Factors affecting the yield and properties of bacterial cellulose
Factors affecting the yield and properties of bacterial cellulose
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DOI：
10.1038/sj.jim.7000303
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发表时间：
2002-10-01
影响因子：
3.4
通讯作者：
Bielecki, S
中科院分区：
文献类型：
--
作者：
Krystynowicz, A;Czaja, W;Bielecki, S
木醋杆菌（Acetobacter xylinum）E-25是一株高效生产细菌纤维素的菌株。该菌株在静止培养条件下在BC生产中显示出显著更高的稳定性。相反，强烈的搅拌和通风似乎大大减少纤维素合成，因为这样的条件诱导形成自发的纤维素非生产突变体（Cel-），这在文化中占主导地位。突变频率严格取决于搅拌培养物中的培养基组成。用1%乙醇富集标准SH和Yamanaka培养基显著增强了静止培养物中的BC生产。水平发酵罐配有旋转盘或辊，成功地应用，以改善培养条件。相对慢的旋转速度（4 rpm）和大的表面积使得能够有效地附着细胞是纤维素生产的最佳参数。BC样品的物理性质，无论是在固定的文化或在一个水平的发酵罐中合成显示，从固定文化的纤维素表现出更高的杨氏模量值，但持水能力的值低得多。
Acetobacter xylinum E-25 has been applied in our studies in order to find optimal culture conditions for effective bacterial cellulose (BC) production. The strain displays significantly higher stability in BC production under stationary culture conditions. In contrast, intensive agitation and aeration appear to drastically reduce cellulose synthesis since such conditions induced formation of spontaneous cellulose nonproducing mutants (Cel-), which dominated in the culture. Mutation frequency strictly depends on the medium composition in agitated cultures. Enrichment of the standard SH and Yamanaka media with 1% ethanol significantly enhanced BC production in stationary cultures. Horizontal fermentors equipped with rotating discs or rollers were successfully applied in order to improve culture conditions. Relatively slow rotation velocity (4 rpm) and large surface area enabling effective cell attachment are optimal parameters for cellulose production. Physical properties of BC samples synthesized either in stationary cultures or in a horizontal fermentor revealed that cellulose from stationary cultures demonstrated a much higher value of Young's modulus, but a much lower value of water-holding capacity.