types of lignocellulosic biomass so that it can be used for industrial level ethanol production.
从运动发酵单胞菌中克隆了乙醇发酵基因，如丙酮酸脱羧酶（pdc）和乙醇脱氢酶II（adh II），并将其转化到三种不同的纤维素分解细菌中，即阴沟肠杆菌JV、奇异变形杆菌JV和菊欧文氏菌，研究了它们产生纤维素乙醇的能力。当使用羧甲基纤维素（CMC）和4%氢氧化钠预处理的甘蔗渣作为底物时，发现重组阴沟肠杆菌JV分别产生4.5%和3.5%（v/v）的乙醇，而使用相同底物的重组奇异变形杆菌和菊欧文氏菌分别只能产生4%、3.5%、1%和1.5%的乙醇。重组阴沟肠杆菌菌株产生的乙醇百分比比野生型高两倍。通过培养基优化提高其乙醇耐受能力，以及通过组合多基因纤维素酶表达以增强从各种木质纤维素生物质生产乙醇的能力，重组阴沟肠杆菌菌株可以进一步得到改进，从而可用于工业规模的乙醇生产。
