摘要
为获得具有机械强度及弹性模量高等优点的细菌纤维素,满足其在食品工业、生物医学、造纸、声学器材和石油开采等方面的广泛应用。本研究通过初步活化和分步富集的方法获得细菌纤维素生产菌株,经过16S rDNA及形态学鉴定后,利用单因子试验对该菌株的发酵条件进行了优化,并利用扫描电子显微镜、红外光谱分析以及X-衍射等技术对获得的细菌纤维素进行表征。最终筛选获得一株细菌纤维素生产菌株,经鉴定为木葡糖酸醋杆菌Gluconacetobacter xylinus,命名为G.xylinus 5-2;经碳源、氮源、pH及其他影响因素的优化,该菌株发酵生产的细菌纤维素纯化干燥后干重达到13.2 g/L;发酵分离产物经扫描电子显微镜、红外光谱分析以及X-衍射等表征分析,证明该产物为细菌纤维素;对细菌纤维素进行力学性质表征分析,表明该细菌纤维素的弹性模量达到3.38 GPa。因此,本研究筛选获得了一株在生产效率和产品性能等方面都较为优异的纤维素生产菌株G.xylinus 5-2,并对其细菌纤维素的发酵条件进行了初步分析,为工业化生产高性能细菌纤维素奠定了基础。
Bacterial cellulose （BC） is widely used in food industry, biomedicine, paper making, acoustic equipment and oil production for its high purity, crystallinity, mechanical strength and elastic modulus. And the aim of this study is to obtain the cellulose-producing strain. The screened bacterium was identified through morphological and physiological characterization combined with its 16S rDNA gene sequence and data analysis. The culture conditions were optimized by single factor tests, including nitrogen, carbon source, initial pH and other factors. The fermentation products were identified with Fourier transform-infrared spectrum （FT-IR）, scanning electron microscope （SEM） and X-ray diffraction spectra. A cellulose-producing strain was identified and designated to be Gluconacetobacter xylinus 5-2 strain. After optimization of culture conditions, the bacterial cellulose of this stain was purified and reached to the dried weight with 13.2 g/L. The cellulose products were identified to be cellulose I by the analysis of FT-IR, SEM and X-ray diffraction spectra, with a high elastic modulus of 3.38 GPa. G. xylinus 5-2, a bacterium which is identified to be able to efficiently produce cellulose with high elastic modulus was obtained by the screening in this study. The culture conditions were optimized and its production of cellulose was qualified. The results provide data for the industrialized production of high performance bacterial cellulose.
出处
《纤维素科学与技术》
CAS
CSCD
2016年第2期77-84,共8页
Journal of Cellulose Science and Technology
基金
国家自然科学基金(31201489)
川渝中烟优质烟叶原料研究与开发(川渝中烟工业公司项目)
