摘要
以木醋杆菌为生产菌,在静态培养条件下,通过改变碳源及初始pH值等条件,初步研究了发酵过程中pH值、残糖以及纤维素产量的变化,并初步测定了纤维素的性质。结果发现在葡萄糖、麦芽糖、蔗糖、甘露醇四种碳源中,甘露醇获得的纤维素产量最高;菌体在初始pH值4～6范围内生长较好,pH值为4.5时产量最高;扫描电镜观察菌体长度大约为2μm,宽度为0.8μm左右,纤维直径分布在10～80nm之间,其中80%主要分布在20～50nm,在30～40nm之间最多;红外光谱显示了细菌纤维素葡聚糖的特征吸收;热重分析表明,细菌纤维素最大失重速率温度为342.9℃,在622.2℃,失重率达到72.26%;每克湿纤维素膜含水130～210g,含水率超过99%,而每克干纤维素膜能吸水3.1～5.0g。
The contents with respect to changes of residual sugars, pH values and output of bacterial cellulose （BC） in Acetobacter xylinum static cultivations by using various carbon sources and initial pH values were investigated. In addition, the cellulose＇s physical properties were characterized. The results indicated that among four carbon sources, the highest BC yield was obtained using mannitol. The optimal initial pH for getting the highest yield was 4.5, while bacteria grew well at pH 4-6. Scanning electron microscope （SEM） images showed that the length and width ofA. xylinum was about 2μm, 0.8nm respectively. Diameter distribution of BC ranges from 10 to 80 nm, among which 80% distributes between 20 and 50 nm and the range of 30-40 nm was most. Fourier transform infrared （FTIR） spectroscopy demonstrated the characteristic IR bands of the BC glucan. Thermo-gravimetric analysis （TGA） indicated that thermal decomposition temperature was 342.9℃ and the percentage weight loss of cellulose was found to be 72.26% at 622.2℃. One gram of wet BC membrane contained 130～210 g water, which indicated the water-containing ratio of BC was morn than 99%. One gram of dry BC membrane could absorb 3.1 ～5.0 g water.
出处
《纤维素科学与技术》
CAS
CSCD
2007年第4期1-8,共8页
Journal of Cellulose Science and Technology
基金
生态纺织教育部重点实验室科研项目培育基金
高等学校学科创新引智计划(B07024)
长江学者和创新团队发展计划(No.IRT0526)
教育部留学回国人员科研启动基金
关键词
细菌纤维素
木醋杆菌
静态发酵
物理性质表征
bacterial cellulose
Acetobacter xylinum
static fermentation
characterization ofphysical properties
